Home of the Injun Engine!
At CVMS, we prefer to build each engine as a "custom" engine, designed for a specific application. We feel this is the best way to accomplish the goals of the individual customer.
We do get the question: "What engine packages do you offer?" In order to please our customers, we do offer one engine package that is very popular. We refer to it as our "restoration" package, for providing a power package and the original look, so desired by the early GTO and Firebird owners.
400 Pontiac; 455 Pontiac; and 421/428 Pontiac
In order for a muscle car engine to perform well in today's "real world" environment, the compression ratio must be reduced, usually by 1-1 1/2 points. Muscle car engines were all produced with an advertised ratio of at least 10.25:1. Some were as high as 10.75:1. Because Pontiac used the volume of the combustion chamber, and not the piston head, to control the static compression ratio, a problem exists when attempting to do a "numbers match" restoration.
On today's 93 octane fuel, a static ratio of any higher than 9.5:1 WILL detonate, causing internal engine damage. We've read of "tricks" used to fend off detonation. One of our Pontiac builder peers (and competition) said it best. The laws of physics are the laws of physics. You can't cheat them. If you don't lower the compression ratio, or you don't use some type of octane improving concoction, you WILL have detonation.
If doing a true restoration for a numbers-match, 100 point show car, you simply live with it. The car won't see the road, and the little running time it gets can be treated to 100+ octane "racing" fuel. Actually, the vast majority (50:1) of engines we (those in the engine-resto business) build, are for those wanting to DRIVE their cars. It's not practical to mix fuel on a weekly basis or run straight 100. Even if you have sufficient resources to feed the thing, you can't always count on that fuel being available. You could be in Podunk, Arkansas, and they never HEARD of racing gas or octane booster!
Our solution is to dish the piston to achieve a static ratio of 9.2:1. This will allow you to keep your original heads intact, without modifying them. It also allows for poor fuel quality. At 9.2 rather than 9.5, you can use 92 octane. In some areas, that's as good as it gets. Our experience shows such a minute loss of power from the .3 drop in compression, you won't be able to feel the difference. It may make .01 or .02 difference in your ET.
The drop from 10.5:1 to 9.2, will make a significant difference. By using a modern camshaft design, we've found the way to restore the original power level, and more! We use Comp Extreme Energy cams, almost exclusively. The "smaller" grinds offer excellent performance and good street manners. The lift and duration are such that idle quality is still very good, similar to the 068 Pontiac cam. Low speed vacuum is also very good. XE274H is an excellent replacement for the venerable "041" or Ram Air IV cam.
We upgrade the timing set to a modern "true roller" design. We use either SpeedPro or Comp. The oil pump is upgraded to the 60 lb. high volume Sealed Power or Speed Pro (Melling). The valve springs are Pontiac, Sealed Power, Comp or Howard's. We choose these parts based on requirements, availability and competitive pricing. The pistons are Federal Mogul "Power Forged" (TRW), in the first oversize necessary to insure a clean bore (many 400s clean up at .020" over). We use Sealed Power or Hastings moly rings. SpeedPro rings are available at additional cost. If you ever plan to race the car, we recommend the SpeedPro.
We use Federal Mogul main and rod bearings (Clevite rod bearings are optional), Felpro gaskets (or Victor/Reinz on "numbers match" cars), Pioneer brass expansion plugs and woodruff keys, and ARP rod bolts.
All blocks are thermally cleaned and magnefluxed. The align-bore is checked and corrected as necessary (Pontiacs rarely need attention here). The heads are also cleaned and magnefluxed, as are the crankshaft and connecting rods.
The crankshaft is measured for roundness, taper, and straightness. Unless there is obvious damage, it is then chamfered and polished, measured again, and if in spec, used as standard (or current undersize). In a classic restoration, we feel strongly, if the original is still within spec, we use it. You can always remove material, but putting it back is another story.
The cast steel rods used in many engines are the major area of concern. If the car is a driver, subjected to only an occasional burst of youthful exuberance, the stock rods will be fine. We install new bolts and resize the "big end" to factory specs.
If the car is going to be raced or driven hard on a regular basis, we highly recommend upgrading the connecting rods. We offer Eagle "H" beam rods at a competitive price. We've used these rods in many engines, of all engine families. For the money, they can't be beat. We believe them to be a better choice than an "I" beam forging. These rods are available in either a floating pin design, or the original press fit design. SpeedPro (TRW) pistons are not equipped to use SpiraLocks or snap rings, so an additional step is required to make them full-floating.
The valve train may be returned to factory specs, or upgraded to modern performance specs. Your choice. Studs and Polylocks are available, too. We use Comp or Pioneer valve train parts. Others are available (UltraDyne, Crane, Crower, Lunati, etc.). Hardened exhaust seats are also installed if the application requires it, or the heads are damaged. The valve train can be upgraded with rocker arms, studs, polylocks, retainers and locks and modern, one-piece stainless steel valves, add $195.
Blocks are honed using a BHJ deck plate, on a Sunnen CK10 power hone. Rods are resized on a Sunnen horizontal hone.
New valve guides (iron for net lifts under .500", bronze for higher) are installed. A modern performance valve grind is applied (the "3-angle" valve job is an abused term, and really doesn't apply here), using current carbide cutter technology. Valve stem length and spring installed height are corrected. Heads are resurfaced the minimum necessary to assure flatness. Blocks are resurfaced ONLY if necessary to correct a defect (rare in Pontiacs). Zero-decking is available at additional cost.
The oil gallery plug behind the distributor is drilled .030" for positive oiling to the distributor and cam gears. ALL oil gallery and expansion plugs are replaced. The top one near the distributor will appear to be original.
The engine is painted (in subassemblies) the correct color for the era (unless otherwise specified) with quality engine paint. We use PlastiKote. Thermal-barrier coating is available for the exhaust ports and intake crossover. This aids in maintaining that "new" look. Touch-up is performed after final assembly. Expansion plugs may be installed before or after painting, your choice.
The end result will be a numbers "correct" engine from the outside, and modern performance engine on the inside. You really can have it all! And the appearance is "show quality". One of our VERY happy customers, with her "numbers match" '67 GTO 400, has coined the phrase: "She purrs like a kitten, with the BITE of a TIGER!"
While we do have many engine cores available, the more specific codes and castings are getting rare and expensive. If your core is at all useable, we recommend that, particularly if it's the original engine from your car. We can repair many flaws, including cracks in bores, heads or deck surfaces, and even in some cases, freeze cracks. Big windows from blown rods are a little tougher... Core prices vary due to market value. If all you have is a block and a pair of bare heads, we can fill in the blanks, too. We have a good supply of crankshafts, stock rods, manifolding and sheet metal. Don't be afraid to ship a motor. The price of freight may pleasantly surprise you!