Repairing SB Chev Heads

Jeff Goss · 06-26-2013, 08:09 PM

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!

Phillip marvetz · 06-26-2013, 08:25 PM

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.

Alan Roehrich · 06-26-2013, 08:27 PM

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.

Jeff Goss · 06-26-2013, 08:34 PM

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

Thanks for the responses.

Jeff Goss · 06-26-2013, 08:49 PM

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.

BillK · 06-26-2013, 09:05 PM

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.

Jeff Goss · 06-26-2013, 09:22 PM

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!

Steve Williams · 06-26-2013, 09:40 PM

Quote:

Originally Posted by Alan Roehrich

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.

Truth.

Jody Lang · 06-26-2013, 10:42 PM

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.

Rich Biebel · 06-27-2013, 12:27 PM

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

06-26-2013, 08:09 PM	#1
Jeff Goss Member Join Date: Nov 2001 Location: Burlington, WA Posts: 361 Likes: 1 Liked 0 Times in 0 Posts	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!

06-26-2013, 08:25 PM	#2
Phillip marvetz Senior Member Join Date: Oct 2008 Location: Lynden ,WA Posts: 820 Likes: 0 Liked 3 Times in 3 Posts	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. __________________ 2009 V/SA Record Holder

06-26-2013, 08:27 PM	#3
Alan Roehrich Veteran Member Join Date: May 2006 Location: Murfreesboro TN Posts: 5,106 Likes: 1,564 Liked 1,789 Times in 408 Posts	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. __________________ Alan Roehrich 212A G/S

06-26-2013, 08:34 PM	#4
Jeff Goss Member Join Date: Nov 2001 Location: Burlington, WA Posts: 361 Likes: 1 Liked 0 Times in 0 Posts	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.

06-26-2013, 08:49 PM	#5
Jeff Goss Member Join Date: Nov 2001 Location: Burlington, WA Posts: 361 Likes: 1 Liked 0 Times in 0 Posts	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.

06-26-2013, 09:05 PM	#6
BillK Member Join Date: Nov 2005 Location: Waldorf Md Posts: 230 Likes: 12 Liked 30 Times in 17 Posts	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. __________________ Bill Koustenis

06-26-2013, 09:22 PM	#7
Jeff Goss Member Join Date: Nov 2001 Location: Burlington, WA Posts: 361 Likes: 1 Liked 0 Times in 0 Posts	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!

06-26-2013, 10:42 PM	#9
Jody Lang Member Join Date: Mar 2002 Posts: 306 Likes: 28 Liked 89 Times in 28 Posts	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.

06-27-2013, 12:27 PM	#10
Rich Biebel VIP Member Join Date: Jun 2007 Location: Northern New Jersey suburbs Posts: 2,314 Likes: 25 Liked 544 Times in 213 Posts	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 __________________ Rich Biebel S/C 1479 Stock 147R Last edited by Rich Biebel; 06-27-2013 at 06:16 PM.