Busted Rocker

« **on:** April 16, 2010, 05:53:05 AM »

I had a motor I was working on break a rocker....

the damn thing kept coming loose and no matter how often i tightened it, it would wobble really bad left to right....i thought maybe the guide wasnt the right one or something.....finally i took it off and flipped it over.....

busted spindle and super worn out push rod cup

so what caused this? bad rocker? or bad mechanic? they arent the best rockers in the world, but i am also learning valve adjustments

« **Reply #1 on:** April 16, 2010, 06:32:25 AM »

i think the pushrod cup is secondary damage, was the poly lock tight or loose

« **Reply #2 on:** April 16, 2010, 06:36:54 AM »

Could be virtually anything from a manufacturing defect to valve train geometry problems to an overzealous grease monkey trying to impress...

Seriously, that looks like a textbook fatigue of the trunnion from mis-adjustment, or backing off once or twice due to one of several problems...

Going to make an assumption that these were not new to start with? I would take a close look at the rocker stud too...

GT

« **Reply #3 on:** April 16, 2010, 06:36:59 AM »

Quote from: Ralph Brunt on April 16, 2010, 06:32:25 AM

i think the pushrod cup is secondary damage, was the poly lock tight or loose

the poly locks were never loose...nor the set screws. i lashed them per the cam card. (.021)

theres a few other rockers that dont have broken spindles....but have the cup damage...not as bad, but enough where it was originally pressed in there, now it freely spins and falls out when i back it off the pushrod.

« **Reply #4 on:** April 16, 2010, 06:39:55 AM »

Quote from: GT Jets on April 16, 2010, 06:36:54 AM

Going to make an assumption that these were not new to start with? I would take a close look at the rocker stud too...

GT

brand new set of pro-comps.....studs look good.

geometry looks good. roller is centered on the valve stem at all times...no binding.

« **Reply #5 on:** April 16, 2010, 06:51:32 AM »

Quote from: Brad @ SoCalJetBoats.com on April 16, 2010, 06:39:55 AM

brand new set of pro-comps.....studs look good.

geometry looks good. roller is centered on the valve stem at all times...no binding.

Do you know if you had a good flow of oil coming from the pushrods?

Strange to see a rocker beat the cups apart without an obvious system problem...

I have seen where the cups don't fit the rods properly, but that was in the early days of aluminum rockers (Chinese crap to boot)..Are there funny wear patterns in the cups or on the PR?

GT

« **Reply #6 on:** April 16, 2010, 06:56:37 AM »

when priming the motor....i got good flow to all 16 rockers

no obvious weird wear marks...what should i look for?

« **Reply #7 on:** April 16, 2010, 07:27:26 AM »

Quote from: Brad @ SoCalJetBoats.com on April 16, 2010, 06:39:55 AM

pro-comps

And there's your answer. Pro Comp is cheap Chinese junk.

« **Reply #8 on:** April 16, 2010, 07:35:38 AM »

Quote from: Brad @ SoCalJetBoats.com on April 16, 2010, 06:56:37 AM

when priming the motor....i got good flow to all 16 rockers

no obvious weird wear marks...what should i look for?

I have seen it where the cup gets a crescent moon shape worn into it and the push rods look like they need a circumcision

Quote from: Luckie Stiff on April 16, 2010, 07:27:26 AM

And there's your answer. Pro Comp is cheap Chinese junk.

I was thinking the same thing initially, but, this should be dug into IMHO

Sometimes when trying to find a weak link, you should try weakening another link..(something my uncle said once)

Pro Comps really hate heavy springs, but seem to work killer on roller cams with little/no issues... $:-\$

GT

« **Reply #9 on:** April 16, 2010, 07:39:43 AM »

Now I'm wondering if there's any metal bits in the motor? Are all the needle bearings accounted for? All the trunion pieces there? I'm thinking that pulling the engine and dropping the pan will be cheap insurance. I wouldnt stress any of that cheap junk in an engine that I planned on running very long. I have seen lots of that stuff that looked like a good deal untill you have to tear it down and clean the scrap out of the oil pan, and then go ahead and buy the right parts. Cheap parts are just that, CHEAP. Dont trust them!

« **Reply #10 on:** April 16, 2010, 08:09:39 AM »

grasshoppa, have you forgotton allready?

CHEAP AINT GOOD AND GOOD AINT CHEAP

« **Reply #11 on:** April 16, 2010, 10:16:30 AM »

I know this sounds stupid but it looks like it was bolted down with the inner sleeve up side down. They only go on one way. Also. I would step up to shaft mount rockers. You will pick up around 10 hp. eliminates play from side to side you will get a tad more lift. you also don't have to run stud girdles with them and personally their all around better. Ill never go back to em after having the shaft mount ones.
Also clay smith has the strongest studs Ive ever seen. way stronger than arp. check them out there bad ass.

