A+ or 997 Cooper
Turbo Mini Forums

I have a 997 Cooper engine with 295 head in the car ATM and an A+ in the garage. Which one would you turbo as a daily drive?

Paul

Edited by paul wiginton on 12th Feb, 2009.

I seriously doubt it!

The Cooper pistons ust have seen a bit of abuse already (if standard) so would be be able to sustain any boost? I'm assuming you wont be reboring etc. with the turbo but I could be wrong

EDIT: 998 A+ yeah?

Edited by GaryOS on 12th Feb, 2009.

On 12th Nov, 2009 Paul S said:

I think Gary OS has taken over my role as the forum smart arse

Which ever I use would be fully rebuilt with new pistons etc

Paul

I seriously doubt it!

The 997 is a fooking long stroke (second longest A series after the 1098 if I'm not mistaken) so if you want torque then it would be better than the 998.

The A+ would produce more bananas but you would have to rev it harder.

The bore is only about 0.5mm off a 998 bore so I imagine 998 pistons could be used. I would probably use the 997 due to the longer stroke for a road motor.

Do 997 cranks have same journal diameters as all other small bores?

On 12th Nov, 2009 Paul S said:

I think Gary OS has taken over my role as the forum smart arse

You might have trouble finding pistons for the 997, IIRC it's more or less the same bore as a 850 but with a silly stroke.

I would personally go for the 998 being a squarer engine.

Actually, Id forgotten about the stroke of the 997 being long. I quite like that idea if it can be rebored to use an A+ 998 piston either std size or oversize. It could be quite torquey.?

Paul

I seriously doubt it!

Just had a quick look at Vizard. The 997 stroke is 81.3mm whereas the 1098 has a stroke of 83.72mm. That only leaves 1098 pistons 1.21mm further down the bore than they would be in a 998/1098 block. Surely they could be used with a decent skim off the 997 block

On 12th Nov, 2009 Paul S said:

I think Gary OS has taken over my role as the forum smart arse

I seriously doubt it!

what is it going to end up reving too?

will a 997 be happy at that?

I seriously doubt it!

After browsing through the big yellow book appearantly some 997 Cooper S cranks had an oil fed primary. This causes problems with clutch slip. That would obvioulsy need attention if used for a turbo. They were only used upto 63 though so maybe yours is OK

On 12th Nov, 2009 Paul S said:

I think Gary OS has taken over my role as the forum smart arse

The 997 should be fitted with a 12G202 head. I would be inclined to find a 12G202 head, fit it to the 997 and sell it on ebay.

Then take the 12G295 and fit that on an A+ 998. If the 12G295 has not been skimmed, you will have about 9:1 compression ratio.

Other than the 850, the 997 is the worst of all the A series engines, apparently.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Thanks for your thoughts guys, Ill go with the A+ engine I think.
Just thought the 997 might be a bit different

Paul

I seriously doubt it!

I agree with Paul. Don't wreck a 997 block, they are scarce. However, I do like the idea... Why not source an 1100 crank for your 998 block..?

theres an 1100 crank on ebay....

But then you need some decent 1100 pistons.

Finding any without slots was impossible when I last looked - other than forged at megabucks.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

well Paul/Dave is rolling in the mula now he's knocking out these baffle plates

imp?

bit harsh Joe. Just because he has the time and money to experiment like this on a mk1 is no reason start calling people gimps.

lol,

hillman gimp, shorter deck height, decent piston, possiply a bit tricky to get hold of now,

talbot 930 is the same as an imp but a bigger bore, might be easier to get hold of if the block can be bored that far.

For the love of god don’t put a 1098 crank in a 998 A+ block and try to turbo it I think I am going to be in my 50's before my self and Gar get his done.

for a daily drive get a good 998 bore it +120 fit a set of the aus pistons and a 12G940 head a good GT turbo and be done with it, It will be a great motor make loads of power and will go together in no time and work
:)

fair point,

thinking about it imp pistons will be flat tops, it will probably be a chore to get the cr down for turboing.

Fitting an Imp engine is as bad as fitting some fooking bike head to a Mini and calling it A series. lol

Paul

I seriously doubt it!