Building a turbo motor and just want to know what is better to build and why.

Should i start with a au bottom end? if so whats its advantages??
ALSO
if i was to retain my eb motor ive herd that ef-el cranks are better??

Any help would be great

Thanks!

Imo start with an A.U engine in good nick...
It will hold up to 280 - 300 rwkw no issues with good tune.... For about $1200 you should get full serpintine belt and auto...
The bottom end on these motors are nearly bullet proof.. Over 330 rwkw they need better pistons and rods.. But within reason thats due to high compression for a forced induction motor...
9.4 compression is quite high but with good ecu and tune you won't have any issues...
Keep in mind any power over 270 rwkw is going to have long term issues with auto.. If you are considering ? A manual don't use the T5 they will fail very easy...It's the massive torque these engines make...The high comp on these motors as std make them VERY throttle responsive as a street turbo car...

Yep - what he said

Graeme - what about standard motor with decomp head (say ~8.6:1) - bottom end still hold out for a little more than 330 rwkw ?

Oh stop it, 'You' don't need more.

Shhhh - let the man speak !

Reason I ask Graeme in particular is because I am sure he is familair with the trials and tribulations of Michael's EB with its many transformations.

It comes down to tune, from memory 15 Lb can be run with 8* timing .. Retarding timing any more and adding boost doesn't make any more power. From memory that was 280 rwkw. The valve springs require replacing over 12/ 15 Lb anyway... Then we fitted water to air intercooler, 75 Lb injectors and front mounted fuel cell and 044 pump running C16 Then from memory power went to 360 / 380 rwkw with GT42 turbo....
The dump pipe and wastegate was vented behind front wheel...


IMO for street use The std compression is fine. non tickford engines are 8.8 comp which is fine...
You make more power with lower comp BUT you loose low end throttle response...Which esp on a manual car is a pita..
More than 12Lb go at least 1 plug colder than std...
Unless you have an MSD ignition box? Then you'll have to close plug gaps to around .028 / .032 or you get spark blow out...
Michael basically stopped due to regs and auto requires mods to survive or work....New toy is an R1 which runs 10's...So he got there....

Box not a problem as im building a C4 at work for it, just the motor i was wondering which i should start with. i already have all my turbo gear, computer fuel system etc

cqan anyone give me a reason why the au is better?(i beleive you just wont to know the difference)

Thanks!!

where abouts do you work? I am about to call an auto place in sydney in the next couple of days to order a tuff c4 box for my el.

Ha!!! Right now we are fitting a C4 Domminello into my sons ED Fairmont..
Why I say AU? Is they are generally lower milage and with there longer rod combination rev alittle better.. Besides why build an when you can buy one for $600 or so ??? A few klrs on a good engine is about right for forced induction as clearances are about right...They come with better alternator and you can't pass on serpintine belt!!
In anycase If you have EVER had an engine rebuilt ?? It aften takes weeks not days to get it back...