MHG Question, how much to take off of head and block?
- Thread starter 1988SupraDreams
- Start date
1988SupraDreams said:
I think he's talking out of his ass personally. When you install a MHG, ALWAYS have the head AND block machined to the proper RA spec (not the mention flatness). Here's a story for you: My cousin had BHG on his supra, took of the head and had it machined, ARP studs installed, BLOCK WAS NOT PULLED AND MACHINED WITH THE HEAD, 300 miles later (stock boost, full 3" exhaust, hard pipes)... BHG.
starscream5000 said:
Man, to get the block resurfaced, you have to take it all apart, and at that rate I'd be better off rebuilding the damn engine... I am about two seconds away from just putting a stocker on and selling the car.
Yep, that's right, if you want it done right, that's what you've got to do. You should have realized that a supra is a very demanding car by now from being on the forums for almost a year 
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starscream5000 said:Yep, that's right, if you want it done right, that's what you've got to do. You should have realized that a supra is a very demanding car by now from being on the forums for almost a year
Yes.. and it's sucking me dry.
wned: But no matter how much my car tries to make me hate it.. I can't help but love it...
You remove enough material to meet the flatness spec for the head and block. You cannot predict the amount, since it depends on how flat those two surfaces are and there is no way to know that until you pull it apart.
To find out how much has been removed from the head, measure from the deck to the cam cover flange. An uncut head is 116.00 mm.
There are only two ways to get the ra you need on the block. One is to pull the block apart and have it machined on a CBN mill. The second, is to lap the surface with diamond paste with the block in the car. A person only does the second one once, because it is so painful and involves hours of manual lapping. Check out this for more info.
http://www.supraforums.com/forum/showthread.php?t=414911
Both approaches will cost you $$.
To find out how much has been removed from the head, measure from the deck to the cam cover flange. An uncut head is 116.00 mm.
There are only two ways to get the ra you need on the block. One is to pull the block apart and have it machined on a CBN mill. The second, is to lap the surface with diamond paste with the block in the car. A person only does the second one once, because it is so painful and involves hours of manual lapping. Check out this for more info.
http://www.supraforums.com/forum/showthread.php?t=414911
Both approaches will cost you $$.
good point, you would be better off rebuilding the engine, thats what im doing, and i know i wont regret it when im ready to mod!:evil2:1988SupraDreams said:
3p141592654 said:
I'm gonna have to read over all the links inside that thread a few times... *Headache ensues*
JustAnotherVictim
Supramania Contributor
I'd look at it like this, if you're ok with the possibility of being in this same position down the road: could be next week, next 3 years, maybe never, then go ahead and just have the head done. If you're sure the block is pretty flat you should be alright but just realize it increases the chance for a problem later.
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It will most likely be flat, but you will have grooves etched into the block where the six gasket fire rings sit. Also, the area around each bolt hole will be pulled up about a mil.
Forget the MHG if you aren't willing to prep the block.
Forget the MHG if you aren't willing to prep the block.
so if you don't have a bhg and want to switch to a mhg then use 1.2mm? without getting anything machined.
Nope. You must do the prep work involved just as if you had a BHG. And most likely you will need a thicker gasket than a 1.2mm to keep compression the same after material has been removed .
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mg89 said:
http://www.supramania.com/forums/showthread.php?t=27433&page=2&highlight=stock+gasket+compressed
according to post #19 the stock head gasket is 1.37mm compressed
JustAnotherVictim
Supramania Contributor
180 Bucks to get them shaved at my local machine shop. But you have to pull the pistons and cams yourself.
Call up Rob's Auto Machine in Hayward...Those guys build race engines and have worked on Supra engines.
They charge $50-$60 to get the head machined on their CBN which is capable of producing good finishes for Metal Head Gaskets.
Real friendly guys too.
Cheers,
Roy
They charge $50-$60 to get the head machined on their CBN which is capable of producing good finishes for Metal Head Gaskets.
Real friendly guys too.
Cheers,
Roy
