Roller rocker issues

[54belair]

First of all, Im old school! Ive never used roller rockers---but, I have two sbc that have roller rockers. One set is a Comp set, the other looks like it might be Crane (just from pics Ive found).

My question is: Are they more prone to failure than the old stamped steel rockers?

The reason Im asking is, On the Comp set, there is evidence that maybe the barrel adjusted broke (steel chunks and shavings around a head bolt), the other set appears to have eaten three push rods. The ball end on the push rod show significant wear--as does one of the sockets on the rocker.

Is this kind of wear usual on these things? One engine has about 15K and the one Im saving has less than 5K (thats the one with bad push rods)

For a street engine, is there any advantage to the roller rockers over the stamped steel??

Anyone have any similar issues with rollers?

[Husker]

I am interested also.
I would think the would more reliable over the non roller type.
Ron

[1968SWBBigBlock]

Based upon everything I have seen your experience is not the norm
The roller rockers last for many years - some folks have 100K on thiers
Quality roller steel full rollers are your best bet

[GASoline71]

Do you have true roller rocker arms? Or roller tip rocker arms?

Gary

[meatwagon83]

i have harlan sharps on my dually and i probably have 20k on them, other than them being a little noisy i have no complaints

[54belair]

Well, now I guess I have anothr question----whats the diff betwen roller rockers and roller tip rockers? Both sets that I have seem to run aprox. $200. in price--and Ive seen some that sell for $350+. Ive got bigger issues now( grrr), I pulled the cam today and discovered a gaulded front cam bearing----the fun just keeps comming!!

[meatwagon83]

roller tip only has a roller on the tip and not at the stud, rollers have a roller at both the stud and at the spring

[Rufton]

For reliability I'd bet on OEM quality stamped steel RA in it's OEM unmodified engine.
Stamped steel is very reliable but they do eventually wear out.
Roller rockers occasionally fail but they are needed in many high performance engines.
I ran roller tips in a high lift cam and they looked almost new after about 8000 miles.
Roller tip rockers freely adjust to plane of valve tip w/o binding risk.
Full rollers may bind if alignment is off.
Should get slightly more HP w/ full roller.

[54belair]

Thanks guys for the clarification. With that info I can tell you that both sets are full roller rockers.

As I mentioned yesterday, I just went from a cam change to a full rebuild!! When I found the scuffed front cam bearing I was not a happy camper. For what Ill be using the engine for, when it goes back together Ill go with the stock stamped steel rockers.
Im still nt sure Why the damage to the rockers and push rods with so few miles. Maybe too aggressive valve springs?? dont know. I do have some questions for the guy who build the engine for my friend. Anyway,, after I throw a ton more money at it---it will be right!!!!!!?? (and Ill be much further over budget on my build)

This is a classic example of my "second thought" that I list below!!!
Thanks for the input guys,,,

[1968SWBBigBlock]

Ii can assure that your valve springs are not to aggressive - that's one of the deciding factors on running rollers or not - the stock stamped steel rockers will deflect at high lifts and spring pressures.
I wonder if they put used rockers in when they rebuilt it?
Rockers will wear pattern with the push rods and the angle that they both run in at - so changing one or the other can create a failure. Not every time but I have seen this occur.
Keep us in the loop looking forward to the results.
Pictures would be great

[Rufton]

Originally Posted by 1968SWBBigBlock

Ii can assure that your valve springs are not to aggressive - that's one of the deciding factors on running rollers or not - the stock stamped steel rockers will deflect at high lifts and spring pressures.
I wonder if they put used rockers in when they rebuilt it?
Rockers will wear pattern with the push rods and the angle that they both run in at - so changing one or the other can create a failure. Not every time but I have seen this occur.
Keep us in the loop looking forward to the results.
Pictures would be great

I knew lifters must keep the same address if reused.
I thought PR address wasn't critical on stamped RA applications.
Some flipped PR in economy stamped steel engine rebuilds.
I guess full roller RA PR are less forgiving especially at hi spring rates.

[Rufton]

Originally Posted by 54belair

Thanks guys for the clarification. With that info I can tell you that both sets are full roller rockers.

As I mentioned yesterday, I just went from a cam change to a full rebuild!! When I found the scuffed front cam bearing I was not a happy camper. For what Ill be using the engine for, when it goes back together Ill go with the stock stamped steel rockers.
Im still nt sure Why the damage to the rockers and push rods with so few miles. Maybe too aggressive valve springs?? dont know. I do have some questions for the guy who build the engine for my friend. Anyway,, after I throw a ton more money at it---it will be right!!!!!!?? (and Ill be much further over budget on my build)

This is a classic example of my "second thought" that I list below!!!
Thanks for the input guys,,,

I would spin oil pump w/ drill and verify oil flowing to valve train and cam journals.

I would dissect oil filter, cut element out, press oil out in vise, and see if magnetic and/or non-magnetic metal is visible.

Does scuffed bearing have ferrous metal particles embedded?

I would measure cam bearing clearances and verify bearings were installed correctly. I wouldn't be happy till gremlins found.

[54belair]

All of your suggestions were good, many of them I have done. I was a little bummed at first (still am some) about having to do the rebuild--- but all in all it will be a good thing.

I did not see any contamination in the cam bearing that I had good vision of--just significant wear. I did run a magnet around the bottom of the pan after I drained the oil and did find a small amount of material clinging to the magnet. Im also upset by the condition of the oil in the pan--nasty and thick (on an engine with 5K or so miles), so as I said a complete rebuild is prob best.
Actually the "complete" rebuild will only cost me a couple hundred more.
Im more upset of the condition of the engine since I bought it from a friend------I have to go with the idea that he didnt realize how close the engine was to having a noticable issue (either that or loose a friend)

Im including pics of the rocker and pushrod (the worst one) Its hard to tell but there is wear inside the rocker cup as well as wear to the ball on the pushrod and wear on the side of the pushrod.

