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MG MGB Technical - Rotary engine conversion

i have a 1968 mgb rd and i want to put in a 13b fuel injected rotary engine out of a 2nd gen rx7. what steps would be involved in doing this? what would i have to change? and about how much money and time will it take?


thanks everyone

scot
scot

I saw a beautiful conversion at Watkins Glen last year but I have no idea what is involved to install one. He did tell me that it required a lot of fabrication and invention along the way. The problem w/the rotary is the crank is in the middle of the engine, not the lower 3rd like a 'normal' engine. This makes the engine sit a lot lower in the car which is good for handling but not so good for driving on the street where there are potholes and driveways.
MaGee

GrassRoots Motorsports magazine has a project Rotary Spitfire that is almost complete. You may want to look at some of their back issues and see what is involved. I don't think the crank sitting in the center would be a major issue for the road but the engine is wider than the MGB engine and you may haveproblems getting the engine in. It will probably cost a least two as much as you plan on and take two or three times more time than expected. I wouldn't attempt such a conversion as there are two or three well proven types of MGB engine conversions. With them you don't have to fabricate everything. My opinion. Clifton
Clifton Gordon

I saw a B at a British car show that had a rotary engine in it. It didn't appear that the body had been modified noticeably, but the engine say extrememly low, way down between the front frame members. There must have been a foot of clearance between the hood and the engine.
Paul Noble

Can't answer your question about HOW to install a rotary engine in a B, but may we ask WHY? Sure it may be lighter and give more power, but will you be that much ahead with a couple of seconds shaved off 0-60, and a more dangerous top speed?

For humor (hopefully), there are some things all men want to do, but most are smarter than that:

1. Build their own boat
2. Build their own house
3. Invent the perfect inflatable doll
4. Put a higher powered engine in a car

I think I once heard of a guy who installed a strange engine in a car, only to find that it turned in the opposite direction than the one he took out. Sure nice to have 4 reverse gears, but he wasn't often seen on the freeway.

On the other hand, a friend of mine supplied kits to put Chevy 350 engines in Jaguar XJ6's. He said they were more reliable, and I had no trouble with that. Then he said that the Chevy engines were also lighter, gave better fuel mileage, and gave more power. "So," I said, "why do people like a Jaguar engine in the first place?" He replied, "More hi-tech". So I inferred that that WAS a good engine swop, but it was a case that the tranny was compatible, and others had verified that it all went together OK.


Not intended to make fun of your plan, Scot. But I suspect you'll get hi-tech at vast expense and trouble. So . . . WHY?
Daryl

Scot,

Aside from the school marm admonishments (which I do not share, particularly), there is one difficulty associated with the rotary that is fairly significant. The output shaft on the rotary is very high in the block. That is why the engine would have to sit quite low. The alternative would be to have a rather high transmission tunnel. There are a few rotary B's and midgets out there, but they tend to be dedicated to sporting use only, perhaps due to a general lack of tractability. I am very satisfied with a Burgess engine, but for pure bang for the buck, one would have to also give a good look at the Moss SC kit. If you are going to look into an engine change, the V-8 is your best reference point by which to judge all other options. The bottom line answers to your questions are 1) Many, many complicated and difficult steps would be required, 2)You would have to change many, many things, and 3) It will take many, many duckets and many, many months or years to complete the project. By the way, the Grassroots Motorsports Ro-Spit has been competing for a season or two now, but continues to evolve.

Cheers,

Dean
Dean Lake

Scot-
Another option is Chevy V-6 (2.8-3.4L) which can be found in 82-94 Camaros and Firebirds. Requires very little modification for your year, I believe a small cutout on the passenger footwell. The engine drops right in with special mounting plates and the T-5 transmission shifter comes out in the same location. If you're interested, check out this website. Not sure where you are in CA. but Classic Conversions is based out of the LA area. http://www.classicconversionseng.com/
I'm in the process of doing this conversion on a '75B and Clifton is right. Costs mount quickly for unforeseen events. (ie. modified engine wiring harnessess). Good luck. Drew
Andrew Fletcher

Dean Lake wrote:

"The output shaft on the rotary is very high in the block. That is why the engine would have to sit quite low. The alternative would be to have a rather high transmission tunnel."

Just out of curiosity, how did Mazda handle this? It seems that it wouldn't be any more trouble to locate the engine in a B than it would in a Mazda. Is the transmission tunnel that much higher in a Mazda? I have driven Mazda RX7s, several years ago, and I don't recall that the tunnel was excessively high, but then I wasn't looking for that, so they may have been.

I have seen a few rotary engined Bs, but I really didn't look close enough at them to see what all was involved. I just know they looked pretty odd in the B engine bay. According to the owners, though, they go like stink. I know the RX7s I drove did.
Dan Masters

Some links to a rotary MG Midget conversion:

http://www.mgcars.org.uk/v8_conversions/midget/files/briankraus.html

http://hometown.aol.com/ursnoozin/myhomepage/auto.html
Daryl

This thread was discussed between 04/08/2003 and 13/08/2003

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