Did I blow my motor?

[fivebob]

Anyone know if the 3SGTE pistons are forged from factory?

LOL, this should be good for a few arguments
http://forums.toyspeed.org.nz/viewtopic.php?t=25880

[fivebob]

I've just done some more checking and I can confirm that the 3S-GTE cylinder head combustion chamber from a ST215 is the same as a Gen III head not a BEAMS head.

So, if you bought ST215 pistons, then I fear you have wasted your money as they are not suitable for machining to increase the piston dish. They are fragile in stock form and removing the required metal to reduce the CR to an acceptable level, or to accomodate the BEAMS valve angle, will likely result in catastrophic piston failure. Running them at a CR above 9:1 is also likely to result in the same sort of failure.

[Leiden]

The rod was bent because the guy hydro locked the engine, his Mechanic said the pistons and 3x other rods are ok, but yes, I've heard that the rods are weaker than previous generations,

Shame about the Pistons though, just went a bought them

All I can do now is hope and pray my stock pistons are OK and the engine just needs some new con rod bearings...

Sweet 9.0:1 with the 3SGTE ST215 pistons in the Beams Block, sounds like a perfect little set-up really!

It would be sweet if it were true, unfortunately for you it is not

3S-GTE cylinder head has approx 47cc combustion chamber and 11cc piston dish (these figures aren't as accurate as they could be because I don't have the right tools at hand to measure them properly)

I believe the BEAMS cylinder head has a 33cc combustion chamber. So ST215 pistons in a BEAMS engine, assuming the same piston to deck clearance and head gasket thickness, would give a CR of approx 11.25:1

Also I don't think the valve angles are the same as a BEAMS head, as the ST215 engine uses the same basic head as the GenIII SW20/ST205, not the BEAMS head as Celica RA45 has stated (maybe he's confused it with the 3S-GE ST215 which is a BEAMS engine.)

As to the conrods, the ST215 rods are lighter (and weaker) than the SW20/ST205 rods, that's probably why the one on tardme is bent Sadly that's a common fault in Caldina engines that have had the boost raised, and I certainly wouldn't recommend using a set of pistons from a motor that has had a bent rod

Why don't you do things properly and buy a set of Toda pistons which are made for your engine and will give you the correct compression ratio?

[Leiden]

Isn't the valve angle for all 3S-G engines 44.5 degrees?

[Leiden]

Found out the pistons I bought are ST246 Caldina pistons... Does the ST246 use a different revision engine than the ST215?

Isn't the Caldina GTT engine a Yamaha Beams engine?

Celica_RA45, can you confirm the compression ratio and valve angles?

[RomanV]

I've got some 11:1 beams pistons here if you want to compare.

[Celica RA45]

the heads on the beams motors have the valves standing up to get more cam lift as five bob said maybe i was wrong but if you ask him how far away are the cam pulleys from each other ,if he says 25mm.then gen 3 motor .if he says 5mm then they are the same as a beams head in valve angle

[fivebob]

Found out the pistons I bought are ST246 Caldina pistons... Does the ST246 use a different revision engine than the ST215?

Apart from the intake manifold it's the same basic engine as the ST215. Although the pistons are a different part #, the cylinder head sub assy, crankshaft, and conrod are exactly the same part # as the ST215 so any difference in pistons would probably be minor.

Isn't the Caldina GTT engine a Yamaha Beams engine?

Nope it's a modified Gen III 3S-GTE without a variable valve in sight

the heads on the beams motors have the valves standing up to get more cam lift as five bob said maybe i was wrong but if you ask him how far away are the cam pulleys from each other ,if he says 25mm.then gen 3 motor .if he says 5mm then they are the same as a beams head in valve angle

The cam pulleys are 25mm apart. Also the exhaust and intake gaskets are the same part # as a Gen III, not a BEAMS engine, so that pretty much confirms it as a Gen III.5

[Leiden]

Noooo! Aw crap

Shame about that, went and bought some ST246 3SGTE pistons thinking they would fit...ah well,

Theres no point getting them machined is there? Is there any improvement in design with the ST246 pistons? Dont want to machine them if they just end up weaker than BEAMS pistons,

I found out why it died, 18psi overboost, air restrictor blocked up so it wasn't opening the wastegate at all

Probably a ringland or something, they're usually the first to go on boosted 3S motors arent they?

I think that the small amount of metal in the sump might have been from when the motor was rebuilt, well at least I think it was, looked like aftermarket sealant on the sump pan and sump assy...but ultimately will find out when I pull the sump assy wednesday.

Might just throw in another factory BEAMS piston, use the ST185 rods, and stack 2x metal gaskets, then get rid of that stupid restrictor in the wastegate line...been told I can run 10-12psi safely at 10.5:1 compression.

[Celica RA45]

have you thought about 2jze turbo pistons they use 22mm pin and are 86mm as well you will just have to see how much less negative dome there is

[Leiden]

I would but to use 2JZ pistons you have to shave the pin end width, machine the piston skirt, and then shave the crank counterbalance weights because they interfere with the piston, then you have to get the whole lot balanced, so it adds up pretty fast