Part of building a redblock for tight squish is knowing the thickness dimension specifications of the brand of head gasket that is going to be used in the build.

I decided to confirm the HG thickness specs for the Elring HGs that I use. So I contacted Elring in 2006 to get that dimension confirmation, as well as to find out if other thickness were available.

...this was done prior to the program [initiated by Jonathan at RSI] to get Cometic to make MLS (Multi Layer Steel) HGs for the OHC redblocks.

I already knew what Volvo listed the head gasket thickness specifications for Volvo brand head gaskets at: THAT information is listed in the green manuals.

I have included pics of some of those green manuals, and the pertinent pages thereof, from my service manual bookshelf.

Elring and Volvo specify the new thickness to be 51 thou [0.051in], or 1,3mm.

Elring and Volvo specify the compressed thickness to be 47 thou [0.047in], or 1,2mm.


Obviously, if someone is going to use a brand of head gasket other than Elring or Volvo, then it is their responsibility to confirm the thickness dimension specifications for that brand.


I hope that this clears up some of the total BS that I see being spewed about on the internet regarding the head gasket thickness specifications for the Volvo head gaskets for their OHC redblocks.

UPDATE 8-05-08:

Since I opened this gallery, some information has been presented that would...at first glance...appear to contradict the specifications appearing in my Volvo green manuals.

There is no contradiction; despite the vacuous ranting and specious posturing I encountered.


UPDATE 5-06-09:

After going through the "correct channels", [i.e., 'all' technical questions must now be asked through an authorized Volvo dealership, rather than the old way of just being able to call up Volvo Cars of North America and talk to a helpful customer service representative who would actually take the time to get an answer, and then call back with the answer], I finally found a Volvo Dealership Parts Department Manager who would and DID get me an answer to my questions regarding the uncompressed and compressed thickness dimension specifications for the two head gaskets that Volvo offers for the SOHC/DOHC redblock 4 cylinder motors:

P/N 1378645-4

P/N 1378646-2

The uncompressed thickness dimension is 1,3mm....AKA 51 thou

The compressed thickness dimension is 1,2mm......AKA 47 thou

As far as the supposed "contradiction" mentioned above:

The two part number head gaskets listed above were added to the parts manual in 1986, superceding a total of at least three older part numbers.

What the thickness dimensions are/were for those three superceded head gaskets is up for debate....a rather MOOT one. A green manual printed in 1984, in Europe, lists the thickness dimensions as being thinner than the dimensions for the head gaskets issued in 1986, and which are still current in the parts catalog.

...and it may very well have been the case that those old part number head gaskets were thinner.

BUT...that was 23+ years ago!

If someone has some of those VERY old head gaskets [having been superceded 23 years ago] , and wishes to use them, then it is their responsibility to confirm the thickness dimension specifications for those head gaskets.

as in: their choice....their burden.

I know what the thickness dimensions are for the three brands of head gaskets that I can buy and use TODAY....the Elrings, the Cometics, and the Volvo OE (Original Equipment) replacement HGs....

...NOT 24 or 25 years ago.

I hope this lays this 'non-issue' to rest.