1380 to 14.. Something
Turbo Mini Forums

Hi guys,

Got to rebuild my 1380 over this winter. Doing the work myself this time to learn more and save some pennies.
Just wondering what bits I would need to stroke it to 14somthing. Don't know if it would be 1430 or 1460??
Is it worth doing?

Cooper s rod, stroker crank, 1430

I beleve

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

plus short pistons.

fook that, stick a turbo on the 1380

Andy has a point!

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

The crank, rods etc are getting rare and will be expensive if you can find some...

Use mg midget conrods

Oh and youll need an a series crank for it as they have ground fillets rather than rolled!
84.3 mm stroke to 1430

Edited by Oli on 29th Oct, 2012.

for the sake of 50cc I would rather stick with the large journal crank 1380, put a bigger cam in it and rev it harder.

Lot of hassle and expense for not a lot of gain really.

Or just turbo it!

On 29th Oct, 2012 apbellamy said:
fook that, stick a turbo on the 1380

I have started posting on Instagram also my name on there is turbomk1golf

Nothing is impossible it just costs more and takes longer.

Unfortunatly i've just spent a small fortune getting my bike carbs setup and running right so i want to stick with NA for this engine. Looking at building a 998 screaming turbo engine as a side line project.
If i wanted to up the revs pasted the 6500rpm limit it goes to know what would you advise? mega light flywheel, SW10 cam? already got centre mainstrap and all that normal stuff

What do you use it for?

with decent pistons, arp rod bolts, balanced crank and light flywheel 7500rpm is fine.

Edit: sw10 is a nice cam. I run a kent 895 which is a good road cam, though still revs to 7.5k easlily enough.

Edited by minimole23 on 29th Oct, 2012.

I don't use it really..... comes out now and again during the summer for a good old fashion good time.
Don't need it to drive to work or do anything "useful" just to put a smile on my face and a scared look on passengers faces

You will have to get the carbs set up again it you stroke the engine and the compression ratio changes???

How good is the head, that will obviously have a bearing on how mad you can go?

but dan has a point, any changes may well throw the fueling out.

true. thinking stroking might not be the way to go. (must go for a brain clean, that just sounds rude)

Long strokes don't like revs, I'd say of it a 296 scatter cam and maybe improve t he head a bit which will about the same cost as stroking it and you'll get more gain

I seriously doubt it!

Right plan is, Stick to 1380cc, head is already large valve something like 37,31 can't remember exactly, swap the cam for a sw10 or sw5. swap flywheel for a preverto ultra light thing with a uprated diapham. replace all the bearings, oil pump etc

What parts will i need to swap to a preverto flywheel?
I know the clutch arm is wrong but can it be converted?

The issue you have is. Anything you do will affect the tuning of those carbs.

Just a heads up.

yep, but now i have the jetkit installed and already having a base setup a little tune up to match the new mods won't be too hard.

SW5 will be too tame so forget that one!

To convert to pre verto you need. Flywheel assembly like this.

http://www.med-engineering.co.uk/catalogue...-light-assembly

Then new long clutch arm, slave cylinder, release bearing, and accompanying arm the release bearing goes on.

I've forgotten how expensive this lightweight flywheel business is, swear mine wasn't that expensive a couple of years ago.