Triple head gaskets

martymoose

martymoose

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Sydney, Australia
Ok. Opening Pandora's box here. What options are there these days. The head gasket I have in stock, been hanging on the wall for more years than I can remember, is branded Sirolon. Is that a good one? Cheers. Marty
 
No idea of the brand Marty.
I keep four different thickness in stock to suit different heads and barrels regarding fire wall height of cylinder liners and deck height of head.
Contact me if you need any clarification.
You have my number.
Chris Italbrit Classic Motorcycles.
 
I found this interesting, I know nothing more.
Quote
Btw, you dont need the infernal O rings in the head gasket if you use one of Keith at Laverdascozia new gasket design
 
Cccg said:
No idea of the brand Marty.
I keep four different thickness in stock to suit different heads and barrels regarding fire wall height of cylinder liners and deck height of head.
Contact me if you need any clarification.
You have my number.
Chris Italbrit Classic Motorcycles.
Click to expand...
There have been issues of late...fixed by Keith Nairn designing a version which does away with O rings, uses built in crush washers. Flame ring does its job too, unlike others, no names...
 
Has there has been any real consensus on the head gasket issue or any definite identification of the the manufacturer or supplier. I have asked different people and had different opinions. I wouldn't know if the gaskets I have are any good or not until I use them. How do you tell? It's all a bit he said, she said if you ask me.
 
IMHO, anything that does away with the o-rings is a good idea. Not robust enough from the placement and stay-there points of view.
 

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Recently recieved a couple of Keiths' gaskets. Although I haven't yet fitted one, they look to solve all issues one may come across. The flame ring has the necessary thickness, the o-rings have been substituted with pressed-in copper rings, similar to the flame rings and the whole gasket is coated with what seems to be a silicon-like sealing agent, doing away with the need for additional sealing.

pf1 said:
Has there has been any real consensus on the head gasket issue or any definite identification of the the manufacturer or supplier. I have asked different people and had different opinions. I wouldn't know if the gaskets I have are any good or not until I use them. How do you tell? It's all a bit he said, she said if you ask me.
Click to expand...
Pat,
If the gasket is suitable or not depends a fair bit on the condition of the cylinder barrel casting and the liners. In new condition, the liners were slightly recessed from the gasket surface, the gaskets were made to suit, ie, the flame rings were thicker, to fill the recess. Fast-forward 45 years and thousands of heat-cycles later, the castings have deteriorated/shrunk and the liners now mostly protrude, no gasket on earth is able to seal the entire surface properly. While the combustion chamber may be properly sealed, with any gasket, the remaining surface cannot attain the measure of oil-tightness that is necessary, thus the bloody things piss from the sides of the head... and the o-rings are (wrongly) blamed. These can be, and are, often replaced without really addressing the true issue.
The gaskets generally available from manufacturers such as Athena or Centauro undergo a final "flattening" that eliminates the necessary flame ring thickness. This would be OK in the case of the liners being truely flush with the remaining gasket surface, but this is rarely the case. The flush flame rings cannot seal the combustion chambers properly if the liners are recessed, allowing oil to pass through from the corner passages to the head. The gasket will be outwardly oil-tight though, but the engine will be a real smoker and oil consumption will go through the roof.
It's not as much a case of who made it, it's more a case of how it's made. The overall quality of the gaskets is generally very good, just that some simply will not work as designed. If the top deck of the barrel can be machined completely flat, as is the case with 1200s only, the flattened gaskets should work just fine.

piet
 
sfcpiet said:
Recently recieved a couple of Keiths' gaskets. Although I haven't yet fitted one, they look to solve all issues one may come across. The flame ring has the necessary thickness, the o-rings have been substituted with pressed-in copper rings, similar to the flame rings and the whole gasket is coated with what seems to be a silicon-like sealing agent, doing away with the need for additional sealing.


