Engine build..but want turbo now!!
Turbo Mini Forums

Hey,

I have a 1275 A+ which I am rebuilding

Specs below

+20 with 21253s which have 8.4 cc dish
Reground crank
minispares road weight flywheel with orange diaphragm
stage 3 head 21cc I think with steel guides and road valves
gearbox rebuilt with 3.44 diff and cross pin diff
Sw5 cam
1.3 ratio roller rockers

I'm planning to use a mirage setup with t2 turbo

would I be able to get away with having the chambers enlarged to lower compression?

Will the clutch be okay?

Do i need a centre main strap? The engine is currently being machined

will the cam and rockers be suitable?

Thanks
I'm planning to use 10" wheels and it will be going into a mk2, will the mirage manifold be okay?

I would do an upgrade on the pistons mate, either go with cast omegas if on a budget or accralites if funds allow. The mirage manifolds have proven themselves up to around 200bhp so should do well for you

Hi,

Thanks, I'll look into the pistons

What I really need to know is if the head will be suitable? Its new with road valves and steel guides, will it take the temps ect

Also the clutch? Orange good enough? There is a road rally plate as well

Also will the SW5 with 1.3 rockers be okay?

And will the mirage manifolds and turbo be okay in a mk2, I think the bulkhead doesnt have as much of a dip as the later shells?

How much boost are you planning to run?

If you go with the 21253's and a standard head then the chambers will probably need opening out. Benross or turbo phil on this site can do that for you.

Centre main strap wise, unless you intend to turn it to some serious rpm its most likely not needed.

The cam and rockers should work well for a turbo engine.

Edited by minimole23 on 1st Feb, 2010.

Cheers

I know going with the Omega would be wise but if I could stick with the 21253s that would be good

I was looking to stay on standard boost..is it 8 psi on a T2?

What's the life expectancy of a turbo engine? 30ish k?

What sort of power with standard boost as well?

Thanks

the 21253's will be fine, the only trouble i can see you having is getting the compression down with such small chambers in the head.

If you only want 8psi then try and get down to around 9:1cr by opening the head or pistons out a little.

ive got the same head, and clutch, putting it in the car. turbo phil is having a look at my head for me. one thing to look out for, if you have a hevy right foot you might want to do the drop gears, have a little search on them. good luck

reliability is mainly in the hands of the driver, id guess at that motor making 120bananas with 8psi and a good setup, 30k miles should be no problem if you treat it nicely but you will want more power after about 1.5k anyway


it depends on what your t2s off as far as what psi actuators on it, im not a t2 expert though