Close up of the inlet ports, 3S-GE first. You can see this is a fairly uniform size right the way down:

And the 3S-GTE one, this tapers quite severely from the large size required by the T-VIS system, down to roughly the same size as the GE head:

And finally, here's a shot of the combustion chambers. The valves appear to be the same size, but I'll measure them later. 3S-GE first:

and 3S-GTE:

Notice how the 3S-GTE is much whiter on the exhaust valves? I'm guessing this is due to the extra heat created by the turbo engine.


Anyway, the question now is, do you think the 3S-GE head is worth a try?

 

After seeing this, I'm guess that a 3SGE TVIS will not work on a 3SGTE?

sent you a PM as well

 

the gen 2 3S-GE doesn't have T-VIS, only gen 1 3S-GE and gen 1 and 2 3S-GTE had it

 

My rev 1 j-spec engine did not have tvis, it had a thing called acis, did the udsm have tvis like the gte engines?

Graeme

 

ah here's where the naming gets tricky.
Your 'rev 1' sw20 has a gen 2 3sge in it (gen 1's were in st162 celicas, carinas, coronas etc)

It's worth noting that all the heads pictured are JDM, and AFAIK the USDM didn't get the gen 2 3sge.

 

The only thing I think might loose perfomance is the 3SGE ports may not cope with the additional air from the turbo.But I have heard there are advantages with the 3SGE head over the 3SGTE.If you re-shaped the inlet ports like A Gen 3 you would definately have improved flow over a Gen 1 3SGTE.But not sure whether the cams are compatible.The turbo cam may have a different lift with there being a lower compression.

 

Holy crap, is it my imagination, or is the port floor about a half inch higher on the 3S-GE then on the Gen III 3S-GTE?

For an all out head, honestly the 3S-GE in the picture looks like a much better head.

Is the deck thickness on the N/T head as thick as the turbo head though?

Also, from what I have gathered, there are two different valve spring bucket diameters, correct? Does the 3S-GE head feature the larger or the smaller version?

 

I'm not sure what you mean by the deck thickness, are you talking about combustion chamber size? I could probably measure them with some water later on.

I didn't measure, but the 3S-GE seems to have the same larger buckets as the gen 2 3S-GTE.

 

i think the 3S-GE head flows better

the intake port size may be smaller but the valve size openings are the same...so the bigger intake ports of the GTE are lost.

smaller ports don't always mean less flow, smaller ports have the tendancy to flow the gas FASTER if same pressure is added, resulting in better and faster filling of cilinders and better mixture with fule, therefore more power.

give it a try and get in dyno'd

and euhm, leave intake ports alone, DON't port and polish intake side of the head!!

 

why wouldn't you want to P&P the intake side?

 

I'm no expert, but the 3S-GE head looks like it could benefit from some mild work from a good head porter. It wouldn't flow the 310 CFM on a flow bench like some people are getting with the Gen II 3S-GTE head, but I bet it makes as much/more power. You don't need a port to flow 300+ CFM on a 2.0L to make some serious power anyway. If the port floor is higher on the 3S-GE head, then I would say it is a better head to start with.

As far as the deck thickness, I mean how thick is the material around the combustion chamber. If it's thinner, you could get some deck flex and have issues with blowing head gaskets.

Port and polish is misleading, you don't want to polish an intake port or the combustion chamber. Polishing an exhaust port isn't a bad thing, but it won't make any more power or keep carbon from building up.

 

In order for the flow to be smooth the inlet manifold would have to be exactly the same diameter and shape as the inlet side of the head.Could a 3SGE manifold be used on a turbo motor.

 

the 3S-GE intake manifold is quite different, it uses a interesting system called ACIS (acoustically controlled intake system) which has an extra plenum that opens at higher revs to allow different acoustic (helmholtz?) tuning to suit the higher rev range. I think this system wouldn't suit turbo application as the denser, compressed air from the turbo would have different resonances (or something). I'll get some pics of the system anyway, but the plan was to make a custom plenum to go onto the 3S-GE intake manifold runners.

Back to the P&P thing, surely smoother port walls will reduce the size of the boundary layer forming in the ports, which should equate to better overall flow? Anyway I'm no expert, which is why I'm posting here instead of just going ahead and doing it.

