I dropped my L-98 heads off on 5/28 to be port and polished. The plan was for 255/195 with compression of 10.8. I was promised the work was going to be done and the car running the 5th of June.Then I was told that they would not be done in time. I had reserved some Dyno time and had made arrangments to go to Sebring and drive for the weekend. I was not a happy camper.The new date was last Thursday. I got the call that they were done and wonderful he had to do 50 hours of work on them as the GM castings were so bad. I again make Dyno reservations and headed over for the install. Apon my arrival I was told that they had to use some epoxy on two of the walls where he had cut through on the exhaust side. I was told that was common and not to worry. The install was not done when the car was supposed to be at the Dyno. Whats new?. Well finally the car is back together and it idles. He starts adjusting the valves and one starts shooting oil in the air at idle. I was told it was not a problem. Then about 4 minutes later the engine quickly runs up to over 3 grand. 3 hours later after checking everything on the engine he dicided that he must have not installed the base properly as he did it when he was tired. It turns out much later that one of the "epoxy"jobs had let go and that is where the engine was getting all its air. I wonder where the epoy went and if it hurt the engine?. I was told its not a problem they just had to redo the epoxy. I told them that I was going to take the car and leave. I had no confidence in their (work?). They told me that drag cars run ALL the time with epoxy. I told them that I needed 100% reliability as I drag my car around the East coast to race. They then dicided that they could send the head somewhere to have some sort of special welding done. I dicided it was time to bring the car home to stop the damage.
Here is the other problem. I am schedualed to go to the 50th next weekend with my car and wife. Then on to Roebling for 2 days of practice and then to Mid-Ohio for a couple of races. Everything has been paid for and reservations make long ago.
Do I have any options? can I find a local place to weld?epoxy? It seems that for now its my only choice. If he went through on 2 I am sure that the rest are weak. Instead of 10.8 on the compression he ended up at 9.6 is their anything I can do about that?

any suggestions,solutions ?
Thanks,


Robin
:cheers:

 

Have you considered just getting another set of heads? That's what I did when I found out that one of my L98 heads was cracked after taking them to a machine shop for rebuilding.

Corvette-only salvage yards like Just Corvettes (that's where I got mine) have L98 heads in stock and usually get them out fairly quickly. Then you can either find a good shop to do a good port and polish job or you can just have them rebuilt with some good quality components (ie. LT4 valves and springs, titanium retainers, 7/16" rocker studs, hardened guideplates, etc...) just to get you back on the road.

Another option would be to look at a set of Edelbrock heads. They make a very nice L98 replacement head that's complete - just bolt 'em up and go. The flow a little better than the stock L98 heads so you'll get a little boost in power and their cost is very comparabe to getting a used set of L98 heads and rebuilding them. But their biggest advantage is that they will ship quick and get you back on the road with minimal effort.

Of course, if you have really deep pockets, you could always look at the Lingenfelter prepared L98 heads. Full CNC port and polish, built using all new castings and LT4 parts. And they are available outright or exchange. Just like the Edebrock heads, they are a bolt 'em on and go product. But they are expensive.

There are alot of options for you. But it sounds like your biggest obstacle is time. And in that regard, the set of used L98 heads from a salvage yard have one big advantage - they don't need to be retorqued after installation. With a new set of heads (new casting that is) the heads need to be retorqued because of creep-relaxation and core shift as the heads head cycle. If you don't retorque them you will get what's called 'head float' and you'll end up having to replace your head gaskets. A set of used heads have already been heat cycled several times during their lifetime and have already suffered all the core-shift/creep-relaxation they are going to undergo so there's no need for retorquing. And if you've ever take the heads off of one of these cars before (and by the sounds of it, you have) then you'd know all the stuff that needs to come off before you can retorque the heads.

Hope that helps. And good luck.

 

That really sucks. Was it on the 87 or the 90? I'm guessing the 90. That especially blows since the d-port heads are nice heads to begin with. I hope they plan on giving you the $ for a replacement set. Thats rediculous that the epoxied your heads. I've personally never heard of it. Who knows, maybe its common.

 

Actually Scorp I've never heard of it either. I've seen epoxy used on intake manifolds, but never on a set of cylinder heads. Epoxy doesn't stand-up well to heat, and I don't think there is a commercially available epoxy that can withstand the kind of temperatures a cylinder head would encounter. I have heard of welding a cracked cylinder head, but never epoxy.

What is the name of this shop anyway - maybe it can help other Corvette owners avoid going to these guys for any work.

 

Yep, my passenger side head is welded. :yesnod:

 

What these guys say is true. You can't epoxy cylinder walls!! That is absurd.
Welding is fine and it must be done right. Then the walls need to be machined. I would have that shop give you the money for what it would take to replace your heads. Do not go back to that shop for additional work. They ruined your stuff.

