4.3 compression ratio.

[MPO]

carsy said:

MPO said:

Carsy

What part number is stamped into the pistons?

Cheers

MPO

Managed to look from the underside today and there are two different numbers stamped into the pistons.

As said they are Hepolite with numbers HRC1827 and 22058A.

[Mimic]

Hi,

I project to rebuilt a Rover 4,0 TVR engine to 4,3 (opportunity to buy a 4.2 RR crankshaft).
I a little bit lost about TVR 4.3 spec:
- crankshaft : 4.2 RR
- conrod: same length 3.9RR
- piston : 3.9 RR hiComp with 2mm less

If the conrod are the same between 3.9/4.0 & 4.3: the crankshaft are different 77mm vs 71 mm => 6mm ... So the piston will be raised 6mm and not 2mm, isn't it? ((piston compression height doesn't change).
But 6mm will be too much with a risk for the first fire ring.

Thanks in advance for your answer.
Mimic