Hi, I have an EA 3.9lt project car I am doing up, the engine at the moment has quite a bit of head work and a stage 3 crow cam with a chiptorque J3 to suit, but has no bottom end work ( well I dont think so anyway) I purchase this from my brother inlaw who had never started it, it just sat in the shed but aparantly he knew the gvuy who had the engine before him. So I am about to pull apart and look for my self. The engine has dyno sheets which state it had 192HP at the wheels. I think that is almost unbeleivable concidering no bottom emd work but as I have not driven with it im not too sure.
Any way my question is this has anyone done a hybrid engine with ea head and au botom end???
As they are both high compression I feel it would make a very good strong NA engine, what does everyone think?? Also isthere any mod needed to do so?
I will have a au xr6 write off turning up in 3 weeks so this is why I am concidering the hybrid engine.

just use the whole AU engine. 157 flywheel kw out of the box. and if it's a AU XR even more than that.

just tickle the AU head a bit. get a different cam etc. should move alright for an N/A

No I wont be doing that, I have an au falcon as my daily driver and it definatley does not have enough power for what I want. I defiantley want to use the 3.9 head for my project as its all about how cheap i can do it and its already got the headwork, massive cam and computer to suit. Also I was thinking about putting the auxr6 head and xr6 computer into my au daily driver to beef that up a bit... or sell it as, as far as I know the only difference between the standard au motor and the au xr6 motor is the head, cam and computer. So I would esencially turn my car into a xr6 ( minus the looks of course.

Serious? I've just dropped an AU XR motor into my EF, and with some mild head work it pulls every bit as hard as my old motor which had a 1673 cam! Not to mention being 11ty times smoother.
If you're keeping it NA you'd be bloody silly not to seriously consider an AU motor.

Also there are other things like diff ratio, suspension and interior which set the XRs apart.....

192 hp at the wheels isnt mind blowing stuff either lol, can be easily achieved without bottom end work. Maybe you need to hunt around the forums a bit more?

you have to remember you AU is standard by the sounds of it. and heavier than a EA

thanks for the input guys, well if 192 hp is not all that hard to get then mayb it is true.
From what I can make out the AU motor would be alot better option if I had the money to get a new cam and head work but I can spend no money and have a more powerful motor with the hybrid.
I think maybe I should use my 3.9lt as it is and save some more cash and work the au xr6 motor.

Yeah my Au is stock as a rock and slow as a wet wig lol.... just a Question, I have a t5 gearbox to suit the ea motor.. Will Ineed to modify or change the bellhousing to fit i upto the au motor?

afaik AU T5 is longer

AU motor in an AU needs an AU box.

AU motor in an E series needs an E series box.

Thanks guys