Question on Valve Reliefs
08-30-2004, 04:31 PM
#1
Question on Valve Reliefs & CR When I ordered my SB from ARE, I asked for and discussed with ARE that I wanted valve reliefs in my pistons. In looking at the build information from ARE that Dave recently found, there is a contradiction. In one place it says I have pistons with reliefs; in another place it says that I have flat tops. 
Is there any way (with the head on) to test for this? If I pull a plug and get some light in there would I be able to see them if they exist?
Is there any way (with the head on) to test for this? If I pull a plug and get some light in there would I be able to see them if they exist?
Last edited by Ragtop 99; 08-31-2004 at 08:16 AM.
08-30-2004, 10:02 PM
#2
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Flat top is just the term for the type of crown on the piston. Dome, reverse dome, and dish are other types. I would bet you have valve reliefs cut in. How many cc's I couldn't say. You would need to take the head off to find that out.
08-30-2004, 10:17 PM
#4
Do you know anyone that works on airplanes? Most A&Ps will have a borescope in their tool box.
http://www.harborfreight.com/cpi/cta...emnumber=46703
http://www.harborfreight.com/cpi/cta...emnumber=46703
08-31-2004, 08:16 AM
#7
This is the info I got from ARE:
The build sheet shows "Piston Make / Type Ross 70353. Compression Height 1.330." When I look on Ross's website, I do not see that model number. They show valve relief's for their LS1 pistons and only a 9.0 CR for the stock length rod assuming 1.326 C.H. I'm pretty certain that my LS1 current heads were milled .030, maybe .035 if they were cleaned up (They were originally on another car and were touched up before going on my motor). I can run a lot of timing so it would not surprise me to have a relatively low CR.
I guess the bottom line here is how do I figure out what CC combustion chamber I'll need when I switch heads. I'm trying to avoid having the car down for a long time.
Ross website: http://www.rosspistons.com/items.php...&ItemTypeID=26
the piston sheet shows flat top, so zero cc's...But it also shows Valve Pocket Depth... I can't remember what it had, flat or reliefs...
If it is a flat top, obviously zero cc, but it has reliefs they will be 4cc's.
If it is a flat top, obviously zero cc, but it has reliefs they will be 4cc's.
I guess the bottom line here is how do I figure out what CC combustion chamber I'll need when I switch heads.
I'm trying to avoid having the car down for a long time. Ross website: http://www.rosspistons.com/items.php...&ItemTypeID=26
