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Discussion Starter · #1 ·
my engine was originally n/a its being turbo`d so comes the question what type of head gasket is the most reliable what about copper gaskets any good?
also i was thinking of getting some metal removed from the combustion chamber of cyl head to lower the cr is it ok to do so ?
and for the turbos oil return pipe can i get a return connector tapped into the sump so the oil can drain strait back into the sump?
thanks
:confused:
 
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Discussion Starter · #2 ·
hmmm i've been thinking of a copper headgasket myself - would drop the CR in my car slightly (more boost - yeehaw) - and has to better then the STD equip...
 
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Discussion Starter · #4 ·
the thing is the engine acording to mazda factory manual has a cr of 10:0:1 which is high for turboing,after some research i found the same engine that was used in the kia sportage to have a lower cr of 9:2:1 so i was going to use the pistons from that engine combined with say a 2mm copper head gasket to get the desired cr i think this is important as i will be using the ct26 toyota supra turbo which has been hi flowed. i want big horespower but also reliability at this stage im sitting down and thinking about the best possible way, would custom forged pistons be the best? thanks :cool:
 

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here's the low down with metal gaskets. THEY ARE TOUGH TO GET SEALED. The head and block's mating surfaces must be completely flat, by completely I mean absolutely. Unlike the composite type that mazda used, the gaskets are very tolerance related. You'll find many SBC (Small Block Chevys, and Big), Ford as well, builders use copper gaskets to increase CR, not to decrease it. Reason is, copper is stronger than the composite stuff so it can be thinner. Also I don't know if GM continues to do so, but all V8s (at least) came from the factory with copper gaskets.

As to CR decrease via combustion porting, ask your local machine shop (or speed shop).

Since the turbo gaskets in Aussie and US are the same pattern as the fe3, I'd go for it.

The sportage is not the same engine, it is similar however. Head design is different. Block is the same. Pistons/cranks are not Forged. Apparently Mazda used forged pistons/cranks for any engine they produced, if I remember correctly.

The oil return sounds good, what are you doing about the coolant return?

Be sure to install a oil cooler. You'll need it, the oil gets mighty hot with a turbo.
 
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Discussion Starter · #6 ·
in regards to the oil cooler, i have two fe3n dohc engines one is installed in my 85 626 n/a the other is in pieces getting rebuilt for the turbo.the one in my car has an oil cooler were you screw the oil filter on it is also cooled by two coolant lines that are connected to it. the other engine did not come equipped with the abovementioned oil cooler.do you think this oil cooler would be enough?
re coolant lines to turbo well i will be using two other spare coolant lines that the idle controll motor use to use,the reason is with the aftermarket ecu i didnt use the idle control which i removed and blocked off with fabricated aluminium plates.im also considering an external water pump (electric microprocessor controlled)made by a company called davies craig in auswould it be worth it.soon i will have step by step pics of the rebuild on my website.my mazda 626
 

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Sealing Copper Gaskets

You could use Hylomar jointing compound to seal the copper gasket.

Rolls Royce use it "instead" of a head gasket and those motors are pretty damn good.

It is reputed to be able to compensate for upto 120 thou warpage. And machining tolerence is well within that.

Wòó
 

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The oil cooler that you mentioned is the same unit as the turbo ones. So I think you're good to go. Mazda called a Stage 4 oil cooler.

Never heard of that hylomar stuff before. Sounds interesting.
 
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