Cam and lifter problem

-
fishy68

fishy68

Tyr Fryr's Inc.
Joined
Jan 11, 2005
Messages
16,584
Reaction score
1,272
Location
Central, IL (Hooterville)
Ok got a problem with clattering lifters in a 454 Chevy I rebuilt for a buddy. I know it's not a Mopar but I also know alot of you engine guru's know more than just Mopars. Here's what we did.

I totally rebuilt his 73 454. Hot tanked, checked all clearances, turned crank, new pistons, bearings, new oil pump, rebuilt the heads and set the valve spring height, the whole 9 yards. I double checked everything I could think of. The lifters fit good and tight in the bores also. I installed a new Comp Cams XE268 cam and used Sealed power lifters (these were the lifters Northern sent, I was going to send them back for Comp's brand but they swore they were the same product so I used them). I used plenty of cam lube. We got the engine in and fired it right up and took it right up to 2200-2300 rpm for about 1/2 hr. BTW: We used the recommended Rotella oil. Shut it off and changed the oil. 80 very easy miles later a lifter started hammering and we checked it and a cam lobe was going flat so we yanked it back apart and installed another new XE268 cam and lifters this time using Comps brand lifters. Changed the oil before ever starting it and installed fresh Rotella oil and a new Wix filter. Fired it up, ran it for 30 minutes at 2200-2300 rpm. Shut it off and drained and changed the oil. Now with the Comp brand lifters the lifters clatter at idle after the engine is warm. My buddy ran them again and they were set right (we have the preload set at approx. .030-.035 per Comp Cams recommendation). The oil pressure is 35 at idle and goes right up to 48-50 as soon as you give it gas. We put another Autometer gauge on it to make sure the first was reading correctly and got same reading withing 2 lbs. Were about to pull our hair out with this thing. I've done everything by the book and it still don't work. At least with the Sealed Power lifters they didn't all clatter when it idled.

Tried calling Comp Cams and their tech line is a joke. I was prepared for them having all the numbers written down. After we told them everything we had done and it was as they recommended all they could say was we had to be doing something wrong. They don't make bad lifters. They treat you like your the worlds biggest moron. Of course their can't possibly be something wrong with one of their products. It has to be you.

Sorry about this being so long but can anybody else give me an idea what to do. My next step is to just go with a different cam maker at the moment.
 
Are the valve springs dual springs, or spring and damper. Cam should be broken in on dual spring setups with inner spring removed. Maybe theres not enough clearance between the retainer and the valve guide. I seem to recall I had to have the guides cut down on my 454 I had in my jetboat, and the cam did not have that much lift, around .520. I have heard that Comp Cams lifters do make some noise, just like Rhoads lifters. Good luck. Bob
 
i didn't know there was a preload on chebies that's a bad word my uncle's been building them motors 4 30 years he say's when it's warm pull the covers adjust valves while running loose em till ticking then tighten em till ticking stops + one turn more he don't care what anybody says only way to adjust valves on an chevy
 
Bob their the single springs Comp cams calls for with dampers. We have every part comp cams calls for right down to the pushrods and roller tip rockers. We didn't measure the clearance from retainer to guide cause this isn't a very big cam and a local that builds big block chevys all the time said it shouldn't be a problem but since we have to pull it apart again I'll check it. Funny thing is though the Sealed Power lifters didn't all clatter like this. You'd think if it was retainer to guide interference they would have done it. It is a very good suggestion to check though and I willl do it when we tear back into it tuesday.

Mr.318 the adjustment your uncle refered too is setting the lifter preload. When you take the rockers down to no tick then 1 turn past you have pre-loaded the lifters approx. .050 inch. The rocker arm stud is a 7/16 20 thread per inch stud. 20 threads per inch comes out to be .050 per turn. The service manual calls for preloading 1 full turn. That's a stock specification. Comp cams says to only preload them .030 + or - .010 which is just slightly over a half turn. That's what we did. We even tried preloading more but the results were the same. Lifter tick.

Thanks guys.
 
Bob just reread your thread and noticed I missed the last part about the Comp cams being noisy like Rhodes. I have heard they are too but never heard one yet. I wonder if this is case. Funny thing is it don't do it when cold???
 
I think the Comp lifters have that bleed down valve like the Rhoads lifters and maybe when the oil gets hot and thins out it rattles.
I remember when I had my 454, it had Rhoads lifters in it and they did make noise. But I never had any experience with Comp lifters so I'm just guessing. You could try a anti pump up lifter since you have a adjustable valvetrain.
Bob
 
The oil gets thinner after warm up and bleeds out faster than when it's cold. At idle, being pressure is low, the lifters could be squeezing out the oil, thus the clatter.
(This is just thinking out loud.)

My Rhoads clattered a bit. Went away at a few rpm's above idle. Perhaps the Comp lifters have a larger oiling hole in the lifter body?
(This is just thinking out loud. Again.)
 
I have heard acout soem of the XE268s being "noisey" like that. I've installed a bunch of XE grinds big and small. The XEs larger than the 268 can be a little noisey at idle, but they call for the anti pump up lifters, which can be noisey. (IE Rhodes lifters). If it hasnt eaten the cam, and you are certain the preload is fine and not changing, then I would not sweat it. I also tend to think all roller rockers are noisey at idle. Sometimes made worse by the style of valve cover used. If it's indeed ticking, use a long extension as a stethoscope to figure out what it is. Cup the female end with your hand with the extension being the 'outside" end, and your ear being the "inside end". Then place the male end against the head, or block, or valve cover with the engine running. You will hear the tick...
 
I've never heard the Rhodes lifters but the guy who owns the 454 says he had some in a 350 once and they sound allmost as bad as them. I talked to the owner and he's going to call Comp cams again and see what they say. Tomorrow I think we'll also try using the extension as a stethiscope to listen and see if it for sure sounds like all of them. From outstde it does.
Thanks for the input guys.
 
You must log in or register to reply here.
-

Back
Top