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Discussion Starter #1
it turns out the previous owner of my car overheated the engine pretty badly. i got the car, removed the heads, had them shaved and checked for cracks at the machine shop, installed new gaskets and properly torqued them down with ARP head bolts.

fast forward a few weeks, i finished installing my single turbo setup, the mechanical part at least. got everything setup for 5psi and went out to get into a little bit of boost to see what would happen (still on eec-iv w/ stock parts) i warmed it up to operating temp and just passed around the parking lot a few times. needless to say in a matter of minutes the head gasket blew again. that put a bit of a damper on my project. the whole setup looks nice and should work well but i don't think the gasket should have blown that quickly.. the heads must be cracked or something.

i would like to know what you all would recommend for getting as a stock long block at the junkyard. i would like it to have the forged internals and it needs to have the standard E7 head exhaust bolt pattern (i thought i heard somewhere the gt40p heads are different?)

the other option would be to get a set of junkyard heads and bolt them up to my current block, i would really like to be able to do it this way but i am a bit worried about any damage that might have occurred to the block when it was over heated. what are the chances the block is cracked or the deck is no longer true?

so concisely here are the two questions:

1) do you think i could get away with junkyard heads on my current block?
2) if i have to pull a long block what should i look for?

thanks in advance.
 

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The first thing I would do is check the blocks deck for flatness. It’s not uncommon for the block to change shape over thousands of heat cycles. While it’s fine as long as the heads remain on the block untouched, as soon as you remove them things change.

I would stay away from junkyard heads on your turbo application. The problem I see is that they will immediately need an upgrade just to handle the extra air from a turbo setup. At a minimum they are going to need new upgraded valve springs/locks….and possibly valve seals. You should also get them cleaned and have it’s surfaces checked for flatness….and possibly machined. In the end, what you’ll be left with is a set of heads that are prone to lifting due to their thin deck design.
 

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Discussion Starter #3
my other inclination is to start fresh with an unmolested explorer motor.

i want to know if they have forged pistons like the 1989 motor i have and is the exhaust manifold bolt pattern the same?
 

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The explorer motors do not have forged pistons….but that’s not to say they won’t work. As long as you don’t detonate too badly…the hyper pistons hold up quite well to boost.

Keep in mind though, you’ll need to upgrade the springs especially on the explorer motor as they are extremely weak. You may want to upgrade the came too…or atleast throw some 1.7rr’s on them.
 

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Discussion Starter #5
my issue is money, this a super budget turbo setup for me. my goal is the most horsepower for the least money. this engine/turbo setup is actually in a volvo. i don't want to dig into my pockets too deep because i know once i start i won't stop.

i don't mind taking a hit on head flow for forged internals. i have a box full of volvo cast pistons from my 4cyl race car and i prefer to start with forged.

if everything post-'93 is the hypereuretic stuff i would almost rather pull a mark vii motor and just boost it stock. i worry about the engine cracking down the center a bit so i don't want a tremendous amount of power. 400whp should make me happy.

i haven't even had time to install my megasquirt or anything because i am still trying to get a mechanically solid setup.

this whole lifting the head thing is new to me as well. i think i understand what it all means but not sure i understand why it happens. my turbo experience stems from volvo 4 cylinders which i can throw 20 psi at with stock head bolts that have been re-used 6 times on an el cheapo head gasket.

i really want to see what i can get out of a completely stock ford HO motor with just the turbo and 32lb injectors and a decent tune.

bang for the buck is key. theres a few nice '89-'91 302HO motors at the junkyard that i have had my eye on.

the other thing is that since my current motor is a 1989 mustang engine and it's in the volvo, i am trying to eliminate any variables from year to year changes.

is it going to be possible to boost a completely stock '88-'92 ho motor and get 400-450whp or would i be just pissing in the wind?
 
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