Do people repair the cracks or do most of you get new heads and where from ?
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Where do people get 3B /7A heads from ?
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Originally posted by smh View PostSearching for days have found a few but still the fact that they are so rare and most of them dont have cams1989 B3 2.0 3A 80 quattro... Budget 1.8T Project.
1992 C4 100 2.8 Avant quattro... Mobile Sitting Room.
1995 RS2... MTM K26/7 380 BHP Conversion.
1990 Corrado G60... Breaking For Parts.
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Yeah, it even says in the factory manual that cracks up to certain size are permissible and nothing to worry about, can't remember the spec's off the top of my head but minor cracks between valve seats aren't anything to worry about.
I also agree with Alex's point about 7A heads being more stable due to years of heat cycles.1989 B3 2.0 3A 80 quattro... Budget 1.8T Project.
1992 C4 100 2.8 Avant quattro... Mobile Sitting Room.
1995 RS2... MTM K26/7 380 BHP Conversion.
1990 Corrado G60... Breaking For Parts.
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Originally posted by G60Rallye View PostI don't know why everybody gets so bothered about the cracks. Most engines are running around fine with cracks. These supposedly untracked 7A ones will crack eventually on a turbo engine.
But sometimes damage is way to big:Attached Files
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If the crack gets under the valve seat,fun is gone.What alloy to use if you remove valve seat,weld the head,rebore and turn on lathe another valve seat?
What OD should the seat have at room temperature compared to the bore in the head,so when the seat is cooled it will get inside and stay there when things heat?
I was thinking of repairing some heads,i can do the machining,and welding to external company.But i can not yet guarantee on a good seat material.I have 2 cracked heads,one client has 2 also.
And does it worth?How much should,i or a company charge for all this?For the moment is way cheap to get a not cracked head or a small cracked one.
I am prepairing a 7a head for the engine build i will put inside my b2 cq.I think getting the sharp edges more round will help little.Can anyone confirm a polished chamber cracks also if egt is kept in limits?
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If anyone is looking I have 8 complete 7A heads... shipping might be a killer though.www.quattro.ca
B2: 82 Urq into Sport quattro, 82 4000 2-door, 83 80q 2 Door, 83 Ur-q CDN, 85 Ur-q Euro with 3B, 86 4kq, 59,000km
B3/B4: 91 CQ, 93 90q 2.5TDI, 94 80q avant 2.5tdi, 94 S2 Avant
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