Long rod v Stroker kit

pablo · Post by **pablo** » Mon Dec 17, 2012 7:28 pm

You hear a lot about evo's with either a 2.0 long rod engine or a 2.2 / 2.3 stroker kit. So what is in either conversion, i'm just a nosey b*****d, sorry.

Post by **Stuart** » Mon Dec 17, 2012 8:33 pm

Long rod allows lots of revs
Stroked increases capacity through increased piston travel

That's about as far as my knowledge runs

Danny@APT · Post by **Danny@APT** » Mon Dec 17, 2012 9:04 pm

Trust you to pick the precise moment when both Gary and Ross are most likely to be rat-arsed!

The basics, as Stu has said, is that the Stroker (longer stroke crank- 100mm opposed to the stock 88mm) increases the capacity, usually to 2.3l, which drives more gasses through the turbo at a lower rpm, thus aiding spool and bottom-end torque over a 2.0, at the expense of topping out at 7-7.5k rpm for power.

The Long Rod set-up is based around the principle of the ideal rod-ratio (google is your friend!). The stock Evo 4G63 rod/stroke ratio is 1.70, but by increasing the rod length by 6mm (and correspondingly moving the gudgeon pin higher in the piston), you can improve the ratio nearer to the considered ideal of 1.75. The benefits are less side loading into the cylinder wall due to the improved rod angle, and a smoother transition as the piston reaches TDC and begins to accelerate back down again- giving a longer 'dwell' time at TDC, improving efficiency and allowing a higher rpm limit (Logan's revs to 8.5k I believe).

Then you get into the Super Long Rod, using the 2.4 4G64 engine combined with a long rod set-up, giving large capacity and the ability to rev it, although a suitable headgasket can be hard to get hold of.

In the Ford world, Martin Hadland (Reyland) utilised a long rod set-up in his Escort Cosworth, although he had a spacer plate made between the head and block to allow for the increase in rod length.

Post by **Stuart** » Mon Dec 17, 2012 9:10 pm

Check you out Dan

Bloody awesome answer that..........one Ford owner to another

Danny@APT · Post by **Danny@APT** » Mon Dec 17, 2012 9:22 pm

I'll admit I had to do some 'research' for the exact reasons and numbers!

Bart · Post by **Bart** » Mon Dec 17, 2012 9:34 pm

Danny@APT wrote:
In the Ford world, Martin Hadland (Reyland) utilised a long rod set-up in his Escort Cosworth, although he had a spacer plate made between the head and block to allow for the increase in rod length.

i thought it was his RS500 that he did the stroker kit on?
the RS500 is running 500bhp and 500lb ft torque on low boost.

Post by **Stuart** » Mon Dec 17, 2012 9:36 pm

Bart wrote: the RS500 is running 500bhp and 500lb ft torque on low boost.

That'll do it

A few quid in that build though I reckon.

Danny@APT · Post by **Danny@APT** » Mon Dec 17, 2012 9:41 pm

He pioneered it in the Escort first- (pic taken from their site, you may need to zoom in to read the mag article)

I'll try to find the build thread.

Danny@APT · Post by **Danny@APT** » Mon Dec 17, 2012 10:34 pm

Arse, most of the build pics are long gone... just some threads with engine specs left- http://passionford.com/forum/general-ca ... 6-7-a.html

And one with some block pics- http://passionford.com/forum/general-ca ... -bits.html

Bart · Post by **Bart** » Mon Dec 17, 2012 10:39 pm

cheers dan

i carnt get onto passionford anymore think it has something to do with my laptop, just wont load up.

last year he ran his engine in driving to south of france and back,
one way to do it i suppose

is that the escort cossie he rolled in america on the cannonball?