I previously posted this in the engine section. I am hoping that Harold will respond.

I want to update the cam I am currently using.
The engine in question is a 454, SP #7060 pistons (same as TRW 2399, block was decked .027, Edelbrock heads, about 10:1 CR, 170 cranking psi. I currently run an old Crane hyd cam-use the link to see.

Crane Cam (http://www.cranecams.com/?show=browseParts&lvl=2&prt=5&Vehicle_Type=Auto&Cylinders=8&Engine_Make=CHEVROLET&Year=1970&Engine_Size=396-454%20C.I.&partNumber=134561&partType=camshaft)

I would like to use a more modern solid, preferably a UD/Lunati. I read a post where UD Harold said to measure the piston to valve clearance at TDC and he could determine which cam would work with it. I measured today and found .230 intake and .440 exhaust. I am thinking about the 402A3LUN or 402A4LUN or?

Thanks.
Bill

I thought the 7060 was the .2xx dome piston?
Well FYI
with the 18cc 2399 number, I got 10.14 CR with zero deck. And a DCR of 8.19. So the A3 is about the smallest you want to go. IIRC there are a few 8.2 DCR bbc's here so it should work especially with AL heads.
Why, well I've been waiting for somebody to do a 10-1 A3 motor. I just had to go 10.7 w/an A7 so I could use the 781's I've had forever.
Should make more power everywhere than the old CCH296 crane. And idle a lot smoother too.
I think it will be a real sleeper with that cam.
I have one in my 383....

wait a minute, I think the 2399 is only 13cc for a 9.73 CR. Have to look when I get home.
DCR would be 7.86. Definite A3 territory. Although, UDH has seen the A7 in a 9.x motor.

The old Speed Pro 7060's I believe have a .090 dome, about 14cc. Right now it has a fairly decent idle when warmed up. I don't want a sleeper, a choppy is fine with me. I just need to know what the cam options are based on the piston to valve clearance. This engine is not octane sensitive at all. I run 20 deg at idle, 40 total on 89 octane. It doesn't lack for power but you know how it goes, if I can make more with the same basic engine.....why not.

ttt

I really want to hear from Harold on this. I tried calling his number on Saturday and find that I have to call weekdays, when I'm at work and can't make the call.

ttt (again)

Bill,

You're not going to like what I've got to say.
I think your piston-to-valve measurements are messed up. A clearance of .440" on the exhaust seems very big, and .230" for the intake seems small. It sounds like everything was way advanced when you measured.
Having said that, the 502A3 should work just fine. Lunati grinds it 4° advanced, so you can put it in dot-to-dot, and it should clear your pistons---still check though.
Make sure you've got a decent fuel system, with 1/2" fuel lines, etc.
I will not be able to answer any more questions before next Saturday. I will be all week in Bowling Green, Ky, at Holley. And I'm not a lap-top guy......

UDHarold

Harold, I think you misinterpreted what I wrote. The clearance is the total available space with the piston at TDC. The cam has no effect and there is nothing to advance. I removed the rocker and measured how far down the valves would move before hitting the piston. I understood from this info you could select a cam that should not have interference problems. Also, I am looking for a sold flat lifter cam not roller.

Bill70,

I really didn't, I understood you completely. It's just that .230 intake, .440 exhaust seems so unusual.
However, the 402A3LUN, when put in at 104° ATDC, has a NET valve lift of .152"(.107X1.7=.1819, or .182", then .182-.030 valve lash=.152"). You have .230" from valve seat to piston top at TDC, or .078" clearance. I generally run .070"-.075" on the intake in racing apps, so maybe you're OK. I recommend .090"-.100" on the intake for street apps.
Before you cut anything, re-check your measurements. It looks like you were a few degrees AFTER TDC.
We normally have NO trouble with the 402A3LUN as far as piston-to-valve clearance is concerned.

UDHarold