head pitting & cleaning - advise please
#1
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Thread Starter
head pitting & cleaning - advise please
Looking for some opinions from you guru's on this forum. I spent the better part of the afternoon trying to clean up my head to re-assemble. I used scotch brite pads with carb cleaner and gasoline, and also carefully used a razor blade in some spots. I can't get all the old gasket stuff off (visually), but the stuff that's left won't catch with a razor blade. Any other tricks out there I can use?
Also, the area's circled is actually pitting into the head. How concerned should I be about this? This is only around the #2 cylinder. The rest of the stuff on there is what's left from the head gasket and won't catch on a razor blade.
Also, the area's circled is actually pitting into the head. How concerned should I be about this? This is only around the #2 cylinder. The rest of the stuff on there is what's left from the head gasket and won't catch on a razor blade.
#2
Rennlist Member
Very hard to tell from internet pictures, but that pitting looks fairly serious. I'd take that head to a machine shop for sure and have them resurface it. It'll come back looking like new...
(p.s. If the pitting is too deep to machine off, then it's absolutley too deep to run as is...)
(p.s. If the pitting is too deep to machine off, then it's absolutley too deep to run as is...)
#4
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Thread Starter
Faaaarggghhh. Not what I wanted to hear. I think you'd have to shave off quite a bit to get rid of the pitting. All the pitting is in the coolant area, none near or inside the cobustion chamber - does that help or make a difference? I guess I'm taking it to the machine shop... Can you guys tell me where the 'magic line' is on the head so I can see how much can be shaved off?
#5
Rennlist Member
Faaaarggghhh. Not what I wanted to hear. I think you'd have to shave off quite a bit to get rid of the pitting. All the pitting is in the coolant area, none near or inside the cobustion chamber - does that help or make a difference? I guess I'm taking it to the machine shop... Can you guys tell me where the 'magic line' is on the head so I can see how much can be shaved off?
#6
I had some pitting on my head when I was doing my build. The machine shop told me exactly what Tom M'Guinn said about the fire ring. The machine shop also said they could weld the pitting and then resurface it, but were iffy about it since they didn't know if it would hurt any special heat treat done from the factory. Maybe someone will come along and clarify that issue. Good luck.
#7
I had a local shop resurface the head where they had to weld a very bad relatively deep chunk/score where the stock gasket ring sat on cyl#3. It came out great and with a new widefire installed have had no problems for a few years now.
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#9
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Thread Starter
Looks like I'll be talking to my only local machine shop today. I've been meaning to talk to them to see if they can sleeve a block anyway. The existing pitting will not contact the fire ring on the head gasket, even a widefire ring. I really wanted to get this all back together ASAP, but I want to do things right. I guess I'll talk to them about some mild porting too. I assume they're going to have to pull the valves out to do the welding and they're going to talk to me about doing a valve job too.
#10
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I understand wanting to get it back together, but I'd guess you are way better off just biting the bullet and having it surfaced and having the valves and seats inspected and cleaned up (with new valve seals). Before doing that, however, clean out the exhaust ports and check the condition of the ceramic liners. You want them to be in good shape without cracking or missing chunks. If they are cracked up, then you'd be better off finding a core with good exhaust ports and fixing it up instead...
#11
Rainman
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Looks like I'll be talking to my only local machine shop today. I've been meaning to talk to them to see if they can sleeve a block anyway. The existing pitting will not contact the fire ring on the head gasket, even a widefire ring. I really wanted to get this all back together ASAP, but I want to do things right. I guess I'll talk to them about some mild porting too. I assume they're going to have to pull the valves out to do the welding and they're going to talk to me about doing a valve job too.
I asked them about sleeving and they said to bring a block by the shop so they can check it out. I might be able to do that today and get a price.
#12
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Thread Starter
Turns out there are 3 machine shops in this little town now, so trying to get some feedback from racing friends (off road racing) on the best place to take it. After my little one's Girl Scout (Brownies) dinner tonight I'm going to check out the ceramics in the exhaust ports.
Spencer - was that head for a 951? Sounds like a good deal. If my local shops don't want to deal with it I may be sending it down that way. Talking to someone at work today, it sounds like you have to have the cast head heated up to a certain temp to weld on it. As in you might have to weld it while it's on an oven. Not sure if this is really the case or not. Do you think Wayne's would have a problem filling in the pitting? Or would be willing to have me mail the head down there and deal with sending it back up?
Thanks again guys!
Spencer - was that head for a 951? Sounds like a good deal. If my local shops don't want to deal with it I may be sending it down that way. Talking to someone at work today, it sounds like you have to have the cast head heated up to a certain temp to weld on it. As in you might have to weld it while it's on an oven. Not sure if this is really the case or not. Do you think Wayne's would have a problem filling in the pitting? Or would be willing to have me mail the head down there and deal with sending it back up?
Thanks again guys!
#13
Rainman
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It was a 944NA head, not a 951, but I wouldn't think there'd be any difference to their process since they don't touch the ports, just clean it all...valve guides are the same and the stem seals go on the same way. I think they could do welding to fill, can call them if you like or you can 951-684-2222
#14
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Thread Starter
Wasn't sure if they would be scared off by the ceramic liners. I'll give them a call along with the local shops. Thanks for the number! Should I mention you?
So, if I bought the Victor Reinz head gasket kit (which I haven't openned yet) I should have the valve guides & seals in there?
So, if I bought the Victor Reinz head gasket kit (which I haven't openned yet) I should have the valve guides & seals in there?
#15
Rainman
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Wasn't sure if they would be scared off by the ceramic liners. I'll give them a call along with the local shops. Thanks for the number! Should I mention you?
So, if I bought the Victor Reinz head gasket kit (which I haven't openned yet) I should have the valve guides & seals in there?
So, if I bought the Victor Reinz head gasket kit (which I haven't openned yet) I should have the valve guides & seals in there?
The stem seals were included in the Reinz kit I got for the job on that particular head. Pelican lists a particular part # for the 951 stem seal, I don't know if they interchange or not. I imagine they should, but someone else could answer better.