Mk3 Compression ratio following skim

[Sandy Gibson]

.012” lighter and looking good!

Many thanks to everyone who read/posted opinions.  Forums like this keep amateurs like me on the right road!

[johny]

Did the machinist give any feedback on the prior flatness he found?

[Sandy Gibson]

Just that there was a very low point between 5 and 6 push rods and the adjacent cooling ports.

[johny]

Ahhh well thats sounds like a possible explanation of the problem....

[Iain T]

4 hours ago, Sandy Gibson said:

012” lighter and looking good!

Nicely cleaned up! As it's off are you going to match the ports/manifolds? 

Iain 

[Sandy Gibson]

Already started!

[Casper]

Quote

Triumph where "happy" to recomend removing 30thou from the 4 Cyl head. In that context measuring the CR`s was not an issue.

That was in 1962 when a HC head was 8:1.  The CR was later raised to 8.5:1 as standard.  How?  Byu taking 30 thou off, so you sort of lose the safety margin.

Not suggesting it would be a problem but using out of date data doesn't necessarily apply to up to date kit

C,

[JohnD]

2 hours ago, Casper said:

That was in 1962 when a HC head was 8:1.  The CR was later raised to 8.5:1 as standard.  How?  Byu taking 30 thou off, so you sort of lose the safety margin.

Not suggesting it would be a problem but using out of date data doesn't necessarily apply to up to date kit

C,

Absolutely!    Measure, measure, measure!   See my previous post here on measuring chamber volume.