998 SC setup.
Turbo Mini Forums

Right here goes, building a FI 998 for my dad, were using an eaton M45 as the FI part (cos I was given it so NOT going for a turbo!)

Have already got the +0.120" pistons from Hypatec and will get a shallow dish machined into the top of those, but what Im wondering, is for a low ratio screamer whats the best to go for in the crank and rod department.

Its going to be based on a A+ block using a modded unleaded 998 head (sticking to std valve sizes but having the ports and chambers sorted), got the pre verto lightened flywheel in stock. Am thinking Kent 500 cam (MG metro profile) standard rockers.

Going to blow through a HIF44 and hopefully a IC across top of engine (bini stylee), aiming for 100 ponies at the fly give or take a few so a CMS is going to be essential!

Ive been talking to the guy who helped with the works upgrades and hes been telling me the real limits on the SC ie they were running them at 2.25:1 engine speeds (18K rpm) without failure (buts lots of heat hence IC).

Any thoughts or comments welcome, but before any of you say it, we arent getting a turbo setup LOL

Edited by eaton_mini on 15th Jul, 2008.

Without sounding like a cnut, you will get a better response if you break that up so people will actually be arsed to read it, as it is very difficult when all in a constant string.

You need to sort out the maths.

The M45 flows 45 cubic inches per revolution. That's about 750cc.

At 2.25:1 that is about 3375cc every two revolutions into about 1100cc.

To get that flow into the engine will need about a 3:1 pressure ratio at which you will generate 30 psi of boost.

The M45 is very inefficient at that pressure ratio, so the air coming out of it will be very hot.

For 100hp you only need to drive the blower at engine speed and everything will be fine.

If you are blowing through, you need a bypass valve to vent the boost at part throttle and idle.

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."

I agree with Paul. at that sort of speed it'll absorb about 50bhp, negating any of the extra power it might make (which would be zero anyway as the charge temps would be hotter than the sun!)

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

www.twin-turbo.co.uk

Is that better t2???

Paul, yep had done a couple of calcs on air flow and then got hopelessly lost!!

So your saying if I drive it 1:1 it will be good for 100 ponie power?!?!?! (Im guessing thats 10PSI???)

I see what you are saying about the valve as well, are we talking BOV's or just some form of pressure release mechanism?!?!?!

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."

So what you are saying then is its easier to do a suck through job??? No need for the valve then.

The bini must have had a similar thing on it, I will have to do some research and find out...................ie when cruising pressure is lost to atmosphere or something?!?!?! And at WOT the valve closes.

Edited by eaton_mini on 15th Jul, 2008.

Best bet would be to contact one of the specialists that do the kits like Vmax scart. The M45's have an integral bypass that can be modified to increase boost pressure but im not sure if this would allow it to run in a blow through config

Hmm Ill give the guy that did the Works kits a ring and see what he says about it, didnt know they had an internal bypass................

FI= Fuel injection..

In this instance FI = Forced Induction.

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."

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."

The BMW MINI uses an external by-pass valve, which are unreliable by all accounts.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

www.twin-turbo.co.uk

Vegard that would be EFI would it not????

Wil_h, I havent even had a chance to look at this yet, but thanks for the heads up. There must be an after market gizmo that can be used instead?!?!?!

Paul S, what Gen is your M45???

Edited by eaton_mini on 16th Jul, 2008.

BINGO!!! http://www.magnusonproducts.com/bypass.htm

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."

My god man do you not work or something?!?!?!?

Mines a 5th Gen with the teflon rotors. Ill have to see what else I can find out about it.

Edited by Paul S on 16th Jul, 2008.

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."

just a thought my g60 golf, although a differnt type of charger, being a g-ladder not a screw had a vent to atmosphere instead of feeding the hot air back into the charger, kind of defeating the object of an IC? It had a blanking plate and vented just unde the inlet manifold. not sure if that helps?

"Cars are a lifetime of pain"

I have a brand new M45 sitting on the shelf - Magnuson with bypass valve, non of this crap bini stuff ---hmm lovely

If Carling made Mini engines
it would probably be like this one!

Same shelf as that gold mini, John

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."

So the magnuson bypass works with the M45 then??? Which one do you have (bypass valve not M45!)

Paul S, you are one lucky buggar then!

I have an M45 with the bypass valve - its the magnuson m45 from the linky

- tut tut Paul -not too longto go now!!

If Carling made Mini engines
it would probably be like this one!

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."