Mazda 13B power. Question and opinions needed.

Moving cautiously forward on the 356 coupe, I wanted to ask for any opinions on using the Mazda 13B rotary engine as a powerplant. I KNOW that current wisdom favors the Subaru for a watercooled engine, but I don't have the knowledge to deal with the ECU and such to successfully hook one up and keep it running right. Too many electronic variables for me. I have a buddy who is supremely familiar with the rotary and will help me out with the purchase and upgrades needed. He also has a nice DCOE Weber intake set-up and Racing Beat header that will eliminate the silly little quad and provide for a much more responsive engine, with rpms in the high sevens.

He's totally pushing me towards the rotary, I'm asking for some help. Anyone have any experience with these little engines or know of/heard about how they perform when use in a VW conversion?

Thanks !

T

SO in FL picked one up couple years ago - but decided rebuild cost and heat generation (so near to flamable fiberglass) were too great. He has engine plus the adapter plates/flywheel for VW. Don't see him post too much lately. I'll forward your note to him. Think he went with big T1. Seems they are thirsty and not very eco friendly -- but they do produce some power for engine size! Now could that go mid engine (might have to wear Nomex underwear)?

I posted this link awhile back - there is forum thread on rotaries.

http://frost.bbboy.net/vwengineconversions

I was honestly thinking of getting the KEP or another manufacturer's adapter and trying for a mid-engine installation. I've been measuring things out for a mid-engine VW set-up, but the Mazda seems like a much more compact piece. It throws way more heat for sure, but it's cooled by traditional water cooled means. My worry about the mid-mounted VW engine was the cooling aspects and how many holes and louvers would I need to cut into the body shell to keep things in check.

Plus, there's the power band available from the basically stock 13B. Horse power can be easily brought up to 150 and revs in the 7,000/8,000 range aren't impossible. With my trans and gearing and those rpms it would mean potentially 160 miles per hour. The 356 coupe is pretty much a tear drop in over-all shape, and the VW pan is just that, a full length belly pan. An inner perimeter skirt to cheat the air out from underneath, forward air dam just beneath the radiator and louvers on the hood and fenders to release any trapped air. Three small aluminum "fins" on the roof way back by the top of the rear window, and a discrete splitter just under the nose and I ought to have a pretty darned stable platform that would stick to the pavement at that speed.

For now though, I need to sort through the power plant, and Chris is making the rotary look more and more like a possibility.

If you could get in touch with your friend and maybe ask him for some info on my behalf, I'd appreciate it greatly. Do you think that he wants to part with his adapter kit of he still has it?

Lemme know.

Thanks !

T

Another option is to buy a Subaru Engine then buy an ECU with a pre-loaded program. It will work just fine until you can have the car put on a chassis dyno. I'm guessing the ECU would cost in the $1,500 dollar range and quite frankly, once you have a fuel injected engine, you'll never want to return to Carb's.

I have a friend that designed the Redline computer and it comes complete with an easy to understand set of instructions on how to wire up the loom from the ECu to the engine.

PS, all the guys that I know that go to the sand dune that had Rotary engines have all changed to a Subaru. The Subaru runs better, starts easier, gets better mileage and lasts longer.

TC, I don't know a lot about the rotaries, but I do know they don't have a heck of a lot of torque. Once they're spun up, watch out -- but getting them to lose their patience from the tree is a trick we see a lot.
At the track on Friday nights, it's not uncommon for the non-turbo, pushrod set to line up against ricers with their rotary engines wound up, and the more patient racers will out-wait the rotary guys.
As soon as the ricers' revs start to drop, the big-block guys punch it. The Mazdas almost always lose.
For what it's worth.

Larry, I can't justify spending $1,500 on an ECU in addition to the Subaru engine and adapter and radiator and header and exhaust and . . . I can get a fairly well race-tuned rotary with 45 DCOE, manifold, header, coil pac(s) and such for just a bit more than the cost of the ECU. Another few hundred for the adapter plus the cost of tubing and such and I'm ahead of the Subaru conversion by a huge margin. Of COURSE a rotary isn't a Subaru. But, I have a buddy who races Mazdas and he can set me up and guide me through the pit falls.

Cory, I've driven Chris' RX7s for the past couple of years and have gotten used to the flat torque curve. With the gearing in the VW trans and the complete lack of torgue in a stock VW engine, I think that the rotary will be a massive improvement, honestly. For around town driving, I'll just let the gearing take care of things, on the highway I'm counting on the flat torgue curve and the simple stupid ability of the rotary to continuing building rpms until the tripple nickle is hit to make up for all of that lack of big bad off-the-line kinda stuff.

I'm still wondering about the regular day to day driving and any problems that might surface in a conversion that wouldn't be obvious in a production Mazda.

"the more patient racers will out-wait the rotary guys. As soon as the ricers' revs start to drop, the big-block guys punch it."

That trick isn't allowed on any drag strip here in the North East, and certainly not on any strip anywhere that's sanctioned by the AHRA or NHRA. There's a restriction on the amount of time that's allowed for staging to prevent just that kind of thing. During the points events, the time limit is even shorter to prevent the fuel from getting too hot. I'm really surprised that you've witnessed that kinda crap AND that fights haven't broken out when it's pulled.

An old trick that nobody puts up with around here . . .

I have one on my dune buggy And It has internal dammage from over heating .. Not the right radiator If ya want it for the adapter parts and the Delero carb . Make me a offer. But realy Im not going to mess with it any more or try to rebuild it ,Just to darn expencive and deleicate to fix.

