what can i use to fill pontiac head blind hole

The stock Pontiac V-viii block is constructed of cast fe. When introduced in 1955, it displaced but 287 ci. Its robust pattern allowed immediate adaptability to future displacement increases. Though external dimensions remained very shut to the original 287 blueprint, the V-8 eventually displaced as much as 455 ci by increasing bore bore and stroke length. With today'due south long-stroke aftermarket crankshafts, a total displacement nearly 500 ci using a stock block is quite possible.

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Block Design

The basic cake is compact and rigid. Its deck pinnacle is relatively tall at 10.24 inches equally measured from the crankshaft centerline upward. The deck surface is very thick and uses ten 1/2-inch-diameter bolts, which pass through the deck surface and into individual bosses within the coolant jacket walls to retain the cylinder heads. The private bosses limit cylinder distortion when the head bolts are torqued appropriately. The holes are also blind and do non extend into the h2o jacket, which would otherwise require thread sealer during installation.

The stock Pontiac 5-eight block evolved from its original displacement of 287 ci in 1955 to as much every bit 455 by 1970 without grossly diffusive from its original external dimensions. Its robust principal saddles and thick deck surface are among the many features designed to improve rigidity and durability. Original 400 and 455 blocks are the most pop for modern operation builds upwardly to 600 hp or slightly more than.

When selecting a cake for your build, a complete running engine makes a suitable candidate. I found this 1974 400 locally for $250 and confirmed that it retains its original 4.12-ci diameter after removing the cylinder heads. With some hunting, you tin can likely find a similar bargain. I don't recommend spending more than $500 to $700 for whatever Pontiac engine unless for a numbers-correct case.

Nearly Pontiac blocks from 1970 forward have four or 5 engine-mount bolt holes on each side, which allows easy installation into any chassis. Earlier blocks, such every bit this 1968 400, and even some very belatedly 1970s blocks take a limited number, and that tin present installation issues. While adapter kits are available, they may compromise durability in farthermost applications. Be sure the block you select has the right mounting points for your chassis.

A symmetric 90-degree design allows for easy and precise cake machining. The main journal saddles are quite thick, which improves cake rigidity and allows the employ of long connecting rods for good rod-to-stroke ratio. From 1959 on, engines displacing between 326 and 400 inches contained a chief journal diameter of three inches, while 421-, 428-, and 455-ci engines featured 3.25-inch journals. The main bearing caps are fastened to the block past two large bolts in most instances and located by dowel pins to prevent the caps from wandering during high-speed functioning.

Oil is collected in a sump at the rear of the oil pan. It's drawn in, pressurized, and dispersed past a positivedisplacement rotary pump that'south driven by the camshaft. The oil is filtered earlier information technology passes across the rear of the block and into a machined galley that runs parallel to the crankshaft on the left side. As the oil travels forward, it lubricates the camshaft, crankshaft, and left-side lifter bores. It then crosses over to the right side of the block at the forepart journal before traveling toward the rear lubricating the remaining lifter bores.

The original V-8 block pattern saw a number of changes over the years, and that can limit straight component interchange. That includes a variety of displacements, revised engine mounting points, transmission bellhousing bolt patterns, starter locations, main journal diameters, and cooling organization variances. Other differences less concerning include the number of h2o jacket plugs and rocker arm oiling path.

Selecting a Stock Cake

When considering a block for your particular build, whatsoever casting from 1965 and later is probably the best choice. Blocks of this era are constructed of high-quality iron and contain all of the desirable characteristics to accept almost modern aftermarket Pontiac components and accommodate piece of cake chassis installation. Some earlier blocks may be of similar or amend quality (specially the 1960s Super Duty castings) just such examples are rare and may present compatibility concerns with today's parts.

Though 400 and 455 blocks are most pop for modern performance builds, the 455 was far more desirable for many years for its larger displacement and cost reflected it. Information technology wasn't uncommon to pay several hundred dollars for a usable cadre with standard dimensions. While the 455 allowed Pontiac racers to remain competitive with larger-cube engines of other makes, reliability issues in race applications were common. The area required to adjust three.25-inch-bore principal journals created excessive friction and was hard to properly lubricate at loftier speed. The wider journal also compromised main saddle rigidity.

Start in 1968, Pontiac located the block casting number on a ledge merely rearward of the number-viii cylinder. Many numbers were available. This detail block, number 488988, was used in late-1974 400 applications and contains all the desirable characteristics for performance use.

A block I recommend avoiding is number 500557, which was introduced in 1975 and normally used through 1978, at which point 400 product ceased. Thickness in certain areas was reduced to save weight and whorl pins were used in place of dowels for main cap retentiveness. While completely suitable for depression-RPM production applications and builds up to 400 hp or then, it doesn't possess the durability required for high-functioning use.

To improve the immovability of its 1978–1979 T/A 6.six engines, Pontiac revived the 481988 casting, which was beefier than the 500557 used elsewhere. To identify the new casting, Pontiac added a large "Twenty" in several places. That includes on the lifter bore, which otherwise commonly contained the concluding two digits of engine displacement (such as "55" cogent 455). The XX-481988 blocks are every bit durable as any earlier block, and tin be considered an excellent pick for performance use.

The somewhat-recent introduction of long-stroke aftermarket crankshafts with iii-inch main journals has revolutionized the hobby. When compared to a 455, a 400 block is far more plentiful, making information technology cheaper and easier to find. Any performance enthusiast or competitive racer can easily achieve displacement greater than 460 ci using a typical 400 block and an aftermarket crankshaft. The smaller journals reduce bearing speed and improve block integrity, giving racers the performance and reliability required for high-speed operation.

