Nervous as f**k, deja-vu
Turbo Mini Forums

He is very good!I have no doubts in his skills, knowledge and ability before anyone questions it. Im confident all those on her that have met him, or used him for tuning will back me up.
Shane

Best out of three?

Erm, no, this is attept no four!
Shane

Right, engine is out and torn down. firstly I found the crank pully woodruff keyway has woen causing backlash on the woodruff key, possibly causing scatter/ gain in timing.

Crankshaft is ststic.
Secondly, the pistons dont look good, a few cracks in the lands, and damage or errosion to the top edges above the gudgeon pin, have thought about this and think that as mentioned earlier that the piston has got too hot, expanded and fouls the bore, the areas of damage are then obviously at the p[oint in the bore where water does not flow in the jacket. Some of the edges look as if the have got fooking hot, and material has been peeled off on the down stroke.





Bores look worse than they are.
Your thoughts?
Shane

Ah shit! that is a bit of a mess :(

What bolt are you using on the pulley? I had this onece, it opened out the keyway in the crank and the pulley and the key was worn. I was using the Minispares cap head bolt and there was no posative location and slackened off even with medium stregnth loctite. I use high strength loctite now

Please mate, im not trying to be funny, but use some one else to set your engine up. My mapper charges £75/h +VAT, it usualy takes 2 1/2 hours from a good base set up. He listens to the engine using a knock sensor with an amplifier and head phones specific for the job. I would be expecting more than what you got with your ignition map. It seems a little too coincidental that the last two failures of a similar nature happened on the same dyno

Have a look at this http://www.powerpage.dk/tuning_ignition-fi...rtsmap_v106.xls You already know where your peak power and torque will likely be, you just have to estimate the charge temps, and for that I would use this http://www.not2fast.com/turbo/glossary/turbo_calc.shtml

Also have a read of this http://www.autospeed.com/A_109132/cms/article.html

They do resemble what Jackmans pistons did, but not as severe as the first and fouth pics of the pistons.

It'll be right soon enough

has it gone again mate? I just can't believe it. so sorry for you.
I'm wondering if you have an intermitant (spelling) Problem some where, IE the fuel pump slows up of stops making you run lean. It has to be some thing that doesn't show up on the rollers, other wise i just can't see how this had gone and deted like that.

Best 1/4 mile 13.2 seconds @116 mph
First 5 port miniturbo to make over 200 bhp on a carb?
First 5 port miniturbo to make over 200 bhp on Injection?

http://www.mattwoodsphotography.com

The crank pulley being loose might not have helped, but those advance figures are a little high even at 26 degrees.

Det in the higher RPM is not always audiable without the correct listening devices. Det in the higher RPMs is the most damaging and can lead to runaway det which results in total devastation in seconds.

Forced induction engines run in what is called det limitation, where the ignition advance is retarded some what from MBT (MBT is the lowest value of ignition advance that produces maximum power). As det happens before MBT, the maximum power is limited by the onset of det, hence the term det limitation.

NA engines will noramaly run at MBT and any more advance usualy results in loss of power before det occurs. This is the big difference between forced induction and NA ignition characteristices, and why its apparently easy to break the engine in forced induction aplications.

Also remember that airflow across the intercooler and radiator is piss poor on most dynos and as a result engine and charge temps are abnormal, this can also hava a dramatic affect on where det occurs.

You have modified the carb jet holder to remove the temperature compensation?

Edited by Sprocket on 19th Jul, 2009.

well shane that does look a mess, but looking at your map you could do with more advance of boost eg around 32 deg and then tail it of to 26 deg when coming on boost.

how ever sevrel things need doing eg have you calibrated the difference between actual adv and the mega jolt, as mine is about 2 deg out.

also do what i done once fixed and that is run the puter with some one with you whilst driving and read of advance with boost as mine was way out and was getting 32 deg at 10 psi and hence melted my pistons.

but ray does normally run with det cans so cant seem to see what went wrong plus he always uses the the fan.

how ever one realey inportant bit of kit you need and that is a intake temp gauge they are well handy as i always back off when mine gets to 60 deg c also the afr gauge is well handy to, i still think the damge was set before you even got to rays.

always looking for them bigger bunches of bannanas

bloody hell shane ,,thats rotten luck .

those pistons have been experiencing localized air fuel pockets burning between the wall ,and the side of the piston .its been happening for a while ,probably at the top end at avon .

usual suspects ,are ,too low octane ,too high air temp ,too lean ,and too much advance .

to eat away an omega means its pretty chronic ,and the depth and width of the erosion would make me have a good look at piston to bore clearance ,which would let the fuel collect in the side cavity above the ring ,and then light up uncontrollably .

do a timing light check on your high rpm timing with a syringe in the map port on the mjlt ,to simulate boost ,and see if you really have the timing you think you have .

another thing is to check the effectiveness of the ic .on a rr run ,if quick, the ic can act as a heat sink and cool the gases in that way ,but , once the ic is up to temp ,it can stop being very effective ,it may be yuov come off the line with a cool ic ,as it was at the rr ,and settings to suit ,and then ,at the top end ,the ic is up to temp and the inlet temp soar and then all you settings are critically wrong .instant meltdown.
also ,make sure the rr test is done with the bonnet shut at the end ,just to ckeck you dont have some sort of localised hot air going inot the inlet .. i had a car on the rr once ,tuned it from 93 to 128 bhp ,shut the bonnet and it had 98 !

oh and check rad ect for cooling probs .

regards
robert

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

i was going to throw my MJLJ on the turbo but not sure i will now. i have boost and inlet temp correction and never been nice to my car.

