Turboed Altezza 3SGE w/ 5S Crank - Has anyone in here done it?

[c-red]

Howdy All,
I've found all the threads relating to this, and there is plenty of theory on it, but as far as I can find in here - no-one has actually done it.
I can appreciate the rod/bore ratio isn't ideal but I would dearly love to know how one actually goes.
Many Thanks In Advance,
Jeff

[OnAll-FOUR]

People have done 3sgte and 5s I believe not sure if starting from 3sge complicates it or not.

Roundy on thins forum is doing one of these at the moment http://www.roadandtrack.net.au/ has some stuff on their website about possible combinations.

[Roundy]

You are thinking about the rod stroke ratio i believe.

Hardest thing you may find going with a 3S-GE will be finding suitable pistons with a suitable pin-height and compression ratio.

This isn't an issue with a 3S-GTE as there are off the shelf pistons available for 'stroker' engines using a 3S block and even the 5S block with 3S head.

What exactly do you want from it?

[c-red]

Roundy,
About 300rwkw with supporting turbo and ancillaries. I'd also like to turn it to 8500rpm. I've read the most excellent conversion guide on Road and Track's website but I am beginning to think that some 9:1 forgies and decent rods is going to be a better option for me.
How far along are you with yours?
Jeff

[Roundy]

It is at the machinist as we speak, however my 5S crank was cracked

8500rpm is a LOT on a 5S crank, that pushes the piston speed beyond the 5000fpm mark that is generally regarded as the upper limit of reliable piston speeds.

Any particular reason you want 8500rpm? Probably don't need that many revs to make 300rwkw, But i suppose that would give you the broader power band with the turbo that will be required for 300rwkw.

[jonathan yee]

sounds similar to my build tho i'm sticking with the 3s block. from my reasearch you'll need forged rods to relivee some of the stress placed on the crank. i had varing advice some saying the 3s/5s crank's are fine to be revved hard provided they're apprpriatly machined and stengthened.

other say they will crack if constantly revved above 7500rpm.

i'm guessing you already have the 3s block and that's why you want to machine the crank to fit yes? it may be worth while instead to pick up a complete 5s block(they're cheap anyway) as they have stronger walls and arent prone to cracking between bores 2/3 that way you'll also get the full 2.2 displacemant.

you can get pauter rods spec made to suit the 5s crank(well they can make the rods anyway you want actually)

i think puater sell of the shelf rods to suit the 5s crank block combo and CP make the pistons.

i looked at it but as i'm only chasing 300rwkw and a garret GT3076 and a wide power band i dindt think it was worth the hassle to try and get the extra displacemant as the turbo wont be unbearably laggy or anything.

BTW is this THE C-RED in welshpool? for some reason i'm surprised to see you asking questions, norm people go to you for advise.

best place for loacl WA advise on the 3s/5s motors would be to go see tristan at WTFauto in kelmscott.

[c-red]

Roundy - I've done my time with SR20s and found the limited rev ceiling to be a hinderance for what I like to do in a car with 300rwkw. The thought of having a 8500rpm rev limit and 300rwkw gives me a bit of a James May feeling in the nether regions. I'm in 2 minds as to what to do. I'd like the extra capacity in the IS, but its not that straightfoward.
Jonathon - Yes I'm Jeff Ash from C-Red. I ask questions because the Toymods guys are very switched on and I personally have had no experience with the late 3S motors. I would have run the 5S crank in the 3SGE block, machined down the bearing caps rather than touch the crank. The 5S rods are available forged in an Eagle type arrangement and CP make the pistons.
Tristan at WTF was my first port of call as I know he's already done it in an MR2.
Jeff

[Radar]

Why not just get some custom pistons made?
It's about $300 more expensive but you'll be able to push the gudgeon pin (difference between 5S and 3S crank) into the oil control ring.
Problem solvered you'll be able to run the 5S crank with the new eagle rods..
I Could be wrong, but this is the way I'd go if I was putting in a larger crank.

[Billzilla]

If you're going to want to use a 5S crank then use the 5S block as well as they have a larger bore. You're going to need to get custom pistons made anyway so why not? It'll give you a bit more capacity as well. I certainly wouldn't be revving as high as 8500rpm though, more like 7500rpm maximum due to excessively high piston speed and I'm guessing the 5S crank isn't as strong as the better 3S ones.

[Roundy]

No need for custom pistons.

CP and Wiseco do off the shelf pistons with the pin-height already the required 3mm higher, they also do the pistons for a 5S block as well i believe.

My setup is going to be:

Gen 2 3S-GTE Block
CP 86.5mm pistons, supposed 9:1 compression ratio
3S Eagle Rods
5S Crank with the big ends turned down 3mm for the 3S rods

This will give me a capacity of 2.134L i believe it is. Seems a lot of effort to go to for such a small gain, but then the cost actually isn't much higher.

The 5S crank is reportedly very strong, at least according to all the guys in the US and they rev them to 9k for who knows what reason...

One mini-issue with the 5S block is i believe you need a rather late model one to line up with all the water passaged etc in the 3S head. But i have to say i haven't done a lot of research into the 5S route.

The flywheels can be an issue, the 5S crank has a 1mm larger PCD on the bolts, some flywheels have 'slotted' holes that will work with the 3S or 5S crank.

The rear main seal will need to be a 5S item, not the 3S item

Also you need to make sure you get the 8 flywheel bolt 5S crank, not the 6 bolt one. (So i have recently found out)

[jonathan yee]

pretty sure fidanza make a flywheel to suit the 5s crank pcd and mate up with 3sgte clutches.

tristan revved his 5s bottom end gen3 3s topend to 9000rpm.

it'd be good if someone with unlimited funds could to comparison builds, like build a 5sgte and a 3sgte to the exact same specs and see what diff the extra 200cc (or less )makes.

i personally have deciced against the eagle rods for my app as i dont think they're suited to high rpm, they have smaller rods bolts for starters. they'd prosibly be fine but i've decided on puater even tho they're twice the price of eagles just for peace of mind.

[senn]

they are worth the cost if it saves you lunching an engine.

[Thino]

might be worth having a chat with these boys in the states as they build 2.2 stroker shortblocks for the mr2's. they might have some more info or be able to point you in it's direction

http://www.atsracing.net/

[Radar]

Have you thought about going the 3S crank with longer connecting rods (3mm) with the off the shelf pistons with the pin height 3mm higher...
You'll raise the rod/stroke , lower the piston speed, reduce the cylinder wall loading, and get a tighter piston to bore clearance...
Then you'll get your 8500 even 9000 using the correct cam...
Torque can be made in other ways other than crank throw, so why not opt for more RPM and just UP the boost to make up for the smaller crank throw.

[big_zop]

Just wondering if this document would be of any use?

http://www.roadandtrack.net.au/image...5SG_engine.pdf