While most whatever 400 block produced between 1967 and 1978 is a suitable candidate for loftier-operation utilize, there's one block casting I strongly propose avoiding entirely. To shed total vehicle weight, Pontiac revised its 400 during the 1975 model year. The graceful 400 block is easiest identified by its 500557 casting number, and lacks the immovability required for high-performance applications.

When searching for a stock cake, purchasing a complete and running engine is fine and then long equally you lot're aware that yous have no style of predetermining the block's condition and adequacy. It may be easiest to detect a casting that's completely disassembled and thoroughly cleaned so every portion of it tin be thoroughly inspected. A grungy cake must be properly cleaned so the block tin exist inspected to determine if it'south a suitable candidate.

The deck surface of a Pontiac block is very thick, and can measure out more than .375 inch. Surfacing to remove irregularities and improve gasket seal, which is known as "decking," should be part of whatsoever rebuild. Slightly more than can exist removed so the deck surface and piston face are level to maximize quench area and promote greatest performance. Gross decking can affect compression distance on subsequent rebuilds, nonetheless.

A honing plate (or torque plate) is an excellent investment if you lot're serious about performance. It replicates the load a block sees when a cylinder head is installed. A quality machine store uses it to account for cylinder distortion during machining, merely it can be beneficial for habitation use as well. That includes curing time for water jacket filler and for light cylinder honing during a refresh. BHJ offers steel and blend units for the Pontiac Five-8.

All cylinder machining should be performed with a honing plate installed. Most Pontiac blocks tolerate an overbore of at least .030 inch, and possibly upwards to .060 inch or slightly more. Since production variances and cadre shift are normal, I recommend measuring the cylinder wall thickness using an ultrasonic tester earlier machining. That allows y'all to calculate thrust wall thickness and ensure information technology's at to the lowest degree .120 inch afterward deadening and honing.

Once perfectly clean, the block should exist magnetically checked for cracks, and then closely inspect for porosity or rust problems externally also equally in the water jackets. A vivid light and small mirror can provide you with an idea of what the block looks like internally, particularly toward the bottom of the cylinders. You should too inspect the primary saddles and bulkheads to ensure uniformity throughout and look for casting voids or signs of core shifting.

If you lot accept access to an ultrasonic thickness tester, it'southward wise to measure out cylinder walls thickness on all sides, but the thrust side is virtually critical. A nominal wall thickness of at least .150 inch on the thrust side, and .100 inch elsewhere should provide plenty of wall material for boring. There's no concern using a block with greater wall thickness, but anything less than about .120 inch on the thrust side afterwards machining may neglect in extreme applications.

If yous take any dubiousness about your own opinion, take along an experienced friend or a trusted machinist for a second opinion. It can never hurt!

Stock Block Modifications

A stock Pontiac block is completely adequate for most high-performance builds. Good rebuilding and reconditioning techniques, which includes thoroughly cleaning the oiling passages and precise machining with mod equipment mostly produces a cake that's well equipped for applications producing up to 600 hp, or slightly more.

The deck should exist machined to provide a polish and consistent surface for optimal gasket seal. Generally measuring somewhere near 3/8 inch thick, information technology can be machined liberally without worrying near compromising its integrity. Any time material is removed from the deck surface, you demand to physically verify that the cylinder head bolts do not lesser out with the cylinder caput installed.

Nigh Pontiac blocks can tolerate an overbore up to .060 inch, and perhaps more than later proper thickness testing. Ho-hum and honing should always include a honing plate. Also called a "torque plate," it'southward a rigid piece of steel or aluminum that bolts to the block's deck surface and replicates the load it sees when a cylinder head is installed.

The front oil galley plugs in most stock Pontiac blocks are a printing-fit design that are driven into place and staked for maximum retentiveness. Loose-plumbing fixtures plugs sometimes push out when exposed to very high oil pressure, and that can consequence in a massive internal oil leak. A pop modification to is tap the front end holes to take common three/eight-NPT pipe plugs. Utilise caution when installing the plugs, still. If the plugs are threaded in too far, oil flow through the block may be restricted.

When Pontiac developed its tunnel-port Ram Air V, additional ribbing was added to connect the lifter bore banks in the block's lifter galley, improving rigidity and durability. Though the R/A Five never reached regular production, the characteristic was incorporated into the 1973–1974 SD-455. It's beneficial when running a camshaft with very aggressive specifications.

Extreme camshaft duration and/or valvespring pressure creates an excessive amount of side loading on the lifter during normal functioning. That can cause the lifter bores of a typical Pontiac 5-eight block to crack and/or break. The Mega Caryatid by SD Functioning is a bolt-in kit that strengthens the lifter galley in a stock block. Information technology's an excellent design that'due south used by many professional Pontiac engine builders.

The stock Pontiac block delivers a large volume of pressurized oil for proper hydraulic lifter function. Solid lifters do not require it, and that can require the installation of lifterbore restrictors that limit oil catamenia. The modification consists of cutting several threads into the lifter diameter using a 1/iv-twenty or i/4-28 tap, and and so inserting stainless-steel ready screws with a .030- to .060-inch pigsty to effectively limit oil flow. A few manufacturers now offer Pontiac-specific solid lifters that are internally restricted, lessening the need for this modification.

Hard Blok is ane of the best water jacket fillers available today. It doesn't generate an excessive amount of rut during the curing procedure, and doesn't expand when exposed to temperature increases during normal functioning. Even though distortion is minimal, I recommend that it be poured and cured earlier any block machining.

Adding water jacket filler is an first-class way to improve the rigidity of any block. Poured in as a liquid, it encapsulates the cylinder bottoms past replacing the coolant that otherwise surrounds them. Once cured it essentially becomes a permanent role of the block, preventing baloney and absorbing harmonics. Installation of a honing plate and the main caps during the cascade is strongly recommended to maintain ideal block dimension during the curing process.