« **Reply #12 on:** April 16, 2010, 10:20:31 AM »

Quote from: Brad @ SoCalJetBoats.com on April 16, 2010, 06:39:55 AM

brand new set of pro-comps....

Brad,, I think you have located the problem. While I have used some Pro Comp stuff on occasion, I have located quite a few problems with their parts. They are pretty good about warranty replacement, or perhaps even a refund or credit towards something else if you don't want to risk another set of their rockers.

We had one set of sbc on a dirt track engine that didn't outright fail, but the bearings felt lousy after only a couple of races (40-50 miles total I think). They replaced them, basically no questions asked, and we did not use the "free" set, bought another brand.

« **Reply #13 on:** April 16, 2010, 12:36:56 PM »

Quote from: ROMPERSTOMPER on April 16, 2010, 10:16:30 AM

I know this sounds stupid but it looks like it was bolted down with the inner sleeve up side down. They only go on one way. Also. I would step up to shaft mount rockers. You will pick up around 10 hp. eliminates play from side to side you will get a tad more lift. you also don't have to run stud girdles with them and personally their all around better. Ill never go back to em after having the shaft mount ones.
Also clay smith has the strongest studs Ive ever seen. way stronger than arp. check them out there bad ass.

If it wasn't a 1k investment on a cruiser motor it would be the best route.
Shaft mount IS the way to go though.

-beerjet-

« **Reply #14 on:** April 16, 2010, 01:10:22 PM »

Simply stated.....Assembly problem or cheap parts...or both

« **Reply #15 on:** April 16, 2010, 01:11:56 PM »

Just another reason to build Mopar

Yeah yeah yeah flame on haters

« **Reply #16 on:** April 16, 2010, 02:34:33 PM »

Quote from: beerjet on April 16, 2010, 12:36:56 PM

If it wasn't a 1k investment on a cruiser motor it would be the best route.
Shaft mount IS the way to go though.

-beerjet-

Yea but a good set of roller rockers is about 500-900 $ plus another 200 for girdles puts you at, or over the 1k mark

« **Reply #17 on:** April 16, 2010, 06:13:13 PM »

It looks like it was on right, sure has the look of being soft aluminum where the cup area opened up.
What brand were the rockers? Pro Crap?

I'm using the comp cams pro magnum or what ever they called it. With the stud girdle
they are very nice rockers.

« **Reply #18 on:** April 16, 2010, 06:57:37 PM »

YOU START OUT WITH CHEEP JUNK YOU END UP WITH JUNK

« **Reply #19 on:** April 16, 2010, 06:59:39 PM »

Quote from: bruntracing on April 16, 2010, 06:57:37 PM

YOU START OUT WITH CHEEP JUNK YOU END UP WITH JUNK

Hey pops...

Sometimes I start with expensive top of the line parts, and still end up with junk...LOL

GT

« **Reply #20 on:** April 16, 2010, 07:06:31 PM »

COMP CAMS OR JESSEL MAKES THE BEST ROCKERS FOR THE MONEY YOU CANT GO WRONG

« **Reply #21 on:** April 16, 2010, 07:09:49 PM »

THEN YOU ANT DOING SOMTHING WRIGHT ?

« **Reply #22 on:** April 16, 2010, 07:14:06 PM »

Quote from: bruntracing on April 16, 2010, 07:09:49 PM

THEN YOU ANT DOING SOMTHING WRIGHT ?

Or drive like a jackass.....Whitewater rivers be hard on stuff...

GT

« **Reply #23 on:** April 16, 2010, 08:18:05 PM »

Quote from: Ralph Brunt on April 16, 2010, 08:09:39 AM

CHEAP AINT GOOD AND GOOD AINT CHEAP

Everytime i go to buy something for my project, i hear these words

then i spend the extra $

See if you can get a refund then step it up a bit, Comp has some real nice rollers at a good price.

By the way , that sucks!!!

« **Reply #24 on:** April 17, 2010, 12:54:42 PM »

Quote from: ROMPERSTOMPER on April 16, 2010, 02:34:33 PM

Yea but a good set of roller rockers is about 500-900 $ plus another 200 for girdles puts you at, or over the 1k mark

I agree , but I think these rockers are on a stock-ish cruiser motor .

-beerjet-

Brad @ SCJB

Ralph Brunt

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