 

The rougher port will make a more turbulent boundary layer, like you are suggesting. This will help to keep fuel from sticking to the port walls and dropping out of suspension.

Air pressure (by it's self) will not change the velocity of the waves. The part about the denser air from boost changing the resonance tuning is not correct. The increase in air temperature from turbocharging could definitely change things a bit though.

 

the ge head would be a good choice bar two things.
1. the missing stud is there for strength and works well holding up a constantly moving turbo and manifold. not having it is a big downside as far as im concerned.
2. im assuming the gte head has better cylinder head coolant passages? based on the plug under the stud. can anyone confirm this?
other then that i bet its cheaper and easier to get a hold of.

 

from what I can tell, the coolant passages look very similar, but the GTE one might have extra cooling around the exhaust ports. I'm not going to be slicing the head apart to find out, however.

The lesser number of manifold studs is a bit of a worry for me too, but with a good turbo support, and one on the downpipe, it might not be so bad. People have turbo'ed 3S-GEs using stock 3SGTE parts and I haven't heard any complaints about manifolds warping/leaking or studs pulling out of the head, so it might not be so bad. Higher grade studs might help also

 

why wouldn't you want to P&P the intake side?

smaller ports with same pressure added (turbo pressure) will cause in faster flow of air/fuel so increasing filling speed of the cilinders.

ported is needed to match the GTE head with the GE manifold BUT:

dont get it to big, have you noticed the port size of the GTE and GE are the same width where the valve openings are? this has a reason....to create more speed.

a very common used tuning principle on engines (especially bike engines like yamahas etc) is DECREaSING port width of the HEAD increasing flow speed, giving better mixture of fuel and air resulting in MORE power. on a regular yamaha engine of about 170hp decreasing port size (with epoxy) generally results in +-15hp MORE power.

now applied to our engines:
if you are using the GTE head with GE intake plenum, its best to port the plenum a little to match the size of the bigger ports of the GTE but its not neccesary, because it goes from smal to big...now if you use a GE head with GTE plenum its the other way round, bigger intake plenum ports and smaller head ports, this is good for flow and speed increase but air will slam to the sides, so porting it a little to make it a little lineair doesn't harm. however don't port to deep! you'll want it to be steady flowing (same port width) BEFORE the mix enters combustion chamber

about polishing INTAKE ports -> DON'T ! if you polish intake, the fuel will stick to the walls and drip/slide down against the walls because the air can't pickup the fuel, this is why you need edges and ridges, to create turbulence, this way fuel will stick to the edges so air can pickup fuel particles much easyer, resulting in a better mixture, more power.

on exhaust side you'll want to polish. exhaust gasses need to leave combustion chambers as fast as possible, therefore removing edges and polishing makes it much easyer for the engine to push gasses out, less stress is again a little more power.

Now think of these 2 different ports, ruff intake and polished exhaust:
because the engine doest require much power to releave gasses, it's also able to fill cilinders faster on intake side (you always have to remember that a cilinder moving upwards (pushing gasses out) equals a cilinder moving down (pulling fresh air in)), resulting more flow, better mixture and POWER

now another option is putting a GE head AND GE plenum on a GTE block.
this will increase performance up to about 300hp, above that the GE head flows out of capabilities, from there you really need the bigger ports of the GTE, the GE head was designed to be good to around 300hp, and this brings us to the point where the GE engines was designed for, indeed GT300 and formula 3 racing. limited to 300hp.

our 3S-GE engines are based on a RACE engine (all know the 503E right?), i have to say the 3S-GE and 503E are not the same engine, but the 3S is bases on it.

....

RESUME:
polish:
intake - NO
exhaust - YES

port:
intake - allowed, not much
exhaust - allowed

 

If you polish the exhaust, the carbon will still just build up on it an make it's own turbulent layer.

If you really want to see a smooth surface on the exhaust port, have at it. But after a few cruises down the freeway, it will have a carbon layer built up and that polish won't do anything.

 

if i'm not mistaken if you get a newer 3S-GE head like the one in the beams red top motor the cams are much more aggressive. i think its like 246 duration vs. the 3S-GTE's 236 duration.

 

my 'old' 1990 3S-GE has also 244? of duration