I've got a set of the new style comp R's, and I am thinking they could be causing my false knock problem. I'm running lt4 heads, hot cam, and a P1SC @6lbs of boost. I am getting ready to do a high flow y pipe, new header gaskets and plugs. It wouldn't be too much more work for me to pop the intake and put in a new set of lifters. Should I spend the money on Morels or get a set of OEM replacements. ATI rates the boost @ 5750 rpms so I won't be seeing high RPM use. I'd rather spend my money once and get a superior part then wasting my money like I did with the comp R's. I could reuse the Morels when I build big motor

 

How do you know it is false knock? What makes you think its the lifters?

That said, get the comp r's out of there, some stock replacements will be just fine. So will morels. It's about how much piece of mind you really want and what the goals for the car are.

 

add another name to the list of failed comp Rs. I pulled the intake off and found 2 of them sitting in the valley. I still haven't checked out all the lifters yet. I'll see how many are gone.


I just skipped to the end of this (its too late to read 120 replies lol) but is there any other symptoms besides louder valvetrain? is there a noticeable power difference between properly working lifters and failed comp Rs?

 

I think its interesting how his pictures are dated 9-11-04. I'm glad I decided to skip the lifter replacement.

 

so what's the consensus on the old comp Rs? the ones with the c-clip? are they good or no good? my stockers are doin fine to 6500 so far, but when I put my ported heads on next week, I might swap the Rs in there.

 

So is there a new batch of these that seem to be good or are the comp r's still bad news? I am buying an engine that has yet to be run and am kind of worried about the fact these lifters are in it. what do you guys think?

 

My new 383cid came with Comp R's lifters. Yesterday we did first startup, but I'm very nervous about Comp R's. I ordered a set of Morel lifters, and pushrods lenght checker (different size). I don't want to take a risk for 500$

 

Can Comp OEM lifters (850-16) handle ~180lbs pressure???

 

Been a long time since I've visited this thread and I still have to just chuckle at some of these replies... Just FYI... My year old Comp R's have been in my turd for close to a year. Probably have 10K miles on them with several 6500rpm ventures. No problems yet. I still must be lucky.
How in God's holy name could that be the problem of the lifter? How can it be the lifter's fault that the pushrods walked?
It reads more like the rockers weren't adjusted for **** which would cause the EXACT symptoms you describe. When you say "pushed in" do you mean the plungers? Well... when your engine is not running hydraulic lifters have a tendency to bleed off. Some faster than others especially with higher spring pressures.

 

can they?

If so, I will replace them. From Comp R's to Comp OEM, there is no need to change pushrods right?

 

I've had my comp R's in my car for close to 2 years now, no problems, and no c-clips found on the magnetic plug. I'm going to put on my ported intake manifold tomarrow, so I'll know for sure. I think this problem got overyhyped by a bad back, like the 918 springs a few years ago, and now everyone runs them.

 

I re-inspected mine while changing out the roller rockers and studs. They looked great, have about 5000 miles on em now.

 

Man I don't know what the probem is! I have had a set in a box going on four years now! Not a singal problem with them

 

I have 1 fail on me when I first got them, the clip was missing when I opened up the intake, I don't drive the car much so I can't say now but hopefully it was just one bad lifter.

 

I also had a set of comp r's go bad on me
I put 2000 miles on them and the number 8 intake lifter
came apart and the push rod got slamed behind the plunger
the lifters are no good