Cam and Pistons for 63 Fuelie

[Larry Stewart]

Does anyone have a recommendations for make, stock, or part number for a solid lifter cam on the market that is close to the original spec that came in a 63 fuelie? Getting ready to rebuild a block for my 63 and looking to purchase a new cam...any suggestions would be greatly appreciated!

Also any recommendations for pistons would be great also.

Car is used strictly for fun...a driver; comes out on sunny days; mostly all stock with original fuel injection system.

...Larry Stewart...

[John H.]

Re: Cam and Pistons for 63 Fuelie

Larry -

Assuming you want to keep the solid lifter setup, several outfits (Federal-Mogul, etc.) make "blueprint" duplicates of the original "097" Duntov your engine came with, and the "30-30" and LT-1 solid-lifter cams as well, all of which work fine with stock valvetrain components. The LT-1 is the best of the bunch, and was the final chapter in the development of Chevrolet factory solid-lifter cams. Not sure if the LT-1 characteristics are compatible with the F.I. unit, but someone else will know.

[William C.]

Re: Cam and Pistons for 63 Fuelie

I'd try to keep the duration down, as that was one of the problems that caused the change in '64 from the 375 to the 380 unit. The cranking signal valve will leak with the low vacuum produced by the 30-30 cam and tends to flood. The solenoid starting system cured that.

[Duke W.]

Re: Cam and Pistons for 63 Fuelie

LT-1 cam for sure and the Speed Pro (nee TRW) replacement pistons from Federal Mogul. The pistons should work okay with a .040" composition gasket as this will give a true CR of about 10.5:1. You also have the option of having the dome machined off if you want a bit less compression. You may be aware that most '63 SHP/FI engines were assembled with two (.015") steel shim gaskets per side due to detonation complaints on these high compression engines. The change to two gaskets was done fairly early in production and was the field fix for single gasketed engines where the owner complained about excessive detonation going back to the '62 models equipped with these engines.

The LT-1 cam has very similar idle vacuum characteristics and idle quality to the original Duntov, but it will make more torque across the range, and I recommend this cam for ALL mechanical lifter SBs including those with the 30-30. The 30-30 has much more overlap. It will make marginally more top end power, but kills the low end torque big time.

My older Speed Pro catalog shows TP245 for the LT-1 cam (3972178), but this number might have changed. The forged 1/8" domed pistons are LF2166NF-XX where the suffix is the overbore - 20, 30, 40, 50, rf 60 thou. Go with the minimum overboard to clean up the cylinder walls. You should be able to go 20 or thirty at the most if the engine has not been previously overbored.

Check all these part numbers for availability with a Speed Pro dealer. You also might find some of them listed at www.federalmogul.com.

Select a machine shop that will do it YOUR WAY. DO AS LITTLE MACHINING ON THE BLOCK AS ABSOLUTELY NECESSARY. Boring and properly honing the bores for the type of rings - usually moly faced - is all that should be necessary. Don't let them deck the block and align bore the main bearing saddles, "just because they always do that." If that's their attitude, take you job elsewhere.

When the heads are off, measure the piston to deck clearance BEFORE disassembling the short block. If it's consistent down the line, the decks are likely parallel to the crank and decking is not required. RESIST HAVING THE BLOCK DECKED WITH YOUR LIFE. Most shops like to deck blocks to insure that the surface is parallel to the crank, but good shops have fixtures and tools to measure, and if they are parallel, which they usually are, it's okay to bore with a boring bar that indexes off the deck. Better shops have boring equipment that indexes off the crank centerline, so even if the decks are a bit off parallel the block can be bored dead perpendicular to the crankshaft axis.

If the block deck, main bearing saddles, and head surfaces pass the machinist's bar and .0015" feeler gage test, they DO NOT need to be machined. A compostion gasket will stand about .003" warp.

My simulation work has indicated that there is some benefit to opening up the exhaust valve seat to accept a 1.6" exhaust valve, but DO NOT open up the inlet seat to accept the 2.02" valve. The gain is marginal and the larger inlet valve will have more tendency to cause a crack between the valve seats.

Pocket porting and port matching the head to the inlet and exhaust manifold is time/money well spent, and a three angle valve job with .040" inlet seats and .060" exhaust seats will yield both good flow and good seat longevity.

