Is 9.4:1 compression high?

[Ross_Thoma]

Here is a question for all the engine performance nuts out there.

So is the 4.6l disco engine running @ 9.4 : 1 a high compression engine? And what are the ranges for the levels of a regularly aspirated engine.

Just curious about fuel grades and compression.

Thanks
Ross Thoma

 

[deltadude388]

Here is a question for all the engine performance nuts out there.

So is the 4.6l disco engine running @ 9.4 : 1 a high compression engine? And what are the ranges for the levels of a regularly aspirated engine.

Just curious about fuel grades and compression.

Thanks
Ross Thoma

not in my books. 9.4:1 is anything but high today, may be 10 yrs ago it was.

 

[Peter-man99]

I got a 94 2.slo 8 valve golf that is 10:1

 

[ShaunP]

The Rover motor comes in 2 comp ratios 8.13:1 Low comp and 9.4:1 High comp depending on the market in which it was sold. The vehicles are designed to operate in areas where fuel octane/quality may be in question and this is the main driver for conservative ratios. Lotts of guys in OZ who have rebiult their engines have upped the comp with no trouble as long as the fuel is ok. I know of a couple of guys running P76 blocks with Rover heads, inlet manifolds and an aftermarket injection ECU who run 10:1 with no problem.