Liquid Cooled 911 Motor in a 911 G-Body

[supradan]

Hello everyone,

I'm in the process of researching a new project. The project in mind is putting a liquid cooled 996 motor into a G body 911 (possibly a 3.6 TT motor).

In my research I found the following threads that highlight the same type of build that folks have:

PVX build thread: one view from the slope

1970 911E yard find.

Simplest 3.6 install into SC

For the most part all these threads are dated and can't really find other similar builds that have been done recently. As you can imagine this makes it challenging to design and plan.

However, when asking the google machine, I found there are some builders out there that have done it, but these are rare and honestly overly engineered, which I get they are trying to showcase their shops (RUF, Bisimoto, etc.).

Being that the costs of air cooled motors have sky-rocked, why haven't more people done these conversions seeing that a 996 motor is at least half the price?

Also, from a high level would the approach below work:

• 996 3.6 TT motor
• G50 Trans
• 2 High efficiency front mounted radiators
• Standalone ECU

Here's where I need help:

Has anyone done this conversion outside of a builder? If so, can you point me to them?
What are some of the issues you see with this conversion?

Any input you can provide is greatly appreciated!!!

Regards,
Daniel

[Andy Somogyi]

Check out Michael’s channel, he’s doing a twin-turbo Subaru flat-6 build:

https://youtube.com/playlist?list=PLpd6y-3BC1Z4BJ4KQ36wQDshyliZHyYfM

I’m in the middle of doing a built N/A Subaru 4-cylinder build in my 76 912.

A water cooled Porsche engine would work, you’d need an adaptor plate from Kennedy. But honestly, a Subaru flat-6 is a much better engine. Subarus don’t have any of the catastrophic failures that the 996 has like bore scoring and IMS.

I’m fitting a pair of custom made radiators in the front fenders, and I’m making custom molded fiberglass ducting to maximize pressure drop across the rads.

I’ve got a pretty good radiator design, but been busy and haven’t been able to fabricate it yet.

In my case, I want to stay with the core idea of the 912, of a light, simple, agile car. That’s why I’m going with a built N/A 4-cylinder, it’ll be same weight as a standard 912, but with about 215 hp.

Some want more power, so a twin-turbo Subaru flat-6 would be a good choice.

You can also check out Mike’s STi swapped 912, it’s been an inspiration for my build.

https://youtube.com/playlist?list=PLpd6y-3BC1Z4BJ4KQ36wQDshyliZHyYfM


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[supradan]

Thank you Andy for the background.

I've been following Mike throughout is build. He's my inspiration as we both come from the same background and love to tinker with these cars. The stuff he's doing with his blasphemy build is certainly blazing a trail for everyone.

I have toyed with the idea of putting in a Subaru motor, but I would like to stay with all Porsche hardware.

The 996 motors are reliable if you do the provocatively do the IMS fix and maintain the engine. My first choice will be a 996 TT motor which is more reliable than the NA.

Love the approach to your build, light, nimble and reliable. I wll certainly reach out on the cooling design once I get to that point.

[Andy Somogyi]

Originally Posted by supradan

Thank you Andy for the background.

I've been following Mike throughout is build. He's my inspiration as we both come from the same background and love to tinker with these cars. The stuff he's doing with his blasphemy build is certainly blazing a trail for everyone.

I have toyed with the idea of putting in a Subaru motor, but I would like to stay with all Porsche hardware.

The 996 motors are reliable if you do the provocatively do the IMS fix and maintain the engine. My first choice will be a 996 TT motor which is more reliable than the NA.

Love the approach to your build, light, nimble and reliable. I wll certainly reach out on the cooling design once I get to that point.

I think the 996 TT is the Mezger based engine, in that it’s based on the air-cooled block and bottom end, but with water cooled heads and cylinders. If that’s the one I’m thinking about, it’s not related to the standard 996 engine, hence its way more reliable. If you can afford one of those, then yeah, great choice!

with a TT setup, I’m guessing you might need to go to a 3-rad setup.

Glad to help with anything I can, I’ll shoot you a PM with my email (I’m not super regular on this forum).

I’m basically following this style for the coolant lines, and going along the pinch weld for the under car bits.

I’ve got a build page on Facebook here if you’re interested:

https://facebook.com/ArrowBlau





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[Ryan_Cunningham]

If you go this route please document this build. YouTube would probably add a significant amount of time for documentation due to editing, but it'd be worth it.

I've had fantasies of turning my water cooled 1972 911 into a 996TT powered monster. Time and lack of ability are the current limiting factors.

[Ryan_Cunningham]

I just looked and 3.2 air cooled engines are going for $15k on LADismantler and they have two 996TT motors for only about a thousand dollars more! Obviously much more complicated but I'm not sure why more people haven't tried this!

[Andy Somogyi]

Originally Posted by Ryan_Cunningham

I just looked and 3.2 air cooled engines are going for $15k on LADismantler and they have two 996TT motors for only about a thousand dollars more! Obviously much more complicated but I'm not sure why more people haven't tried this!

That’s $15K for just a core. It’ll be another $15k for parts and machine work.

Any used air-cooled engine has to be treated as a core, and if you’re very lucky it might be buildable.


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[MrRPJ]

I have the same cooling set up. i woudlnt do it again its a nightmare to bleed and mount the tank high enough