Mating a 3.0L SC Engine to 914 gearbox
 

I am in the process of converting a '73 914-4 into a 914-6 GT replica. I am planning on using a 3.0L SC motor with the 914/901 gearbox. I was under the impression that I could use a special conversion 9 bolt flywheel to mate with the engine to the gearbox. I have searched for this flywheel and have not found anyone selling one. I also came across this conversion kit from Patrick Motorsports that supplies the entire clutch system and ring gear.

https://patrickmotorsports.com/collections/flywheel-and-clutch-packages/products/clu901228ckspms

It seems like this would work with my existing stock 9 bolt flywheel. Am I correct? Anyone have any experience with this kit?

That looks just like the Kennedy Engineering Products adapter that I have been using on my 3.0 conversion. The big ring bolts to your flywheel changing it to the correct setup for the 901 transmission. I don't see a thowout bearing in that kit. Maybe you use the stock one? Call PMS

Thanks for confirming!

I may be wrong, but isn't the 3.0 a six bolt cranks. And if so (as is my 2.2) you can just use a early 911 fly wheel. Every thing just bolts up the same as for the four cylinders. Works great. Mark

I wish it was that simple. The SC and 3.2 cranks are all 9 bolt

Get the stage 2 kit from KEP
https://www.kennedyeng.com/6-cylinder-engine-list

The 3.0 euro Carrera is 6 bolt

3.0 >901
 

Mark is correct.
That Carrera 3.0 crank is the way to do it using all Porsche parts.
BUT.....first you'll have to find that unicorn. Start saving. :)

I have a Euro Carrera engine in boxes. All ready to build. Just haven't had the time. I sold another running one to a 914 guy. It was a ripper.

You can use a 70-71 911 transmission, and some of the bits from a 914 transmission to bolt together a transmission/clutch setup that will work with a SC/Carrera motor. The only drawback is it uses a throwout bearing that is expensive these days. But it does eliminate the clutch cable pulley and the stress on the clutch tube in the chassis. If you want the details, let me know.

BTW... this setup is from an old upfixin der porsche article. I can't take credit for it, but I know it works. I have it on an engine in the garage.

Clay

If you want to use the 911 transmission, you still need to do stuff like flip the ring & pinion, change the gear selector bits, and use a 914 tail cone/nose cone. It's doable, but not quite as straightforward as just bolting up a 914 box to an SC engine using the converter flywheel deal.

--DD

Clay and Dave are both right on the money.
My efforts started with the need to use a 'pull' clutch
I converted a '70-'71 911 trans for just this need.....before I had the engine that rquired it.
As for the original question, I have to add an alternative solution that is much simpler.
914 trans cases can be converted to use a '70-'71 throw out arm and throw out bearing.
You'll need to tap a boss that all of our 914 transmissions have then use a pull type arm and
TOB
There is an important detail that I can't remember maybe someone can fill in...
Will a SC flywheel/pressure plate fit in a 914 bellhousing ?

To be able to use a 70-71 911 throwout bearing and clutch arm, you have to move the location of the pivot for the arm. The geometry is different. And the 70-71 911 transmission have a top hat shaped steel insert in the case where the clutch arm pivot point is located. The mag case would strip out the threads from the pressure from the pull type clutch. Yes, it can be done, but it requires the disassembly of the transmission to properly install the insert.

So if you go this route, you are better off using the 70-71 911 trans case with the 914 tail cone and shift rods installed.


Clay

And you cannot use the SC pressure plate. You have to use a 70-71 911 pressure plate and throwout bearing. The SC plate is much heavier and will over stress the transmission case.

Clay

Thanks for all the input and interesting information. My take way from all this is to use the Kennedy/Patrick Motorsport conversion kit with my 9 bolt 3.0 flywheel, 914 gearbox and the 901 release bearing. Am I missing anything?

Save up the $$$$$$ to do a possible overhaul of the 901 gearbox each year as they are not very strong. Additionally get the parts from Jim over in Phoenix to make the shift linkage bullet proof as in stock mode with the joints as they are made by the factory are way too sloppy.
John

John

Thanks for your suggestion

I am planning to have the gearbox rebuilt with the addition of a custom machined Al intermediate plate.

Which Jim are we talking about regarding the shift linkage? I am considering the Tangerine Racing linkage kit.

Check with Jim Patrick or KEP. My kit for my 3.2 included a special throw out bearing.

With respect, I have to disagree with John Rogers regarding rebuilding the transaxle every year. I have a 3.2 in my car and run a rebuilt 901. I street drive it and generally do not hammer the car but I do use the horsepower. I just do not hammer it in first gear from a stop. If you are aware the 901 has a weak 1st gear situation, and act responsibly, you should be fine. SirAndy (914World.com owner) has a 3.6 in his 914 with a 901 and he has been driving that for at least 10 years with no issues. I have to say he is harder on his 901 than I am on mine.

Having said all that, if my wife would not pack my bags and toss me out, I would do a 915 conversion by Patrick Motorsports.