Issues with roller cam
 

I installed a Howard’s brand roller cam as well as a set of their lifters in my Gen IV 454. Put about 1500 miles on it when I began to hear a knocking noise from the valve train accompanied by a noticeable drop in power. Figured a lifter had collapsed, but it had actually worn down the #6 exhaust lobe to basically nothing. I’m thinking that the knocking noise I heard was the cam beginning to chew up the lifter casing...

Looks like the retainer that keeps the lifters in line broke off which allowed the roller to rotate 90* on the cam. Any idea what could cause this other than a faulty part? You can see the broken stud laying on the right side of the lifter valley in the second picture.

At this point I’m looking at a complete engine rebuild, there is a TON of glittery stuff in the oil, and almost every cam lobe has been damaged.

Re: Issues with roller cam
 

Man, that is terrible! Hate to see that.

Recently when installing a set of COMP roller lifters with the same sort of anti-twist bar you have, I was looking down through my BBC slots there and noticed one set was just plain wrong. I could see the roller tips on the lifters were not oriented correctly with the lobes. They were pointed off in about a 40 degree angle instead. After quite a bit of scratching of the head, the solution was to simply invert the lifters on their bar and reinstall. In the oil bath, this set of two had simply gotten switched around on their bar, as if you'd held the bar with the lifters pointed down and twisted it 180 degrees, then allowed the lifters to point down toward the ground again. This made the roller tips not travel the same arc as the lobe.

If I hadn't noticed this, I suspect something like you describe would happen.

EDIT: There were two sets of lifters found inverted after install and pre intake install!

Hth,

-klb

Re: Issues with roller cam
 

Standard failure for these design of roller lifter....
he
Dogbone style roller lifter guides like the Jesel units are much stronger...

Lifter bore misalignment is the usual root cause...or excessive cam end float....

It only takes one impact of a roller lifter body against a next in line cam lobe and the lifter rotates and rips the pin out of the body...instant failure...

Full rebuild...all oil gallery plugs out and full gallery clean....

Check the valve spring pressures....note...the roller rockers will most likely be ready to fail as well from the contamination...

Seriously...look at the Jesel style lifter retainers....

Take it slow and keep us informed...

:chevy::chevy::chevy:

Re: Issues with roller cam
 

It may be just me, but the way the tie bar is setting on cylinder 8 does not look right to me. It kind of looks like the lifters are switched in the wrong holes. Take a mirror and light and make sure that the rollers are square to the cam on number 8. The bar should lie flat front to back at each lifter, and slope outboard to the exhaust lifter and inboard to the intake. The odd bank lifters look correct.

Re: Issues with roller cam
 

#8 cross bar is upside down. The lobe in view there has received damage as a result. This is the what I described above. Cross bar rotated 180, installed with roller tips not aligned with lobes.

The Howards logo on the crossbar is upside down.

-klb

Re: Issues with roller cam
 

Dang duplicate.

Re: Issues with roller cam
 

UffDah...

Man I feel for ya after all that good work. Only one thing to do now. Wish I could help out with the oncoming rebuild.

Re: Issues with roller cam
 

retro fit like that I hope you are running a good timing chain , cover , and button , torington bearing behind the big gear , check endplay , check your bearings , new cam and lifters ,

Re: Issues with roller cam
 

Also take a close look at your piston skirts in the area of the failure. The river of metal flowed down and a good portion of it landed on a piston skirt.

Re: Issues with roller cam
 

Could have just been a faulty part. Check the lifter bores make sure no damage before another set goes in. I had the comp cams solid roller lifters in a small block, after a 2 passes a lifter hung up in the bore. Bent valves luckily all that happened, but the culprit was the lifter body had cracked and pushed out. Take a look at the lifters, real close in case something similar happened.

Re: Issues with roller cam
 

Lifter sets on cyl 6 & 8 were definitely in upside down. Look at the wear pattern on the cam lobes of cylinders 5 & 7 compared to 6 & 8

Re: Issues with roller cam
 

Hopefully the OP can get by with new main/rod/cam bearings, oil pump, cam and lifters along with a full disassembly and cleanup. Unfortunately the retro fit lifters and cam are the most expensive bits of the retro fit parts list.

Not sure reusing the undamaged lifters is an option -- whether it's possible to flush and clean them internally. If so it would take some of the sting out of this as those are 400 to 600 bucks for a new set. The cam is maybe 350.

The block doesn't appear to have been damaged there in the valley area from the pictures. If it's OK then the OP should be about 1000 in parts and a few hundred in machine shop fees away from getting back running again ( and some dis/assembly ) depending on whether the lifters can be reused and whether the cam bearings need to be replaced.

I'm hoping for the best OP.

-klb

Re: Issues with roller cam
 

The cam bearings should be pulled out so the oil galleries can be totally cleaned out...same goes for the gallery plugs etc.

Depending on whether the rod pins are pressed or free floating, these should be totally pulled down and measured.

Oil filter mount boss clean out, oil pump will be junk, check distributor drive gear, roller rockers is fitted may be ok but will need to be pulled down....

Oil cooler system if fitted will need total flush out.

Finally, debur the liter gallery drain slots of all those tiny pieces of shrapnel and left over factory cast metal....add some epoxied in screens in each of the drain slots and then paint the entire lifter gallery with Glyptol....heat lamp dry it for 12 hours...and no, it doesnt flake off and clog oil pumps....

Note...if the glyptol doesnt stick, the engine block isnt clean enough!

Bad luck there young man...

:chevy::chevy::chevy: