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blown head gaskets - machine short block?

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at some point I'm going to rehabilitate my turbowagon with the half compression engine. I pulled off the downpipe to get a hole in it welded up and to check out the exhaust ports in the heads. they aren't cracked, so I'm going to assume that the half compression is from valves or HGs. (the pistons rarely fail, right? is there an easy way to check without splitting the short block?)

I'm going to have to put new HGs on when I take it apart anyway, and I plan to have the heads milled flat at a machine shop at that time.

Should I have the shop mill the short block flat as well? thanks.

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Rguyver rebuilt the engine 12k miles ago for Tyrel Neufeld in BC. I bought it from Tyrel and when installed, it turned out to have this compression problem. I found out from rguyver that Tyrel ran it at high boost and had overheated it once and had rguyver reseal it. Tyrel didn't bother to tell me this or I'd not have bought it from him. So I'm assuming that it's recently been overheated TWICE and I'd not want to reseal it again after I fix it, so I'm interested in the millwork. you're right though, i can check the heads and block myself.. i was trying to get a fixd on what kind of costs i'd be looking at. thanks!

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On the other hand, I can attest to three different sets of EA81 heads that were warped far beyond the limit. I have a set sitting in my garage, the set on my brat right now (had them milled flat again), and another set that's on an engine Buagru pulled from his hatch. In each case the heads were warped at least .006, with the limit being .002.....

 

I have another set of heads in my garage that are not warped at all, and have the same mileage on them as my Brat's heads. Go figure.

 

I will also say that my Brat ran just fine with heads warped three times the allowed limit, and the head gaskets were not blown. I thought they were, but was mistaken. Had them milled anyway before assembly - cost was $35 per head (same price for ANY aluminium head). Used brand new Fel-Pro gaskets, and nary a leak to be seen for the 1000 miles I've driven so far. I'm not careful with it either - I shift at 6,000 every time.

 

GD

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