"Hot honing" consists of heating the cake until it's virtually its normal operating temperature (effectually 200 degrees F) before machining. While it's not practical or necessary for every performance level, hot-honing may benefit those chasing every concluding horsepower when racing at the most competitive levels.

An aggressive roller camshaft and the valvespring pressure information technology requires profoundly stresses the lifter bores of a stock Pontiac block. Lifter bore brace kits, such as the Mega Brace from SD Operation contain formed plates that are bolted, epoxied, and/or welded into the lifter valley to improve lifter bore strength.

Another mutual modification performed to the lifter bores in a stock Pontiac block is to tap the lubrication holes and insert small restrictors whenever a solid-lifter cam is used. Stock lifter bores supply a relatively large volume of oil for proper hydraulic lifter operation. Solid lifters simply pass oil through to the rocker arms, and if restrictors are not installed to limit oil menstruum, oil will freely menstruation to the superlative of the engine, reducing the supply bachelor for the main journals. Many Pontiac builders nonetheless offer lifter bore restrictor kits, simply many modernistic solid lifters (flattappet and roller alike) are restricted internally to control the corporeality of oil that reaches the top end.

Water Jacket Filler

A stock Pontiac block can be dimensionally unstable if subjected to excessive cylinder wall side loading from a long stroke crankshaft, extreme cylinder pressure, and/or excessive RPM associated with max-performance engines. Some other instance may be if the cylinder walls are at the minimum recommended thickness afterwards tedious. That instability can pb to a number of operating issues that can negatively impact operation or consequence in engine failure.

Water jacket filler is a thick liquid that's poured into the coolant jacket of a cake, encapsulating the cylinders. Once permanently gear up, it makes a block less susceptible to flexing, which improves cylinder-wall strength and seal, dampens harmonics, and reduces chief-cap walking. If a torque plate is bachelor, installing it only after pouring ensures that the cylinders are located properly during the curing process. Most h2o jacket fillers expand slightly while curing, and because of that I highly recommend that machining be performed only later on the filler has cured completely.

Well-nigh builders suggest filling the block to the bottom of large freeze plug holes in the side for maximum durability in applications producing at least 600 hp. It reduces book of coolant circulating in the block, and that can mayhap increment oil temperature slightly. A "short fill" is best suited for street/strip engines producing more 550 hp where some additional rigidity is benign, but withal allows for plenty of coolant circulation. It typically consists of filling the cake until the filler reaches nigh ane inch beneath the large expansion plug holes in the side. A variety of h2o jacket fillers are on the market today. I recommend premium filler such every bit Hard Blok or that from Ken's Speed & Motorcar Shop. Following the supplied mixing and installation instructions provides the best results.

Main Caps

The middle 3 main journals of a Pontiac Five-eight endure the greatest load, and the corresponding bearing caps were generally retained by only two bolts early on. Pontiac determined that using beefier main begetting caps and four retaining bolts in the number-two, -three, and -4 journals improved rigidity and reliability, specially in applications with three.25-inchdiameter main journals, where more of the main cap is lost to journal area. Factory four-bolt caps are commonly plant on certain Ram Air, H.O., and Super Duty engines of the 1960s and 1970s. Most Pontiac blocks during that era were machined to take two-bolt caps only, merely 455 blocks produced through almost 1974 were mostly machined for four-bolt caps even though ii-bolt units were installed most oft.

Pontiac used two-bolt chief caps in most of its production engines. Although some blocks were drilled and tapped for four-bolt caps, most were originally fitted with twobolt units like this. They are sufficient up to nearly 600 hp. Honing improves alignment and bearing life without grossly altering the position of the crankshaft centerline.

4-bolt main caps were used at the center three journals in high-performance applications. The iv-bolt cap is larger than a two-bolt unit, and serves to better main saddle rigidity and overall immovability, particularly with three.25-inch main journals. Stock Pontiac caps were constructed of a cast-atomic number 26 alloy. Installing used caps onto some other block requires proper machining.

Pro-Gram Engineering produces topquality aftermarket main caps for the Pontiac V-8 synthetic of billet steel. They're platonic for loftier-operation applications where additional cap strength is required. Though Pro-Gram produces all five principal caps for iii- and 3.25-inch blocks, the heart three are retained by 4 direct bolts or with angled outer bolts. The block and caps must be machined appropriately.

A main cap must offer some absorptive quality to prevent main saddle fatigue. Milodon'south ductile-steel master caps are an fantabulous high-forcefulness choice for such applications. Only bachelor for the center 3 journals and with four straight bolts, they install and machine easily and offer the durability required for the most extreme applications.

Stock Pontiac main caps are quite durable and adequate for power levels budgeted 550 hp. Manufactory four-bolt caps can likely sustain even greater power levels. At virtually 550 hp aftermarket four-commodities main caps should strongly be considered for the center 3 journals. Installing four-bolt caps isn't as like shooting fish in a barrel as bolting them on, yet. A block and its main caps are a precision associates that's machined as a unit. Whenever a different main cap is used, whether a used original from another block or a new aftermarket unit, information technology must exist precisely machined. That can include marshal-boring, thrust machining, and/or perchance relocating or resizing the dowel holes.

Billet-steel main caps are very strong and a few different aftermarket companies offer Pontiac Five-eight units. Lesser-quality steel caps can exist too hard, which makes them extremely difficult to automobile. In those instances, the line-bore cutting equipment tin can bounciness erratically, removing valuable material from the block in the process. Once installed, the main caps go an integral part of the block and improve rigidity while arresting crankshaft daze load. Lesserquality billet caps tin also exist so difficult that they resist shock load, leaving the block to absorb it all. Over time the cake can fatigue and fail.

