1380 turbo - New engine build
Turbo Mini Forums

I got my turbo mini on the road earlier this summer. The current engine is a budget one, built on a non turbo metro bottom end. It goes well but im in need of some more power. A large oil leak that has come from a damaged gearbox casing has meant that I am going to get a move on putting my new engine together.

I have started my new engine build this evening. I stripped a genuine turbo unit that had a melted piston that I picked up quite a few years ago for a good price with a lot of turbo spares

This is what I found – the edge of the piston was slightly melted looking down the bore, didn’t think the damage would be that much!









The block itself looks to be a low mileage unit, still in original paint etc. the cam and followers were also almost unmarked. Though im not sure what the previous owners oil pressure would have been like – the big end bearings have worn right through the bearing face!







Luckily it has a hardened turbo crank fitted – the crank journals are unmarked, will have to measure up properly to see if it needs a regrind but I think probably not. This one has certainly lived up to the turbo crank reputation!

As it stands at the moment, the block is stripped. I am not able to work on the engine until next weekend, though I hope to get the machined faces cleaned, as well as the rest of the engine, before I send the block for machining work.

Edited by welshdan on 5th Oct, 2012.

Someone got greedy with boost me thinks.

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

www.twin-turbo.co.uk

That beats Sprocket's piston damage.

Wat psi wad it running when that happened?

13.95 1/4 mile on a 2.95 fd. Carnt be that hard to beat!

Wow! still think there should be a section for dead pistons on here! hint hint..

Yes i thought it quite spectacular! The guy i bought it off was running a standard metro turbo engine, with a dump valve a bleed valve. As said i think he must have just opened out the bleed valve and overboosted. Im not sure what psi this happened at...

WTF! the worst case I have ever seen, WOW!

incorrect fueling, timing. More advance than voyeger star treck warp engine, compression ratio too high........ and Wayyyyyyy too much Boost,

holly shit thats fecked that mate , looking at the crank shells i doubt if the crank wont need a regrind fingers crossed

give em hell

Crank looks good, not a mark, as said i will need to measure it up properly.

So i cant re-use this piston then? Think of the weight saving, lol

lol yeh just weld the piston up and stuff it back in pmsl

give em hell

so i sent to block to be machined to 73.5 mm bore so that i can fit my 18cc forged accralites. i have had a call to say that on boring the second cylinder the block is porous. so i am in two minds as to what to do here. i may get it sleeved to 1275 and build it up as a standard engine and sell it on/keep it as a spare. another option would be to have it sleeved to 1275, have it machined to 1293 and fit some of these pistons

http://www.minispeed.co.uk/content/forged-...er-applications

with a deck height of around zero and my head cc at 25cc, it would give a compression ratio of around 8.1:1, which is what i was aiming for on the 1380. has anyone tried these pistons?

the other option would be to strip another 1275 that i have and have it machined to take the 1380 accralites. i will have to get some quotes for the cost and take things from there. a bit disapointing really!

on the plus side the crank has no wear or marks to any of the journals.

Edited by welshdan on 22nd Oct, 2012.

Just get another block, cheaper then buying new pistons.

You must be seriously unlucky there as you never really hear about problems boring to 73.5mm.

yes this is my thought. i have a few engines there so i will strip one down at the weekend. i have priced up the cost of building up a fast road 1293 bottom end and selling it on, but its really not worth it. i might get the turbo block sleeved and keep it as a spare, i then have the option of using re-ringed metro turbo pistons or some 1293 ones after further machining work in the future.