GM Sm Blk Rockers

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GOSFAST
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Re: GM Sm Blk Rockers

Post by GOSFAST » Sun Aug 27, 2017 7:40 am

ProPower engines wrote:I tried the elgin rockers and they had the same issue as the SBI rockers.

We found many years back the GM rockers that had the "O" on the tip were by far the most durable and never broke through the push rod area as well.
I had 3 rockers break on the dyno after break in of the cam but I did look at every aspect mentioned for durability and longevity but they still let go.
They have tons of oil and the slots do not bottom on the rocker. The push rod fits well that is after checking a few sets of them.
Most rockers as mentioned show creases around the push rod cup area that the old GM rockers do not.

Has anyone tried the Crane nitro carb stock type rockers??
Crane claims they will be fine with the pressures being run so I may give them a try. [-o<
They look better made they any shiney stock rocker looked at this last week

Thanks for the suggestions

Any more please feel free

Dave C
Hi Dave, if it's any help I have a number of sets "stashed-away" (used) "O" stamped rockers from numerous builds over the years where we did upgrades to rollers. Most are very low mileage and in mint condition.

Thanks, Gary in N.Y.

P.S. I have them packaged with "slotted" R/A balls and new nut lock nuts. If interested get back to me with an e-mail: Theengineshop@aol.com Will respond quicker than back here through PM's.
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Re: GM Sm Blk Rockers

Post by engineguyBill » Sun Aug 27, 2017 2:19 pm

^^^^^^^^^^I imagine that Elgin manufactures the "Nitro-Carbide" rocker arms for Crane ^^^^^^^^^^^

Also a pretty good chance that Elgin also manufactures the OEM rocker arms for GM. Elgin is a major supplier to many of the OEM manufacturers.
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Re: GM Sm Blk Rockers

Post by pamotorman » Sun Aug 27, 2017 8:21 pm

ford used to sell a stamped steel rocker arm with a ball bearing trunnions conversion.

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Re: GM Sm Blk Rockers

Post by midnightbluS10 » Sun Aug 27, 2017 10:55 pm

pamotorman wrote:ford used to sell a stamped steel rocker arm with a ball bearing trunnions conversion.

I think the Vortec 4.3L came with those. There's another version that looks similar to the LS style rockers, also. They look exactly like the ones in the 2nd pic.

Image


Image

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Re: GM Sm Blk Rockers

Post by pdq67 » Tue Aug 29, 2017 1:22 pm

midnightbluS10 wrote:
pamotorman wrote:ford used to sell a stamped steel rocker arm with a ball bearing trunnions conversion.

I think the Vortec 4.3L came with those. There's another version that looks similar to the LS style rockers, also. They look exactly like the ones in the 2nd pic.

Image


Image
Any V-8 sets like the Vortec 4.3's set above??

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Re: GM Sm Blk Rockers

Post by ProPower engines » Wed Aug 30, 2017 12:13 am

engineguyBill wrote:^^^^^^^^^^I imagine that Elgin manufactures the "Nitro-Carbide" rocker arms for Crane ^^^^^^^^^^^

Also a pretty good chance that Elgin also manufactures the OEM rocker arms for GM. Elgin is a major supplier to many of the OEM manufacturers.
I looked at the Elgin rockers and they look nothing like the long slot Crane rockers stamped rockers I received today. I compared them to the several brands today and they are similar to the SBI rocker I tried 1st that was breaking but being a stock type rocker but the crane compared to the SBI needs a different length push rod then I was using.

I use a ton of Elgin stuff but the issue is the slot is not allow to be lengthened in any way that is obvious like leaving any grinding marks on them they would be considered illegal and they would be DQ'd during tech.

I will let ya know how these Crane rockers work out

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Re: GM Sm Blk Rockers

Post by MadBill » Wed Aug 30, 2017 2:04 pm

Another fine example of ill-considered regulations. If they want to limit valve lift they should just say so. What other possible benefit does a zero-cost lengthening of the rocker slot permit? #-o
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Re: GM Sm Blk Rockers

Post by MadBill » Wed Aug 30, 2017 2:22 pm

Although this thread is about the pushrod end of the rocker, I just had a thought about the rocker ball*. The slotted ones are controversial, as while directing oil, the slots also reduce contact area. *(I've re-invented dozens of wheels over the years; no reason this wouldn't be another...)

