here are the stats on my "new" engine:
heads: 624 castings, 76cc stock, shaved to 70cc, 2.02/1.60 valves
pistons: stock GM part #'s, CR 8.8:1
engine cr = 9.4:1 with the shaved heads.

cam: unknown?

intake: 64 gm corvette hi-rise (for now), probably performer RPM later, if i find someone interested in the vette intake.
carb: holley 4bbl
exhaust: SLP tri-y headers


i could run it as is but i dont know what if any cam is in it. i THINK it may have a cam (someone obviously did the heads before), there was rtv on the timing chain cover so i'm sure it was off in the past even though the old timing chain had play. but the rest of bottom end appears stock, so i really dont know!

i'm considering just doing the cam now while i have it apart, i'd hate to have a dog when i put it in and have to do a cam later. i'm looking for opinions. its a cruiser/driver, not really a track car so i dont need anything crazy, just a little respectable. i dont want to be breaking parts.

i do have a crane compucam 2040 (IIRC) sitting on the shelf from a TPI motor that spun a rod bearing. the advantage being its a freebie, but i dont know that it would work well in my NA motor. thoughts?

 

http://www.compcams.com/Technical/CamSelection/

 

What rear gears?
What, if anything, has been done to the heads to increase flow?
Do you need hydraulic flat tappet or Hydraulic roller tappet?
If roller, would it be retro or factory?
Where do you want the powerband to be?
What kind of idle quality do you want?

So many questions to be asked...

 

thanks john, i faxed them the sheet, we'll see what i get for a response.

What rear gears? 3.27 9 bolt
What, if anything, has been done to the heads to increase flow? nothing that i'm aware of
Do you need hydraulic flat tappet or Hydraulic roller tappet?flat (early block)
If roller, would it be retro or factory?retro fit if i did it, but i dont intend to put that much into it
Where do you want the powerband to be?i dont need a high rpm motor, my driving style keeps me in the low range, rarely if ever push it over 4500
What kind of idle quality do you want?goal is a daily driver with a little nuts, doesnt really have to idle really smooth but i'm not looking for anything crazy either.

thanks for the help :hail:

 

How do you know your CR is 9.4:1, did you measure it? I bet ut signifcantly lower, probably 8.5-8.8:1. If thats the case a Comp XE262 will be awesome for your intended power band of 0-4500 rpm. Any bigger and you will lose all your low-end power, and be making your power past 4500.

 

The cam u have sitting on the shelf is just about ideal for your motor. Put it in. Here is the cam card.

Compucam 2040

 

That is a very mild cam for his setup. I don't think it would be worth the time. If you're replacing the cam you don't want to do it twice. I think something around the 224/230 range at least.

 

For his goals, im with F-BIRD and ME LEIGH, either of those cams would be just fine. At home in an engine that rarely kisses the 4500+ range. But a little more balsy than stock. You might see a little bit more power out of the 262 than the 2040. But i dont think the differences will be anything to write home about. All in all, now, between those 2 cams, its a matter of preference.

 

me leigh, the pistons are 8.8:1 with 76cc heads. the heads are marked on the sides as 70cc's from an engine shop so i ran that through a calculator and came up with 9.4:1. i dont know for sure, i didnt measure.



thanks guys. i'd rather use the 2040, being as its free. i know it really made a difference in the previous tpi 305. it has less than 10k on it but who would buy a used cam anyways?? if i can use it i may as well do it.