18 replies to this topic

[BritishRacingGreen]

Well the projects been a year in the making, started life as a standard Racing Green with a 'rebuilt 998'. drove it around for half a year, whacked a stage 1 kit on it then drove it for another six months.


It was then i noticed a lack of oil pressure at idle, which, after checking all the other options, we decided was mains bearings. while this was going on I'd been looking into turbo conversions, and noticed a lack of 998 turbos, and thought, 'that would be fun to do'

so it got a Megajolt ignition, and a quick run on the dyno (made 48 at the flywheel) and I was left collecting parts while i drove the engine into the ground.



finally sourced an engine for rebuild, which I did myself (mistake..) swapped the engines over, chucked the turbo on, turned the key, and nothing.
Before:


After:







lots of fiddling and fettling later with no results it got shipped to slark race engineering in hampshire. he got it running but it was running terribly, and was making a fatal sounding crunching noise when you press the clutch. so, off came the turbo...



Then got the car trailered to Spot-On Minis in buntingford (cracking mini garage) and he re-rebuilt the engine (properly this time) and it was decided to run the engine in N/A, just to make things simpler and to give me a chance to modify some of the turbo bits.



Currently got the turbo parts mounted on a spare short engine so I can tinker..



So currently 1000 miles into the running in process, just a case of waiting for it to stop smoking and me to finish some of the bits needed for the conversion and it can all go on! hopefully February time when I have not much uni work.

Apologies for the essay and swamp of pictures, but there was a lot to catch up on...

Edited by BritishRacingGreen, 26 November 2015 - 02:35 PM.

[chris211083]

Looking good but why is it still smoking??? Shouldn't have smoked at all after the rebuild???

Chris.

[BritishRacingGreen]

I was under the impression that because it has had new piston rings and a hone, the piston rings werent bedded in, so weren't sealing completely. This means oil can sit in the scores on the bore walls and gets past the piston rings into the combustion chamber while they bed in. It is much, much better now, just a bit on idle when there isn't any explosion/compression to push the piston rings out against the bore.

That's the impression I had anyway

[Tomm]

I have read up on your build thread on TM.

Your manifold sparks my interest as I see you have left your bulkhead in tack which is something I want to retain on my project.

Is that manifold a home made item? I initially thought it was a mirage unit but the bend in it looks a little different?

[BritishRacingGreen]

It was bought from another member of TM, who assures me it's a genuine Mirage kit. But you're right, it is slightly different to the one pictured on their website (the only other picture of one i've seen). However they are hand made items, and made individually (to order I believe) and are only constructed on a jig, so it may well be that it's a slightly different shape to some.

It does the job though, and I didn't have to put a bulkhead box in, and the downpipe fits perfectly

[steven]

turbo will be watching this

[Wil_h]

Looks like a mirage to me, there are a few copies around, but all the ones Ive seen are as good, if not better in some cases.

I'd be worried about the smoking, this won't go away. When is it smoking? What colour is the smoke? Have you had it setup? what can happen is an over-rich mixture can cause borewash. this smoothes the bores and causes smoking.

[BritishRacingGreen]

Well the manifold looks good quality but I suspect its a copy or has been damaged at some point because one of the studs almost fouled on 90 deg piece. hopefully using k nuts should help this.

as for the smoking, it's between blue/pale blue/white- ish colour. which is what lead me to that assumption. it only occurs on cold start up, and is fine when warm. I wouldn't have thought it would be rich as it currently has the same needle that I used when it just had a stage 1 kit, and now it has an mg cam, 12g295 head and 1.3 rockers. I I would have thought it would be lean?

the only other possibilities are the head Gasket or the head itself, and the head was reconditioned with new guides, seats and seals. and I doubt it's the head gasket, there's no other symptoms of a blown HG.

[Wil_h]

haha, it's deffo a mirage, the fit on two of the studs was exactly as you described.

