Dropping a 3.6 930 Engine into 1976 911 SC

[quattrorunner]

If that is indeed a short bell 930 I'm seriously jealous. You are way way ahead of the game my friend.

[TrickyDSE23]

Have had a good look at the engine, I now believe it's a 3.3 litre turbo engine with the later, longer 930 gear box, the serial code stamped on the engine is 67d1672.

Apologies for the miscommunication, by wings I was indeed referring to the front fenders. When you refer to differing pick up points between the SC and the 930 does that relate to the rear trailing arms, do they have different fixing points? That is more out of interest, as I was planning to use the rear suspension from an 86 Carrera convertible, which I have dry fitted and seems to offer up nicely. I can't see why that wouldn't be a good option.

I'm now just hoping the engine will fit, so I'm thinking my next job will be offering it up to the body and see if either of the sets of driveshafts are close

[IMR-Merlin]

Looks like a short bell to me, look at the link I sent on the tranny source.

[quattrorunner]

But looking closly at the puictures, it looks like this trans is not cut short. It looks standard 930. Look under the scavange line over the bell housing and see that it has about an inch longer than the short bell.

[TrickyDSE23]

I don't think it is a short gearbox, the longer gearbox would have come as standard according to the website helpfully posted by IMR-Merlin, also the bell housing appears to be the longer of the 2 in the photos provided, I think the photo I took may be from a deceptive angle! Would it have been a better fit with the short housing?

[IMR-Merlin]

The short bell housing cars move the engine a bit more forward, giving a better front rear weight ratio without adding drive shaft angle. As I am building a G50 car, my 930 box knowledge is limited.

Brendon

[RarlyL8]

Looks like a standard box from what I can see.
To put this drivetrain into a '76 will take an adjustment of the tranny mount and engine mount as the tranny moves the engine 1" further back in the car than the 915.

[Jim2]

Tricky, to answer your question above, yes 930 trailing arms do have different mounts on the inboard end. They look similar to your Carrera arms but the inboard pivot point is about 2" farther rearwards which results in a different camber curve.

Since your motor is intercooled it likely has a long bellhousing trans, both the intercooler and long trans started in 1978. Here are two pictures robbed from other pelicans posts:

SHORT bellhousing trans (used through to the end of 77 - non intercooled 930)


LONG bellhousing trans (used starting 78 and onwards - intercooled 930)

[TrickyDSE23]

Thanks again for all of the very useful replies, I'm now definite about the long bell housing.

Just a couple of what I'm sure are pretty rookie questions, but would the use of the Carrera suspension affect the handling significantly? Also if the engine and transmission fits 1 inch further towards the rear of the car would it still fit using the standard mounts, albeit shifting the centre of gravity rearwards by an inch. And by doing this would the handling/balance be severely affected? Also I don't suppose anyone fabricates adaptor plates for the engine and tranny mounts so that I wouldn't have to cut into the body?

Many thanks

[Jim2]

Originally Posted by TrickyDSE23

would the use of the Carrera suspension affect the handling significantly?

You mean the trailing arms, Carrera vs 930? Both work equally well. Perhaps under track conditions one would be preferable over the other, on slicks versus radials...

Originally Posted by TrickyDSE23

Also if the engine and transmission fits 1 inch further towards the rear of the car would it still fit using the standard mounts

Perhaps other who have done the conversion will chime in and advise which trans mount fits better Carrera or 930, and what mods you need to do to the mount. You do have to modify the trans mount slightly to locate the trans about 5/8" rearward from the torsion bar tube. The rear engine mount beam might need to be tweaked slightly by ending the beam rearwards or forward, perhaps not at all though.

Originally Posted by TrickyDSE23

rearwards by an inch. And by doing this would the handling/balance be severely affected?

Not affected. Proportions will be identical to the 930. Some hardcore track guys go the extent of locating a short trans to try and improve front to rear weight bias and reduce the moment on the rear, difficult to notice an improvement on the street. 930s are fine as is.

Originally Posted by TrickyDSE23

so that I wouldn't have to cut into Thr body?

No cutting into the body required. Almost bolt up except for the mount mods.

Again, I'm not an authority on the subject and hopefully some others here will share details about what mods you need to do to the trans and engine mount.

[TrickyDSE23]

Thank you for taking the time to reply Jim, that has made me feel alot more confident about the whole thing!!

[quattrorunner]

Not long ago a guy with a 911 put a 930 engine and trans into the 911 and went through the issues you'll have. Thread was called something like "some german name the great" Can't remember the name. His car had some issue but all were engine related and not really swap related. I think the trans size is an issue but not a large one. I think there is a trans mount change that will require welding or fab work. Thats it? Diffrent axles I think.

[quattrorunner]

Here it is
Frederick the Great

[spuggy]

Originally Posted by TrickyDSE23

but would the use of the Carrera suspension affect the handling significantly?

My middie had 21/30 torsions when I got it, and 3.2 brakes.

Squat/weight transfer was very abrupt with a 3DLZ. Sometimes surprising, sometimes inconvenient, sometimes scary - I would think you'd be much happier with some serious uprating of the TB rates. I even debated coilover helpers - until I discovered that it was much more manageable with a hybrid (K27/HF) turbo.

You probably also want to fit the bigger sway bars (or "anti-roll bars" in English ). They don't do all that much - but no/skinny rear sway would not be an improvement. You can't fit Type 2 (78-) sways to a '76 without special drop links - available through Pelican: http://www.pelicanparts.com/cgi-bin/smart/more_info.cgi?pn=PEL-TE-911RDLNK&catalog_description=Tarett%20Engineering% 20Adjustable%20Drop%20Link%20Set%2C%20REAR%2C%20fo r%20use%20with%2078-89%20911%20factory%20swaybars%20only%2C%20fits%209 11%2F912%20%281966-89%29 or making your own adapter http://www.dietersmotorsports.com/tech/2002/01-2003.htm. Type 2 sways are much easier to pick up used in the bigger sizes, if you don't luck out and have one already.

BTW, I no longer have 3.2 brakes. They were never impressive, although they were undoubtedly better than the 911S brakes they replaced. You probably want to look into bias and/or a proportioning valve for the 3.2 brakes, as there's a lot of rear bias without. You can tolerate a fair bit more rear bias with a asymmetric limited slip - but I'd be fairly concerned if you had an open or factory diff; the front/rear bias is insane with 3.2 rear calipers without a P/V. You'd be better off using SC rear calipers and rotors, IMO.

The sporto oil tank is the same oil tank as the 930. Same part # - the turbo return and the sporto return use the same fitting.

I run a single Bosch 044 motorsport pump in the front location.