Sonny's Semi-Hemi head cracks

[wheelsup330]

Hello, I am looking for some guidance / information here. I was looking at buying a set of used Sonny's Chevy Hemi heads and the deal looks pretty good, until I got some close up pics emailed and seen that almost every cylinder have cracks between the spark plug hole and the Intake Seat. Many plug threads are repaired with inserts. (The guy says that every set of these Sonny's heads he has ever seen have these cracks.)

Is this true? or just a typical comment for a guy trying to sell a set of cracked heads? Just my gut instinct tells me that they're junk, need welded at a minimum, and every one that is cracked, the intake seat is likely to come loose at any given moment...

My experience has been with conventional motors, so I been searching and reading, and trying to learn about these newer 800+ cube mountain motors. I found a bryant crank and its on the way, finding blocks and etc showing up in the classifieds, kinda exciting to be going into a new build as the right deals come along.

Thanks for the help!

[rally]

Call Sonny. If its me, this is what i would do. Sounds like you are very concerned about this problem. Talk to the main guy Sonny. I am sure he can tell you what you need to know. Hear say isnt always a good thing. And if it is a problem on his Chevy Semi Hemi Heads he will tell you and they probably might even repair them at his business. Always go to the source.

[wheelsup330]

I sure didn't want to come across in a negative way on Sonny's shop, my subject line reads harsh was was intended to be a simple question. I tried to go edit the title to read "question about sonnys hemi heads" but it was locked from editing?!

I work a crazy schedule, so I posted here thinking it will be available 24/7 for answers. I will try to call Sonny's. I'm not too sure of the clone rumors, I have read that they were from a similar design from the founder of Trick Flow. I mean even if they were built from the exact same casting, but weren't made / machined AT Kaase's shop then they are not even remotely comparable. Sonny's is the best source for the info, without argument. I lean away from calling shops with questions, because I know when I am in my shop running my machinery, getting phone calls results in delayed work and etc. As always thanks for the help.

[rally]

If a business cant take calls with questions from potential customers or product they have sold or if they have issues, they dont belong in the business. Customers come first.

[racear2865]

If a business cant take calls with questions from potential customers or product they have sold or if they have issues, they dont belong in the business. Customers come first.

I totally agree with your thought process and I feel Sonny will answer any and all questions. BUT, I do work for the public and sale quite a bit of "HIGH PERFORMANCE' products. Here is the dilemma in your hypothesis. You are speaking of a used product that the user now, did not purchase. There is "no" way that he knows how the product in question was used and abused. I get phone calls every day of how a good part went bad. I try to field those question. some of those people feel that I should know every aspect of a part that should not have torn up. Example, just had a person that purchased a set of aluminum heads about 2 months ago. Installed on car and ran well until he sprang a fuel leak and car caught on fire and absolutely burned to the ground. He sold the motor to a person on Craigslist. This person removed the heads and immediately installed them on a 400 SBC. He called me and just could not understand why the heads were running so poorly. They were on 2 months old. First problem, the heads had no steam holes for the 400, they were on a 350 originally. . and the heads got so hot when burned, the seals melted. They also got so hot, it changed the molecular structure of the heads. That doesnt count that the valve covers melted down into the head. Of course, we know the springs had to be still good. The point I am making is, not all people are truly honest. Our society wants something for nothing. My thought are the original customer may be first but Im not convinced of that for the 2nd customer. MO
reed

[rally]

If a business cant take calls with questions from potential customers or product they have sold or if they have issues, they dont belong in the business. Customers come first.

