383 Stroker, fresh build, rocker stud broken...
 

:whine:

What are your thoughts on Stud girdles ?


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Re: 383 Stroker, fresh build, rocker stud broken...
 

Has about 700 miles on it.

Re: 383 Stroker, fresh build, rocker stud broken...
 

What's the lift on the cam, and are the springs rated to handle it? That could have been from coil bind. Also it appears the pushrod guide is gouging the pushrod as well. A girdle will help more at high RPM to stabilize the studs from flexing.

Gary

Re: 383 Stroker, fresh build, rocker stud broken...
 

What else was going on when this happened? High RPM? Pulling a hill? No load condition in neutral? 700 miles on those components are not even broke in. Some opinions may vary, but yes those details may matter, tremendously.

Odd things happen in the begining, for example when I did a top end on my truck, after the intial oil was dropped I went for a rip down the freeway. Added 10 gallons of AV gas to some premium at 115 to see if it would hold.

Sure did, except for one thing. The exhaust manifold gaskets, burned and blew them right out!

Re: 383 Stroker, fresh build, rocker stud broken...
 

I’ll get the info on the cam and springs.
Thanks

Re: 383 Stroker, fresh build, rocker stud broken...
 

Spinin’ down the road around 75 MPH, for about 3 hours. Flat ground for the most part.

Re: 383 Stroker, fresh build, rocker stud broken...
 

In the picture the other rocker is way out of alignment. There is a lot of stuff going on here with the side load on the pushrods the stud breaking and the alignment of the rockers. Who built the engine and where did the heads come from? Were the springs installed to match the cam specs and were the pushrod lengths measured and the correct length pushrods installed. Are those the correct guide plates for those heads. Some heads take special guide plates. And lastly are those ARP or elcheapo rocker studs? I lied, time to pull the intake and check the lifter. If you were running 75 when it let go there is a good chance you got the lifter.
Jimmy

Re: 383 Stroker, fresh build, rocker stud broken...
 

Are you running 1.5 or 1.6 ratio rocker arms. For 1.6 ratio rockers, I would recommend 7/16" studs. Easy enough to change.

Many aftermarket heads with 195cc or bigger intake ports will cause the intake side of the rocker arm to be slightly cockeyed. This is very common. Several head companies have this notice on their website. This picture shows the intake way off. But, often times when one rocker, valve spring, or pushrod fails on a cylinder, the other gets knocked out of whack from the back pressure or firing of a valve suddenly slamming shut.

Guide plates are supposed to be softer than the pushrods. They are the sacrificial lambs when pushrods rub too hard against them. That is why you are supposed to run hardened pushrods with cylinder heads that have guide plates.

In any case, this could be nothing more than a parts failure from anything from bad metallurgy to something going wrong in the machining process of the stud. Unless you start having several failing, one after the other, then I wouldn't worry too much. Worst case, you call up someone like Comp Cams and replace all the rocker studs and guide plates.

When you replace everything, reset the valve lash and roll the engine over making sure the rocker is not binding or hitting the stud or valve spring. Also make sure the rocker is staying center over the valve tip.

Good luck.

Re: 383 Stroker, fresh build, rocker stud broken...
 

If the rockers are not aligned then the guide plates need changed to the adjustable ones. Post pictures of the rest of the ones on that head. Still need the info in the post above to help you sort this out.
Jimmy

Re: 383 Stroker, fresh build, rocker stud broken...
 

Any update on your engine?

Re: 383 Stroker, fresh build, rocker stud broken...
 

Sorry I’ve gone silent on this, been so dang busy with “stuff” just have not had a chance to follow up.
As of now there are all new ARP rocker studs installed. I still don’t have the specs on the engine which is my fault. I’ve had an overheating problem ( new radiator, new thermostat, new water pump, new fan) that I just can’t figure out and now I’m getting a backfire thru the carb so I’m parking the fella for a bit till I have the time to dive into it.
Thank you all for the help and insight, it is greatly appreciated!

Re: 383 Stroker, fresh build, rocker stud broken...
 

I am going to through this out, cause your here. Coil bind. What is your ratio on the rockers and are the valve springs binding due to lift, or not enough clearance with the seat pocket.

This part is something I personally was not aware of from Scott:

Many aftermarket heads with 195cc or bigger intake ports will cause the intake side of the rocker arm to be slightly cockeyed. This is very common. Several head companies have this notice on their website. This picture shows the intake way off. But, often times when one rocker, valve spring, or pushrod fails on a cylinder, the other gets knocked out of whack from the back pressure or firing of a valve suddenly slamming shut.

That is not how I want to build my next engine. What is the Head manufacturer?

Re: 383 Stroker, fresh build, rocker stud broken...
 

"Backfire through the carb" I don't like the sound of that. Broken rocker stud too......You might even want to pull the intake and examine the lifters.

Re: 383 Stroker, fresh build, rocker stud broken...
 

Don't forget to address the pushrods wearing on the guide plates. Something is amiss there too.

Gary

Re: 383 Stroker, fresh build, rocker stud broken...
 

A bad lifter and/or overtightening that valve lash can do that. Don't ask... ;)

Re: 383 Stroker, fresh build, rocker stud broken...
 

The frickin frackin distributor was loose and it got waaay outa time. Can’t believe I never reached back and checked it :crazy: all kinds of stuff got in my head and never thought about timing, runs much better but still some issues. Valve train seems a bit louder than it should be. I’ll be bringing it back next week to spend some more time on it.
Thanks y’all for the input and help, I’ll keep ya informed.

The overheating is air in the system I’m almost sure, ordered a “UView 550000 Airlift Cooling System Leak Checker and Airlock Purge Tool Kit” off amazon for 125 bucks. Ive needed one before so now I’ll have it.

This was in the shop getting tweaked, massive blown hemi in it :smoke:

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