G80CS Short Stroke pushrod tunnel seals
Posted: Sun Aug 12, 2018 7:13 pm
Hi all,
I've done some forum searching but can't seem to find a definative answer on this one.
Finally got my '56 G80CS Short stroke running on the weekend after 2 years of trying to get it right. Starts first kick and runs like a brand new modern bike.! However, oil was pouring out of seals between the head and barrel.
I note that there is a couple of comments on this forum stating that this engine did not have a head gasket. The 'gasket set' I got, included a copper head gasket (that didn't fit over the 4 studs and I subsequently filed out the 4 holes to get it to fit) and, 2 rubber o'rings that fit loosely in the pushrod tunnel recess in the barrel, and, are only 2mm thick. They fit fine, but do not seal. I suspect the o'rings need to be 4mm at least to give enough squish to seal.
So 2 things.
1. I don't have and can't seem to find a parts list for my '56 G80CS which is the first of the short stroke engines and has enclosed push rod tunnels. My '56 manual does not show the short stroke engine. I have a 'supplement manual' covering the short stroke 350 and 500 but, is only a few written pages and does not include any parts information. Is there a parts list manual for the short stroke?
2. Does the short stroke really NOT have a head gasket? I note that Don Madden has made comment that he makes gaskets out of thin (2 or 3 thou from recollection) sheet copper from hobby store. My copper gasket is of a 'normal' head gasket thickness. Would that be causing my pushrod tunnels to not seal? Ie, does the lip of the cylinder that protrudes the barrel top, sit up in the head, and therefore, the thickness of my head gasket is separating the barrel and head too much?
Ok 3 things... hehehe.
3. I note that Don Madden had mentioned he uses 'X' rings for the pushrod tunnel seals. (top ones between barrel and head). Anyone got a source for these or, at least, good sized and quality o'rings?
I've ordered a few sets of o'rings from the club spares, but am not sure what thickness they are so only time will tell. If I can source some 'X' rings or other that would be great.
Cheers.
Marty
I've done some forum searching but can't seem to find a definative answer on this one.
Finally got my '56 G80CS Short stroke running on the weekend after 2 years of trying to get it right. Starts first kick and runs like a brand new modern bike.! However, oil was pouring out of seals between the head and barrel.
I note that there is a couple of comments on this forum stating that this engine did not have a head gasket. The 'gasket set' I got, included a copper head gasket (that didn't fit over the 4 studs and I subsequently filed out the 4 holes to get it to fit) and, 2 rubber o'rings that fit loosely in the pushrod tunnel recess in the barrel, and, are only 2mm thick. They fit fine, but do not seal. I suspect the o'rings need to be 4mm at least to give enough squish to seal.
So 2 things.
1. I don't have and can't seem to find a parts list for my '56 G80CS which is the first of the short stroke engines and has enclosed push rod tunnels. My '56 manual does not show the short stroke engine. I have a 'supplement manual' covering the short stroke 350 and 500 but, is only a few written pages and does not include any parts information. Is there a parts list manual for the short stroke?
2. Does the short stroke really NOT have a head gasket? I note that Don Madden has made comment that he makes gaskets out of thin (2 or 3 thou from recollection) sheet copper from hobby store. My copper gasket is of a 'normal' head gasket thickness. Would that be causing my pushrod tunnels to not seal? Ie, does the lip of the cylinder that protrudes the barrel top, sit up in the head, and therefore, the thickness of my head gasket is separating the barrel and head too much?
Ok 3 things... hehehe.
3. I note that Don Madden had mentioned he uses 'X' rings for the pushrod tunnel seals. (top ones between barrel and head). Anyone got a source for these or, at least, good sized and quality o'rings?
I've ordered a few sets of o'rings from the club spares, but am not sure what thickness they are so only time will tell. If I can source some 'X' rings or other that would be great.
Cheers.
Marty