Last year I bought a Toyota 3SGTE engine out of an MR2 Turbo and was planning on installing it in the car. Then I started wondering if I should stay all Porsche so when a buyer appeared for the 3SGTE I sold it. For a month I looked around for an engine - even bid on a couple on e-bay - preferring to go with a 3.6.
I checked with Brad on prices for engines and he returned a call.
(Thanks Brad - I know you are really busy ).

I was just about give Brad a call back when another friend mentioned he had found a twin turbo Mazda 20B 3 rotor engine in Canada for $3000 Canadian ($2200 US) which is almost 1/2 of what they go for normally. Naturally I was interested so I called the guy up and ended up making a deal on it. That was last week and it should be here sometime next week. I phoned Hobart Kennedy - a very patient man - with Kennedy Engineering regarding an adapter plate and he told me they make one but that they were about a month behind schedule due to the sandrail market getting hot recently. I ended up ordering the adapter plate and flywheel ($430 US) and told him I would most likely end up getting a pressure plate and clutch from him as well.

The ignition on a 3 rotor engine is a little more difficult than the two rotor and my engine management system won't control it so I am looking at buying a Haltech E11 which many in the RX7 community have used on 20b's. A multi-talented friend of mine has offered to build the subframe, install the engine & transmission, install the E11 and get it running if I give him my old (never used) Haltech E6k. I'm thinking of taking him up on it.

The 20B makes 300 hp/300 ft-lbs torque in stock form and by running the turbo's in parallel plus increasing the boost 400-500 is easily in reach. More than that will require a big single which I may do at some time but not for a long time to be sure. I'm thinking that 400 hp will be more than enough for the transmission and driver to handle for a few years to come. Can anyone see any obvious problems or concerns with doing this swap?

The 3 rotor is a light weight engine and I have friends in the rotary community who can rebuild it for under $2000 Canadian if it ever needs to be done. Plus it makes cool noises in stock form - something like a mating between a Ferrari and a Buick Grande National.

Here is a video of a 3 rotor in a Delorean plus a sound clip of a big turbo 3 rotor on a dyno for you to enjoy.

I can't wait to get it in my car!!!

20B Delorean Video

20B on the Dyno

Sounds cool.. Not a huge fan of the sound of the 2 rotors, but a 4 rotor was one of teh sweetest sounding engines I've ever heard. Never heard a 3 in person.

-Aaron G>

HEAT!! Being a x Mazda certified rotary tech and having installed them in various Lotus projects your major goal will be to provide sufficient cooling. Griffen can fab a radiator to your specs to meet thermal requirements. Did you get a whole front clip with harness or ????

Four problems that I thought of right away were: radiator, intercooler, oil cooler and starter.

I know the rotory gets really hot so a good radiator is a must. I was considering a fluidyne unit but will definately look into a Griffin. My car already has an oil cooler so I will probably use it. Currently the oil cooler completely fills the front opening so I may have to move it to get adequate air to the radiator. For intercooling I may use one or two 944 turbo cores (I already have a spare one) and consider mounting it above the engine or in the trunk like I have seen in other turbo 914's.

The starter on a rotary has to spin the engine a lot higher than a piston engine to get it started. Kennedy Engineering recommends putting 12v to a 6v starter to get the desired cranking speed. Hobart told me that this was for Volkswagen starters and that you had fewer options with Porsche. I will be using a stand alone EMS because my car did not come with a wiring harness so I am hoping that I can get the car started at a lower cranking speed. (LS6/914: I got the engine w/turbo's and transmission only. No front clip)

Keep the comments coming.....dialogue is always welcome.

Here is a dyno (rwhp) comparison between a 20b at 10 lbs and 15 lbs of boost. Same car - same engine, just with the boost increased.

20B Dyno

I wish they showed the torque curves as well.

That will be one wicked car. If I knew ANYTHING about rotaries I would have gone that way for my car, but I do like boxer engines and I don't - know anything about rotaries.


There is a guy on the megajolt list that is going to do some rotary work:

What Mazda came with a three rotor? I thought all of the RX-7's were two rotors, including the last twin turbo cars.

I've been a fan of the Mazda powered sports racing cars. I was at LeMans when Jim Busby's Mazda powered Lolas beat the Mazda factory team cars in the C2 class in 1984 (wave the Stars and Stripes ). I also always rooted for Jim Downings Mazda powered cars in the IMSA series.

Mike

If you're concerned about cooling the car you might contact Renagade Hybrids. They provide complete cooling systems for the V6 and V8 conversions, which is who I'll use. They're in Las Vegas and their motto is 'If we can cool a 914 in the desert, we can cool it anywhere'.

Great project, keep us informed.

IMI Hi torque starters makes a starter with a higher speed just for this application. Give them a call I don't know if its listed in there standard catalog or not.

I looked at a 914 with a Mazda engine a few years ago. It had been done by a shop that does development work for GM. This car was really nice.

Bob

Mazda made a 4 door luxury car called the Cosmo that came with a twin turbo 20B three rotor as well as a 13B twin turbo two rotor. They were available in Japan and the rest of the world. All the RX7's were 2 rotors.

Thanks for the tip. I will see if I can find them on the web and get in contact with them.

I've been a member of www.rx7club.com/forum for the last 3 years, and I just want to add two words - exhaust heat. Rotary exhausts get incredibly hot, and even with the stock shielding they can start fires when parked off the road/driveway. The heat of the exhaust is a critical factor that must be taken into account when doing this conversion, and you need to route the tubing so it is well away from any fuel lines or heat-sensitive materials.

A well-known Seattle-area member of the RX-7 forum who goes by the handle 3Rotor would be a good person to talk with (PM) on that forum.. I think he just finished dialing-in his ignition system.

Reverie: I am also a member of the rx7club forum. I have been there for 3 years as well. I also own an 87 T2 and can be found hanging around in the Canadian forum. What EMS is your friend using? What turbo or turbo's is he using? Does he have a website?

I brought up the issue of exhaust heat on this forum and was considering getting the exhaust ceramic coated. Anyone have experience doing this? How well does it work?

My son has been on that list forever (still is -RX7passion). He almost completed his project car, a 84GSL that I sold him that he was stuffing a 89 13b turbo motor (japanese version) and tranny into. We had it running with the Haltech and had taken it to a tuner to be finished. It was stolen from the car lot (inside job). He fab'd all the wiring required to make it work.
We also looked at doing a rotary into a 914 and that heat is going to be alot of work to get rid of. Good luck.
We just sold the 89 T2 he bought, fast effin car!!!

Geoff

For the Lotus 7 that I "assembled" with a 13b I used thermotec wrap to cover the header and down pipe. The exhaust is covered to the point where it exits the body panel. Very little paint blister. Iam sold on the performance of this product in thermal efficiency.

you have to think if you want to do it you can... any obstacle is not to big when a 914 owner decides it got to be done

Hello Soloracer, I just got your posting sent to me by Muller, I am also looking at doing the same project as you have here stated from 2004.

I was wondering if you have already completed and how dificult was it to fit and run in a 914.

Thanks

Quilmes ( Martin(

I just found the post on this thread. I don't remember getting an e-mail but then again I don't remember what I had for lunch last Monday either. smile.gif I'm going non turbo now - peripheral port N/A all the way to keep things simple. The plumbing for the intercooler and the extra costs involved with turbocharging didn't make sense. Especially since I can make 400+ hp in N/A form and a N/A car is easier to drive at the track.

I started a build thread at:

http://www.914world.com/bbs2/index.php?sho...35&hl=rotor

Feel free to check in from time to time.