I totally agree with your thought process and I feel Sonny will answer any and all questions. BUT, I do work for the public and sale quite a bit of "HIGH PERFORMANCE' products. Here is the dilemma in your hypothesis. You are speaking of a used product that the user now, did not purchase. There is "no" way that he knows how the product in question was used and abused. I get phone calls every day of how a good part went bad. I try to field those question. some of those people feel that I should know every aspect of a part that should not have torn up. Example, just had a person that purchased a set of aluminum heads about 2 months ago. Installed on car and ran well until he sprang a fuel leak and car caught on fire and absolutely burned to the ground. He sold the motor to a person on Craigslist. This person removed the heads and immediately installed them on a 400 SBC. He called me and just could not understand why the heads were running so poorly. They were on 2 months old. First problem, the heads had no steam holes for the 400, they were on a 350 originally. . and the heads got so hot when burned, the seals melted. They also got so hot, it changed the molecular structure of the heads. That doesnt count that the valve covers melted down into the head. Of course, we know the springs had to be still good. The point I am making is, not all people are truly honest. Our society wants something for nothing. My thought are the original customer may be first but Im not convinced of that for the 2nd customer. MO
reed

Sir,
I totally understand what you are saying. My point is, maybe i didnt make it clear enough, this gentleman had questions about these heads. All i am saying is call Sonny and see what he has to say, did Sonny ever have issues with these heads directly coming from him, purchased by a customers. Sure i understand your point, heads get sold and re-sold, were they abused, etc? But again did Sonny have any of these heads crack overtime from direct buying customers. Its always good to see what a customer or buyer has to say, if this is a problem the quality of the head can be upgraded. I got to believe Sonny puts out great products. His engines are killers on the strip. Never hurts to ask.

[Unkl Ian]

When in doubt, walk away.

[wheelsup330]

I got ahold of the guys at Sonny's, very helpful, very prompt service. Top notch actually. The guy gave me his cell, we emailed a few pics of the cracks and he said that they were an old casting, but no, they are not common, they would have to check them out in their shop. Which i feel is a totally legitimate answer.

I found another set of heads for sale, and the guy gave me the number to the head shop where they were at being checked out, and freshened up. I called that shop, they said they work on those style heads frequently, and often find the same cracks. These are being run in tractor pulls. They confirmed most are not harmful, don't go thru to water, or anywhere for that matter, though some people demand they be welded up. That would be me, following my fear, would be dropped seats. Any Crack between seats could mean a loose seat and a big kaboom. Not worth an experiment in crackology. Just wanted to forward the results. Really pretty happy with the service from Sonny's tech.

[BILL-C]

Some blown alcohol applications don't run coolant. This would be a possible cause for the cracks.

[Sweet P]

The Semi-Hemi engines that I know of in tractorpulling are NA engines, if you know of any blown can you tell me names, I'd like to talk with them, thanks

[The Radius Kid]

I got ahold of the guys at Sonny's, very helpful, very prompt service. Top notch actually. The guy gave me his cell, we emailed a few pics of the cracks and he said that they were an old casting, but no, they are not common, they would have to check them out in their shop. Which i feel is a totally legitimate answer.

I found another set of heads for sale, and the guy gave me the number to the head shop where they were at being checked out, and freshened up. I called that shop, they said they work on those style heads frequently, and often find the same cracks. These are being run in tractor pulls. They confirmed most are not harmful, don't go thru to water, or anywhere for that matter, though some people demand they be welded up. That would be me, following my fear, would be dropped seats. Any Crack between seats could mean a loose seat and a big kaboom. Not worth an experiment in crackology. Just wanted to forward the results. Really pretty happy with the service from Sonny's tech.

It's your money,but I wouldn't buy heads with cracks in them either ... not even between the spark plug hole and intake seat.
"It's common and not harmful" doesn't wash with me.... just an excuse to get rid of a repair.
I've seen that exact situation cause a car loose control at 120 MPH.
Good thing the driver saved it.

[JoePorting]

It really shouldn't be that big of a deal to fix. Sonny would probably grind out the crack, reweld and remachine. Heat treatment might be an issue, but probably not much. I've seen lots of heads go out with reweld and not have any issues.

If you can point out the faults with the heads and talk about the cost of repairs, maybe you can get the heads for twenty cents on the dollar.

[Truckedup]

Wow, Sonny's heads are 12-17 grand new...

[Sweet P]

It appears that approximately 1.300" valve lift is common in an engine like this, I wonder how long the valvesprings last if 8,000 RPM is the max RPM