Essentially all the parts you need for the rebuild are available from Federal Mogul/Speedpro/FelPro. These are all OEM equivalent parts. Avoid using "hot rod" parts. Use the companion Speed Pro mechanical lifters. Any valvetrain components should be replaced with OEM or equivalent. The LT-1 cam used the same valve spring as all contemporaneous small blocks. It's a bit different that the '63 springs, so use 1970 model springs. YOU DO NOT NEED AFTERMARKET HIGH RATE SPRINGS WITH ANY CHEVROLET CAM. The LT-1 cam has mild action and will work okay with pressed studs as long as the engine has no history of pulling them with the Duntov cam. Use stock valvetrain components for best operation and long service life.

My stock '63 L-76 yielded about 300 HP on the Desktop Dyno 2000 simulation program and this was backed up by someone who had a stock rebuild '63 L-76 dyno tested at 304 HP SAE gross. With the above changes my engine shows about 350 HP in the simulations, a 16 percent improvement. Peak torque is up about ten percent, and there is no loss of low end torque. In fact, it is marginally better. You should achieve similar improvements with your FI engine, and fuel metering should not be upset due to the similar low speed vacuum characteristics of the LT-1 cam and Duntov cam.

When you're ready to assemble, e-mail me and I will send you a document with the secret of how to properly adjust mechanical lifter cams.

Duke

P.S. Be sure to replace your vacuum can with a Delco "236" or equivalent such as the NAPA Echlin VC1810. This can was used beginning in early '64 on SHP/FI engines and its full vacuum advnance of 16* at 8" will greatly improve idle quality. The orignal '63 vacuum can didn't provide full vacuum advance until 16". This is okay for the 250/300 HP engine, but the SHP/FI engines only generate about 12" at idle ('bout the same with the LT-1 cam, only 10" with the 30-30), so the advance dithered around, which contributed to idle instability.

[Craig S.]

Re: Cam and Pistons for 63 Fuelie

Duke - fyi, I just bought a Speed Pro Cam (CS 165R) as a replacement in my 66 L72. The companion Speed Pro solid lifters were no longer available, nationwide. However, my local speed shop had a bunch of Crane 811 solids that look just like the GM units. The Comp Cams were Eaton, and they had a narrower window area for catching oil. The Crane units were Johnson. The fellow that runs this local shop and has been in the business for about 40 years said while hydraulic rollers are the most constrained, the solid lifter market is tight also. He also said all companies buy from either Johnson or Eaton, apparently they are the only suppliers, and Johnson shut one plant which has exascerbated this shortage....Craig

[Duke W.]

Re: Cam and Pistons for 63 Fuelie

Interesting situation. I've always used OEM GM lifters. SBs through '63 used a so-called edge orifice mechanical lifter. Beginning in '64 GM switched to a piddle valve type that increased overhead oiling by about 10-20 percent. These lifters look like hydraulics because they are two piece held together with a snap ring. The piddle valves were used on all '64 to '69 mechanical lifter SBs and all mechanical lifter BBs regardless of year.

Beginning in '70 with the new LT-1 cam they reverted to the edge orifice type for SBs.

As far as replacement is conncerned I believe the edge orifice is best for a SBs, but BBs need the additional overhead oiling of the piddle valve type.

I don't know how current replacement lifters correlate to these two OEM types. Maybe Clem can clear it up.

Duke

[Craig S.]

Re: Cam and Pistons for 63 Fuelie

Duke - these lifters are both piddle valve just like the original GM lifters (I have a few left but not a set). They do also have an edge orifice style per Clem through Speed Pro, but these were not the ones I ordered since I wanted piddle valve for my big block. It appears both styles are available through the two aftermarket manufacturers....Craig

[Clem Z.]

Re: Cam and Pistons for 63 Fuelie

F/M AT992 are the P.V. and AT840R are the E.O. lifters.

[Craig S.]

Re: Cam and Pistons for 63 Fuelie

Clem - yep, but the AT992 are in a nationwide backorder with no expected availability. So I got the Crane 811 piddle valve lifters, made by Johnson, and they look the very close (moreso) to the GM units than the Comp Cams (Eaton) lifters due to the oil timing window space in the necked down area...the Eaton units this band is much narrower, reducing the oil flow path timing....so I opted for the units I could get that were closest to original. According to the local speed shop guy that has been into running this shop and racing for about 40 years, these are the two main aftermarket (and possibly suppliers for the mainstream auto industry as well) suppliers....I didn't check on the EO lifters since they were wrong for my BB...Craig

[Larry Stewart]

Thanks! Re: Cam and Pistons for 63 Fuelie

Thank you for all the information and advise. This will be a first rebuild for this block so I expect it wil be fun. I will send you a note Duke when we get close to the setup for you advise on setting up the lifters (not unitl spring). Getting the parts at present...thanks again!

...Larry...