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MG MGB Technical - MGB/ Miata driveline swap?

I realize that it's probably not considered "good form" but I have an MGB with a decent body, but no engine or transmission. I am considering putting a Miata drive line into it. I have no idea whether it would be practical or not. I know where I can buy a badly wrecked Mazda Miata that has a low mileage engine, transmission, and differential. I tried a search of this site, but didn't turn up anything about this swap. Does it sound even slightly practical? Has anyone done it? I'd have all the pieces, computer, wiring, you name it.
Chuck Asbury

I don't know if they mount correctly, you might be the first. How about a Buick 215 V8 and a 5 speed? That is a common swap
Frank Baker

Do it! I'm sure somebody has; I've been looking into it - the only significant problem is wrapping the sump around the crossmember. Mazda and many others now use some complex bracing structures in, or part of, the oil pan to give block rigidity with the very light engines, so making a sump might be more complex than it used to be.

From my book, it looks like the Miata will not be a problem here - but it's a Chilton book and it is as bad as every other Chilton I've seen in 40 years - full of obvious errors!

You will not be using the diff, as the Miata is IRS with a subframe that doesn't look like it's going under a B - at least not unless you are sufficiently talented (or mad) that you wouldn't be asking the question!

Based on my experience with a 323, I am certain this swap would be among the wonders of the world if done well. I am in serious danger of Mazda Mania just now; I am possibly looking at my second (a Protege)this weekend, and have just found a BP twincam (1.8 version of Miata) to go in the 323. And there is danger of one getting comfy with a Magnette.

Would be glad to consult.
FRM
FR Millmore

My wife owns a Protege5, and that is one zippy little car. The engine isn't appropriate here - it's a front-wheel drive car and all - but Mazda makes excellent motors, and the weight and size of the Miata and the B are pretty close. FRM is right - do the "what-if" thing with measurements and sketches, and see where it leads.

I used to have a MX-6 that got smooshed by a deer, and I've always wondered "what-if" with that V6/5-speed combo. Sigh....

R.
Rick Stevens

I'm still waiting for a B engine in a Miata. Someone with the time and expertise must want to do it as badly as I would! Can you imagine the confusion when you bring such a creature to a British car show? I wonder if they would let it in?
Steve Simmons

http://www.eclecticmotorworks.com/miatab.html
mw michel

I've got a friend who has a Miata-powered MGA and is working on the same drive train in a BGT.

I can pass on your address if you want info.
Simon Austin

In the UK a chap has recently fitted a K Series engine in his B. Not directly relevent I realise as these engines are not easily available in the US. However, he did need to modify the crossmember and this might provide some pointers.

See http://www.kewengineering.co.uk/upgrades4mgs/ed_bracklik_k%20conversion.htm

Interestingly another chap is currently in the process of fitting a KV6 engine into his B, which could end up in a very interesting car!

Iain
I D Cameron

I always thought the BMW M3 Engine and Box would go well in a B:)
K Harris

I couldn't get the K-series link to work.

This should get you to the site, then follow the link for the K-series...

http://www.kewengineering.co.uk/upgrades4mgs/engine_choices_for_the_b.htm
Dave O'Neill 2

Carl Heideman has an article in the June issue of Grassroots Motorsports magazine about his Miata to MGB driveline conversion. There will be several articles on the conversion in future issues of the GRM. See the link posted by mw michel above for some photos of his conversion. Carl will probably conduct a seminar at import Carlisle later this month. Carlisle has combined the import Carlisle with modern imports this year so there will be a million cars with wings. coffee can exhausts and boom box stereos. I had planned to go but I went several years ago when the combined the show and it was a big mess, so I'm passing and will go to a local car show that weekend.

I also have a Protege 5 and it's a great little car. Too bad they only made them for two years. No mechanical problems, the front spoiler gets chipped easily and rocks have cracked both driving lights. Most of the 55k miles on it were on long trips, that accounts for the chips and cracked lamps. It's also difficult to find tires for them and they are expensive due to the odd size. You can get performance tires but they will not work very well in rain or snow.

Clifton


Clifton Gordon

Early this week we had our local MG Club meeting and also discussed upon different engines for the MGA and B.

There are many possible solutions here in Europe, that would fit an MG engine bay without cutting the front crossmember. The drivetrain of a crashed car might be the cheapest solution if not a MG B engine and box is to be used, but don't underestimate details to be develloped and fabricated to make it a satisfying solution.
The main problem with this kind of swaps is, that they are one way tickets if not the Buick/Rover 215 route is to be taken ona post 1977 car. This V8 conversion is not that expensive and will be comparable to the costs of differnt alternatives but makes the B a perfect drivable car and can be straight forward.

Another solution should be a development of an EFI crossflow MG based upon the 18V H engine, using a Megasquirt blackbox and an EDIS ignition system.

By now an expensive and time consuming way but are there some more interested drivers or clubs to develop a kit for this modernisation of the engines?

