Head Gasket thickness selection

[IJ.]

Seen this question asked on many occasions, here's the HG's for dummies version

1) Stock HG = 1.37mm compressed

2) Stock head = 116mm deck to valve cover surface

3) Stock block = 198.5mm from deck to main bearing saddle

If 2 and 3 are less that amount needs to be added to 1 to retain the stock compression ratio and squish/quench.

 

[Zumtizzle]

Ummm.....

Is this aimed at me?

Good Information for people trying to retain the Factory Static Compression with factory pistons.

With aftermarket pistons: To figure static compression; you're better off having the combustion chamber volume measured after headwork using this method, then use that figure, your piston dome volume, bore size, stroke (always 91MM's), projected head gasket thickness, head gasket bore diameter, and VERY VERY IMPORTANT measured piston deck clearence; plug it into this equation, or using this online calculator.

You can find most of the Head Gasket Bores and thicknesses on this site. (Titan Motorsports is 86MM Bore.)

But this should all be common knowledge.

 

[IJ.]

LOL no it's aimed at the common question "I'm rebuilding my 7M and don't know which HG to get to make up for the machine wrork"

 

[mk3 turbo]

Hay guys im trying to get my car back to gether and looking at the formula above is the compresset gasket really 1.37mm thick that just seems wrong but please help

 

[IJ.]

Yeah of course it's wrong I have this bad habit of posting misleading/incorrect/bogus information.... :nono:

 

[suprarich]

The 3 new un-used vintage asbestos OEM 7m Headgaskets I have on hand are 1.270mm thickness with a 84.633mm bore size.

A current 2010 OEM Toyota head gasket is 1.524mm thick with a 84.709 bore.

There could be many other OEM sizes in between these as we all know Toyota has used different suppliers over the years.

 

[laxboy36]

ok so how would i know what size to get bc i have another 7m i wanna rebuild and put in and the block has been machined?

 

[IJ.]

ok so how would i know what size to get bc i have another 7m i wanna rebuild and put in and the block has been machined?

Measure it all of course.

 

[mk3-4-me]

Why is there a 1mm mhg for our car if stock is 1.37? When would we need a 1mm hg? For custom higher compression?

 

[IJ.]

yes