I measured a 496ci Chevy I'm building that had been align-honed. Using Cloye's formula, I
The point of this exercise is to determine the distance between the two shaft centerlines. Compare this measurement on your engine with the stock big-block crank-center-to-cam-center distance of 5.152 inches. As an example, let's say the crank snout diameter is 1.605 inches, the big-block Chevy camshaft journal diameter is 1.948 inches, and the MOS is 6.922 inches. Doing the math, this makes the center distance 5.146 inches, which is 0.006 inch shorter than stock and would make a stock chain a loose fit. A 0.005-inch-shorter chain will reduce the distance and tighten the chain. Cloyes makes shorter chains in 0.005- and 0.010-inch under sizes. I priced all these pieces and discovered something interesting. The Summit Racing price for a 9-3110 Original True Roller set is $43.95. If you just buy a replacement stock-length chain, the price is $59.95. The 0.005-inch-longer chain (PN 9-3110-05) is $68.69.
It might also be a good idea to run a cam button on the engine even though flat-tappet camshafts are designed to prevent the cam from moving fore or aft in the engine. This is accomplished by grinding the lobes with a slight taper that pushes the camshaft rearward to counteract the distributor gear thrust that pushes the cam forward. Roller cams cannot be machined with this taper, which explains why roller cams need a cam button or thrust plate to prevent cam movement. If a hydraulic or mechanical roller cam is installed in an early engine without a cam button, the distributor gear thrust will push the cam forward and retard the cam and ignition timing at higher engine speeds. A roller cam button such as the Cloyes PN 9-200 ($16.88 from Summit Racing) is a good choice, since it is equipped with a roller bearing. The buttons can be shimmed to limit cam movement to between 0.005 and 0.010 inch.
Fort Smith, AR
This is a shot of an aluminum block 5.3L motor that we're about to drop into our '67 red R
LS and Tremec Swap
Manny Red, San Diego, CA: I just bought a '68 Firebird with two years of hard-earned money. Should I go with the motor that's in it now? The person I bought it from said it is the original Pontiac 350. It seems to be a Powerglide tranny since it only says P R N D L on the tree. What I want is more power and better gas mileage. I have a 50-mile round-trip commute to work. I would like a five- or six-speed, but I don't want to hack up the car. I could settle for a four-speed overdrive trans. I'm only looking for 300 to 400 hp. Should I use my current motor, a Gen I Chevy 350, an LT1, or a newer LS motor? I know someone who has a 5.3L from a newer truck. It has aluminum heads and an iron block. I'm pretty sure it's similar to the one you guys used for a buildup once. I'm looking for the most I can get for the least money. I could see spending maybe $5,000 over the next year. Now that I've got this baby, I hope to be joining you guys at one of your cruises, a race, or whatever I can get myself into.
We saw this at a vendor booth at the Grand National Roadster Show in Los Angeles recently. The kit comes in assorted colors!