This kind of development would keep the charakter of the car, does not ask for changes of the engine bay and would be much fun to drive at it would be capable fore more fun than a stage 2 or more at comparable costs but still with the feeling only an MG engined MG will give.

Ralph




Ralph

Ralph, check out this thread from the MG Experience forum: http://www.mgexperience.net/phorum/read.php?42,538713

R.
Rick Stevens

The Miata engine fits quite easily in the MGB. You will have more work on electrics than worries about cutting and welding - advice from a friend that has done several - keep as much of the Miata harness as you can.

The easiest swap into an MGB is the GM V-6 - it is basically a bolt in with the various motor mount and trans mount kits available. I only wish it had been as easy into my Jamaican MGA!

If you want to add injection and alloy heads to an MG engine, by all means have at it, but IMHO you are trying to tart up an old boot to look like a new shoe. The Miata is a modern engine with all that entails. The MG engine will never perform in the same league as a DOHC 4 valve with up to date electronic control.

Now the GM Solstice 4 banger also has possibilities especially in turbo form......
Bill Spohn

Thank you all very much for your replies.

I went to the salvage auction this morning to bid on the Miata that might have been my MGB's donor car. It was about as bad a wreck as it could have been, and not have hurt the driveline. There were no wheels with the car. The only straight piece of sheet metal on the whole thing MIGHT have been the passenger door. It would not open.

I was outbid at $800 as I had bought three other cars on Wednesday, and didn't have another $1000 in my budget. The buyer's fees would have made my total that high. I know buying a driveline from a salvage yard will cost me more than that, but It's all I brought to the show. Perhaps there will be another opportunity in the future, and if it's an older Miata it will be cheaper.
Chuck Asbury

I'm with Steve Simmons, a hopped up 'B' engine and trans in a Miata!

LOL

But seriously, you should consider a Camaro 3.4 V6 transplant in your 'B'


And here's just the guy to fix you up.

http://bmcautos.com/home.shtml

Yeah, he's my son. But these things work great, same weight, double the torque and HP.
And they go like a Corvette.

SF
Dwight
DCM McCullough

I've messed around and installed an early Nissan 300zx v6 in a late MGB. It took some cutting and modification of the front cross member, and the headers are pretty tight, but other wise fits without much problem. In hindsight the GM 3.4 v6 is more compact and has kits available.

It would be cheaper tho' to attach a Moss supercharger and have nearly the same performance for a lot less $.
Barry
Barry Parkinson

Dwight,

I was wondering how long it would take for somebody to add the V6 option to this thread. Especially for North American owners since this is a well-tried successful route and the engines are readily available.

But I have a question: have you, or has anybody, successfully transplanted a GM 4.3 into an MGB?

Thanks,
Allen
Allen Bachelder

Hello,

This site discuss many swap for MGA but one interesting is a Toyota swap. It could help for a MGB transplant:

http://mgaguru.com/mgtech/power/pp507.htm

Cheers,

JGC
Jean Guy Catford

Allen
If you look in the archives several years back, a kid modifying his dad's MG decided to put a 4.3 in. He was advised against it as the 4.3 is a 90 degree engine (the 3.4 and smaller is a 60 degree engine) and is bigger wider and heavier.

A few months later there were plantive cries of help regarding how to modify the frame etc to get the engine to fit.

I never heard whether he got it going or not.

The small block Ford 289/302 has been reported to be dificult but successful. The reports as I recall is that the stock front suspension was not up to the additional weight.
Barry
Barry Parkinson

http://www.britishv8.org
Dan Masters

The Ford 302 conversion is a very popular modification these days...the engineering of the transplant has been fine tuned quite nicely..and when done with some thought and planning, the MGB front crossmember handles the powerplant quite nicely.
rick ingram

In this list there is one MGA with a 4.3 Vortec V6 and one MGB with a 4.3 V6. Several interesting conversions are shown.
http://www.britishv8.org/Photos-MG-Conversions.htm

Several years ago there an MGB with a 90 degree V6 engine conversion at the BMW Euro car show. It was a very nice conversion with lots of detailed work. The header tubes exited through the inner fenders. As recall the car was from the Asheville, NC area.

Clifton

Clifton Gordon

Put in a fuel injected V8.
1-It's easier, its been done 1000's of times-no nasty suprises.
2-It's cheaper, off the shelf parts from many suppliers.
3-It has market legitimacy, because the factory did it (two versions) it is a "real MGB" so it holds its value. In Australia the V8 MGB's (even conversions) are worth much more than the fours and way more than other engine swapps. Caution- This may not be the case where you live.
4- It sounds magnificant and is very drivable.
5- Ecconomy is around the same as a SU carberated four. It is lighter by about 30 kg.
6- It goes like a bat out of hell.
Peter

This thread was discussed between 04/05/2007 and 07/05/2007

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