Compression

Luke · Post by **Luke** » Mon Nov 29, 2004 8:35 am

Is 98 octane ok for 11:1 compression? Or do you need to a fuel additive?

Nick Moss · Post by **Nick Moss** » Mon Nov 29, 2004 8:38 am

My 2.8 with 10.8 CR pings on leaded 4 star fuel. Are you going with twin plugs as that should help.

Luke · Post by **Luke** » Mon Nov 29, 2004 9:19 am

yep twin plug ignition, super unleaded, just want to make sure 11:1 will work before I get the final engine spec sorted

Ian Donkin · Post by **Ian Donkin** » Mon Nov 29, 2004 2:48 pm

Luke

Whilst (stating the obvious) a much later car, 964's initially ran 11.0:1 with 95 RON fuel; only when the CR was raised to 11.3:1 did they move to 98 RON.

Of course these were twin plug from the outset.

Hope this helps.

Luke · Post by **Luke** » Mon Nov 29, 2004 2:55 pm

cheers Ian, it looks like 11:1 compression is GO! I finally have the full spec for my engine build now, lets hope Santa is good to me this year!

Nick Moss · Post by **Nick Moss** » Mon Nov 29, 2004 4:43 pm

964's initially ran 11.0:1 with 95 RON fuel

and a sophisticated engine management system, probably with knock sensors......

Ian Donkin · Post by **Ian Donkin** » Mon Nov 29, 2004 4:46 pm

Forgot to mention that minor detail. Oops!

Luke · Post by **Luke** » Mon Nov 29, 2004 4:53 pm

but as long as everything is set up within tolerances there shouldn't be much of an issue running 11:1 as compared to 10.3:1, I just wanted to make sure I'd stillget combustion rather than detonation, all I really need to worry about is the clearances, which will be damn tight!

Ian Donkin · Post by **Ian Donkin** » Mon Nov 29, 2004 5:07 pm

Luke

Nick makes a valid point. You don't want to destroy your [freshly built] pride and joy...

Suggest you stick a post on Pelican's forum if you want to ask a wider audience - some of those guys have done some pretty interesting stuff!