Question on WBX head corrosion
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FP1201
- Posts: 4
- Joined: Sun Aug 15, 2010 2:45 pm
Question on WBX head corrosion
The heads off the engine I'm rebuilding are/were new OEM heads from VW as the engine was a factory reman: it sat for a long time and now there are corrosion pits, however they don't appear to be too severe, and I'm thinking/hopeing that the sealer will fill making them usable. Sorry these pictures are crap, but unless someone can suggest a better way then....
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Jim Andritsakos
- Posts: 309
- Joined: Wed Jan 23, 2002 12:01 am
Re: Question on WBX head corrosion
This is minor corrosion and the heads will work well.
We use Wurth liquid metal to fill these on wbx heads.
It works very nicely and never had an issue.
Good luck
We use Wurth liquid metal to fill these on wbx heads.
It works very nicely and never had an issue.
Good luck
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tencentlife
- Posts: 424
- Joined: Tue Apr 25, 2006 8:13 am
Re: Question on WBX head corrosion
Yes lots of people have been fairly successful with filling pitted areas with a metal-filled epoxy, JB Weld is popular here, then smoothing the whole surface.
The "proper" approach, though, is to mill off enough of the large flat area to clear all pits, then flycut the same amount from the combustion chambers to keep the channel seal gap the same. This also slightly raises the compression, which with a wbx is a good thing because they are very detonation-resistant so long as you keep the squish clearance to .040". Both heads must be milled the same amount, so begin with the worst one.
Your pics aren't lit in a way that shows up the pits very well, but from what I can see the pitting looks to be very light, so either approach would be good for you if these pics are representative.
Before doing anything to the heads, though, now that you have them so clean, inspect for cracking between the seats and also down inside the exhaust ports. Between-seat cracks are OK as long as they are still close (spec is less than 1mm wide, but that is HUGE) and don't progress below the seat, but exhaust port cracks are not uncommon and will allow water to leak into the exhaust. Also look for cracks on the external surfaces of the head, emanating from the top stud holes, these are also not uncommon. It isn't worth making any repairs to a wbx head with cracks, in my opinion, but then every engine I sell gets brand-new heads anyway.
The "proper" approach, though, is to mill off enough of the large flat area to clear all pits, then flycut the same amount from the combustion chambers to keep the channel seal gap the same. This also slightly raises the compression, which with a wbx is a good thing because they are very detonation-resistant so long as you keep the squish clearance to .040". Both heads must be milled the same amount, so begin with the worst one.
Your pics aren't lit in a way that shows up the pits very well, but from what I can see the pitting looks to be very light, so either approach would be good for you if these pics are representative.
Before doing anything to the heads, though, now that you have them so clean, inspect for cracking between the seats and also down inside the exhaust ports. Between-seat cracks are OK as long as they are still close (spec is less than 1mm wide, but that is HUGE) and don't progress below the seat, but exhaust port cracks are not uncommon and will allow water to leak into the exhaust. Also look for cracks on the external surfaces of the head, emanating from the top stud holes, these are also not uncommon. It isn't worth making any repairs to a wbx head with cracks, in my opinion, but then every engine I sell gets brand-new heads anyway.
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fastback
- Posts: 1670
- Joined: Wed Sep 12, 2001 12:01 am
Re: Question on WBX head corrosion
yes the small pittings can safe be filled with the sealant.
i have mediablasted the heads, primed the surface with 2k epoxyprimer (which claimes to be 100% waterproof) and used a sealant from Innotec called Adheseal. and have had noe leaks after.
i have disassembled some of the engines(as they are my race engines) and can't see any signs of corrosion.
i have mediablasted the heads, primed the surface with 2k epoxyprimer (which claimes to be 100% waterproof) and used a sealant from Innotec called Adheseal. and have had noe leaks after.
i have disassembled some of the engines(as they are my race engines) and can't see any signs of corrosion.