7 replies to this topic

[who_loves_the_mini?]

What engine size would you get with a 1293 or 1330 and a 84mm stroked crank?

[miniboo]

not sure but i thought this might help.

http://www.theminifo...?showtopic=8736

but i dont think the sizes you want are on there

[who_loves_the_mini?]

Found the formula and worked 1293 out as 1334762.8301952 so would that be 1334cc?

[pikey7]

1337 & 1375 respectively

[who_loves_the_mini?]

whats the advantages of having a stroked engine? is the increase in torque noticable?

A stroked 1330 has 2 re-bores left which is an advantage but what else?

[minimole]

short stroke engines tend to be able to rev higher (look at bike engines) long stroke engines tend to have more torque

[Guess-Works.com]

A +60 realy only has one bore left, and as per a previous post, it's better to get the +60 offset bored which makes the machining to 73.5mm easier and more reliable. 74mm is a last resort and most A series engine builders will not do it as standard.

As minimole says

Stroking the engine (long stroke) will improve torque, but will adversly affect red line and top end power. Also you may have to consider where the piston ends up, in relation to the block deck. On an 84mm stroke which is 2.72mm longer than std, means the piston crown will end up 1.36mm higher in the bore, which can significantly increase compression ratios, equivalent to removing 5.5cc's from the final compressed chamber volume.

the other issue with stroking is getting hold of the rods ( which is the problem I'm having at the moment ) you need cooper S or Midget rods which have a 1.625" bigend, so you can use it on a std crank which has been stroked, or you'll need a bespoke built billet crank with 1.75" bigends to use std rods...

[The Matt]

....................the other issue with stroking is getting hold of the rods ( which is the problem I'm having at the moment ) you need cooper S or Midget rods............

ooooooooooh, that reminds me GW!