I feel the best billet primary caps available today for Pontiac 5-8s are produced by Pro-Gram Applied science. They're strong enough to add significant benefit, however machine relatively easily and exhibit excellent dampening ability. Pro-Gram offers complete main caps for all five journals in 3- and three.25-inch diameters. While the forepart and rear caps are sold individually, the center three are sold as a set and are designed for four-bolt memory only, with straight or splayed outer commodities options. Pro-Gram main caps sell for about $300 and tin can exist purchased directly from the manufacturer or from your favorite Pontiac vendor.

Milodon has been producing highquality ductile steel main caps for the middle three journals of Pontiac V-8s for several years. Retained past 4 directly bolts, the caps are very stiff and install relatively hands. An added benefit is that the thrust surface on the number-iv cap is the same diameter as the cake, which means less machine piece of work when compared to others. Expect to spend around $300 for a set.

Aftermarket Blocks

Though complete failure with a stock block is rather rare when output is less than 750 hp or and then, there are distinct applications where an owner is looking to grossly increment displacement, or the intended performance level surpasses the adequacy of a stock pattern. The cost to set up a stock block for a race application is nearly as much every bit the aftermarket Pontiac Five-8 blocks available today. New blocks that incorporate additional material in disquisitional areas are available for hobbyists looking to go to the adjacent performance level, and are an excellent investment if future performance modifications are planned.

Two separate companies presently produce aftermarket Pontiac V-8 blocks. Each contains external dimensions similar to an original Pontiac unit of measurement and will accept many original Pontiac pieces, but are generally much beefier throughout. AllPontiac.com produces its cast-iron IA Ii cake and an all-new aluminum casting. G&Yard Performance produces its MR-1 in cast atomic number 26 or cast aluminum. Available from many Pontiac vendors, the aftermarket blocks are an excellent foundation for most max-operation applications, especially where displacement of 541 inches, and perhaps more is desired.

Whether cast-iron or aluminum, aftermarket Pontiac blocks are designed to allow for easy installation into any chassis. Each side contains the appropriate bosses to accept most original engine mounts. Information technology also accepts the original oil dipstick tube that's driven into the cake. Coolant jacket plugs are printing fit or spiral in, depending upon the manufacturer.

There are a few different aftermarket Pontiac V-8 blocks shortly bachelor that are ideal for applications budgeted 750 hp and across. AllPontiac.com manufactures two distinct units. The IA-II is a cast-fe block that's been on the marketplace for several years, while the all-new aluminum block was a contempo release. Both generally boast beefier main saddles and four-bolt principal caps to significantly meliorate lesser terminate rigidity, particularly when using a very long stroke aftermarket crankshaft measuring 4.v inches or more than to produce a maximum displacement of 541 ci.

Thou&G Performance produces two aftermarket Pontiac Five-eight blocks. They are nearly identical, except the MR-1 is constructed of cast atomic number 26, while the MR-1A is constructed of cast aluminum. A maximum displacement of 541 ci is possible. The lifter galley is heavily reinforced to accommodate the most radical camshaft and the main saddles are much thicker throughout.

The aftermarket blocks from AllPontiac.com and K&M Performance feature steel principal caps and loftier-quality main studs. The center three caps are designed for 4-bolt (or studs in this case) memory with outer-holes angle for maximum block rigidity. The main caps are drilled to take a stock windage tray and/or oil dipstick tube.

The IA Two block is synthetic of loftier-nickel iron and features siamesed cylinders that tolerate a bore diameter up to iv.four inches while maintaining a wall thickness that'south nearly .300 inch thick. The deck surface measures .750-inch thick and is delivered "dry." The coolant passages must be drilled for "wet deck" applications. A tall-deck option that increases compression altitude for specialized applications is also available. The lifter galley is greatly reinforced and is designed to accommodate the very long duration and high-lift camshafts that can impairment or destroy the lifter bores in a stock Pontiac cake.

Primary journals are available in 3- or three.25-inch diameters. Billet-steel main caps are standard, and the center three are a four-bolt design with angled outer bolts. All caps are registered to the main saddles and use larger 3/8-inch dowel pins for positive location to prevent walking, which tin negatively affect oiling and bearing alignment at high RPM. The camshaft oiling passages that extend upward from the chief journals are drilled smaller to strengthen the center of the block and preclude bang-up in extreme conditions.

Master registering creates an oil pan rail that's .125 inch deeper than stock. It improves block rigidity, but besides requires a slightly longer oil pump driveshaft, which AllPontiac.com supplies. The IA II cake comes with threaded freeze plugs and a bellhousing flange containing two singled-out bolt patterns for both Buick-Olds- Pontiac or Chevy-type transmissions. Information technology also features v mounting holes per side to accommodate whatsoever original chassis motor mounts. At about 250 pounds with main caps, the IA Two cake weighs xl to fifty pounds more than a race-prepped stock block, only the actress weight is well worth it the IA II is extremely durable. Look to spend effectually $3,000 for a basic IA Two block. A wide diverseness of options are available at extra cost.

AllPontiac.com has recently developed and released a completely new lightweight aluminum Pontiac block for those most serious most functioning. While containing many of the same design features and options equally the castiron IA II, the high-quality aluminum casting is even beefier than its atomic number 26 counterpart. It weighs nearly 140 pounds with the main caps, or near 115 pounds less than the cast-atomic number 26 piece, only with a nearequal amount of durability. Expect to pay nearly $five,000 for the standard block. Many extra-cost options are available. K&M Performance produces the castiron MR-i. Many mistakenly believe that it'due south a copy of the IA 2, merely the MR-one was actually designed to eliminate the weaknesses associated with the stock Pontiac block in max-performance applications while accepting equally many stock Pontiac pieces every bit possible. The MR-1 allows for a bore diameter up to 4.4 inches while maintaining a wall thickness of .200 inch. The deck surface is very thick and is drilled for "wet deck" applications. The coolant passages are sized to accept mutual pipe plugs after tapping. The lifter galley is heavily reinforced.