[Rufton]

I would check for valve spring and PR binding.
Maybe lift was a bit over when up to temp.
Once gremlin found I would completely disassemble and inspect bearings, etc.
Maybe you caught it in time to avoid too much damage.
I don't understand the thick oil?

[Rufton]

As mentioned, don't use stamped rockers unless using near OEM cam and near OEM springs that were designed for stamper RA. Your intake doesn't look like a match for stamped RA design to me. Roller tip RA likely ok.

Should buy a cheap PR length checker tool to verify geometry.

[54belair]

The cam Im going back with is close to stock, its a comp 256h--made for low end and mid range power. Ive ordered as well new springs that are close to stock specs and Ill be using the stock stamped rockers.
After I got over the initial shock of having to completely dis assemble the engine to install new cam bngs, Im better with the idea of replacing most everything. Ive also ordered a new oil pump, timing chain, etc. If Im gonna have to bite the bullit---it might as well be a big one!!!

I heard the engine run less than a week before the truck it was in was totaled--sounded good then and I believe the mileage quoted to me because I helped install the engine early last fall. The engine was in a friends' kids' truck-----so, it doesnt look like it was cared for much---as well as something just not being right in the valve train.

I had the option of buying a complete rebuild from a local engine builder for right at 1K or it became an option to buy this engine from a friend for $600. I made the wrong choice!! Now its gonna still cost around $800 to have this one gone thru--having all the machine work double checked and all new bngs and rings and all new valve train.

No fool like an old fool!!!!!. But then, a couple years from now, when Im cruising in my truck, I wont even be thinking about that wrong engine decision!!!

[Rufton]

I wouldn't replace timing chain, oil pump, etc if look ok.
Oil pump, bearing, etc inspection is pretty easy.
Lucky for chevy folks, some new parts are dirt cheap.
Makes it easier for when in doubt throw it out.

Help me understand that thick oil?

[cableguy0]

Your problem isnt the rocker arms. Your problem is that those heads are not clearanced properly for a larger cam. Full roller rockers need screw in studs and guideplate. That bow at the top of the pushrod is where the pushrod rides through the head. Can you take closer pictures of the top of the where the pushrod comes through? Is it just a small circular hole where the pushrod comes through. On second view..... Your friend hooked up likely because he didnt know any better. If that cam has any sort of lift whatsoever your going to continue to have problems. Those heads look dead stock and the pushrods are getting stuck on the guide hole in the heads. You simply have a mismatched combination. Pull that engine apart.

[cableguy0]

On another note that valve train has been beat up pretty hard because of the pushrods sticking in the holes. I would personally tear everything apart and start over. If the top end was done half-@ssed then I would expect the bottom end to be in the same condition. Your rocker arms didnt cause the problem. Also remove all the rockers and make sure it didnt already start pulling the studs out of the heads.

[Rufton]

Originally Posted by cableguy0

Your problem isnt the rocker arms. Your problem is that those heads are not clearanced properly for a larger cam. Full roller rockers need screw in studs and guideplate. That bow at the top of the pushrod is where the pushrod rides through the head. Can you take closer pictures of the top of the where the pushrod comes through? Is it just a small circular hole where the pushrod comes through. On second view..... Your friend hooked up likely because he didnt know any better. If that cam has any sort of lift whatsoever your going to continue to have problems. Those heads look dead stock and the pushrods are getting stuck on the guide hole in the heads. You simply have a mismatched combination. Pull that engine apart.

Good point. I was considering different ratio rocker arms but didn't because the RA passage in heads would have to be clearanced to prevent push rod from kissing head.

What ratio are those rocker arms 54belair?

I'd still get a PR length checker to verify geometry and have a look at push rod to head clearance like cableguy said.

There is no guide plates?

Need guide plates even w/ roller tip RA.

[54belair]

Nope,, actually the pushrod wear comes from the guide plate in this case.

I dont know what springs were used, the cam was a comp 270h--I think the lift is about .454 and the rockers are 1.5 ratio.

I just went out and looked---I have three pushrods with wear---#3 intake, #7intake---the worst is #8 exhaust (pictured)

[cableguy0]

You see the wear on the pushrod guide hole at #8 exhaust valve? Those holes in the heads should be completely open with material removed to allow free movement of the pushrods. Something in your geometry is very wrong. The guideplates and screw in studs were invisible in the first pictures but you have some issues. Im kinda surprised the rockers arent hitting those raised guide plates. I guess you just didnt have quite enough lift to make it happen.

[54belair]

I think youre right, the lift isnt too high so that might have kept them from hitting.

When it all goes back together-- itll have stock height screw in studs along with the rest of the stock GM valve train (except cam)
Years ago I ran a new 69 z28 on the strip week after week with the only mods being screw in studs and traction bars on the car. Turned that engine 7000rpm every gear, she was still running fine when I sold it.
Im old now--and slow, this engine will see maybe 5000rpm Occasionally

[Rufton]

I would replace cam and reuse undamaged parts. You can test spring rate using bathroom scale, press and ruler. Lower lift cam will cause less valve spring open load.

I always hear stories of wiped cam lobes so I'm a little shy about reusing cams. Plus it's nice to pick cam you like.

I understand there are many ways to skin cat.

[GASoline71]

Be cautious of any trash in the oil that is still sitting in the oil gallerys throught the entire engine. With all that wear, the displaced metal had to go somewhere.

Gary