Offset crankshaft grinding

[CHB]

jonathan, you pretty much can reads my mind now haha...

[CHB]

actually i need a torquey motor at low revs... it'll runs low boost with a .63 T3/T4 combo... still try to work out the parts needed though...

[trdee]

i personally wouldnt do it as then you'd have to use shorter rods and the rod/stroke ratio will be getting worse....funny i'm trying to find out if i can destroke the 3s.........

ye i think it's called a 4A

they did actually destroke a 3S in america, it was an SW20 turbo used for small capacity land speed records by some university over there if i remember right.

[Hiro]

ye i think it's called a 4A

they did actually destroke a 3S in america, it was an SW20 turbo used for small capacity land speed records by some university over there if i remember right.

They swapped in a 20V and destroked that......and turbo'd it.

[jonathan yee]

yeh read that article, mad....

was only looking to de-stroke something minimal as using the 5s block i've got a 87.5 bore and 2070cc with standard 3s stroke, so if i could de-stroke it a little to get better rpm reliability etc and retain 1998cc then i'd be on a winner.....

[CHB]

if you destroke the 5S crank (91mm - 4mm = 87mm), it will become 87mm stroke and you are a winner mate!!

[jonathan yee]

if you destroke the 5S crank (91mm - 4mm = 87mm), it will become 87mm stroke and you are a winner mate!!

except that the standard 3s stroke is 86mm....hah, so i'd be a loser.

[TH Performance]

I have 2.3L that I did exatly what you describe here.

I have 7500 RPM limit, 640HP at the crank, and the difference between old 2.0 and new 2.3L is 70Nm in the midrange. The car runs great, so strong low down that this is unbelivable for Celica.

This engine made 30 000km without any problems, and believe me, I drive it hard.

If you want to make a revable destroke, you need 5sfe block, 3sgte rods and crank, and 88mm pistons. You will gain in RPM (easy 9300) and it will be 2.1L engine.

95mm is great and you don't have any worries at all.

My crank is made at Castillo's crank in California, heat treated and ION nitrided. No problems whatsoever.

[Sam_Q]

hold on how could you have a reduced stroke with a 3S crank and end up with a bigger displacement?

[jonathan yee]

hold on how could you have a reduced stroke with a 3S crank and end up with a bigger displacement?

well it'd be standard 3s stroke not really destroked but the 5s bore is bigger than the 3s and with a 0.5mm overbore you'd end up with 2070cc not quite 2.1

[TH Performance]

yep u r right, bu still it is more closer to 2.1 than 1998

check that I wrote 88mm pistons, which are 1mm overbore from 87mm

[Sam_Q]

oh you mean a revable S engine that has a short stroke, not a crank that has been destroked, is that what you mean?

so you had a crank offset ground off the 5s crank with custom rods to get 2.3L

[TH Performance]

sam

I have 5s crank offest grinded to 48mm 3s rods. ANd 88mm pistons, which gives me 2311cc.

For destroke version, just use 3s crank, rods and custom 88mm pistons. You will gain shorter stroke (86mm) and bigger bore (88mm) which will give you oversquare engine ggod for higher revs.

[jonathan yee]

i wans't aware you could get 1mm OS pistons for the 5s CP only list .05 but i'm sure there a other options.

personally i'd avoid over boring, altho the 5s has stronger bores (hence why i'm using one for my build) it already has significantly bigger bores and i wouldn't want to make the walls any thinner otherwise i'd be going backwards.

[jonathan yee]

sam

I have 5s crank offest grinded to 48mm 3s rods. ANd 88mm pistons, which gives me 2311cc.

For destroke version, just use 3s crank, rods and custom 88mm pistons. You will gain shorter stroke (86mm) and bigger bore (88mm) which will give you oversquare engine ggod for higher revs.

stock 3s rods? or shortened? what stroke do you have now?