Lotus Europa Forums > Technical Articles and DIY tools and tips

Renault 697-04 pistons and compression

(1/3) > >>

lotuseater:
Does anyone know the performance difference between the original Lotus crowned pistons which gave a higher compression than the Renault 16 flat topped pistons?

Mine has been fitted with the Renault variants - they run well and rev freely. Engine currently in bits as I had a bit of mayo in the cap so I checked compression for suspected Head Gasket Failure -  I've got low compression on No 4 cylinder (165psi on 1,2 & 3 but only 112psi on No 4). As yet, I have found no reason for this - gasket contact looks good to both head and block, valve seats slightly pitted, but not leaking with a water test (inverted head and filled with water). Nothing else looks out of order.

Is there a source for the crowned pistons and is it worth it? Current pistons & liners look to be in very good condition.

TurboFource:
I believe the surface tension of water is to high to test for valve seat leakage, usually a solvent is used.

lotuseater:
Thank you...will try thinners or panel wipe.

BDA:
It's too late now but one thing you could have done before you took your engine apart is a leakdown test. That would have told you where the leaks are.

MRN I J:
paraffin is commonly used

Navigation

[0] Message Index

[#] Next page