Hole in exhaust valve bowl, leaking coolant.

[TOONAH]

Please see the attached photo and give me your opinion on whether or not it can be welded. The tip of the phillips screw driver is right on the small hole.

 

[donniekak]

Looks like someone went a little heavy on the porting. I've seen worse fixed.

 

[300dollarGSX]

Probably. It's pretty far down in there. Have you taken it anywhere to see what they said? From your other post a while back, I was thinking it was closer to the valve seat. As long as somebody can get a tig torch in there, it won't be a problem. You didn't have any problems with any of the other bowls?

 

[TOONAH]

I had Bob Pake (Pakes Machine Shop) pressure test it. It is the only leak. Over all I was pretty happy with Jason's CNC port work, except as you say, he may have taken too much out of the bowl. It fired and ran awesome with 272 cams. Until I saw the coolant coming out of the manifold flange on the down pipe. I flushed all the coolant out of the rings and swamped the piston bore with oil, turning it over by hand til I was certain there was no more coolant in the rings/bearings. That is a small phillips, I don't see how you would get a MIG tip onto the hole. Course there are angled tips. I just finished crating it up and and am debating whether to send it back to Jason or to a guy up in Sheboygan. I don't entirely trust Jason to do me right. So far I have close to $2K into this Stage 5 head. Wish I had got a pre-made one from FFWD. The things we do for a few more HP!!!
Thanks for the comments.

 

[300dollarGSX]

That is a small phillips, I don't see how you would get a MIG tip onto the hole. Course there are angled tips.

Not that this part matters, but TIG, not MIG. The TIG can minimize the heat needed and pulse for the thin metal in the area. A MIG would, more than likely, just burn right through. Did the machinist offer to fix the hole for you? Then again, if you don't trust him, then don't send it back.

 

[BogusSVO]

it most likely not the shop that did the port works fault, bore more to do with the casting itself, I would have to say when the head was cast by the factory it suffered from core shift, wich jst made that area thinner than the norm, then with the porting it just became too thin to hold heat/pressure in that area

 

[tkelly27]

it most likely not the shop that did the port works fault, bore more to do with the casting itself, I would have to say when the head was cast by the factory it suffered from core shift, wich jst made that area thinner than the norm, then with the porting it just became too thin to hold heat/pressure in that area

Even with core shift being unpredictable, the reason you spend $2k on a ported head is because you don't want to deal with these issues. I say he should fix it for free.

 

[BogusSVO]

Even with core shift being unpredictable, the reason you spend $2k on a ported head is because you don't want to deal with these issues. I say he should fix it for free.

I understand tat, and I am not saying the shiop should not do something to help him out. The shop should have pressure tested the head after the port work, If they would have, they would have found this issue before the head was shipped back out.

I Think he should atleast call the shop that did the port work and find out what they are willing to do for him.

He has every right for being angry after spending that much cash on a head.
But most shops will work along with a customer to find a solution that will make all involved happy.

 

[TOONAH]

Well, Jason of Performance CNC, that did the work, did offer to fix it for free. But then he told me he pressure tested it before he sent it back. I suppose that it could have popped the moment I fired it up.
The reason I don't trust his work has to do with another issue I posted about this head. When he machined the gasket surface he cut a a little too deep and the cutting tool hit the valve seats and drug the hard steel across the aluminum surface leaving furrows in it. I have a photo somewhere that I posted some months ago. I really cannot recommend this man to the DSM community. He does do good work on Hondas and has a good following. Even if it is welded sucessfully, how reliable is my head going to be?

 

[BogusSVO]

Well, Jason of Performance CNC, that did the work, did offer to fix it for free. But then he told me he pressure tested it before he sent it back. I suppose that it could have popped the moment I fired it up.
The reason I don't trust his work has to do with another issue I posted about this head. When he machined the gasket surface he cut a a little too deep and the cutting tool hit the valve seats and drug the hard steel across the aluminum surface leaving furrows in it. I have a photo somewhere that I posted some months ago. I really cannot recommend this man to the DSM community. He does do good work on Hondas and has a good following. Even if it is welded sucessfully, how reliable is my head going to be?

Its not uncommon to "tink" a valve seat when surfacing a 4G head, but that suould not be an issue with the proper cutter bit, they differ between alum and cast, I have found that using the cast Iron bit works better and leaves a better finish when you have to mill thu the seat.

some how I would want to say the hole you have is at the parting line where the 2 parts of the cast alum where fused during manufacture, if you have a unported head take a look and you will see a rough line running in the middle of the port wall. it may have popped there when you reache operating temp (thermal expantion)

with a decent weld and some blending work, and another pressure test, the head may be just fine to use.

measure your head from the valve cover rail to the head deck surface.
new thickness is 5.193-5.201 with a Min thickness of 5.185 if you are thinner than 5.185 get a thicker head gasket.

 

[TOONAH]

Thanks Bogus SVO. Can you recommend a welder to me?

 

[BogusSVO]

I just use a local welder, ask around, check your phone book is about all I can say.

 

[4pistons]

I can't see your picture (the dreaded RED X) but I had a ported head on my GSX for 3 years and THEN it leaked! It was caused by corrosion from inside the water jacket, not the porting. I had two reputable shops try to weld it but they couldn't. It was corroded too thin in too big an area. They were just chasing the holes around. The head ended up as an aluminum paperweight.

Rick - '91 GSX