8 replies to this topic

[neil_g]

probably really silly questions but im not up on mini engines yet, need to sit down with my newly aquired vizard books when ive shaken this cold..

can someone explain what needs to be done to get to 1380cc? is it just overbored? recommended for road? good performance? any kits available rather than modding existing? additional parts required?

sorry its a bit of a long winded one..

cheers guys

[bluebottle]

the block has to be whats called offset bored to maintain the thickness between 2+3 cylinders, if you dont the head gasket lasts minutes!

there are plenty of kits out there, you pays your money, and takes your choice, but generally you pay for quality, which i think is better in the longrun.

[Bluemini]

It needs boring to 73.5mm if i remember rightly...

Does the crank need stroking too or is that for 1430?

[bluebottle]

just the rebore for 1380, if you stroke it you get the 1430, or if you stroke it the other way, you get a short stroke sreamer!

[Bluemini]

And... according to one of my books, if you do both carefully, you can get it to 1600

[siggy]

Don't think that you need to off set the bores at 1380 only 1399 and above.

I have not heard of anyone having head gasket problems, my own has done 5,000 so far and no problems.

Siggy

[bluebottle]

i have first hand experience of not having a block offset bored, the headgasket lasted a week, and dont know anybody with a 1380 that hasn't had their block off set bored.

i guess you were just lucky.

[TimS]

just gota be carfull really from blowing through the walls of the cylinder, usually cheap kits arnt offset bored as its alot cheaper to just reem straight down!


u can if u get a long trow crank(bit oyut for the relms of being stroked reach nearly 1600cc but then u have to line the cyluinder walls to stop them blowing through usually, must b mad to drive though, i bet someones done it!


back on to the question of relibility and performance, a 1380 will have differnt power increases depending on the state of tune of the engine, e.g. head, cam and so on

reliability wise, in a mild state of tune the 1380s are extreemly good, they give good power with high reliability if built correctly. and i would say go for a deerer offset bore as it will last longer and have better reliability, especially in heated moments.


they are good for the road, over all more power(nto just a top end screemer) unless u start changing crank strokes, than a 1275 and can see 100bhp given the right treatment.

[siggy]

I am not lucky, its a well built engine

Siggy