13 replies to this topic

[Sillsy]

Due to a piston ring breaking i have decided to rebuild my Mini turbo's engine. Iam aiming for a safe 120-130bhp at the flywheel and was just woundering what turbo pistons other members of the forum would recommend. I only have a small budget of £300 as iam an apprentice technician and dont have much money. Any advice would be appreciated

[haz]

Due to a piston ring breaking i have decided to rebuild my Mini turbo's engine. Iam aiming for a safe 120-130bhp at the flywheel and was just woundering what turbo pistons other members of the forum would recommend. I only have a small budget of £300 as iam an apprentice technician and dont have much money. Any advice would be appreciated

omega cast see med-engineering on google

they do a flat, 7cc and 11cc dish variants too, so you can drop your CR for the turbo

[haz]

eeps, sorry... not 100% sure they do a 1275 piston... ill go check

[haz]

my bad , they only do the forged piston in +20 and they're £425, mega are your next best bet from minispares or powemax - not sure who stocks em tho

Edited by haz, 05 August 2008 - 06:39 PM.

[Turbo Nick]

get in touch with simon at morspeed, i've been running a set of std AE 21253 pistons he machined out to 11cc for the past 3 years with no problems at all. I think he does them dished up to 13cc for around £180 a set. mines been running 15psi and 160ish bhp and they're still in great nick, going to give them a whirl at 20psi and see how they cope.

[Turbo Nick]

avoid the minispares mega pistons, had loads of failures lately with the ringlands breaking up on them.

[Sillsy]

ok thanks for that i will give morspeed a call. Does anyone know the volume of the piston dish of the standard metro piston?.

[Turbo Nick]

off the top of my head i *think* its 12cc but not 100% sure. If you speak to simon and tell him what spec you've got currently he will be able to advise anyway.

bit tricky getting hold of him on the phone sometimes but i think there's a contact email on his website.

[Turbo Phil]

Standard Metro Turbo piston dish is 12cc.

[minisparesnorth]

avoid the minispares mega pistons, had loads of failures lately with the ringlands breaking up on them.

bud666, please can you clarify actual cases where people have had problems with ringlands breaking in these pistons, there seems to be a bit of a internet forum wispering campaign going on at the moment concerning these, we have only ever had one set returned (see below) and no one who is claiming to have/had problems will contact us about them.

below was posted on the turbo forums, ive cut&pasted it for viewing here.

will anybody who has had problems with the mega 22357-40 pistons please ring Neil Booth on (01423) 881800 and speak to him about it, if he is not in please leave your number and he will get back to you.

also, please send the faulty pistons back to mini spares north (att rich) with a letter explaining the problems and a copy invoice, we can then send them back to ae technical to get them inspected and have a proper technical report done on them.

we have only ever had one set of 22357-40 sent back here with broken ring lands, they where inspected by ae and the report clearly stated that detination was the root cause of the land failiure.

here is a copy of the report we received back from federal mougal concerning the one and only set of 22357-40 megas that have ever been sent back to us

i cannot upload the pictures.


Mini Spares North
Unit 6
2 Freemans Way
Harrogate Business Park
Wetherby Road
Harrogate
HG3 1DH

FTAO Mr. Neil Booth

28th September 2007
Without Prejudice
Dear Sir

YOUR REF
F M CLAIM No: C-334343-GB
PART No: 2 x 22377@ .040
Reference the above-mentioned pistons returned via Mr. David Taylor with a complaint of land breakage after being fitted to a Mini ‘A’ series turbocharged engine.
Visual examination confirms land breakage between the top and second compression rings on both pistons with one piston also sustaining second to third ring land fracture. The piston with the double land fracture has run with a full fracture, evident by the presence of carbon across the fracture faces, suggesting these sections of the lands had totally detached during operation and had been trapped between the pistons rings. The second piston reveals a clean fracture with heavy indentations present on the second to third ring land, possibly suggesting the section of land had been partially fractured and forced out once removed from the engine. This piston also reveals carbon staining at the rear of the ring groove and erosion of the aluminum on the topside of the groove commonly a cause of excess fuel (see photograph).
These observations along with the angle of fracture, as per photograph, are classic examples of land fractures caused by detonation.
Enclosed is our service bulletin SB2105 which shows examples of how fractures occur.
Please find the pistons attached.


Yours Sincerely




Martin Wardle
Technical Services Warranty Engineer

cheers

rich

[Turbo Nick]

only going off what i've read/spoke to people about from TM dude, here's a couple of links i've found from a quick search over there.

http://www.turbomini...p...&tid=235052

http://www.turbomini...p...&tid=175568

http://www.turbomini...p...&tid=235363


P.S. good to see you're on the mend mr guru

[stevenford_uk]

looks to me like the ones on TM are caused by poor setups, have seen failures in mazda mx5's similar to this usually have detonation marks on crowns/edge of crown.
For the money these pistons cost you cannot compare them to the forged omega ones for hardcoreness, however if you are on a budget and want relativly low power they are great. (if set-up right)

[Sammy D]

Another vote for the AE 21253 pistons

Slarks use them in all thier race engines, I was recomended them and I've got a set in my 140hp 1293.

[Surfbluegarage]

Omega casts. "260 for a set from M.E.D. there beautiful!.lol got them in my 1380 supercharged