The MR-one is available with three- or 3.25- inch primary journals. Billet-steel main caps are located using typical 5/16-inch dowel pins. The centre 3 are retained by four bolts and the outer most bolts are angled for better block integrity. Like a stock Pontiac cake, the MR-1 uses pressed freeze plugs and the oil pan rail is in its original position, which allows the apply of many typical off-the-shelf Pontiac parts. A typical MR-1 block weighs around 250 pounds and features 5 mounting holes per side for ease of installation. The base block sells for around $3,000 and many extra-price options are available. K&One thousand Operation states it's capable of safely indelible upward to ii,500 hp or slightly more.

Shortly after introducing the cast-iron MR-i, Yard&M Performance adult and released an aluminum variant known as the MR-1A. Essentially a cast-aluminum re-create of the iron MR-ane, the blocks share the same design improvements and tooling. At a svelte 125 pounds, the MR-1A weighs about half equally much as its cast-iron brethren, but because aluminum isn't near as durable as iron, G&M Performance presently recommends it for applications up to 1,500 hp. Pricing starts around $iv,500 and many extra-cost options are available. For the virtually serious racer, G&M Functioning besides produces a billet-aluminum Pontiac 5-eight block on a custom-order basis. Wait to spend around $10,000 for what may be the strongest Pontiac block ever available.

Camshaft Bearings

Camshaft bearings are not required to carry very heavy loads. Generally a onepiece, two-layer design, it includes a steel shell and a very soft overlay. ACL, Clevite, Dura-Bond, Federal-Mogul, and Male monarch produce quality stock-replacement cam bearings suitable for near applications.

Dura-Bond offers a performance bearing that better resists the high valvespring pressures associated with aggressive roller camshafts. It even offers an optional dryfilm lubricant coating intended to reduce friction in extreme applications. While most cam begetting sets come in standard size, Dura-Bond also offers a .010-inch oversize for instances where honing the camshaft tunnel is necessary.

Camshaft bearings generally are non subjected to the same pressure every bit other engine bearings. The stock replacement Pontiac units available from many sources are usually more than sufficient for the moderate spring pressures associated with hydraulic and solid roller camshafts. Cam bearings must exist installed using the proper equipment or impairment tin can result.

Dura-Bond offers a high-quality Pontiac camshaft bearing set that features a dry-picture lubricant coating. The coating reduces friction in applications where farthermost valvespring pressure can harm standard bearings, such as with a very ambitious solid roller camshaft with high-valve lift.

Specific camshaft bearing sets with needle rollers are available for other makes. They tin be adjusted for utilize in the virtually severe Pontiac applications where the highest camshaft loads exist. The cake's camshaft tunnel must be bored appropriately to have the oversize bearings, still, and that can remove valuable material within the main saddle of a stock Pontiac block, possibly compromising integrity. Roller cam bearings are a more viable option when using a beefier aftermarket cake for a build.

Rear Main Seal

Pontiac originally used a woven rope synthetic of graphite-coated asbestos to seal its V-8'due south rear primary journal. The ii-piece seal was packed into a respective groove machined into the block and main cap. The seal grooves had cavities drilled in them. As the rope was packed firmly into identify during installation, it filled those cavities, finer anchoring it and preventing rotation during functioning. Excess portions of rope were then trimmed away, and the chief cap installed.

Asbestos was called for forcefulness, with a graphite blanket to reduce friction. The original rope seal worked quite well for many years. It was lubricated during normal operation by small-scale grooves on the crankshaft contact surface. While some oil "wicking," or seepage that causes an occasional drip tin be considered normal, larger leaks that result in small puddles were rather uncommon. New OE-spec replacement seals, such every bit those from Fel-Pro, were too constructed of asbestos and rarely problematic if installed as Pontiac originally instructed.

Authorities legislation eventually restricted the utilise of asbestos and companies were forced to discover new materials for rope seal construction. Fel-Pro's solution was braided fiberglass with a graphite coating. When compared to an original asbestos unit, the fiberglass replacement was less flexible and slightly more difficult to install, merely it was constructive.

Fel-Pro changed the base of operations textile of its rope seal from fiberglass to Kevlar in 1998. Since Kevlar better tolerates heat, Fel-Pro felt it would improve longevity. Though the recommended installation is identical to that of its predecessors, the Kevlar seal is even more difficult to piece of work with than fiberglass. It's much firmer and that makes it even more difficult to pack and trim accordingly. In fact, it's not uncommon to use several fresh razor blades trimming a single seal during an installation.

Kevlar rope seals are generally included in every modernistic Fel-Pro engine gasket set up. While I experience near other Fel-Pro gaskets offer the best functionality, the modern rope seal is one to avoid. It isn't very forgiving and can leak severely fifty-fifty with careful installation. Though used successfully on occasion, most study poor results. Fel-Pro reports it has no plans to deviate from the electric current design since it'southward as close to OE-spec as modern regulations permit. That has forced many hobbyists and professional engine builders to resort to other alternatives.

The rear main seal groove machined into the block and cap features drilled holes to anchor the original rope main seal and prevent it from rotating during normal performance. These holes must be filled with silicon sealer to prevent oil leaks when using an aftermarket lip-type seal. Aftermarket blocks and main caps practise not incorporate these anti-rotation holes, so a small scroll pivot is required when using an aftermarket rope seal. Also note that the seal diameter varies amongst three- and 3.25-inch blocks.

Pontiac originally used a rope seal synthetic of woven asbestos (bottom), and it performed quite well. Modern replacements are constructed of woven fiberglass or Kevlar (superlative) and can be much more hard to work with. Unless you have a supply of NOS originals, avoid the mod replacement considering severe leaks tin can effect fifty-fifty with careful installation.

