2.9 pistons / 1.6 diesel conrods

[Halatajfun]

hello all
please help me
compression ratio of 2.9 pistons +1.6 diesel conrods in pinto with not skimmed head + 1.5 mm head gasket?


Thank you

[dt36]

Try this on Android if you know your measurements :
https://play.google.com/store/apps/d...=cal.ratio.com

[Halatajfun]

hmm

[Halatajfun]

heeeelp , i haven´t got all parameters
thanks

ps: low comp or high comp?

[snapper1]

There are a lot of assumptions here so please check...
Pinto Rod 127mm
Cosworth Rod 128.5mm
Diesel Rod 130.2mm
V6 2.8 piston is 1.5mm shorter than Pinto piston ARE 2.9 PISTON THE SAME?
My V6 piston was 0.38 below deck

V6 2.9 on Desiel Rod could be 1.32 above deck
You need 0.9mm (0.75 min) piston ring head clearance

With a 2.2mm gasket your compression ratio would be 10.425 to 1
With a 1.5mm gasket your compression ratio would be 11.34 to 1
Your clearance would only be 0.18mm

PROBABLY MAYBE

[Halatajfun]

2.9 piston is forged
Heigh 39mm
Diameter of forged part IS 60mm x 1.5 mm

[snapper1]

2.9 piston is forged
Heigh 39mm
Diameter of forged part IS 60mm x 1.5 mm

I don’t know what “diameter of forged part is 60mm x 1.5” relates to so my calculations are for a flat top piston.

Taking all my assumptions from my previous reply but reducing the piston compression height by 1.1mm gives
10.25 to 1

For A really accurate compression ratio you need to know
Numbers in () are my assumptions
1. Bore (93mm)
2. Stroke (76.95mm)
3. Combustion chamber volume (48cc)
4. Piston deck height (-1.282mm) - = Piston above block deck, + = Piston below block deck
5. Gasket bore (94mm)
6. Gasket crush thickness (1.5mm)

Rod length is not important if you can measure the piston height above or below block deck.
Combustion chamber volume is important as these can vary between 48cc and 50cc on a standard head or could be much less if skimmed

[snapper1]

2.9 piston is forged
Heigh 39mm
Diameter of forged part IS 60mm x 1.5 mm

If that is a dome on the piston then your compression ration is now 10.431