 

They are the 113 heads. The car is a 1990. What I would like to do is see if I can get some overnighted to me if possible. But, If that is not possible I am wondering if a local engine shop can weld alum.? Maybe that would be enough to get me through the net 2 weeks.
I really do not want to say who this is yet. I have emailed him and called him per my attorneys suggestion and am waiting to hear back. I am hoping that he will step up to the plate and make it good.

Robin

 

:iagree: This place needs a big caution sign out front, lol.

 

Welding may or may not be your cheapest/fastest option right now. If it was a simple or small crack, then it might be - especially if the shop is close to you. But from the sounds of things, it may be a big job and one that might take some time. Welding aluminum heads is not something that you can get done just anywhere - it's VERY specialized work that really does require the hand of someone experienced. This translates to $$$s!

If you need heads fast, my advice would be the Edelbrock Performer Centerbolt for Corvette heads. The complete assembly is model number #60879. Check them out on their site:
http://www.edelbrock.com/automotive/index.html

I've never used these heads, but I know people that have and they say they are good. According to the notes for these heads, they do require that you use 0.100" longer pushrods and Felpro 1010 headgaskets (great headgasket BTW), but when you order the heads you can order these at the same time too. Places like Summit or Jegs may be able to get them out to you overnight, but the longer you wait to order the longer it will be before you get them so you may want to move quick.

The option of the Lingenfelter L98 heads is good if you want/need to use still use 113s AND have deep pockets. My guess is that they have them in stock and ready to go. But you'll have to call them.

Have you tried e-Bay at all? Sometimes you'll find someone selling a complete ready to bolt-on set.

The option of getting them from a salvage yard is not a bad one, but it will take longer because most salvage yards will take a few days to rip them off of a car (if they haven't already). Shipping overnight will cost you a premium from most of these places (Summit or Jegs may throw it in because of the dollar value of your order). Then you'll have to get them rebuilt when they arrive which will add another couple of days at least.

You're probably right in not saying yet. You don;t need to get anyone in trouble (especially yourself) for something that may have just been an innocent mistake. Besides, priority #1 is to get you back on the road as soon as possible!

 

I have to use the 113 heads. I am taking the engine apart today and will take the heads to be looked at tomorrow morning. I hope LPE has some in stock. The other issue here is I bought LT-4 valves for the work. I need to see if LPE uses those valves.
Thanks,
Robin
:cheers:

 

I sent you guys a pic of the one that let go. What do you think?

Thanks,

Robin

 

I've just looked at the picture you sent. It doesn't look TOO bad, but I wouldn't feel comfortable trusting it for race-duty. Don't get me wrong, I don't think you should throw them out. My advice would be to take the heads off, get them repaired and then try and sell them off.

But if you can find a place close by that can take care of them, then all the better I guess.

As far as replacements are concerned, there is one option that I forgot to mention. GM Performance Parts sells a cylinder head based on the 113. It's a very good product using new castings, and it comes complete. The part number is 12556463. Check them out here:
http://www.gmgoodwrench.com/gmgoodwr...373&section=ep

They come with LT4 valve springs and I think they come with LT4 valves (but I'm not sure). These are a good option and the price is comparable to the Edelbrock heads.

As for the Lingenfelter stuff, I'm pretty sure he uses LT4 valves and valve springs as well in his heads. The LPE heads are awesome, but as you will see by the price, they are EXPENSIVE.

P.S. You may be wondering why I haven't mentioned just getting a new set of 1990 Corvette heads from a dealer. Well the truth is, they are VERY expensive (around $700 EACH) and they only come with guides and seats. Everything else you have to provide! The GM Performance Parts units are less expensive and come complete ready to bolt-on.

 

Corvette Kid,

THANK YOU for all the effort to help me out !

Robin
:cheers:

 

Takem down to St.Pete to the guys @ CNC heads?

 

That's some great advice! I didn't realize you where in Florida. The guys at CNC do EXCELLENT work and if anyone can repair these heads for you quick, it would be them. And if they can't I'm sure they will know someone in Florida who can.

I recently had to replace the cylinder heads on my '89 and I've looked at virtually ALL the options available. But my situation was a little different because I had the time to think about what I wanted to do and how much I was willing to spend (I worked on the car all winter). In my case I ended up getting a used set of 113s off of another '89. I then had these heads rebuilt and I bolted them back onto my car. I still have my original 113s - they had cracked because the car overheated - and I plan to have them welded to repair the damage. It was alot of work, but worth it in the end.

But if I can help someone make a decision based on what I've learned having to change my heads myself, then I'm more than happy to offer up the knowledge.

Good luck and keep us all posted on what you decide to do.