Instead of a slotted ball if a fat, snug-fitting Viton® O-ring was rolled onto the stud before installing the rocker assembly, it would move down with the rocker as it was adjusted but stay in contact, forming a seal and resulting in an oil 'pool' immersing the ball and socket.
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Re: GM Sm Blk Rockers

Post by Leftcoaster » Wed Aug 30, 2017 3:54 pm

MadBill wrote: Instead of slotting the ball, if a fat, snug-fitting Viton® O-ring was rolled onto the stud before installing the rocker assembly, it would move down with the rocker as it was adjusted but stay in contact, forming a seal and resulting in an oil 'pool' immersing the ball and socket.
There! Great idea described a tad clearer? :mrgreen:

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Re: GM Sm Blk Rockers

Post by Greenlight » Wed Aug 30, 2017 6:25 pm

Can the OP relate to us whether the problem is related to wear (either in the push rod cup or the rocker ball cup/slot), then breakage, or if there are NO symptoms of wear, only breakage?

I suspect that the problem may be due to valve train instability and not faulty components.
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Re: GM Sm Blk Rockers

Post by pamotorman » Wed Aug 30, 2017 6:32 pm

if you must run stamped steel rockers use piddle valve lifters vs edge orifice to make sure you get extra oil to the rockers. that is why they were used in the BBC when they came out to get more oil because of the stiffer valve springs.

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Re: GM Sm Blk Rockers

Post by ProPower engines » Fri Sep 01, 2017 2:01 am

This class mandates hyd. lifters only.
While they are Isky lifters the engine ran well tonight with the new rockers and will be track testing again tomorrow but at this point it has been just fine.
Checked all the push rod seats and no sign of any thing in the way of wear and wet maged the rockers for fun to be sure no cracking was appearing. All was good there as well.

I think I got it beat but I just got 2 engines in today from Mercury marine with a similar issue and damage out come. All new parts but push rods through the rockers.
These are a valve tip guided rocker but the damage was the same. pushrod cup pushed through.
Although these are Hyd. roller cams they only have 76 lbs seat 230 open pressures so its not too much valve spring :D

Aftermarket off shore heads were used with a big 906 cast in the head and they are definitely not a factory GM head.
There may be a geometry issue here but thats tomorrows project but they don't have much cam in them from what we measured today
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Re: GM Sm Blk Rockers

Post by pamotorman » Fri Sep 01, 2017 8:34 am

I believe some GM crate race engines use kool nuts and they must have found that there is a reason to use them. https://www.summitracing.com/parts/crn- ... /overview/

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Re: GM Sm Blk Rockers

Post by midnightbluS10 » Sun Sep 10, 2017 2:46 am

pdq67 wrote:
midnightbluS10 wrote:
pamotorman wrote:ford used to sell a stamped steel rocker arm with a ball bearing trunnions conversion.

I think the Vortec 4.3L came with those. There's another version that looks similar to the LS style rockers, also. They look exactly like the ones in the 2nd pic.

Image


Image
Any V-8 sets like the Vortec 4.3's set above??

pdq67
I don't think so. These came out around 200/2001 and the LS style came on my replacement GM 4.3L LU3 long block which was a 2012 model, I think. Though you may be able to piece them together using v8 stands and v6 rockers.

Edit: that may not work, either. Seems like the V8 stands are all LS stuff. I didn't know that. And I just realized he said "ball bearing conversion" in the original post I quoted. These have the usual needle bearings.

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Re: GM Sm Blk Rockers

Post by pdq67 » Sun Sep 10, 2017 2:57 pm

Anybody by chance remember the old, "Gotha" rockers? I don't think they were made in, "ball and stud", design, only, "shaft".

pdq67

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