Cam Install Problem - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

toml_pa · 06-09-2012, 02:56 PM

I am in the process of installing a Comp 54-459-11 LSR cam 231/239 .617/.625 113 in a 2011 Camaro LS3. I have the cam installed at 109* ICL as the cam card says. I have verified this numerous times. I am using the checking springs/dial indicator method to check PTV clearance. I am getting about .041 for intake and .100 for exhaust. I have a couple questions about this situation.
I also installed a Cloyes Hex-a-just timing set and was wondering how much I would have to install the cam retarded to get more reasonable numbers like maybe .060 intake and .080 exhaust?
How much would this affect the overall performance of this cam. The car has 3.91 gears so they should help with any shift up in the power band.
Any advice on this situation would be greatly appreciated. Thanks.

Bo White · 06-09-2012, 03:01 PM

http://www.camaro5.com/forums/showthread.php?t=158227

I would flycut the pistons.

Josh @ Spartan LSX · 06-09-2012, 03:41 PM

What kind of valve springs are you using? A good spring will let you get away with a lot less PTV than some others.

.040 is tight. That's one misshift away from a valve/piston kiss. You can retard it back to a 111ICL and should be fine. I've ran PTV as tight as ~.050-.060 before with no issues, but that's with a properly set up valvetrain and good springs. The general ".080" minimum isn't set in stone. Just depends on the set up.

Or go with a smaller cam.

Good luck

toml_pa · 06-09-2012, 05:09 PM

Quote:

Originally Posted by Damian

What kind of valve springs are you using? A good spring will let you get away with a lot less PTV than some others.

.040 is tight. That's one misshift away from a valve/piston kiss. You can retard it back to a 111ICL and should be fine. I've ran PTV as tight as ~.050-.060 before with no issues, but that's with a properly set up valvetrain and good springs. The general ".080" minimum isn't set in stone. Just depends on the set up.
Or go with a smaller cam.
Good luck

Comp 26926TS-KIT ultra dual valve spring kit with tool steel retainers (.675 max lift) which is what Comp recommends for LSR cams. Also did the trunion upgrade and using Comp hi-tech pushrods. 7.400 for intake and 7.425 for exhaust with all having 1.25 to 1.5 turns preload (~.061-.073) from 0 lash.
After retarding from 109* to 111.5*, I now have about .052 intake. Didn't check exhaust yet, but I assume it moved a similar amount in opposite direction. So what else might this affect other than moving the power band to a little higher RPM?

SC2150 · 06-09-2012, 05:49 PM

Damian is correct, we never go with less than .080 clearance.

Also, you can't guess on the pushrod length. You may be close or get lucky.....but no matter what the cam grinder or vendor tells you about pushrod length, you really need to measure for proper pre-load after everything else is installed. There are to many variables to guess.

06-09-2012, 02:56 PM	#1
toml_pa ʇuɐıʌǝp lɐıɔos Drives: 2011 2SS/RS LS3/M6 Join Date: Feb 2011 Location: Pennsylvania Posts: 231	Cam Install Problem I am in the process of installing a Comp 54-459-11 LSR cam 231/239 .617/.625 113 in a 2011 Camaro LS3. I have the cam installed at 109* ICL as the cam card says. I have verified this numerous times. I am using the checking springs/dial indicator method to check PTV clearance. I am getting about .041 for intake and .100 for exhaust. I have a couple questions about this situation. I also installed a Cloyes Hex-a-just timing set and was wondering how much I would have to install the cam retarded to get more reasonable numbers like maybe .060 intake and .080 exhaust? How much would this affect the overall performance of this cam. The car has 3.91 gears so they should help with any shift up in the power band. Any advice on this situation would be greatly appreciated. Thanks. Last edited by toml_pa; 06-09-2012 at 03:13 PM.

06-09-2012, 03:01 PM	#2
Bo White Drives: 2015 Summit White 2SS 1LE Join Date: Feb 2012 Location: Vance Alabama Posts: 8,019	http://www.camaro5.com/forums/showthread.php?t=158227 I would flycut the pistons. __________________ Retired wanna be cylinder head porter 2015 2SS 1LE Clutch reservoir, Vararam DRX, ported TB, TSP 2" headers, MGW shifter Totalled: 2010 1SS Wilkes Performance/Eagle 416 shortblock, TSP custom valvetrain, PRC 260 heads, Edelbrock Pro Flo 102, th400 swap, 8" PTC 5500 stall= 535/435 at the wheels tuned Gen 3 Performance and Dyno 10.97 @ 124 full weight in 3100 DA CamaroFest X

06-09-2012, 03:41 PM	#3
Josh @ Spartan LSX Drives: A wrench Join Date: Jan 2010 Location: East Atlanta Posts: 353	What kind of valve springs are you using? A good spring will let you get away with a lot less PTV than some others. .040 is tight. That's one misshift away from a valve/piston kiss. You can retard it back to a 111ICL and should be fine. I've ran PTV as tight as ~.050-.060 before with no issues, but that's with a properly set up valvetrain and good springs. The general ".080" minimum isn't set in stone. Just depends on the set up. Or go with a smaller cam. Good luck

06-09-2012, 05:49 PM	#5
SC2150 Account Suspended Drives: 2012 Camaro RS, RX supercharged Join Date: Dec 2009 Location: Bradenton, FL Posts: 6,063	Damian is correct, we never go with less than .080 clearance. Also, you can't guess on the pushrod length. You may be close or get lucky.....but no matter what the cam grinder or vendor tells you about pushrod length, you really need to measure for proper pre-load after everything else is installed. There are to many variables to guess.