JJM
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| posted on 9/4/04 at 04:01 PM |
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XE coscast head q.
Could someone tell me where the coscast letters are on an XE head please?? Trying to find out if mine is Coscast or porous...
Regards.
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JJM
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| posted on 9/4/04 at 04:45 PM |
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Never mind-it isnt one.
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ned
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| posted on 14/4/04 at 08:47 AM |
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for your ref i have some pics and details on this on my website..
Ned.
beware, I've got yellow skin
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JJM
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| posted on 14/4/04 at 10:20 AM |
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Thanks Ned-found out it isnt Coscast but not to worry too much as its done high miles and it would have gone porous already apparently??
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ned
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| posted on 14/4/04 at 12:29 PM |
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jjm,
there is a load of hype about gm heads going porous, i've heard various stories about this. from my understanding and from speaking to several
engine builders (race cars) its the oil way that runs between no's 2 + 3 on the head that cracks over time and mixes the oil with the water.
this doesn't happen on all cars and would vary on its use and milage. some people say over 100k, some say over 120 or 150k and it'll go
porous. my gm head (i have a coscast one too) has been welded (before i got it) there are various fixes, including plugging the oilway and re-routing
it round the back of the head or welding the head or putting an insert in it. i would suggest you run the engine or use it and see what its like. is
there any evidence of the head going porous yet? check for froth/toothpaste type gunk in the oil to see if it has indeed mixed.
i wouldn't worry too much unless its showing signs of having mixed water/oil.
imho gm heads are better prted than coscasts ones anyway, especially the later distributorless type ones. coscast heads hjave slightly smaller
combustion chambers (like 1 or 2cc) which i don't think will really make any difference to the compression ratio.
any other questions post them up or u2u me..
Ned.
beware, I've got yellow skin
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