Rocker failure

Tech discussions on the L77 6.0L V8.
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VintageIron41
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Rocker failure

Post by VintageIron41 » Sat Jun 06, 2020 10:58 pm

Hello and thanks for taking time to read this.

About 2000 miles ago I did a Texas Speed camshaft swap with all the parts that come with that camshaft and DOD/AFM delete. This week I heard a tapping?knocking sound in the engine bay, I parked the car, my first concern was that I had gotten a bad camshaft. Closer inspection today isolated the noise to the LH side cylinder bank. In "wiggling" the rockers I found one that was suspect, with excessive side to side play, after removing it, found that there is a lot of play in it, and that there is visible eccentric fresh wear on one side, upon still closer inspection, it looks as though there are one or more bearings missing on that side.

I new Delco rocker is ordered, and stopping down to get new oil and a filter, that car is parked until that work is done.

Question, has anyone heard of this before? And should I have a concern about where one or more of those bearings went?

Thank you!

s/c'd cav
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Re: Rocker failure

Post by s/c'd cav » Sat Jun 06, 2020 11:50 pm

get bushings , and ditch the bearings , also make sure you didnt loose the needles from the bearings , or that they fell into the oil pan

its very common , and always been recommended

https://sdparts.com/i-24101310-sdpc-rac ... n-kit.html

VintageIron41
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Re: Rocker failure

Post by VintageIron41 » Sun Jun 07, 2020 4:02 pm

Thanks s/c'd cav,
Am considering just replacing the rockers with roller rockers that have the bearings caged, is anyone familiar with the PRW Industries part #PQX0236431? Does that set have the offset intake rockers?

Thank you!

s/c'd cav
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Re: Rocker failure

Post by s/c'd cav » Mon Jun 08, 2020 6:39 am

you need to be careful with aftermarket rockers , alot tend not to fit well either hitting the head or rocker covers

and that is part of why the oe rockers with bushings are used in most all builds

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Mooseman
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Re: Rocker failure

Post by Mooseman » Mon Jun 08, 2020 12:47 pm

I'm not too fussy of the bushing type trunion kits because they do wear out and have to be replaced after some time. They're made of bronze, which is a relatively soft metal.

Instead, you could use a kit that uses captured bearings, similar to the ones in those aftermarket rockers.
https://www.ebay.com/itm/111138006719?s ... 1436.l2649
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s/c'd cav
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Re: Rocker failure

Post by s/c'd cav » Mon Jun 08, 2020 4:00 pm

Mooseman wrote:
Mon Jun 08, 2020 12:47 pm
I'm not too fussy of the bushing type trunion kits because they do wear out and have to be replaced after some time. They're made of bronze, which is a relatively soft metal.

Instead, you could use a kit that uses captured bearings, similar to the ones in those aftermarket rockers.
https://www.ebay.com/itm/111138006719?s ... 1436.l2649
people have had alot of issues with the captured bearing kits , with the bearings coming apart , which is why the bushings started , and have been the good to

yes the bushing types will wear out eventually

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Mooseman
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Re: Rocker failure

Post by Mooseman » Wed Jun 10, 2020 2:14 am

OK so how prevalent are failures of the OEM rockers? I mean like there are millions of them out there that probably 99.9% of them will outlive the motors they are in. It may be when they are modified with cams they can't handle or overly high spring pressures, they could fail.

I tried to search for the stock rocker failures and found this old thread on a Corvette forum. It's pretty much all over the place. A couple have had damage of the Comp Cams captured bearings' trunions but no outright failures. One racing engine builder uses stock rockers without any failures.
https://www.corvetteforum.com/forums/c6 ... grade.html

GM uses their stock rockers in their high performance engines. You would think there would be a mob of Corvette owners with torches and pitch forks beating down GM's doors if rockers were failing on a regular basis. The vast majority of them live forever.

To the OP, were the rockers replaced with the DOD delete? How many miles and idle hours were on this engine? What kind of cam did you use? Stock? And the valve springs? If you kept everything at basically the stock specs, I'd just get a full set of new OEM rockers and be happy. The PRW rockers I saw are basically stockers with the Comp Cams captured bearing kit. Overpriced IMHO. You could get the one new rocker to replace the damaged one and rebuild them all with the captured bearing kit. If one failed, others may not be far behind. When I did the DOD delete on my truck, I replaced the cam, all the lifters (some kits only replace the DOD lifters), rockers, push rods, chain, sprockets and oil pump.
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s/c'd cav
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Re: Rocker failure

Post by s/c'd cav » Wed Jun 10, 2020 3:59 pm

ive mostly been around the GTO , G8 , SS sedan , camaro/firebird boards , the comp bearing upgrade , which was the go to for along time , had a very high failure rate , they either changed something or had several batches that were problematic

the factory rockers are only good for so much lift , if you look at the ends of them , the part that captures the bearings, the the hole the shaft comes through is D shaped , and with large cams is part of their issue

but alot have failed on stock cams , not as bad as DOD lifter failures , and lately its been valve springs failing

VintageIron41
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Re: Rocker failure

Post by VintageIron41 » Fri Jun 19, 2020 2:50 pm

Thank you for your reply's to this post!

Yes, I did replace the one failed rocker with OEM, was going to get the PRW roller set with captured bearings, but now Summit says they won't ship for a month. To, having read s/c'd cav's post that there may be clearance issues I think I will cancel that order.

Okay, when I did the camshaft, I did the DOD delete which the Texas Speed kit included new lifters and push rods, so, the only thing I didn't replace was the rockers.

I thought roller rockers with caged bearings would be a good fix and upgrade, but now thinking a non roller set with caged bearings would be practical, any recommendations? I would prefer not to go the bushing route.

Again, thank you!

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Mooseman
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Re: Rocker failure

Post by Mooseman » Fri Jun 19, 2020 3:26 pm

I linked one above and there's the Comp Cams kit. I have no experience with either. The Comp kit did have some failures in early production but I think they've ironed those out since then.

Check reviews and other forum comments on them.
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