Why - Rockers hit retainers!
But yes the rails are under the rockers.
Banned
Joined: Aug 2005
Posts: 154
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From: ohio
It sounds to me like something else is wrong. Perhaps too much taken off the valvetips!? Before you run the lash cap make sure the valve tip is long enough and the lash cap actually sits on the end of the valve rather than on the keepers. I measured a stock 241 5.7 head we have here and the tip is only about .057" above the keepers, I then checked a standard SBC head with a comp 611 keeper which is designed for use with lash caps and it is
.180" from the locks to the tip of the valve. Hope this helps.
.180" from the locks to the tip of the valve. Hope this helps.
It sounds to me like something else is wrong. Perhaps too much taken off the valvetips!? Before you run the lash cap make sure the valve tip is long enough and the lash cap actually sits on the end of the valve rather than on the keepers. I measured a stock 241 5.7 head we have here and the tip is only about .057" above the keepers, I then checked a standard SBC head with a comp 611 keeper which is designed for use with lash caps and it is
.180" from the locks to the tip of the valve. Hope this helps.
.180" from the locks to the tip of the valve. Hope this helps.
To me I don't see any other reason for this issue other than my machinist taking too much off the valve tips when he cleaned them up.. I appreciate the measurements for sure, I'd have catastrophe I'm sure if I had the caps sitting on the keepers and didn't realize it.
Thanks guys.. I'll have update on fri-sat and pics if problem persists!
Ok, does comp make more than 1 style retainer for the 918s? My retainers have a lip that raises up around the inside edge (where the rocker hits), and other pictures I've tried to search for on the internet I've noticed they look pretty much flat on top, wtf?
Well lash caps installed, however, same symptoms... I'm leaning back towards the installed height on the springs are off causing the float. Installed height likely off because my machinist took more off the valve stem than he's letting on.
I may just wipe my slate clean, buy a set of new ls6/6.0 heads, bolt them on with my new springs and know that it's going to run right. Not really sure yet, very discouraged by all of this.
I may just wipe my slate clean, buy a set of new ls6/6.0 heads, bolt them on with my new springs and know that it's going to run right. Not really sure yet, very discouraged by all of this.
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Verdad Gallardo Do you have your stock heads? Might be worth just bolting them down lightly and checking things. Sure sounds like you are on the right track. Do you have a height micrometer, you could check the spring installed height as well.
Can't blame you for being discouraged, I would be too.
Can't blame you for being discouraged, I would be too.
Here are a couple of pics of what sounds like the same type of problem. I bought these 2006 LS2 heads from a friend of mine in Houston last year. They came off of his 2006 GTO that had a HPE "S" cam with the Comp 918 springs and steel retainers, stock length untouched valves and I'm not sure on what pushrods he was using. HPE did the install for him and he had 11K miles on the car when these were pulled off and some TFS heads were installed in their place.
He was not aware that he had a problem. I saw this wear on the retainers when I got home with the heads.
I dont know if the problem was the retainer or locks? But notice how deep the valve stem tip is compared to the retainer. I have a set of Comp titanium retainers for the 918 springs also and they look the same visually side by side, but I have not actually measured them to see if there is a difference in the tapered area where the locks fit.
He was not aware that he had a problem. I saw this wear on the retainers when I got home with the heads.
I dont know if the problem was the retainer or locks? But notice how deep the valve stem tip is compared to the retainer. I have a set of Comp titanium retainers for the 918 springs also and they look the same visually side by side, but I have not actually measured them to see if there is a difference in the tapered area where the locks fit.
I didn't read all the posts in this thread, however basically there are only two ways the problem can arise. First, the the valves were sunk too deep, unlikely. Second, whoever reworked the heads cut WAY too much off the tops of the valve stems. The ******* that redid my heads without my OK told me he surfaced the tops of my valve stems, evening everything up and I would gain like 10 hp.BULLSHIT
After I put the heads on I decided to check the clearance between the bottom of the rocker and the outer edge of the retainer, .020-.022. Guess what the spec says .045 minimum. The way I ended up checking the clearance was miking different gauge wires, that was the only way to get an accurate reading.
Long story short I took the heads to another shop, they agreed the first shop really fucked up my valves. I had Ferrea valves installed. Sad to say the possibility was that I could have nuked my new 408 due to some ******** ineptness.
After I put the heads on I decided to check the clearance between the bottom of the rocker and the outer edge of the retainer, .020-.022. Guess what the spec says .045 minimum. The way I ended up checking the clearance was miking different gauge wires, that was the only way to get an accurate reading.
Long story short I took the heads to another shop, they agreed the first shop really fucked up my valves. I had Ferrea valves installed. Sad to say the possibility was that I could have nuked my new 408 due to some ******** ineptness.
Floman,
Those retainers look screwed up (not where it was hitting, but the design of them). From the photo's it looks like the valve stem is sitting deep in the retainer.
Those retainers look screwed up (not where it was hitting, but the design of them). From the photo's it looks like the valve stem is sitting deep in the retainer.
The picture posted by heavymetals looks like titanium retainers and they look fine. I would say based on the picture posted by floman that comp has a problem with the design of the steel retainer. The rocker bouncing off the retainer would definitely cause some nasty valve train instability. !BAD00SS, if your steel retainers look like the picture above I would just put some stock ones on. I don't think it's an issue with the valves being cut too far, it's a retainer problem.
