AFR install update
Thread Starter
Safety Car
Joined: Sep 2003
Posts: 3,558
Likes: 2
From: Cape Coral FL
AFR install update
Got the cam, lifters, pushrods, and Harland Sharp rockers installed and checked P/V today. The heads are milled .010" and installed with .040" Cometic gaskets. The cam is a Comp 224/228 .581/.588 @112+2. I checked the P/V clearance and had .110" on the intake, and .148" on the exhaust. I could have milled the heads another .014" for 62cc chambers and still had plenty of room. 
Instructor
Joined: Oct 2002
Posts: 181
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From: Windham NH
Originally Posted by ArKay99
Got the cam, lifters, pushrods, and Harland Sharp rockers installed and checked P/V today. The heads are milled .010" and installed with .040" Cometic gaskets. The cam is a Comp 224/228 .581/.588 @112+2. I checked the P/V clearance and had .110" on the intake, and .148" on the exhaust. I could have milled the heads another .014" for 62cc chambers and still had plenty of room.
Thread Starter
Safety Car
Joined: Sep 2003
Posts: 3,558
Likes: 2
From: Cape Coral FL
Originally Posted by phils C5 vette
so ,
hows the car running. whats your compression ratio?
hows the car running. whats your compression ratio?
In addition to the heads and cam I did the LS6 PCV conversion with an AMW catch can. Also new Comp 850 lifters, Harland Sharp rockers, hardened pushrods, flow-matched 30lb. Ford SVO's, JWIS timing chain, and DTE transmission girdle. I've got my fingers crossed.
Thread Starter
Safety Car
Joined: Sep 2003
Posts: 3,558
Likes: 2
From: Cape Coral FL
Originally Posted by bletour2001
How do you check P/V that specifically? Some sort of tool?
Instructor
Joined: Oct 2002
Posts: 181
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From: Windham NH
Originally Posted by ArKay99
Yes, you need a pair of soft springs, Moroso makes them, and a 1" dial indicator with stand, Proform makes one. You set your valve train up with the heads mounted with just a couple of bolts and turn the engine while pressing down and letting go of the rocker to find the point where the piston is closest to the valve. There will be a point that you can press the rocker more than the cam lift and hit the top of the piston. As you continue to rotate the engine you will find that distance will get smaller and smaller, then start to grow larger. You then back off to where it was the closest, set your indocator to zero and press it until it hits the piston and record what the dial says. This will be your minimum piston to valve clearance. I've been told that you need at least .080" for the intake and .100" for the exhaust.
That makes perfect sense now that I think about it... The only thing I am wondering is the hyd-lifters. Without running the engine how can you be sure that the lifters are in their proper state? I mean you really need to preload the lifters and then run the engine to make sure the lifters are in "operating" mode don't you? I guess if you check your valve life to see how close it is to specification then you can adjust for any lifter sag right? Say your max lift should be .500 and your only seeing .450 on the dial you can assume the lifter is currently sagging .050? Does that work?
--Bill
Thread Starter
Safety Car
Joined: Sep 2003
Posts: 3,558
Likes: 2
From: Cape Coral FL
Originally Posted by bletour2001
Thanks.
That makes perfect sense now that I think about it... The only thing I am wondering is the hyd-lifters. Without running the engine how can you be sure that the lifters are in their proper state? I mean you really need to preload the lifters and then run the engine to make sure the lifters are in "operating" mode don't you? I guess if you check your valve life to see how close it is to specification then you can adjust for any lifter sag right? Say your max lift should be .500 and your only seeing .450 on the dial you can assume the lifter is currently sagging .050? Does that work?
--Bill
That makes perfect sense now that I think about it... The only thing I am wondering is the hyd-lifters. Without running the engine how can you be sure that the lifters are in their proper state? I mean you really need to preload the lifters and then run the engine to make sure the lifters are in "operating" mode don't you? I guess if you check your valve life to see how close it is to specification then you can adjust for any lifter sag right? Say your max lift should be .500 and your only seeing .450 on the dial you can assume the lifter is currently sagging .050? Does that work?
--Bill
You would need to preload the lifter if you were using springs with 90+lbs of seat pressure but the soft springs have maybe 5-10lbs of seat pressure. They are light enough by design to eliminate lifter sag and enable you to push the rocker down with your fingers.
The only other way to do this would be to make a solid lifter out of a spare or used hydraulic lifter by filling it with epoxy or something. Then you would need to bolt down your head with a few more bolts and make them kind of tight. Then you would need to use some kind of rocker arm compressor tool, I guess one that works like the spring compressor but with the rocker mounted. I don't know of any. You would be doing essentially the same thing as above but with higher spring seat pressure.
Last edited by ArKay99; Oct 5, 2004 at 11:24 AM.
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Keep us up to date I'm very intersted to see what some home installed AFR #s