Pat,
If the gasket is suitable or not depends a fair bit on the condition of the cylinder barrel casting and the liners. In new condition, the liners were slightly recessed from the gasket surface, the gaskets were made to suit, ie, the flame rings were thicker, to fill the recess. Fast-forward 45 years and thousands of heat-cycles later, the castings have deteriorated/shrunk and the liners now mostly protrude, no gasket on earth is able to seal the entire surface properly. While the combustion chamber may be properly sealed, with any gasket, the remaining surface cannot attain the measure of oil-tightness that is necessary, thus the bloody things piss from the sides of the head... and the o-rings are (wrongly) blamed. These can be, and are, often replaced without really addressing the true issue.
The gaskets generally available from manufacturers such as Athena or Centauro undergo a final "flattening" that eliminates the necessary flame ring thickness. This would be OK in the case of the liners being truely flush with the remaining gasket surface, but this is rarely the case. The flush flame rings cannot seal the combustion chambers properly if the liners are recessed, allowing oil to pass through from the corner passages to the head. The gasket will be outwardly oil-tight though, but the engine will be a real smoker and oil consumption will go through the roof.
It's not as much a case of who made it, it's more a case of how it's made. The overall quality of the gaskets is generally very good, just that some simply will not work as designed. If the top deck of the barrel can be machined completely flat, as is the case with 1200s only, the flattened gaskets should work just fine.

piet
Click to expand...
Yup, had an oil tight rebuild by Keith..smoked like a chimney though! The flame ring fails, the o rings get melted and oil is sucked in..I saw the sorry gasket. No issues since the new design was fitted..others I know too have had the same, now sorted by Keith.
 
Thanks for the explanation Piet, fingers were pointed a while ago by someone I talked to but I was dubious about the explanation. So basically if the flame ring isn't pre-flattened I should be ok. I'll have to take a close look at them.
I have several barrels, might have to take a good look at them too.
 
martymoose said:
Hi Chris, you've pegged my interest with different thickness gaskets, is that for altering compression ratios, or for another reason? Different thickness O rings as well?
Click to expand...
I use the different thickness head gaskets to reclaim lost dimensions, as in you often find heads that have been machined in the past
Have the following new gaskets in stock

Keith's new head gasket version which looks great and good on him for going to the trouble to get them made
1.0mm with 1.0mm steel flame rings that I use on 1200 engines once I skim the top face so there is no liner flange recess
1.25mm with 1.40mm copper flame rings
1.50mm with 1.70mm copper flame rings
2.0mm with copper flame rings, never measured them though

Also have some other UK made head gaskets which am not keen on
Had a couple fail on high mileage engines, they fall apart for some reason

And don't mention 500 head gaskets which are another issue altogether
 
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Paul Marx said:
So far, the gasket I changed on Corinne's 500 is doing fine. I think it was NOS I had.
Paul
Click to expand...
if it fitted initially then it will be fine
issue with the 500 head gaskets these days is that they do not fit anymore

JLO has found a company in Spain that can produce 500 head gaskets that fit fine but avoid the other suppliers
 
All very interesting. I will probably at this stage be pulling the motor in the Christmas holidays, so will measure everything very carefully. I can't remember what was used last time, was more than 20 years ago.
 
martymoose said:
All very interesting. I will probably at this stage be pulling the motor in the Christmas holidays, so will measure everything very carefully. I can't remember what was used last time, was more than 20 years ago.
Click to expand...
Marty,

More than likely none of the beformentioned issues were relevant then! I can't recall anything of the sort while at Moto Witt in the 90's, factory gaskets were still in good supply. I think aftermarket gasket sets hadn't even arrived because OE Laverda parts were still so damn cheap and plentifull.

piet
 
martymoose said:
Hi Chris, you've pegged my interest with different thickness gaskets, is that for altering compression ratios, or for another reason? Different thickness O rings as well?
Click to expand...
As Red has stated, have in stock different thickness gaskets to suit different heads. Alot of them have been machined. Also flame ring height on cylinder liners not consistent.
Give me a call if you want any clarification.
 
Wondering how much the cylinder usually can be machined down without causing trouble with the camchain tension. My 1200 sleeves has sunk a little so think it needs maybe a 0.10mm cut.
 
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