Edward M. De Reyes writes:
> I have the opportunity to purchase a fairly good condition TR-6, and I
> was wondering if anyone could give me compression values.
>
> The owner claims that the engine was rebuilt about 40,000 miles ago, but
> did not specify if the cylinders had been bored or the head milled.
You didn't mention what year the TR6 was, but the early cars (pre '72)
had 8.5:1 compression, '72 and later had 7.75:1. I think it was
further dropped to 7.5:1, with the addition of the air pump '75 & '76,
but not sure about that.
Having said that, you really can't be sure what the ratio is anymore,
as it's not clear what was done to the engine. If the head was
planed, then that can raise the compression ratio slightly.
(Significantly, if you really take some meat off!)
What's really important is that the numbers are consistant across all
the cylanders. If not, then something is wrong in the low cylander.
On a low compression engine, you should see numbers around 125psi.
The early engines should be around 135psi. A variation of 10 psi is
ok, but not much more than that, IMO. If this was a late model car
and was showing 120psi across the board, then I'd be happy with that.
Good luck!
-Scotty
'70 TR6
'75 TR6
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