Head gasket thoughts?

[petex19]

Considering this head gasket from classic performance for my '84 1600 stroker X1/9. It's 5 layers with a compressed thickness of 1.80mm which I need to keep my compression from not going over 11:1
Any thoughts or opinions?

 

[ashmowerman]

Buy it Ive been running an MLS in my 1600 since I built it in 2010

 

[Dan Sarandrea (Phila)]

Another option in MLS gaskets with a thickness of up to .086 (2.18mm):

Fiat SOHC 138.A4 - 0CI/1.5L I4 Gaskets

Cometic Gasket supplies hi-performance gaskets for a variety of motorsports markets: ATV, Drag Race, Domestic Automotive, Harley-Davidson®, MX/Dirt, Off-Road, PWC, Road Race, Snowmobile, Sport Compact and Street.

www.cometic.com

But note:

SURFACE FINISHING​

WHAT SURFACE FINISH IS REQUIRED TO US AN MLS HEAD GASKET?​

A surface finish of 50 RA (roughness average) or finer, is recommended for a proper gasket seal. Anything rougher may conflict with the gasket design.

 

[petex19]

Another option in MLS gaskets with a thickness of up to .086 (2.18mm):

Fiat SOHC 138.A4 - 0CI/1.5L I4 Gaskets

Cometic Gasket supplies hi-performance gaskets for a variety of motorsports markets: ATV, Drag Race, Domestic Automotive, Harley-Davidson®, MX/Dirt, Off-Road, PWC, Road Race, Snowmobile, Sport Compact and Street.

www.cometic.com

But note:

SURFACE FINISHING​

WHAT SURFACE FINISH IS REQUIRED TO US AN MLS HEAD GASKET?​

A surface finish of 50 RA (roughness average) or finer, is recommended for a proper gasket seal. Anything rougher may conflict with the gasket design.

I googled surface finish and see a chart of finishes. Do you know where one gets a surface finish chart or how to know what my block finish is at?

 

[Dan Sarandrea (Phila)]

Chances are the finish on the block is the factory finish, because it's pretty rare for a cast iron block to need resurfacing unless some major event took place with the engine, or unless some significant race mods are happening. FIAT would have finished both the block and heads consistent with the head gasket technology they were using at the time. If I had to guess, I would say that the typical finish on an SOHC deck would be in the range of 60-65Ra, but that's just a guess. If you have access to an automotive machine shop, they might have a profilometer, which is a sensitive electronic device that measures for Ra. The good quality ones are muti-thousand dollar tools so not all shops are going to have one.

Hopefully no one has used any "cookies" (circular abrasives) chucked into an air drill or die grinder on any of the block surfaces!

If you've had the head resurfaced at a shop using modern equipment, because today shops use high speed single bit cutting heads as opposed to older technology slow speed multi-bit cutting heads, and because they would be oriented to accommodating the needs of heads that originally came finished for MLS gaskets, it should result in a finish suitable for MLS gasket use.

If your block has a "virgin" deck surface (no cookie use) and both the head and block check out for flatness (no more than .002 east-west and no more than .004 north south) then you'll probably be OK with an MLS gasket.

 

[petex19]

The block finish when motor was built 3000km ago.

 

[Dan Sarandrea (Phila)]

Again it's uncommon for a cast iron block to require redecking (the term used for refinishing the block surface), and it's not considered a routine requirement even for a total engine rebuild unless accurate measurements reveal that the block surface is out of spec. Having said that, the pix provided are just not high enough resolution to really pass judgment on way or the other.

 

[Dr.Jeff]

Take a look at what Cometic offers in MLS head gaskets for the SOHC. You might need to call them as they don't keep their listings up on the website.

The finish for a MLS is very smooth....almost a polished look (not quite but you get the idea).

 

[petex19]

So after reading all the information given and evaluating my cylinder block. I decided to not go with the MLS head gasket as my block is at a factory finish and not smooth enough for an MLS head gasket in my opinion. I'm not pulling it out of the car. It's clean, smooth and flat so I'm going with an original style gasket sold by Steve. C.

 

[petex19]

So after reading all the information given and evaluating my cylinder block. I decided to not go with the MLS head gasket as my block is at a factory finish and not smooth enough for an MLS head gasket in my opinion. I'm not pulling it out of the car. It's clean, smooth and flat so I'm going with an original style gasket sold by Steve. C.

I feel bad for Steve.C but unfortunately for timing reasons I bought a very similar head gasket from Midwest. A Cometic head gasket. I need all the parts sooner than later.