Are my valves too big?
Turbo Mini Forums

Hi,
I'm looking into turbo-ing my 1380. I know I've got to lower my comp ratio, but I was wondering if my head was suitable? It's rammed full of Rim-flow valves. I've only got a size for the exhaust though 31mm. Obviously the inlet is pretty big too! Do I have too much valve and not enough head to prevent cracking?
Cheers,
Gavin.

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I did have 37.5 mm inlets and 31.5 mm ex valves in my 1380 and the head did crack a couple of times, so I don't like to use such big ones in a turbo car.

However, you have it so try it, it's not costing you any thing and you might be ok, just keep your engine temps down to around 85 degrees or less to help it from cracking.

good luck, one thing i had my head welded up VERY WELL a couple of times to, so if it does crack it's not the end of the world.

Edited by Miniwilliams on 25th Nov, 2005.

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

Hi,
Thanks for the reply. I'm going t2, I don't want to drop the compression too much, and use a little boost. What sort of boost could I use at about 9.0:1 ?
Cheers,
Gavin :)

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with intercooler is a must!

and optimax fuel

around 10 to 11 ish psi

Bens right intercooler is a good idea.

You really need a rolling road to set it up you can then up the boost safely when the car is monitored.

Turbo hogster runs a 9.8 C/r on his 1380cc and with an intercooler he runs 10 psi.
BUT THIS IS SET UP SPOT ON.

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

matt, just out of interest, who welded your head up?

I seriously doubt it!

Sadly it was a local firm that now has closed down, it's a real shame as it was top class work. :(

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

-MINI CLUBMAN 1380 TURBO-

I have had 2 heads with 36/31 mm Rimflos. Both had offset exhaust valves and I had no problems with cracking. First head was totally ruined with valve seat erosion, the current head has same problem, however to a lesser extent.

Hi,
Thanks Benross and MiniWilliams, I've got mappable ignition so I reacon I've got a good chance for 9.8, intercooler for sure though.
Thanks Jukka, are you running a T2 yet? Also what fuel/additive are you using, or do you have unleaded seats?
T3Tone, I once had a cracked diesel head repaired. They screw little iron grub screws into the crack to repair it, try your local engine shop they may know someone....
Cheers,
Gavin.

Edited by Bat on 28th Nov, 2005.

VEMs Authorised Installer / Re-seller. K head kits now available!

WB/EGT gauges. Click here for customers write-up

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My Mini build diary

I ran a T3 until autumn 2004 when I tore the car apart for bare metal respray. It has not been painted yet... I sold the T3 and intend to fit a Mitsubishi TF035 which is about the same size as T2. Could be even smaller, maybe between T15 and T2. I have had the new turbo for 4,5 years but the T3 refused to let go so I never bothered to swap it .

As for additive, I have ran generous amounts of Redline (which is supposed to be good stuff acc. to MIRA tests). I used to have 3 angle seats, now they are worn to one wide angle .

I bought a low mileage MPI head from Germany that has inserts. I will so some quick porting and fit 36 / 29 mm Rimflos. I hope it will last longer. Or maybe I´ll just fit the old head and run one summer and see if I find the interest to do some serious porting ( getting older and older fart equals to lazy SOB )

Seems I took some pics of the turbo and the manifold years ago, see http://www.geocities.com/jharkola/1380turbo6.html

looks great Jukka, and what a top manifold you've made.

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

Quality bit of workman ship on that manifold.

-MINI CLUBMAN 1380 TURBO-

It´s not that bad and only cost like 30 quid or so in parts. The 90 degree elbows were standard DIN size but they had to be ordered since it is not that common size in local industry.