SUPER RICH MIXTURE LOW DOWN
Turbo Mini Forums

Hi Forum
I finally have my turbo motor installed in the mini and have taken it to my local rolling road specialist
Balmuir Garage in Gresford owned and run by Pete Morgan a tuner and racer with many years of knowledge in the tuning business
The motor is fully rebuilt to standard spec pistons,rings,crank,head all standard,
Pete has had it on the rolling road and cannot get the mixture to weaken and has told me its running super rich low down but weakens over 4000 rpm and comes back to controllable,he has tried all the tricks in his book but it wont come down to an acceptable level.
He also found that the inlet valve stem oils seal have lifted causing the engine to smoke from tick over
and that they are standard seals not as fitted to the original car
So any ideas or theory's about reducing the mixture and where to get a set of up to spec oil seals would be welcome
cheers
Roy

The valve seals were only different on the turbo engine because the valve stems were a larger diameter. Are you using the sodium fileed valves?

Is it a totally standard Metro turbo installtion?

What needle have you got in?

Is the plenum fitted with the restrictor?

Is the float chanber valve set up correctly?

Is the fuel pressure regulator and fuel return all set up correctly?

Has the guy had experience of setting up turbo engines?

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

Hi Will

to answer your questions as follows

1 yes completely standard with sodium valves fitted and new guides

2 will check with tuner about needle size

3 will check for restrictor

4 will ask him to check the chamber valve

5 new fuel pressure regulator and return to tank set up

6 no experience of the A series set up but says he is now learning!

looking through some posts on the forum I came across the "tee piece trick" and that none turbo inlet
gasket can cause this problem? I have a feeling we used the new gasket out of the new set to bolt the carb/plen on would this give us the same symptoms?
any ideas on new inlet stem oil seals

Ok.

T-piece trick is for when the folat bowl dosen't pressurise and the fuel leans out; or worst still the engine just stopps, won't help you here.

Now you've said the 'expert' has no experience, that's the first thing I'd look at.

There are some good threads on here about how to 'file' a needle, worth a read and a share with the rolling road guy.

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

Here http://www.turbominis.co.uk/forums/index.php?p=vt&tid=159683

Worth a read

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

Thanks for your input I didnt think a standard set up would need so much technical input with the needle
I will pass on your comments.
Any joy on stem oil seals?
cheers
Roy

Exhaust stem seals aren't needed as there isn't vacuum in the exhaust ports, and a little smoke is nothing to worry about yet- the fueling issue is however.

Edited by turbodave16v on 4th Mar, 2017.

Buy a wideband O2 sensor and do 90% of the tuning and 100% of the diagnosing yourself.

Edited by turbodave16v on 4th Mar, 2017.

Hi Dave
I wanted to know about inlet oil seal replacements not the exhaust
Can anyone point me in the right direction to a good tuner who has experience with A series turbo
motors? dont want to spend a fortune teaching my guy how to tune SU carbs
cheers
Roy

Inlet valve seals are exactly the same as all a+ seals, so no idea why this is an issue.
But these are responsible for just a small amount of smoke, nothing else. Id not even worry about them YET...

You clearly have a fueling issue, but I'd start by maybe buying yourself a brand new BDD needle and spring ( I forget the correct colour) for the 1275 turbo - maybe some monkey went in there many years ago and profiled the hell out of it; maybe it was on a very high powered engine that needed a crap ton of fuel.
Try this first; you might be surprised.
I still recommend you buy a wideband O2 sensor however. These really are pin money, but are a life saver to your engine and bank account....

Now don't take this the wrong way but I don't no too much about tuning etc that's why instead of me trying to understand timing etc I take it to my expert guy to sort so I just pick it up ready to drive ! If your expert carnt do that then he isn't much of an expert ! It's worth traveling for the right guy

Oh, and for the one who really knows his A-series turbo stuff:

http://www.wilshers-garage.com/rolling-road

Was the carb fully rebuilt?

The choke seals can and do leak especially if particularly aged ones have been left dry for some time. Might explain the super rich low down and weakens up later on.

Hi Dave
I need different stem oil seals as mine are poping off the guides all 4 have lifted which I believe is not
acceptable , I have seen that Benross has manufactured some
cheers
Roy

Why is every body jumping on my tuner? I did say he did not have a lot of experience with A series
turbo set ups hence why I am asking questions here. If he was not competent he would not be running
a successful rolling road and tuning business with 3 employees and an army of followers.
If things dont get resolved then I will move the car to another tuner who has extensive knowledge
of the turbo set up
cheers
Roy

Hi Sprocket
Thanks for your input I will have Pete check those out on Monday .I will also go through the list that
Will sent me and report back.
cheers
Roy

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

Pete looks after a lot of historic racing cars including a lot of Austin,Triumph,and MG stuff which all run
SU carbs he also has a comprehensive stock of SU spares so he has indeed seen ,handled worked on
a lot of SU carbs
As I said this is the first Metro Turbo motor he has had in the workshop so problems peculiar to this
set up are first time problems for him,I came on this forum looking for constructive opinions on what
maybe causing the problem not to question the credentials of the tuner I use.so can we now bin the tuner credentials questions please?
cheers
Roy

OK,

So if he's familiar with SU carbs and has a "comprehensive stock" of needles and springs, which needles (three letter code) and spring(s) (colour code) has he tried ?

I suspect the problem is probably a lot more fundamental - because of the gaskets, seals, plumbing etc. that others have mentioned - but a list of needles/springs he has tried might help.

Although I use efi I do have a full (original printed, not an internet generated) set of genuine SU/Burlen needle/spring tables so it would be interesting to know which ones he tried.

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

Ok, so if he knows hs SUs there should be no problem. Tuning a turbo SU is no different to any other SU.

Choke seals is a good one though.

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

Rods/Will
Thanks for your replies I am going over to Petes on Monday with all the information I have had from this forum and questions asked by yourselves I am sure armed with this information we will have a positive out come very soon
I will report back as soon as the problem is resolved,if any one would like to add more information
please do
cheers
Roy

If you're replacing the stem seals the ones to use are the brown coloured viton MPI spec items.
They are much better than the cheap ones.

Phil.

WWW.TURBO-MINI.COM

Turbo Phil
Thanks for that information are these available at mini sport ?
cheers
Roy

I'm not sure, I always use Minispares.

Phil.

WWW.TURBO-MINI.COM

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=6298

I'd check the stuff in this link before changing your stem seals, or heading back to your tuner.
That said, I would also install a wideband. I don't know if I mentioned that before?