Repairing SB Chev Heads
 

Last time I had my Wagon out, I damaged one cylinder head. Small block Chevy 520 casting. 327 engine for SS/MA.

I have a Jesel rocker system, and ran too short of a bolt for the base. I ripped out all of the rocker stud bosses. The one mistake I made in putting this motor together, and I pay for it dearly. My luck.

I want to try to fix the threads myself, as funds are low and I don't want to ask for favors from anyone.

What is the best way to do this, or is it best left to a professional? Be honest-I can take it. LOL!

Thanks!

Re: Repairing SB Chev Heads
 

If you can helicoil or tap it to the next size bolt my local guy could help you out and he is usually open Saturday until 2 or so. I'm sure cast iron Mike could weld them but I don't think that is a great idea. Have you asked the sprint car guy near you? I'm sure that is probably a pretty common repair on aluminum heads for him.

Re: Repairing SB Chev Heads
 

That head needs those stud bosses drilled and tapped on a Bridgeport style mill, they have to be perfect, if they're not, you'll have nothing but trouble.

Re: Repairing SB Chev Heads
 

I kinda knew the answer to this, but was hoping someone would tell me it was no problem-LOL!

Thanks for the responses.

Re: Repairing SB Chev Heads
 

To be clearer, the entire thread is not damaged-just the top 4 or 5 turns.

Is there some sort of drill guide that I can bolt to the exhaust/intake boss to properly locate the other one for repair?

I have read about Time-Serts. Would these work in this application?

I'm clinging onto my potential racing in the future and just want to explore every option. Trying hard to not just give up on this. Money is just not there to pay someone to fix these right now.

Thanks.

Re: Repairing SB Chev Heads
 

Jeff,
Timeserts would work great, but I just cant see doing them by hand. You either need to do them in a Bridgeport or a seat and guide machine to keep them half way straight. If people had any idea how bad they are from the factory, they would cry :( It really is not all that hard of a job, especially if you take the heads apart first and get them clean. I figure no more than an hour and a half to do both heads.

Re: Repairing SB Chev Heads
 

Thanks Bill. These really need to be done correctly. I have a TON of money in this engine, and would never want to take a shortcut.

I'll continue to try and save my nickels-that my 2 Teenagers will take on a whim....LOL!

Re: Repairing SB Chev Heads
 

Truth.

Re: Repairing SB Chev Heads
 

Jeff, you're asking for a favor by asking for help on the forum. Now get on the horn and ask for some help!!! There's 2 machinists we both know that live in the North end that i assume would want to help you out.

A keensert or timesert that has plenty of thread i would think would be the ticket.

Re: Repairing SB Chev Heads
 

I once had a set of small block heads brought to me for repair that had old BRC rocker shafts. Stuff was all worn out and a mess. Needed new valves as well. I convinced the racer a simple set of stud mounted rockers would be fine.

I soon discovered the stud holes had been drilled and tapped by hand as they were all crooked and if you sighted down the side it was rediculously bad.

I was able drill and tap the holes in my seat and guide machine and helicoiled every hole......They were not perfect as it was impossible to get a perfectly straight hole after what was done previously....

It all worked out well and the guy got many runs out of those heads....


Seat and guide machine or a Bridgeport is a must....if there is enough stud boss left to do anything with. I would not consider welding them as I just don't feel that is a good option