911 gearbox in

[Ron LaDow]

Richard,

"The nose cone of the 901 transmission has a large upper portion.
This portion of the nose cone is cut out in the shape of an oval.
The piece is flipped over and welded back into the nose cone.
Remove speedo drive and add a cover plate (custom machined)

that nets 2-3 inches.
the torsion tube has an outer layer of steel to encapsulate the
inner torsion bar end piece.
the inner piece is shaped like a barbell.
remove just the outer skin, and only from the very middle."

Not to discourage anyone who wishes to to the swap; I did it to Speedster #81109 in the early '70s. What you propose here will get you close and you'll find that last 1/2" is *very* hard to come by. Again, it's not that easy.
Thanks,
Ron LaDow

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[Jim Breazeale]

Anyone contemplating a 901 trans in their 356 should take a step back and listen to Ron's advice. He is trying to be polite and tell everyone that it isn't an easy task. He has been there, done that! I got to drive Ron's beautiful Speedster with the 901 trans and rear suspension back in the 1970s! I performs very well but the installation is not for the average backyard mechanic or any person "light of wallet". Mike Moss's car is another example of a very nice 901 trans installation. His car can be seen sitting infront of my shop in the picture I posted about last Saturday. His car is the primered 356C Coupe. The underside of his car shines very brightly, though. He is also an extremely talented and expierenced fabricator, as is Ron. Don't undertake this "at home". If you think for a minute that is the thing to do because 901 transmissions are "cheap and plentiful" and that is the underlying reason for attempting to install a 901 trans...................YOU ARE A FOOL!!!!!!!!!!!!. That said, I do have a bunch of 901 transes for sale!

Regards

[Tom Farnam]

Good grief, what do you mean trying to compare today to the '70s?

Don't you realize that just because you old curmudgeons had trouble doing things in the old days with stone tools does not mean it can't be done easily today?

After all, the web gives the young people all they need to know about auto mechanics and how to make these things fit easily. There is virtually nothing to it.

Just go back to your rocking chairs in the Curmudgeon Corner and let the youngsters show you how it's done.

Tom

[Charlie White]

I guess the "proof will be in pudding", er "engine compartment"! Let's see what these young guns can do. I'd be really interested to see some of them put their money and 901 transaxle where their mouth is, er, engine compartment is! A detailed picture summary would be nice, and get the lighting right so we can see all the detail. Seriously, I'd listen carefully to Ron and Jim at Easy! So matter how young or old you are, at least be forwarned. Just hate to see someone screw up a nice 356 trying to do something over their head. It's ALWAYS easier said than done! And Ron and Jim have done a lot and offer good advice. As they say.......just my two cents worth!

Charlie White
Scottsdale, Arizona

[Jim Breazeale]

Good grief, what do you mean trying to compare today to the '70s?

Don't you realize that just because you old curmudgeons had trouble doing things in the old days with stone tools does not mean it can't be done easily today?

After all, the web gives the young people all they need to know about auto mechanics and how to make these things fit easily. There is virtually nothing to it.

Just go back to your rocking chairs in the Curmudgeon Corner and let the youngsters show you how it's done.

Tom

Tom

Well put! What was I thinking? If anyone of you is under 40, don't pay any attention to what I have to say.

Regards

[Ron LaDow]

OK, private message; 'How hard can it be'?
Let's look at something simple like the throttle linkage. Four bellcranks, six links, two of the later need to be changed. Any cursory look at mechanical linkage shows there are various 'accelerations' available depending on the initial to final (travel) geometry of any bellcrank/link connection. The worst is an over-center condition at either extreme; lock-up. If this is at idle, it's just embarrassing. If it's at full-throttle, it could be worse.
But even ignoring that, you have choices about how much pedal action results in how much butterfly action at various points in the travel. My car has very short gearing, so I really didn't want 'on-off' action at small pedal movements; it's designed for pretty much 1:1 travel throughout the range. You could easily design for 10% (pedal)/20% (butterfly) at the beginning, and the resultant 20%/10% at full throttle; more extreme biases are possible. If I did it again, I might change the bias slightly to favor the top end. How about you?
That's the throttle linkage; wanna talk about wheel location/travel/camber/tire size to fit in the existing fender shape?
Per Tom, 2008/CAD could ease the process, but you're gonna have to know 3D cad pretty well to make it quicker than me with pencil/paper/calculator.
Thanks,
Ron LaDow

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[Michael Moss]

