5sfe crank + 3sge = 5sge?

[NeoNasty]

I presume that due to the difference in head that you cant put a 5sfe crank to make the 3sge engine a larger capacity?

I was lookign at an Mr2 site, and a guy is selling his car and says that he has the 5sfe crank for making his 3sgte into a 5sgte...

Is he dreaming, or is that just the start of what you would need to convert it?

2.2 TVIS 2nd gen 3sge does sound like fun though.

Anyone know anything about it?

[tricky]

5SGTE is also the designation for the old HKS 2.2L stroker kit.

have a squiz in the old forums. There's a fair bit of info on stroker 3sgte's

[Bahnugget]

i was also contemplating/wondering about doing this, however i reckon that the added/reduced stroke whatever will take away part of the rev happiness of the 3SGE, yes? imo thats part of what makes it such a good motor

[matt86sx]

Yeah I'm pretty sure you are right bahnugget - the bore/stroke of the 3SGE/GTE is 86mm x 86mm, ie perfectly square. The increase in capacity with the 5SFE was achieved by lengthening the stroke, meaning that the engine is now 'undersquare' (ie stroke length greater than bore diameter) which does indeed affect an engines ability to rev. I guess the upside would be a slight increase in low-mid range torque though.

Perhaps if you use a 5S crank you could bore the cylinders out a bit to bring it back to square again (or even oversquare, which is even better for revs) and you might just be on to something.......depending on how much material there is available to bore out of the cylinders of course. Someone experienced with building 3S engines should be able to tell you. Since a stroker engine has been done before it doesn't sound as though there are any head clearance issues at TDC due to the longer stroke, although you may not have a non-interference motor any longer should the timing belt fail.

Matt

[oldcorollas]

Since a stroker engine has been done before it doesn't sound as though there are any head clearance issues at TDC due to the longer stroke, although you may not have a non-interference motor any longer should the timing belt fail.

Matt

i would say in both engines, the squish clearnace between piston and head was around 40thou...
if you stroke it, you would need either a shorter piston pin height or shorter rods, or both. if you didn't, then the piston will hit the head by half the increase in stroke... and there is no way there is room to spare to accomodate longer stroke without piston/rod alterations

[Bahnugget]

well when it comes down to it, a 5SFE is just a stroked 3SFE, right? far as i know the engines are very similiar design, so presumably the 5sfe has shorter conrods? would using the crank, and conrods from a 5S solve the whole "piston just ran into my head" problem?

[myne]

3S-GTE
Bore x stroke: 3.39 x 3.39
Compression: 8.8:1

5sfe
Bore x stroke: 3.43 x 3.58
Compression: 9.5:1

[Nim]

You could use the 5S-FE with the 3S-GTE head + manifolds + pistons. However that probably isn't such a good idea. I dunno how strong the 5S-FE conrods would be either... strong enough to rev out nicely with boost?

[RWDboy]

well when it comes down to it, a 5SFE is just a stroked 3SFE, right? far as i know the engines are very similiar design, so presumably the 5sfe has shorter conrods? would using the crank, and conrods from a 5S solve the whole "piston just ran into my head" problem?

Centre-centre height (of the rod) is the same, but the 5S crank has 54mm big end journals (as opposed to the 3S's 50mm big-end journal). So the difference between a 5S piston and a 3S piston is the crown to pin height.

If you want to use 3S-GTE pistons (which you would if turboing) then you'd have to get custom conrods, or if you wanted to use standard conrods, then you'd need custom pistons. The 'under-square'ness isn't as much of an issue for rev-ability as I think the rod/stroke ratio is.

If you use 5S pistons and conrods you may or may not have much success, the compression ratio could be too low (with a 3S-GTE head) or the pistons may have some weakness when running at higher temperatures (remembering that they are cast).

You would definitely want to fit the oil squirters from the 3S-GTE as well.

As far as doing it on a turbo motor - i wouldn't bother. But for an N/A mod i think it's a great idea (which is why i plan trying it with a 2nd gen 3S-GE).

[Nim]

Are the 5S-FE rods going to be light and strong enough to rev out without causing a lot of stress, and ultimately braking in N/A form? Unless you want just a pokey, fairly low revving engine (sub 7500rpm perhaps).

And yes... another 10% displacement is barely worth the messing about on a turbo motor... just up the boost a little.

[Joshstix]

If you want to build a 2.2 3SGE then the best option is to get:
5S crank, flywheel and rear main seal
3S rods, prefferably some eagles
Custom pistons

You will need to get the rod journals on the 5S crank turned down to 3S size. This is both a good and bad thing, the 5S crank is forged like the 3S one but it would still be nice to get it heat treated after machining. This does give an oportunity to machine a much nicer larger fillet into the journal though which should increase the strength over the 3S crank.

I wouldn't run the stock 5S crank and rods as they are too heavy. The Eagle rods are nice and light to improve rev ability.

The 5S flywheel bolt pattern is different to the 3S and the 3S rear main seal will not fit either.

You can also use the 5S block which is stronger than the 3S block. The standard bore is 87mm, all of the cylinders are siamesed, and it has a girdle in the bottom end to hold the balancing shaft which also holds the bottom end together better. On the other hand fitting some of the 3S externals like the oil cooler is going to be a hassle.

As to the suggestion of boring the 3S block out enough to make it a square engine with the 5S crank, I think not. 1mm over bore to get it up to stock 5S bore is pushing things. My 3S cracked with a 0.5mm over bore and only running 10psi boost.

[rolleraction]

5S crank drops straight into 3S block. You 'should' use a later model 5S crank as they have an 8 bolt flywheel that mates perfectly to 3SG f/wheel. The earlier models are 6 bolt and I understand not as strong either. Argo have a pattern for 5S rods as does eagle. (I;ve used both) Custom pistons have to be made. (Arias have a pattern for these (I have used them; as does CP pistons I believe (they advertise them, so...) Have crank balanced and nitrided. 'Revability' is not an issue, but up the oil pressure a bit. Rear seal was never an issue for me, the 3SGE one fitted/worked fine. Very torquey version of a 3S. 8000 rpm no problems all day. I spun big ends at 9000rpm, an oiling issue later rectified by upping preassure.

[Nim]

The 5S-FE conrods are strong enough for 8000rpm? How long have you had the engine running like this?

Wouldn't you want a new flywheel anyway? lightweight... LIGHT WEIGHT!

[suthol]

Use a 5AFE block, 20v head a huge number of trick bits inside and out so it produces a lot of power and revs to the moon.

Call it a Jaeger stroker and charge a very large number of beer tokens for it.

There was a used one for sale on Ozclubbies for around $10K a couple of months ago

[myne]

Except that we're not talking about 4age's