Feel for you mate, i know it would put my motivation down but dont let it get to you!

Who did you get the pistons from? maybe negotiate a discount via TM to ease the pain?

Right, alot of comments there to answer so bare with me.
Colin, am using the std bolt to retain the pully, on further inspection today have found the woodruff key is the issue with play in the pully, so hopefully a simple fix.

Matt, yes its gone again, joy. Yes Ive had the same thoughts as you re the fuel pump, stuck a gague on the supply line to the carb and the pressure isnt cosistant, the needle hunts at idle but does stabalise and keep above the pressure applied to the reg. As for volume delviered per minute Ive not checked, but wondered if on long runs (not experienced on the rollers) if the pump was not supplying enough volume of fuel and the floatbowl is drainin causing a lean burn? New pump has been ordered.

Hoggy, yes we calibrated the difference, believe it was two degrees. AFR and ACT gagues are on the shopping list. As for the damage being ther before Rays, I personally doubt, as was running lower boiost and less advance, if you remember a previous post I said it started smoking after we added more boost?

Robert, was shocked to see the pistons that erroded, and did wonder if it was the difference between running short bursts on the rr and the weekend at avon. Also question if bores are perfectly cylinderical? At the risk of sounding dense could you elaborate on this a little more please "do a timing light check on your high rpm timing with a syringe in the map port on the mjlt ,to simulate boost ,and see if you really have the timing you think you have"

Iain, pistons came from MED. Motivation is total rock bottom, not a good thing with the tight deadline to the IMM.
Cheers guys
Shane

Edited by shane on 19th Jul, 2009.

sounding dense could you elaborate on this a little more please "do a timing light check on your high rpm timing with a syringe in the map port on the mjlt ,to simulate boost ,and see if you really have the timing you think you have"

put a digital ,back to zero, strobe on the pulley to watch the timing ,then put your syringe on the map pipe ,then rev to say 5k rpm ,and watch the timing ,and see if it matches your setting ,then push in the syringe and watch the boost level rise on the screen and then see if the timing changes to where you want it and more to the point ,to where its programmed .
on a digital timing light you may well get a double reading ,so if the readings seem v high ,then half them .

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

Ah I get it, thanks Robert, but im a long way off that at the minute.
Shane

Just an idea...but would an extended float spacer help if fuel pressure isn't consistant? Might counter any pump fluctuations. Really don't know if it would work....maybe talking out my arse.

As said before, take it strait to the rollers after build. Perhaps even different pump & ignition.

Edited by Jason G on 20th Jul, 2009.

how are your fuel pick up and return mounted? could be a fuel starvation issue under acceleration, which would abviously not show itself on the rollers :)

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

Im using the mpi tank so the supply and return is as the tank is std.
Did wonder about the float bowl spacer, but there higher output cars on here that dont use them?
Cheers
Shane

Daft as it sounds..breather on tank? Trying to think of simple things that don't involve cash or time. 9 times out of 10 its something silly.

You thinking blocked so not allowing fuel to be picked up by pump easily? A mate has an MPI cooper, gonna beg him to borrow a pump to prove a point, before going wading in to replacing it with a subframe mounted one.
Shane

Partially blocked etc...anything thats maybe inconsistantly causing probs that are not showing up on RR

obviusly checjk the filter on the pick up pipe too (if its there).

any thoughts on adding piston jets while its apart?

I have an LC1 wideband you can borrow, i think i have a crappy gauge you could connect it too as well, failing that you should be able to rig it up to the megajolt and log it.

No joe, Not thought about oil jets, time restraints and more so cash issues wont allow. Cheers for the offer.
Shane

Joe normally does it more for pleasure than cash Shane!

pffft!!

I have 2 sets of bimmer jets somwhere, i'll lend you a set long term if you like, being as I plagued you with bad luck at rays.

also give me a shove to look over your map before you start the lump up again, i'll give you a copy of the one i'm running, i think mines 22-24 deg at one bar, but it has a lot more advance in at part throttle, about 35 deg at cruise.

also, its probably worth spending 10 mins to knocj=k up a set of det cans from some tube and some ear defenders, feed them through a gromet and bolt to a head stud....

Looking at your second map you have posted the one where it goes to 26 degrees, IMO it should be safe, yes it's basic , but i can't see how this would have been a problem, after knowing what i run. If Ray wasn't any good, i and a few others on here wouldn't have been going to him for years, after all i was with his tuning the first person to possible prove 200 + bhp in a road going mini turbo.

Best 1/4 mile 13.2 seconds @116 mph
First 5 port miniturbo to make over 200 bhp on a carb?
First 5 port miniturbo to make over 200 bhp on Injection?

http://www.mattwoodsphotography.com

Run in the motor on the rollers. Alot can happen doing 500 miles prior to RR.