All:
I put a 901 gearbox in my 64C. After reading Ron's information on his installation I measured, read again, measured again and still couldn't figure how he came up with a stock wheelbase 356 with the 901 gearbox in it. After many nights laying awake thinking about how to get back the 1/2 inch difference in length in the torsion bar center to the axle center, it dawned on me he moved the trailing arm mounts forward on the torsion tube by the 1/2 inch. So I spent two days machining and fabricating fixtures to alow me to cut the mounts from the 900 series torsion tube and reweld them in their orignial orientation. Once the mounts were cut from the torsion tube it became apparent that to move them forwrd by the 1/2 inch the torsion tube would need to be notched where the front mount bolts go. After moving the trailing arm mounts the transmission touched the torsion tube requiring the center section to be notched along with modification to the nose cone on the 901 box. OK four days later and I'm ready to cut the rear seat and floors to allow me to cut and install the 900 series torsion tube. Next problem is to make a set of spring plate like the early 900 series 1/2 inch shorter than the stock 900 series, then how to mount the hoop to the transaxle, clutch linkage ( interfers with the hoop after modifing the hoop to mount to an aluminum chill case 901. Still need to modify the shift linkage and tunnel so you can adjust the shift linkage coupling. Shock mounts needed modification along with the suspension travel limits on the body. Lots of other things I'm sure I forgot, but when I was finished the engine still sets 3/8 inch further back. If you don't modify the torsion tube and move the trailing arm mounts forward the engine will set back 7/8 inch further back than stock. That creates other problems like exhaust interference etc, etc. All in all I really enjoy the conversion and I'm in the process of another for a close friend but unless you have a machine shop and very good welding equipment you'll spend a fortune getting all the bugs worked out and components fabricated. I don't think any two of the cars running around with the conversion are the same. You can always improve on what you did the first time. Anyone interested I have the conversion documented in a PowerPoint document just contact me off line.

Mike Moss 64C

[Albert Tiedemann]

[quote="
, but you're gonna have to know 3D cad pretty well to make it quicker than me with pencil/paper/calculator. [Ron Ladow]



Here, here with pounding on the table as they do in Germany during/after presentations.

The pencil--such an elegant instrument and quite profound when driven by the mainframe*.
You might call it a peripheral*. And, the link* between the mainframe and the periheral has/had no fear of Y2K [or the electrical socket or the battery even though the latter are improving these days.

Thanks for the help, Mark

*for the esoteric group

[Mark Jung]

Michael,
Ron DaLow explained it pretty good. It takes alot of time just to engineer the project. I installed a 915 in my 57 coupe. I wanted to keep the engine compartment intact and looking original so I had to cut the center section of the torsion bar out. Ten inches was removed from the center. To keep the structural integrity of the torsion bar tube I had to connect the tube together again forward 5 inches. This made a nice 10" wide X 5" long area for the 915 nose cone. This mod made lots of room in the engine bay. Of course that's not all that had to be done. Install shorter torsion bars; install 2 inner spline receivers for the torsion bars; modify floor and tunnel; modify spring plates for torsion bars; modify rear seat hump for 915 fit; totally fabricate a new bulkhead for the tunnel end to accept all the cables, ect. ect.
Lets not forget the IRS arms and pick-up points and alignment. All in all, it turned out great and after new interior you can't tell unless you really look close inside at the floor/bulkhead area. Would I do it again? For $10,000 I would.
l

[Kenik Hassel]

OK, here goes, first post...

Having two fresh 901 trannies in both of my 911s and also having a Berg 5 in my '71 Fastback, I can say that there are benefits to the Berg over the 901. The Berg is a MUCH slicker shifting box than the 901 and the gears are quite a bit cheaper. The Berg will hold as much HP as you can throw at in a 356 (even with a twin plug, JE/Nickie big bore motor). All things being equal, go Berg.

[Ron LaDow]

Mark is being a trifle 'modest' here:

"I installed a 915 in my 57 coupe. I wanted to
keep the engine compartment intact and looking original so I had to
cut the center section of the torsion bar out....."

He's also putting a 6-cylinder in there and the workmanship makes mine looked like chopped liver. It *is* going to be at WCH, isn't it, Mark? You promised.
Thanks,
Ron LaDow

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[Mark Jung]

OH Ron...........Your taking away all the fun. Yes I will be there with the little outlaw.

[Christopher Toy]

OH Ron...........Your taking away all the fun. Yes I will be there with the little outlaw.

Mark:
That photo establishes a new standard and re-defines the term bad-ass!
Beyond too cool.

[Charlie White]

LOVE THAT LICENSE PLATE!! (After 2 1/2 years living in Germany in the US Army in the late 60's/early 70's...........with a 64 SC Cabriolet!)

Charlie White
Scottsdale, Arizona

[Christopher Toy]

. . .The Berg will hold as much HP as you can throw at in a 356

Really?