1100 8 valve head on GS 1000

[John Kat]

I know it's possible to fit a D shaped 8 valve GS 1100 head ( S-5) with it's 72 mm cylinders on a GS 1000 but would it be OK to fit the head alone?
If yes, what gasket should I use?
GS 1000 or GS 1100?

[GSScoobie]

1100 gasket will seal.
1000 gasket will not.
The sealing surface is in the folded ring at the cylinder bore.

[Nessism]

The combustion chamber volume is larger with the 1100 head, so your compression ratio will go down (not sure how much) if you fit that head on a 1000.

[rustybronco]

1100 gasket will seal.
1000 gasket will not.
The sealing surface is in the folded ring at the cylinder bore.

Please explain.

As the cylinder head is flat, I would think it possible to use the old style square cut o-ring with and old style head gasket as well as the new style head gasket which doesn't use the square cut o-ring. Why is this not possible?

To the original poster. Be advised if the 1000 is a 1978, most likely there isn't a provision for the extra bolt hole located at the front of the cylinders.

The 1100 2 valve motor used a 73mm head gasket.
http://thegsresources.com/_forum/sho...32&postcount=1

[Nessism]

Dale, I think he's suggesting a 70mm bore head gasket shouldn't be used with a 1100 head. There may be some squish area around the combustion chamber so some measuring may be in order.

[rustybronco]

Ed, understood.

But unless I'm remembering incorrectly, Suzuki did make a 72mm old style replacement head gasket used to replace the original 1000's head gasket. I measure mine tonight to be sure it's 72mm.

Also, a 1983 1100 GK combustion diameter measures 72mm. I just measured the one in my trunk. (NOTE this engine used a 73mm head gasket)

***edit***
This should be a 72mm gasket... http://thegsresources.com/_forum/sho...3&postcount=28

[John Kat]

Please explain.

As the cylinder head is flat, I would think it possible to use the old style square cut o-ring with and old style head gasket as well as the new style head gasket which doesn't use the square cut o-ring. Why is this not possible?

To the original poster. Be advised if the 1000 is a 1978, most likely there isn't a provision for the extra bolt hole located at the front of the cylinders.

The 1100 2 valve motor used a 73mm head gasket.
http://thegsresources.com/_forum/sho...32&postcount=1

My bike is a 1980 model that has the extra bolt.
I don't understand the discussion about the head gasket?
My feeling is that with the 1100 gasket, it would be less exposed to the combustion flame as both sides are in contact with metal.
Maybe the whole idea is stupid as I have the 1100 cylinder jug but...I would need to buy new pistons and rebore!
Mucho dollars

[TeamDar]

The combustion chamber volume is larger with the 1100 head, so your compression ratio will go down (not sure how much) if you fit that head on a 1000.

Is this based on speculation or have you measured? Either by diameter of the combustion chamber or actually measuring the volume of the combustion chamber.

[Nessism]

Is this based on speculation or have you measured? Either by diameter of the combustion chamber or actually measuring the volume of the combustion chamber.

I purchased an 1100 head with the intention of installing it on my 1000. The combustion chamber is noticeably larger diameter, although I didn't measure the volume.

[rustybronco]

If yes, what gasket should I use?

1100 gasket will seal.
1000 gasket will not.

I don't understand the discussion about the head gasket?

The reason for my posting about the old style gasket Vs. the newer style gasket which doesn't use a chain tunnel o-ring is, some of later variants of the non MLS gaskets (old composition type) were of a 72mm bore diameter and I think it possible to use one of those in place of the latest gasket which didn't use the o-ring. Would it be best to use the latest variant 'MLS style gasket if available? Sure it would be.