Budget 998 Turbo Build
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Using buttons because the pistons and rods are designed for use with circlips which have a tendency to jump out at high rpm. So ditch the circlips and use buttons instead.

I could have used press fit rods with these pistons which have no need for circlips or buttons, but that makes assembly and disassembly more difficult.

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."

Paul is there any advantage in running the MD274 over the MG metro cam (KC500) in terms of using port injection?

It looks like a slightly better option than the KC500 as the KC catalogue states it has slightly higher valve lift as well as the longer exhaust duration.

So this should be the same:
http://www.minispares.com/Product.aspx?ty=...id=37745&title=

For some reason Minispares list the cam as the MDM274, it is the same.

The inlet durations, 248 vs 252, are so similar that I really do not think it makes much difference from an injection point of view.

If you compare the lift at TDC for the 274 and 500, the 274 has 0.58mm, the 500 has 0.99mm, so the 274 should also limit air charge robbing more than the 500. Plus, the 274 has higher lift.

However, anything other than back-to-back tests is just opinion though. I'm finding that individual cam measurements bare little ressemblance to quoted timing/durations.

For instance, the Phase 2 quoted at around 264/290 is actually 250/260 at clearance lift.

Edited by Paul S on 25th Nov, 2011.

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've measured and plotted the MD274 whilst setting the timing.

Here it is compared to a PH2:



PH2 data courtesy of Mr Clark.

Edited by Paul S on 25th Nov, 2011.

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 got fed up with the timing wheel slipping between the bolt and crank, plus when you turned it back it could come undone altogether, so I bolted the wheel to a 998 pulley centre. Now TDC stays put.



Bit dissappointed with the "vernier", only 2 degrees incremental adjstment, so the cam is sat at 111 degrees on the inlet which should be OK.

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."

yeah, i'm not a big fan of those verniers,

on my *cough* belt drive I fond that locktab is not really enough to hold the dowel securely, I ended up replacing it with a 3mm thick ally plate that totally covered the dowel holes and loctited the nut,

also to turn the engine over I stick a flywheel bolt in the other end and turn it from there.

Joe, you must have long arms :)

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."

that and looking at the protractor sidways!

Why do you need to look at the protractor and turn at the same time?

I turn from the flywheel end an look at the dial gauge for reference. I measure a point so many thou either side of the maximum lift and average the mid point. I always turn in engine direction to the measurement point.

I guess there's lots of ways to do it though.

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

www.twin-turbo.co.uk

It's really for when I'm plotting the profile. I rotate the engine by either 5 or 10 degrees as a time, then read of the DTI.

As you say, there are different ways of doing it.

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."

Makes more sense.

Jusst as a note, the 266 I run in the sprint is not as nice as the 500 from a driving point of view. Make the car feel les sprightly pre boost.

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

www.twin-turbo.co.uk

Now for the transmission:



Gearbox is standard A+ helical jobbie from the EFI 1275 test engine. It was rebuilt prior to being used on the 1275.

Fitting a 3.1 CWP and 4-pin diff. It already has the central oil pickup.

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."

Gearbox and diff put together. Idler clearance set at minimum tolerance.



Used the last of my thick idler washers. Why do Minispares make that gasket so thick?

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."

You should know by now to buy genuine stuff, not cheap repro stuff:) the genuine gasket is available and much thinner.

When you get to my age, your head is so full of crap that you forget the important things :)

Presumably, you mean this one:

http://www.minispares.com/Product.aspx?ty=...id=34599&title=

Edited by Paul S on 5th Dec, 2011.

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."

What did you decide upon for the cam sensor in the end?

I'm guessing the one on the left is from DIYAT.

I was contemplating using either the Honeywell 1GT101DC or possibly making something up from some of these (from MS forum):

http://search.digikey.com/ca/en/products/A...98-1-ND/2626349

But depends how much the postage to UK is! Should be able to use these for cam, crank and speed sensors.

I'm currently erring towards the gear tooth sensor. I get them from digikey, but it is the same as the DIYA ones.

http://search.digikey.com/ca/en/cat/sensor...1967210?k=55075

The Honeywell one is as good.

Just need to find some mild steel tube of the right size to be able to get on with it.

I think Rod is planning on using the sensors you list for VSS.

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."

Schrödinger's cat - so which one am I ???

I like what this guy has done on the MS forum with the Allegro sensors - it looks very compact and seems to have had good success with them so maybe worth a try:

http://www.msextra.com/forums/viewtopic.php?f=131&t=41370

Whether I could do such a tidy job is another thing

Looks like someone has had a good result.

My only concern... most of these Allegro hall switches don't have the magnet built in, only the "gear sensor" ones from what I can see.

So be carefull you don't get one withouth the built-in magnet.

Schrödinger's cat - so which one am I ???

Yes Paul:)

Thanks Andre, I'll get a few on order and reset the clearance.

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."

Cam sensor sorted. Nice and simple:

Edited by Paul S on 6th Dec, 2011.

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."

Looks neat Paul,

have you left enough of the base for the forked clamp to sit on :)

Schrödinger's cat - so which one am I ???

I haven't touched the base except the flat for the sensor mount.

I will have to grind about 1mm from the inside of the clamp though.

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."