[BritishRacingGreen]

Is yours a Mirage as well then? at least if it fits and seats properly on yours mine will be fine...

[evil ewok]

evening mate, where abouts in herts are you? i'm only about 15 min drive from spot-on minis. he was rather expensive when i went to him before, quoted £3.5k for a new front end, A panels and sills!
seen so many minis around lately, it's making me miss driving mine even more

[BritishRacingGreen]

I'm near St. Albans, and he's the cheapest mini friendly place I've found? And he does a thorough job as well.

[BritishRacingGreen]

So for those that haven't been following the [extremally slow] build on turbominis, here's what's been going on in the two years since the last post. You could read it all on turbominis but I'm bored, frustrated at not making any progress with the build and writing this is more interesting than uni work.

 

Started off by crashing it in the snow and bending a radius arm:

 

Which prompted a rebuild of the rear subframe:

 

Engine smoked like a train, looked like bore wash and oil coming past oil rings:

 

Then crashed again - a lesson to always make sure wheel nuts are on tight!!

 

Swapped the engine for a 1275 I'd built, turns out the adage is right - if you want a job done properly do it yourself...

 

Got the car back in one piece and working!!

 

Got a new job at an engineering company which prompted the evolution of the project to it's current phase - a high quality 998 turbo build, built to make 120hp and last. [sep 13 for reference]

 

The new job meant access to a whole engine building workshop, so things were cleaned and prepared properly:

http://www.calverst....&products_id=81

 

Some new CalverST +040 pistons

 

 

 

 

[BritishRacingGreen]

Plan now is to do a trial build to make sure everything is ok, measure everything for the CR calcs, get the block and head painted at work, then start the build. Spec now is: 
998 Block bored +0.040 
CalverST Pistons 
Standard 998 Crank 
Balanced 998 Rods 
MG Metro Cam 
Verier Timing Gears 
Guessworks Gearbox 
Minispares 4-Pin Diff 
RTS Clutch - 2x 998 Springs (once I've got my head around how it goes together) 
Benross modified 12G295 Head 
9.0-1 CR (?) 
1.3 Rockers 
Mirage Manifold and T2 turbo (planning between 10 and 15 psi)

 

 

Put all the aluminium parts through an alodine coating process that helps prevent corrosion and improves paint adhesion:

 

 

Lots of nice shiny new stuff was bought as well as parts being cleaned and glass bead blasted

 

 

And a professional paint booth is always nice to have access too

 
 

 

 
 
Parts that had been glass blasted were sent for electroplating for corrosion protection. these are the samples I had done
 

 

The Modified 12G295 was completed around Jun 14, chambers enlarged to 27cc and some porting work, was a lovely job

 

 

 

 

[BritishRacingGreen]

I'd made the decision to go with solid fuel lines so bought some MPi lines to run under the car, and used tube nuts and sleves to convert them from hose clip hoses to AN type fittings

 

This is the first batch of parts from the electroplaters, bit of a tart when it comes to looks so colour coded silver for subframe parts and gold for engine parts. 

 

Engine bay was tidied up and resprayed and the loom was eventually removed as well

 

Built myself a custom verto clutch at work that uses two spring plates to increase the clamping pressure, should be much gentler on the thrusts however compared to a grey or double grey plate, considering there should be circa 100ftlbs going through it. [All credit to robert on turbominis]

 

 

Drilled and tapped a FPR so I can use the AN hoses throughout the engine bay:

 

And got a final batch of plating

 

That brings us up to Sep 2014, where I went back to uni and have achieved basically nothing for a year. Summer of 2015 I went back to the company and made some more progress, getting things cleaned, built and painted:

 

 

And with the block sat on it: 
 

Also dry built all the refreshed turbo bits up on the spare engine, everything still fits. 
 

Been ordering lots of bits and pieces for the small fiddly things like AN fittings and hoses for the fuel system, which bar some AN-6 hardline adapters for the MPI tank is complete