QuestionWe have a hobby stock 355 2 bbl carb ..tops out on straight away @6200-6400rpm..688 gears in ford 9".I fear the mainly stock engine(minus cam and pistons).cannot take alot more rpm..we run the manual 3 speed in 3rd..can we run some different gears to relax the stress on this engine,and still have power to pull away and catch other cars? what do you suggest?
AnswerHi Tim
First question is is the motor running out of revs (flattening out), or is the 62-6400 all you have room for on the track ?
Then you should find out from the cam manufacturer what the rev range is for that cam. Then you should make sure you have all the right valve components for othe cam installation. If the cams rev range is 72-7400 , the motor should take it with little difficulty. Chevy rods are good.
I would , however, make darn sure I was using ARP rod bolts. Stock bolts do break and the result is usually both noisey and expensive.
Raising the gear ratio will only cost you punch coming off, not much , but enough that one more guy will slip by.
Here's what I would do:
Forged pistons, Total Seal Rings,
Resized rods, and ARP bolts.
Crank clearances of .002" at rods, and .0025 on the mains.
Synthetic oil ONLY and NOT Mobil 1. Castrol, Valvoline, Kendall but full synthetic, probably 20W-50 racing oil . Amzoil is good too, I use it exclusively.
And a camshaft that meets the rules with new bearings and the best valve gear you can afford. Be sure to carefully degree your cam.
The best advice you're going to get anywhere is available at Summit Racing on their tech line 1-330-630-3030, ask for a circle track guy.
After you get all this done, start working on forward bite, and you won't need all that RPM.
Good luck and let me know what happens.
Dan Liddy
Sarasota, Florida
