Plenum queries...

[need4speed]

Will my hotwire 3.9 plenum be up to the task of feeding my rebuilt/modified 4.6, or would it be beneficial for me to bore it out.. Bare in mind that this is for a defender 110 not a light sports-car..

[need4speed]

Come on guys. Surely its an easy one for guys of your calibre...

[CastleMGBV8]

[quote="need4speed"]Will my hotwire 3.9 plenum be up to the task of feeding my rebuilt/modified 4.6, or would it be beneficial for me to bore it out.. Bare in mind that this is for a defender 110 not a light sports-car..[/quot

Presumably you have modified the engine to optimise torque in which case the 3.9 plenum should be fine for your purposes.

Kevin.

[need4speed]

Thanks for replying Kevin. Yes my engine is currently using standard later-casting heads, skimmed to up the compression a little, and using a real-steel stump-puller cam. I'll also be using MS and EDIS.
Cheers
Phil

[Eliot]

Big plenum is required for high revving large capacity engine - on a 4x4 its less of an issue, as you are maximising for torque in the mid range typically.

[need4speed]

Thanks guys. Looks like i can use the one i have after all.

[Eliot]

Given that you are running megasquirt, all you need to do is compare your MAP pressure at wide open throttle @ max RPM with the pressure you record with the engine switched off - they should be close to one another ideally (~97kpa) - otherwise known as the barometric reading on MS.