I have a buddy who's interested in doing a 20B swap (possibly) into a 914 Porsche. He keeps thinking of using the stock Porsche 901 'box; I have my doubts. It appears with an aluminum center support it's marginal for 300 HP if driven carefully (which is no fun). I'm thinking the later G15? Porsche box (like later 911's) suitably modded for mid engine use.

Anybody have any experience with this? Any other good north/south orientation mid motor boxes out there? Keep in mind this is very preliminary! Also, what are some good sources for Cosmo clips, etc?

 

Hey! That's my project! I already have the parts and pieces to get it installed. I want to be the only 914 with a 20B in it. So back off!

I have a Porsche 911 gear box (called a 915) that has been converted to a sideshift layout. I know that V8 guys have been using this box with success for their 300 hp+ engines. They also say not to use the 901 box if you plan on going over 300 hp. It can be done but you have to be careful about putting too much torque through the transmission. I'm told that it is torque that kills the tranny - no horsepower. For lots of good information on 914's and engine swaps into them go to www.914club.com. The G50 box will require a lot of machining and work to get into a 914 from what I understand. A better choice for strength would be the 930 gear box - if you don't mind having only 4 gears.

I already bought a Renegade Hybrids radiator set-up. I have the Kennedy Engineering adapter plate and clutch system. I bought my 20B last fall and have recently bought a Haltech E-11 to run it. My car has a 911 suspension and was set up for a Porsche 6 but I couldn't swallow the cost of those engines for the power they put out.

Here is a pic of my car without the engine:

 

SoloRacer- What body kit is that and what size rims/tires are you running?

What brakes are on the car or do you plan to run?

In addition are you planning to stay n/a or turbo? Are you going to run triple carbs?

That sounds like a really cool project and should scoot. Better have some good brakes....

-Mark

 

The body kit is made by Sheridan Motorsports. Their website is www.ultimate914.com

The rims are by Kinesis and are 17x10 in the front (285-40-17 rubber) and 17x12 in the back (315-35-17 rubber)

For brakes I have a full set of rotors and calipers from a 1990 Porsche 911 C2. I'm sure they will be enough to stop a car that weighs 1400 lbs without an engine (expected to be 2000 lbs with one).

I'm running a Haltech E11 so obviously I'm going to be using fuel injection. I plan on running the stock twins in parallel and get somewhere near 400 hp. If I could get a cheap single turbo set up for it I would go that route.

Here is a picture of the back of the car that shows the rear tires and front calipers.

 

Sweet looking 914! Thanks for the gearbox clarification. He is pretty adamant about using the stock 'box, (at least his is the later side shift 901) if I can't talk him into using the 915 box I'll try to talk him into a 13B TII swap instead.

One other foolish question: it appears the rotary is a 'modular' engine, is there any reason you couldn't stack another intermediate plate and rotor housing on a 13B with the correct eccentic shaft and tension bolts? Thereby building a 'homebuilt' 3 rotor? Is there a source for the eccentric shafts, etc?

 

That is exactly the problem. There are places in England and Australia that build custom 3 rotor eccentric shafts but they are mucho dinero. The HITMAN in Australia is running a home built 3 rotor with a custom shaft. The only readily available eccentric shaft for a 3 rotor is the one in the 20b. If you look at a 20b engine you will notice that one of the intermediate plates is twice the thickness of the other. I'm not sure why but it is different. I believe it may have to do with the e-shaft on a 20b being a two piece unit. If I understand correctly if you have too long of an e-shaft you get flex which can lead to failure. When rebuilding a 20b a lot of guys replace the 20b housings with FD housings so yes they can be interchanged.

Here is a guy who put a 13b into a 914: http://web2.airmail.net/atl/Rotary.html

The most important thing will be the cooling system. I bought the $1100 Renegade Hybrids set up after talking to guys on the 914 forum. You can do it cheaper but usually they end up not cooling good enough and leading to difficult to diganose overheating problems. Since overheating an expensive 20B usually means a costly rebuild is coming I thought it best to err on the side of caution. The Renegade set up is proven to work on V8 engines in Las Vegas so it should be good for a rotary in Canada.