Broken rocker arm

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May 20, 2019 | 01:28 PM

Andrewhuffman

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From: Jacksonville

Broken rocker arm

Broke a rocker arm with trunion, btr660 and hardened pushrods after a few hundred miles. Cam is 224/236 .629 .604, 6500 rpms, 7.4 push rods with 90 preload, 105 ptv, heads shaved 20

May 20, 2019 | 01:38 PM

G Atsma

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From: Central Cal.

BOTH the rocker and trunnion broke?

May 20, 2019 | 02:28 PM

Andrewhuffman

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From: Jacksonville

Just the tip of one rocker

May 20, 2019 | 02:58 PM

Hodgdon Extreme

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You do a leakdown test?

Is the cylinder in question still good to go?

I've not broken a rocker arm before without PtV contact... :-(...

Last edited by Hodgdon Extreme; May 20, 2019 at 03:24 PM.

May 20, 2019 | 03:50 PM

Andrewhuffman

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From: Jacksonville

I used compressed air to hold the valve up to remove the spring, but not an actual leak down test. Also removed the head and no marks on the pistons

May 20, 2019 | 04:50 PM

Hodgdon Extreme

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Quote:

Originally Posted by Andrewhuffman

Also removed the head and no marks on the pistons

Well that's a good sign. Guess all you can do is replace the rocker and carry on.

May 20, 2019 | 08:14 PM

Che70velle

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Are you positive that the rockers are GM, and not a knockoff? They are popping up lately, ironically in two pieces, on here.

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May 21, 2019 | 08:38 AM

lawrenq

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From: Charleston, SC

OEM is in the bottom, it also has letters and numbers on them. Was this an ls3/l92 style head?

May 21, 2019 | 09:51 AM

#10

Andrewhuffman

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From: Jacksonville

Yes. I might just buy new ones

May 21, 2019 | 11:36 AM

#11

lawrenq

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Quote:

Originally Posted by Andrewhuffman

Yes. I might just buy new ones
j

Mines broke in the same spot, did you purchase them from Michigan motorsports?

May 21, 2019 | 12:25 PM

#12

Andrewhuffman

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From: Jacksonville

Quote:

Originally Posted by lawrenq

Mines broke in the same spot, did you purchase them from Michigan motorsports?

M&M Motorsports
5501 Hooper DR.
Wichita Falls, TX 76306
User BMFRC
Name Lamar Murphy
Email murphywf@yahoo.com

just googled the seller 😭😭😭😭

I talked with him on the phone and he is very knowledgeable, responds fast, quick shipper, all the parts were new and as described. I bought a bunch of stuff from him.

I might need to look for new rockers... do you think the trunion is ok to reuse?

May 21, 2019 | 12:51 PM

#13

lawrenq

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Quote:

Originally Posted by Andrewhuffman

I wouldn't re-use the trunions either, when I bought mine they came with the comp trunions installed. But I was a little skeptical about that and I ended up installing CHE bushed trunions instead. I had no idea that the rockers were not OEM until I broke one and contacted the seller afterwards. You are the third person that I've seen with a broke rocker from them.

May 21, 2019 | 12:59 PM

#14

Andrewhuffman

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What and where do I get new rockers and trunnions? Or is there a better rocker I should upgrade to?

I see btr has em for $330.

May 21, 2019 | 01:31 PM

#15

lawrenq

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I'd buy some OEM rockers from someone here or another trusted seller and I'd use a bushed type trunion kit instead of the roller needle bearing kind. I went with the comp cam bsr shaft rocker which is basically an OEM rocker installed on a shaft.