A lip-blazon seal like this from BOP Engineering is an excellent design that consists of a Viton-coated steel core. The lip is designed to remain in constant contact with the crankshaft's seal surface, essentially eliminating leaks. Information technology's compatible with the serrated lubrication grooves found on stock-type cranks, but journal polishing can exist necessary.

The GraphTite seal from Best Gasket is a modern rope replacement that'due south synthetic of graphite-coated Teflon strands. It fits and functions like an asbestos original and can be relatively leak free when installed every bit directed. Information technology'due south an excellent choice, but I recommend using it simply with crankshafts that contain serrated lubrication grooves.

ARP offers specific commodities kits for many Pontiac cylinder heads including castiron originals and popular aftermarket units. It likewise offers a cylinder caput stud kit for max-performance applications. If ARP doesn't offer a specific fastener kit for your particular cylinder heads, it can assemble a custom set to adjust your needs.

Cylinder head studs reduce the amount of twisting force the block sees during tightening and can provide a clamping load that's more consistent. I recommend ARP cylinder head studs when functioning exceeds 650 hp. ARP'south specific moly-based thread lubricant on the threads and under the washers during install yields the all-time results.

Four-bolt main caps improve main saddle rigidity, just angled outer bolts draw the entire block together. "Splayed" main caps significantly make the outer block walls an integral part of the main saddle, improving overall block strength. An original two-bolt Pontiac block can hands be modified to have splayed caps. Aftermarket Pontiac blocks characteristic splayed caps with main studs equally standard equipment.

Pontiac main cap bolts were quite reliable, but modern fasteners may exist a amend option as the originals are 30 to 40 years old. ARP offers complete stud kits specifically designed for two- and four-bolt Pontiac principal caps. In improver to starting with a new fastener, the studs eliminate the twisting force that principal saddles otherwise run across when you tighten the bolts. A stock windage tray and the oil pan tin can sometimes interfere with the main studs during assembly, only it can be easily corrected.

A lip-blazon rear main seal has been commonly used by diverse other motorcar manufacturers for many years. It's generally constructed of a temperature-resistant rubber material such as neoprene and the "lip" is a formed "flap" that remains in constant contact with the sealing surface on the crankshaft. The rubber seal originally designed for certain large-cube Cadillac V-8s is a shape and size similar to that required for a Pontiac. Many hobbyists have successfully retrofited a Cadillac seal into their Pontiac, but installation is rather complex. Conscientious installation does yield positive results in most cases but anything less can result in a significant leak.

In 2000, BOP Applied science introduced a new molded lip-type seal specifically for the Pontiac V-8 and it proved to be an immediate success. Information technology is constructed of a hardened steel core coated in Viton, a pliable textile that's oil and temperature resistant. It features a multiple-lip blueprint that's intended to improve oil control. A lip-type seal requires near absolute concentricity for maximum sealing ability. Pontiac didn't hold the depth of the rear seal groove to whatsoever particular tolerance during machining, still. Since the rope seal was pliable, there wasn't a great need for the groove to be precisely concentric to the crankshaft centerline.

BOP suggests a variance of no more .010 inch from the crankshaft centerline for proper operation of its seal. I've plant that closely following BOP's installation instructions provides splendid results. A similar seal from Tin Indian Performance is also available, and though I have no directly feel with it, I suspect information technology performs as well.

A new Pontiac 5-8 rope seal was introduced around 2007. The GraphTite seal from All-time Gasket is constructed of braided Teflon that'south coated with graphite. It fits and installs like an asbestos original, and comes with detailed instructions, cutting blade, and template. More recent kits include a pocket-size whorl pin to positively locate the seal when used with the aftermarket Pontiac V-8 blocks and caps, which lack the anti-rotation holes of an original. I accept found it provides an splendid seal.

Information technology'south all-time to use one of the aftermarket rear main seal options mentioned above. The type that'south best for y'all is often personal preference, but information technology can also depend upon the concentricity of the seal groove in the block and principal cap. I propose physically measuring the concentricity of your Pontiac block before deciding which rear master seal to use in your project.

Fasteners

When developing its 5-8, Pontiac used one/2-inch-diameter cylinder head bolts for maximum retentiveness. An original Pontiac bolt in splendid condition tin be reused several times, but there's sometimes no style of knowing how many times information technology's been previously used. Reproduction head bolts are bachelor and the quality can range from very practiced to very poor. Investing in loftier-quality aftermarket cylinder head fasteners is the best choice.

Automotive Racing Products (ARP) produces a variety of premium automotive fasteners. It offers complete sets containing bolts in the proper lengths required for original Pontiac D-port and round-port cylinder heads as well as the aftermarket Edelbrock offerings. Custom sets for other aftermarket cylinder heads are besides available. Information technology's all-time to check with the cylinder caput manufacturer to make up one's mind exactly what's required.

When installed equally ARP suggests, using its specific moly-based thread lubricant, yous can wait excellent results. I strongly suggest measuring the overall length of each bolt and its corresponding hole in the block to exist sure the bolt doesn't lesser out and provide a faux torque reading during installation. This is particularly important if the deck surface of the block and/or cylinder heads has been machined by whatever amount.

Fel-Pro offers two different Pontiac cylinder head gaskets that share the aforementioned basic shape and size. The design is a compilation of the many stock replacement units Fel-Pro offered over the years, and information technology'south compatible with about popular Pontiac blocks. PN 8518 (meridian) is a stock replacement unit while PN 1016 (bottom) is a loftier-functioning gasket with a solid-steel core and premium fire rings. Completely coated in Teflon, Fel-Pro recommends installing its head gaskets dry.

