Has anyone had any experience .... good or bad with Comp big block hydraulic roller lifters part no. 8921-16? I'm converting to these and Comp cam after using the old Mopar 284º .528 solid cam for several years. Just want to hear of any failures or good term results.

Comp has been selling them for a good while now and they have had a ton of problems--they are known for the plungers "sticking" and making a mess! I have had two engines just about kill me and destroy customer confidence when lifters failed a few days in on one and a few hours after install on another--they stink! Comp will do nothing and tell you there are no problems--Cranes are the best but I don't think any are left out there--old stock I mean--a new company has a hyd roller lifter for BB Mopar--I think Hughes and others have them available--as well as other vendors--they seem to be doing good though I am not sure who makes them I am told they are USA--RUN From the Comps !!!! Yea--many will say they have had no issues but do you want a trashed engine?? Comp may supply the top teams with great items but us poor ole street hot rodders get imported and UNTESTED junk day after day from them with NO support--they sell junk and KNOW IT! Ask any engine shop owner and they will all have a note book filled with tales--do some homework and find the others out there--Good luck when that lifter fails, pushrod jumps out, rocker is trashed, valve gets bent, guide ruined and then you pay to take it all out , do it all over, buy new parts --That company could have admitted mistakes, made it right and been the #1 outfit but they hide and admit nothing--just ask crate Hemi owners that had Comp units with "soft" cam cores from China etc etc etc

I had a ton of problems with the comp ones, plungers collapsed in less than 200 miles. My engine builder replaced them for free with some other brand that I can not remember the name of.

I bet Comp has 100 warranty cards on file with my name on them and they would not help one bit--Can you tell I can't stand them?? The customer is the inspector and quality control--If you can find a set of the Cranes in stock on some shelf somewhere BUY them they were great!

I have the XR274HR-10 in my 383 now 438. I also used the Comp rollers. After reading the above comments I feel lucky.

So far I have a total of 2,849 miles on the rebuild and 58.9 hours on the engine. I added a Hobbs meter (engine hour) gauge to keep track. I have had no issues yet. 99% of my driving is cruise as I live in souther NM. The engine has never seen the north side of 5200 rpms.

But that's just me.

Just my

Frank

Almost a year later and I finally have the Charger back on the road. I went with Hughes hydraulic rollers and am very happy so far. It's very quiet (no tappet noise) and responsive. Over 500 hard miles so far with no issues. I won't have it to the track for a while yet, but I know that it will now be well into the 11's. The cam is Comp's XR274HR-10 grind, Part # 23-710-9. The idle is still a bit lumpy, but the vacuum at idle is 13.5" in neutral and 10.5" in gear @ 800 RPM. WOT is pretty crazy, my 275-60-15's are nowhere near enough tire. Street manners are fantastic, I can use overdrive at 30 MPH and can lock up the converter at 45. Will post true MPG numbers after our first cruise next month and real ET's after the track runs in early August.
After talking to a bunch of other engine builders and Comp roller lifter users my advice to anyone is get them out of your engine NOW if you are running them. For anyone thinking of buying them the very common answer is: DON'T!

Latest news is the Hughes are Morels--They can be bought through just about any cam grinder like Bullet, etc and seem to be the best available--I have used several sets now with great luck--quiet as a mouse peeing on a ball of cotton and they can and will accept 1 1/2 turns preload NO issues--that keeps em quiet with NO issues. Now...will they fit a new Hemi block? Not! I am told by Todd at Marsh--call him for details but the hyd rollers are great!

I fitted the Comp 8921-16 lifters a few months ago, cam is a Comp XR292HR. They always rattled for a few seconds when I started it in the morning and twice now I've had one or more lifters collapse. The first time it happened it was just one lifter and after running the engine again for about 15 seconds it pumped back up. Yesterday it happened again, this time two lifters had collapsed. One pumped back up after a while but the other refused.
I now have the lifters out of the engine and I'm going to replace them. I want to use a set of Morel lifters, part number 5319. Will the pushrods still be the correct length if I use them? In other words is the distance between the roller and the pushrod seat the same?

Sorry, but I don't have that information. I never installed the Comp lifters in either motor they were purchased for. I got the word from other engine builders that they were very unreliable, so used the Hughes (Morel) in both engines. I have 4000 miles on mine now with no problems or noise of any kind.

Think i've found the info I was after.

http://johncalliesinc.com/pdf/MorelLifterDim_RollerToTopOfBallOnSeat.pdf

http://www.compcams.com/catalog/COMP2012/pdf/COMP_Catalog_2012_274-291.pdf

Looks like about 0.020" difference in pushrod height between the two so I should be ok with the pushrods I have.

any way to bench test these rollers before installing or is it a roll of the dice?

I'm using Comp. So far so good. Only a few hundred miles though....

No way of predicting failure that I know of . A friend of mine had the roller just disintegrate (Comp roller) on a road trip. The cam was riding on the roller axle for several miles before we could get to a safe place to stop. That engine had about 6400 miles on it. There are many other cases of the Comp failures on the dyno during break-in.

This post started a long time ago--and yes I was not happy with Comp at the time--found out that the Morels work, have been using them ever since and have found out more about them--the Morels like max spring pressure of 140 seat and 350 open--they like a quarter turn pre load--I have run more but...they seem to be able to handle about 6000 RPM but more than that and you risk valve float quick! As time has passed more hyd rollers are coming out that can take more spring pressure, are valved different and thus can do more more RPM--I have used them for Chevys and Fords, so far none for Mopar that I can find.
Take care with spring pressures and use as little pre load as you can get by with and the Morels are the only game in town.
I was ranting about Comp a little too hard at the time but remember I had two customers with issues directly related to the sorry lifters I had from them.
IMO the lifters are heavy, this and inability to use higher spring pressures greatly contribute to the RPM limits I have observed.

I agree with your thoughts on the spring pressures. The numbers you have given are very close to what mine are and I shift at 5000. I did get a little valve float around 6000 when I first started driving this new set-up, so I live with the lower shift point. Still running in the high 11's, so I'm happy.

Hello,
I just registered to ask a question in this thread. I have a 494 RB block in a custom jetboat, running a Comp hydraulic roller cam, with Hughes (Morel) 5319 lifters, Smith's pushrods, and Comp rocker arms. What preload is everyone running with the Morel lifters? Hughes says to run them at 0.030 to 0.035 with iron block with aluminum heads, so I started out at 1/2 turn (.025) and found them to be very noisy at an idle, even warm. I re-adjusted them to 3/4 turn (.0375) with no change in noise. They seem to be not loosing any pressure when I check under the valve covers, and the engine makes great power up top and the noise does seem to subside somewhat at higher rpms. Is this normal for these lifters? I am running 15w-40 Delo 400 during break in, but will switch to 5w-40 Schaeffers 9000 synthetic after break-in. Any comments will be appreciated.
Mike in Washington state
Mild Cam spec: 224/232 @ .050, 112 lsa, .531 lift.
Heads: Indy 440SEZ.
Oil Pressure at idle: 25-30psi. @3200: 65psi