Why can't we turbocharge a 3s-ge?, Compression ratio related Options

[dudeofchaos]

I know that the 3s-ge engine has a higher compression ratio than the 3s-gte (which I guess means that the pistons' head are thiner right?), but what does it change so that we can't (or shall not) turbocharge the 3s-ge?
Is it because it would (I don't know) be too much compressed exhaust gases for the turbo to hold?

BTW: what does the last number in the compression ratio mean? (Like in 10:3:1)

This post has been edited by dudeofchaos: Jun 26, 2011 - 10:51 PM

[3WayStunna]

Found some more info whilst parusing the net. Seems that its true that you can use 3rd-5th gen 3sgte rods and crankshaft with the beams blacktop. But you cannot use the 3rd gen pistons due to a difference in valve reliefs. Actually the valve relifs in the blacktop beams are differnt because of the angle of at which the valves sit.

Beams on the left, 3sgte on the right.
Also you can just look at a diagram of the spacing of the 3sgte and (beams) 3sge and see a noticable differnce in spacing btwn the cams alone.


Also cam across some good info in that the bucket sizes and actual valve size are considerebly larger than on the 3sgte engines. Oil pump is obviously larger due to the increases need for oil in the blacktop engine. Ill list the valve and bucket sizes below.

Buckets/lifters = 31mm (auto)

Buckets/lifters = 33mm (manual)

Intake Valve Diameter: 34.5mm

Exhaust Valve Diameter: 29.5mm

Another interesting thing of note that i hope someone can clarify, is that i hear due to manifold pressure VVTI works up until +0% manifold pressure...In other words, in a turbocharged application, as along as you werent on boost you would be driving around with VVTI engaged up until manifold pressure exceeds +0%

If that is true, then that would be an awesome "stop gap" until you come up on boost, in which case the engine should behave much like any other turbo 3sgte.

So assuming all of this provided is 100% fact, i think its safe to say, there is a very good reason to turbocharge a 3sge........atleast a beams one. Larger oil pump, thicker more improved upon block, VVTI until you come up on positive manifold pressure, larger valves, a better diesigned head (something of note i found whilst searching for info), and the ability to use any other transmission that would normally bolt onto a 3sg block....hmm i see alot of potential there.

Now this leaves me wondering if anyone has ever put one in a 6th gen celica, turbo or not?