A drawback to Fel- Pro's cylinder head gasket is that its coolant holes are rather large and located adequately closely to the combustion band. Information technology's quite visible when overlaid on an NOS original Pontiac head gasket (shown hither). If the band is compromised in any style, compression can push by the Fel-Pro gasket and enter the coolant system, which can result in major impairment. While information technology may not be a concern for applications producing 700 hp or then, it can exist an result with forced consecration or an extreme compression ratio.

Composition cylinder caput gaskets from Butler Performance were adult using the original Pontiac blueprints. This design consists of a steel shim with a graphite blanket on 1 side, and tin can provide excellent seal when combined with copper sealer. Butler Performance was able to size and locate bore-diameter and coolant passages for specific applications simply like the originals. It's piece of cake to see how Butler 's 421-spec unit of measurement (top) differs from the 400/455 unit (lesser).

When budgeted the 650-hp level, it may exist best to consider ARP's cylinder head stud kit as opposed to bolts for improving retention. The stud is threaded into the block and a nut and washer associates applies the clamping load. The stud eliminates the twisting that otherwise occurs when threading a bolt into the block, and it stretches more smoothly when torque is applied to the retaining nut. It reduces cake distortion and improves clamping consistency and thread life.

The fasteners that Pontiac used to secure the main caps are of the highest quality. Those bolts are, however, more than 40 years erstwhile in most instances. If you or your machinist feels new fasteners are necessary, ARP offers a complete stud kit for two-bolt and four-bolt Pontiac 5-8s.

The chief studs offer the same advantages as cylinder head studs, and that includes less twisting on the block, clamping load consistency, and improved thread life. ARP main studs tin can exist used in conjunction with stock main caps at whatsoever betoken, but are required with aftermarket main caps, which may or may not include new fasteners for installation.

Head Gaskets

A cylinder caput gasket is designed to keep combustion heat and pressure within the cylinder and preclude coolant that passes between the block and head from leaking outward or into the cylinders. Should combustion pressure blow by or burn through the gasket'south combustion armor, escaping compression generally leads to complete gasket failure, and that can lead to significant engine damage if non detected in fourth dimension. The head gasket Pontiac used for its V-8 was a composition construction consisting of a coated steel cadre. Many companies produced stock-replacement Pontiac head gaskets over the years, but few were as good those originally supplied past Pontiac.

MLS gaskets are the ultimate in cylinder sealing. The multiple layers allow for varying degrees of thermal expansion while providing maximum sealing capability in applications where extreme cylinder force per unit area exists. MLS head gaskets are commonly used by all car manufacturers in modern production vehicles and are an excellent pick

Cometic manufactures premium MLS cylinder head gaskets. It offers a variety of options for traditional Pontiac V-8 blocks also every bit the aftermarket offerings with diverse bore diameters and compressed thicknesses. Its gaskets are an excellent choice for maximum-functioning applications, and are completely compatible with stock rebuilds likewise.

When cylinder heads and blocks are surfaced, the equipment leaves backside a finishing pattern. The roughness of the finish must be compatible with the cylinder head gasket or information technology can be torn autonomously as the cake and heads expand and contract during normal operation. Most gasket manufacturers publish a roughness average (RA) range for their gaskets. Information technology'south very important to follow the RA recommendations for maximum gasket reliability.

Fel-Pro introduced PN-8518 for the Pontiac Five-8 during the 1970s. Containing a diameter bore of four.3 inches and a preflattened thickness of .041 inch, information technology's a stock-replacement design that's compatible with virtually Pontiac blocks. Constructed of a perforated steel cadre with a Teflon outer coating, information technology features tinplated steel combustion armor. PN-8518 head gaskets sell for well-nigh $sixty per pair and are an affordable choice for whatsoever stock rebuild, and even performance applications with a compression ratio upward to 10.5:i, or slightly more than.

A second Pontiac offer appeared in the Fel-Pro itemize during the early 1980s. PN-1016 is peculiarly designed for high-performance applications with high compression and/or combustion pressure. Synthetic of a Teflon-coated solid-steel core, it features stainlesssteel combustion armor and a wire ring combustion seal for maximum combustion containment. It contains a chamfered bore bore or 4.3 inches and pre-compressed thickness of .039 inch. Selling for less than $fourscore per pair, it's a good choice for naturally aspirated engines with a maximum compression ratio of 12:i and/ or mildly additional applications.

In the early 1990s Butler Operation (BP) began offering its own limerick cylinder head gasket using original Pontiac blueprints. It features a steel cadre with graphite blanket on ane side. BP revised the coolant passage sizes to closer match those in the block to improve reliability. Bachelor with various bore diameters, it compresses to nearly .045 inch after installation. BP recommends a light coating of copper sealer on the steel side for maximum block seal. BP's composite gaskets are very durable and a popular choice for compression ratios upward to 11.5:ane or moderately boosted engines. A pair sells for less than $fifty.

Copper head gaskets accept long been the only pick for max-performance engines with extreme cylinder pressure and/or combustion heat. The durable copper structure prevents the blowouts and/or called-for that tin can occur when exposing composition gaskets to loftier levels of nitrous oxide or boost. It's oft combined with a wire O-ring, which resides in a machined groove in the block and prevents combustion pressure from blowing by the gasket. A copper gasket's primary drawback is its inefficiency to prevent coolant or oil leaks. Liberal coats of surface sealer during installation were once required, simply SCE Gaskets offers topquality copper gaskets with built-in seals, and information technology'southward an excellent concept. Copper gaskets are bachelor from several companies and remain the all-time choice for extreme functioning applications.

Multi-layer steel (MLS) gaskets are today'south option for well-nigh max-operation applications. Equally the name implies, an MLS gasket is constructed of multiple layers of steel gaskets with a tough-yetpliable exterior coating. The multi-layer design improves sealing past spreading the load across the entire gasket surface while the outer glaze seals the gasket against near types of mating surface or load. MLS cylinder head gaskets accept proven to be as durable every bit any copper unit in all simply the about extreme applications, simply they lack the sealing problems that plagued racers for years.

