LCGB Forums

Hello,
Can I open up a head gasket? Reason is that my barrel is 63.2 and will probably end up 64mm. The gasket fitted, which of course will get replaced, is 61ish, it creates a “lip” over the barrel edge.
Any ideas please?
If you read this Paul, I’m not ignoring you, you have gone over and above in helping me, I didn’t want to keep troubling you. Thank you for all your help so far.
Pete

Peterp wrote:Hello,
Can I open up a head gasket? Reason is that my barrel is 63.2 and will probably end up 64mm. The gasket fitted, which of course will get replaced, is 61ish, it creates a “lip” over the barrel edge.
Any ideas please?
If you read this Paul, I’m not ignoring you, you have gone over and above in helping me, I didn’t want to keep troubling you. Thank you for all your help so far.
Pete

yes you can open it up bud
have you tried a RT195 head gasket, that'd be a 65mm

Apologies Hullygully, should have thanked you earlier for the reply, cheers.

Peter, try measuring the squish before fitting a head gasket. My TV175 head clearance was HUGE so I didn’t fit the head gasket.

The head gasket won’t blow if it not fitted.

Knowledge wrote:Peter, try measuring the squish before fitting a head gasket. My TV175 head clearance was HUGE so I didn’t fit the head gasket.

The head gasket won’t blow if it not fitted.

Agree, Martin. My standard engine still runs well with a massive squish mind. Not the fastest TV175 on the block though

I'll 3rd the above 2.

It’s probably something like up to 50 years since I utilised a head gasket, regardless of the state of tune. That can make for changes to the head or barrel & selection of base gasket thicknesses, but - as has been said - usually the squish tends to benefit, besides obviating the incidence of gasket failure.

The squish is important as the minimum practicable head to piston clearance ensures that the head is better able to conduct heat from the piston crown. As opinions vary upon what a minimum squish should be, I won’t state my preference, but it would be dependant upon the state of the crankshaft/con-rod & the bearings.

Obviously, the reduction in squish will have an effect upon the compression ratio, which should conform to parameters that can also vary significantly not only due to opinion, but in the way that it is measured.

However, in my experience, whilst I stress the importance of checking the squish & compression ratio, it is usually the case that removal of the head gasket from an un-molested large frame engine will be of benefit & not detrimental to either.

Thank you all again, the squish on mine is 2.5mm, but taking Paul’s advice and agreeing with the replies, before strip down it ran very well but ran out of “puff” about 57mph. This is disappointing but as I’m learning, this is only what can be expected of a 1963 machine.