So wanting to built a new engine for my car and it looks like the ST170 bottom end and Blacktop cylinder head is the way to go.

The only down side now is Ford no longer do the Focus RS 1.8mm head gasket.

So looking around It seems I can get a MLS 1.6mm and was thinking the best way now is to have 0.2mm taken off pistons.

Any thoughts or advice please.

 

Burton power do a gasket it ain't cheap either. 1.78mm Cometec http://www.burtonpower.com/cometic-m...c4280-070.html Ł110

If your not aiming for the Max output i wouldn't worry about the 0.2mm. The Cr difference will be tiny.

How much have you found a 1.6mm for ? 1.3mm is cheap as chips.

My gen ford 1.8mm gasket was Ł141. I havnt fitted it yet as I want to get the block faced first just to be sure.

 

I called Ford dealer today.
The 1.8mm Ł180 Inc Vat but as he said there system says no longer available.

The 1.6 MLS was Ł140 but it was not a Ford one.

 

My local dealer had to get mine from Germany.

 

most people use the st170 gasket, thicker and tends to be better than the RS one

 

Never knew that Jack.

 

Hi
Been doing some research on head gaskets for this build.

Athena do a 1.6mm MLS head gasket for the Zetec But I don't know if this will lower the compression enough. Anyone know or work out the CR? STD head, Block, Pistons.

I sent Athena and email asking if the could make one (1.8mm) and the email I got back was this.

First of all thanks for your email and your interest in our products.
Unfortunately there is no need for us to add such a small different thickness to our range so it is not among our future development.
Anyway we of course can develop it for you. In this case the gasket retail price would be 113€ each but we need 25 pieces as minimum order and a tooling cost of approximately € 5.000

On the contrary we could manufacture a gasket with 1.7mm thick. Using the same tooling of 338269R, so without any additional cost for the tooling and a minimum order of 15 pieces.



So if they can make a 1.7mm why not 1.8mm. I guess if I ask there tell me and most likely to do me the plates.

So I am now thinking two gaskets or have 0.2mm taken off pistons.

 

i beleve the st170 gasket is thinner than the RS gasket, last one i got one form Ford was over a year ago

 

St or plain zetec Blacktop they are both 0.6mm and the same mls design. The older silvertop has a thicker gasket and is said to be more tolerant to surface finish.

Any way, the guy that has the high horsepower drag fiesta ( ignition advantages ) sells Forged pistons and rods and in the description he lists the Cr against differant hg thicknesses.

0.25mm is a change in Cr of just over 0.1:1. So the differance between 1.6mm and 1.8mm is around 0.07:1.

Now this is a rough and ready assumed calculation but the more I look at it, the more I think I would be just as happy using the cheaper gasket.

If you really really wanted the ford gasket I would sell you mine at what I paid but I am not posting it.

 

Nah i'm pretty sure the ST170 gasket is 4 layer and the standard RS one is just 3 layer.

Iv got a thick Athena on mine, think it could just be the 1.6mm one but il double check later today, seems to be holding 500bhp fine

 

Yep, ST170 gasket is 4-layer. It's what all the big power builds in the UK (600/700/800bhp) run - standard Ford gasket.

 

So what's your build and what is the CR?

 

 

Are you running Low Comp Piston's as well. That just to low on STD piston's

 

 

I am 100% the Ł180 RS gasket is not just 0.6mm thick its way thicker than the ST170 gasket.

infact i think i still have the original ford gasket that was removed from the St170 engine i will check tonight