Cometic is the but company that soon produces MLS cylinder head gaskets for the Pontiac Five-8. Diameter diameters range from 3.75 to more than iv.4 inches and standard compressed thickness measures .040 inch. Any other bore diameter and thickness from about .020 to .120 inch is bachelor on a customorder basis. Suitable for stock rebuilds and max-performance applications akin, the only drawback to an MLS gasket is cost. Expect to spend around $200 per pair, but it's an excellent value considering its durability.

When selecting cylinder head gaskets for your Pontiac, price and application are amidst the most important considerations. The all-time selection is the most affordable gasket that operates reliably in the intended application. Compressed thickness is as well important considering it has a straight effect on static pinch ratio. Each .010-inch difference of head gasket thickness alters the static pinch ratio by about .15:i on a typical 467-ci Pontiac. Certain cylinder head gaskets are also reusable. Bold they are not stuck to the block and do not tear during disassembly, Fel-Pro and Cometic gaskets can be reused with the same block and cylinder heads at to the lowest degree a few times.

The most import attribute of head gasket choice is the materials information technology is used with. Aluminum expands about twice as much as cast iron when exposed to the same heat level. A bimetal engine, or ane that uses an fe block and aluminum cylinder heads, can literally scrub a caput gasket apart as it reaches normal operating temperature if the opposing surfaces have a machining finish that's too rough. That scrubbing can somewhen lead to gasket failure. Pontiac's original head gasket was very forgiving and conformed to most finishes. The stock-blazon gasket from Butler Performance performs similarly.

Commodities-On Components

At that place are two components commonly plant within the oil pan of a highperformance Pontiac V-viii. A windage tray is a baffle that bolts to the primary caps or is an integral part of the oil pan. The aeration created inside the crankcase as the crankshaft rotates at loftier RPM is known every bit "windage." As oil drains toward the bottom of the engine, it can splash when it reaches the sump. Windage can keep smaller aerosol of splashing oil in suspension, which can and so collect on the crankshaft and connecting rods, increasing parasitic drag and adversely affecting performance.

Though the mid 1970s, Pontiac used a stamped-steel baffle bolted to the chief caps to reduce windage in its V-8. It doubled every bit a means of retaining the lower dipstick tube within the cake. Reusing an original Pontiac bamboozle can be dicey, however. After years of enduring engine harmonics, the aged sheet metal can fatigue and fissure during apply unbeknownst to the owner. It can eventually lead to complete baffle failure, which can then cause serious and mayhap even catastrophic collateral engine damage.

Pontiac used a stamped-steel baffl e that bolts to the main caps to reduce crankshaft windage. The unit covering four of five main journals is well-nigh popular because it was designed for use with the 455 crankshaft and is generally a scrap thicker. Years of exposure to engine harmonics can cause fatiguing and smashing. I much adopt the Tomahawk windage tray from Pacific Performance Racing. Information technology's a stock replacement 4/5 unit that'south lightly modified to amend performance and reliability and installs just similar the original.

Canton produces a Pontiac windage tray that uses mesh screen to control oil aeration and improve horsepower. Covering all five journals, information technology rests on the oil pan rail and is retained by the oil pan and its fasteners. It'southward compatible with the stock oil pan and well-nigh stroker assemblies. Canton also offers a like unit that uses stamped louvers in identify of the mesh screen.

Milodon offers a unique stamped-steel windage tray for the Pontiac 5-eight. Information technology requires the use of specific main cap studs which Milodon supplies. While the tray is compatible with the stock Pontiac oil pan and well-nigh stroker assemblies, best results occur when combining it with a Milodon oil pan.

A crankshaft scraper reduces parasitic drag by removing oil that gathers on the rotating assembly during normal operation. A steel shim must be uniquely trimmed for each particular application. This unit is available from Ken'south Speed & Car Shop and is precut for the Pontiac V-8. It requires merely minimal trimming to proceeds sufficient crankshaft and connecting rod clearance.

The aftermarket Tomahawk windage tray is an excellent replacement. A copy of the stock Pontiac unit, it'south constructed of much thicker metal and is improved slightly. With its relatively reasonable cost and ease of installation, I strongly suggest a Tomahawk unit every bit opposed to reusing whatsoever original. County and Milodon also produce loftier-quality windage trays for the Pontiac V-viii. The 2 are uniquely different and, different the stock piece, and may better serve a max-performance application. AllPontiac.com also offers its own windage tray for its aftermarket blocks.

A creepo scraper is most commonly institute inside an oil pan of a race enigne. Information technology's a length of flat metal that'due south installed very closely to the crankshaft and connecting rods on the passenger side o f the block, and "scrapes" oil from them during rotation to keep excess oil off the cylinder walls and reduce parasitic drag at high RPM. Installed clearance is generally betwixt .020 and .060 inch depending upon the application. Due to variances in crankshaft counterweight and connecting rod design, a creepo scraper will require some blazon of custom fitting and requires actress preparation to seal properly. Crank scrapers are bachelor from many vendors and sell for less than $50.

Some experience that with a creepo scraper, a windage tray serves no purpose. Others elect to run both simply to improve oil control and ensure their Pontiac V-viii is every bit free of parasitic drag as possible. I believe at least 1 should be used in whatsoever performance engine and see no harm in using both if applicable. Whether together or singly, the reduction of parasitic drag associated with such components can better loftier- RPM performance by every bit much as 5 to 7 hp. Discuss with your engine builder whether any or either is required at your operation level.

Written by Rocky Rotella and Posted with Permission of CarTechBooks

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Source: https://www.pontiacdiy.com/how-to-improve-pontiac-v-8-performance-engine-block-guide/