3S-GE/GTE mix and match?

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shinny
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3S-GE/GTE mix and match?

Post by shinny » 05/03/18 11:27

I was thinking last night... with 3s-ge engines not worth that much, could I use any parts from the engine coming out of the new shell to enhance the 3s-gte that will going in? We're talking gen3 3s engines in both cases (in fact both from rev3s).

Two plans came to mind:

1) Use the entire GE head on the GTE block

This assumes that the GE head flows better, especially with it's larger lift cams and that is beneficial. It would also come with the bonus of a side feed manifold, negating the tendency of cylinders 2 and 3 to run lean on the GTE manifold. You'd also get the 70mm throttle body compared to the GTE's 60mm. I believe the exhaust manifold will bolt up, making hanging the turbo pretty straightforward still, and using the GTE block would mean there's already an oil feed waiting for the turbo.

The main issue I can see is injectors; the GE uses top feed while the GTE uses side feed, meaning you may not be able to fit the GTE injectors straight onto the GE head.

I had been thinking you would also need to rework the idle control too, as I had thought it simply diverted around the throttle butterfly and would still be injecting pressurized air on the overrun. However, looking at the workshop manual, I think there's a separate ICSV line which could be plumbed into a non-pressurized part of the induction tract.

2) Use the GE cams in the GTE head (and maybe the intake manifold)

With bigger lift and duration, the GE cams are often touted as a performance upgrade on the GTE, but I don't think I know of anyone in the UK who's done it. Obviously I'd need to re-shim all 16 valves.

In the past I've also researched the GE manifold as an easy side feed option for the GTE head, and found forum posts suggesting it doesn't bolt up. However the gaskets are the same part number so I still wonder if it will bolt up.

Also...

With either plan, although I'd hope to start with a "stock" ECU, to make the most of cams, alongside my GT2860RS an aftermarket ECU is going to become a necessity.

I'm guessing others have thought about all this before... thoughts are welcome :th:

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Re: 3S-GE/GTE mix and match?

Post by shinny » 05/03/18 12:39

Evidence that someone in the US put a gen3 GE head on on a built GTE bottom end. Don't know much about the build, mind you: http://www.mr2.com/forums/threads/75282 ... m-end-dyno

Edit: He started out turboing a stock 3s-ge! Thread here: http://www.mr2.com/forums/threads/59044 ... 3SGE-turbo

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Re: 3S-GE/GTE mix and match?

Post by shinny » 05/03/18 17:34

Another good thread here: http://www.mr2oc.com/61-3sgte-turbo/393 ... 3sgte.html

I also realised I'd screwed up the TB comparison between the GE and GTE versions by comparing a TB diameter with the ID of pipework required. First post is not edited as I think they're the same.

Generally more reading today suggests that a GE head may be more work than it's worth, but cams and manifold may make sense on a GTE.

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Re: 3S-GE/GTE mix and match?

Post by dawesy » 08/03/18 9:11

Definitely a possibility, although I thought the exhaust ports were different on the GE to the GTE.
Don’t worry about the ISCV. As the valve will be partially closed on the overrun it won’t cause any issues, and connecting pre turbo will give you a small boost leak.
I had my ISCV feed in the intercooler pipework with no issues.
Yep definitely will require a stand-alone ecu (forged pistons while it’s apart too😉)

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Re: 3S-GE/GTE mix and match?

Post by shinny » 08/03/18 18:45

The more I've looked into it, the more I've been thinking GTE head is still the way to go. As for the components...

Cams: I saw a suggestion that the timings were different between GE and GTE cams and thus I'd need adjustable pulleys to dial them in. I'm not sure I entirely understand what affect extended lift or duration would have on torque / power.

Manifold: The ST205 charge cooler fitment is a really nice feature of the GTE manifold, but the GE side feed would be handy once I can figure out the intercooling. The idea of ACIS on a turbo is interesting too! Fairly easy to undo I'd suggest.

Forging: Yes, I'm increasingly thinking I should get a hone done and drop in some forgies... :th:

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Re: 3S-GE/GTE mix and match?

Post by TonyleFrog » 09/03/18 1:53

shinny wrote:
08/03/18 18:45
Cams: I saw a suggestion that the timings were different between GE and GTE cams and thus I'd need adjustable pulleys to dial them in.
Not sure which source you looked at, but the reason/s are discussed here.
https://www.mr2australia.com/mr2play/tm ... 74&mpage=2
shinny wrote:
08/03/18 18:45
I'm not sure I entirely understand what affect extended lift or duration would have on torque / power.
In simple terms, increased duration will sacrifice lower end for more at the top.
This article goes into more detail - https://www.mechadyne-int.com/app/uploa ... ssions.pdf
shinny wrote:
08/03/18 18:45
Forging: Yes, I'm increasingly thinking I should get a hone done and drop in some forgies... :th:
Might be sensible. What max boost level are you planning to run at?
If you're not living life on the edge, you're taking up too much room!

HM wrote: TonyleFrog aka "The Fog Penetrator"

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Re: 3S-GE/GTE mix and match?

Post by Gazza_DJ » 09/03/18 11:10

It's one of those things that will snowball in terms of parts / cost I think. Not sure it's worth it (in regards to a GE head swap).
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