If this makes you rethink the rotary 13 b,, I understand that too..But it is here and in poor shape The carb may be junk by now as well.


I do want to keep the clutch and pressure plate .But the 6 volt starter with the 12 volt solenoid goes with it..

I do not personally have any experience with the Mazda 13B rotary...or any other rotary, but I remember talking to Bob Sweatt (owner of Metalcraft Products) back in 1990 when I picked up one of his chassis's for my CMC project. One of the things he mentioned that I thought was interesting was that he used most of the Speedster chassis's himself. He said he put Mazda 12A and 13B engines in nearly all of them and sold the cars in Singapore. That was a long time ago and Bob has long since quit the business; just thought it was interesting and he had some success in selling these Mazda powered cars with a significant price tag.

TC, the Capitol Raceway here is a low-tech kind of place. There aren't very many sanctioned events there, either. It's kind of a "keep the kids from doing it on the streets," heads-up thing.
But for twenty bucks, anybody with a helmet and the ability to pass rudimentary tech can go out and kill themselves. It's ten bucks to watch them. Fights do break out, and the lady selling beer doesn't have many teeth.
They call them "Test and Tune" nights; those are the only experiences I've had seeing Mazdas wound up.

I think the rotary motor sounds crap! there I said it, at least a Subaru motor sounds a bit like it should.

Not as expensive as you may think

http://shop.ebay.com/?_from=R40&_trksid=p4684.m570.l1313&_nkw=subaru+engine&_sacat=See-All-Categories

WOW . . .

You're right ! ! Although, wouldn't it still take another three grand or so for the electronics, adapter, radiator, exhaust and such to get it installed and ready to be put up on the rolling road for tuning and all. Maybe not . . .


Barry,

I emailed you about the adapter kit and carb manifold, but got a weird (gibberish) "auto response" . . . could you email me with a different contact address please. Interested ! !

Thanks ! !

TC

TC,
Give me a holler. I may have exactly what you are looking for.
jander1965@cox.net or 850 - 758 - 5268.
Jim

TC,

I had a 13B in a Fiat X1/9 (with a Citation then a Fiero transaxle).

I happen to really like rotary engines. Couple of things. Buy the little doo-hickey that holds the flywheel still while you take the gigantasaurus nut off to remove the flywheel. It's huge and torqued down to (if i recall) over 300 lbs. Watch your height. The distance from the center of the concentric shaft to the bottom of the pan is fairly deep. We rotated the assembly a bit for clearance in the transverse configuration of the fiat. You just got to make sure to mount it high enough that the oil pan doesn't become your bash-guard.

A carbureted 13B with minor porting and headers is a very streetable engine. Looking at around 180hp easily, maybe a little over 200 before driveability starts to suffer. Don't get into the crazy porting for a street engine - they are undriveable pigs at low RPM. Minor port is good, crazy porting is to be avoided.

The exhaust temp on a rotary is extremely high. The headers will glow orange to even slightly yellow. Use VERY thickwall metal for your headers. Support it in a couple of places or the heat combined with the weight will make it sag/bend. The engines make a huge amount of noise and even worse, is the pitch. It is a high, almost vicious sound that is unique to the rotary. In rotary race cars with open exhaust, the volume and pitch is so intense that it will seperate welded sheetmetal on the body - absolutely freaky. So get a good muffler - Racing Beat sells them. Do not *** DO NOT*** even try a glass pack. You wil melt the fiberglass in less than 15 minutes. The liquid glass will then pour out of your exhaust system. It's very intersting but not in a good way.

Oh and go with a fairly heavy flywheel, it helps alot with the low-end torque.

angela

My only experience with Rotary's is my friends turbo in a 2 seater sand rail. Once out in Glamis he said "Ready I'll just go straight" and my eyes teared up so fast I couldn't see anything, and I almost swallowed my tongue. The next day I had bruises all over from the "rocket ride"! He had a 2 speed mid engine setup. Oh ya, the thing's exhaust was "hotter than the hell!"

You know . . . somehow, running a car, at night, at extremely high speeds on a dark empty highway, with an external exhaust header that glows red hot then bright yellow from the extreme heat of an engine which makes a freakish high pitched, vicious sound capable of separating welded metal bulkheads . . . doesn't sound like a bad way to spend an evening.

My thoughts exactly!

Oh TC, it's a truly WONDERFUL way to spend an evening!

Want to know another wicked little trick? Get then engine up to temperature, set your mixture in a little rich, run the RPM up and lift abruptly.

It will shoot a flame about 3 feet long out the rear of the car. It's so bright that it lights up your rear view mirror and scares the ever loving $hit out of the guy behind you!

Also, if your exhaust is very short, it will under normal conditions make a glowing cone out the back that doesn't look like fire, it looks like the cone that you see from a jet at night. You can only see it at night when and everything has to be up to temperature. It's really freaking awesome TC!

angela

All of this WONDERFUL drama, plus the engine also performs outrageously well, pretty much came that way from the factory and was installed in compact pick-up trucks ! ? ! ?

I know that this sort of thing wouldn't be for everyone, but I betcha that everyone would wanna borrow the car for the weekend.

So far, pretty good. I've got some parts, a lot of info, and possibly some other, more crucial parts in negotiation, sure hope that this thing comes together . . .

Thanks all!


T