MGB GT ?

Another "learn me" thread...

For some reason, I'm drawn to these cars lately. I've found a fairly solid one and want to transplant a Miata drivetrain into it...

Before I really piss my neighbors off and just impulsively drag yet another old, dead sports car home, what should I look for when I go to see the car?

rust is the only enemy in this battle. All else is easy to deal with.

I have a 67 GT that I have had for 30 some years. I just like the looks and feel of how it drives. http://www.cardomain.com/ride/2663062

I am doing the floors and rockers on another MGB and can tell you that it will take 100 hours of your life and $1000 in parts to get it done if you want to do a restoration. If you want a detailed pictorial of what is involved: http://www.cardomain.com/ride/3385137

Huge support community and parts availability. Head over to the MG experience if you want a feel for the community: http://www.mgexperience.net/phorum/list.php?1

They are the definition of a grassroots motorcar. Unless you are looking to show the car, $10k would be the top of the heap for good cars that you can drive without doing much.

funny, I was just today reading some old '07 GRM mags in my garage that were when they were doing the MGBGT Miata drivetrain setup....

owning a GT6 an having driven a couple BGTs (non-V8), they're both good options depending on what you want. Stock for stock the GT6 has a peppier engine and (IMO) a better handling car for high-speed work (the GT6+ at least). The BGT on the other hand has a superior ride, more balanced handling, and a more "modern" interior (if you could say that).....

I think the GT6 is more fun to drive on windy roads while the BGT is more fun to drive everyplace else, basically :)

But with a Miata drivetrain swap, you get the extra power and still have the nice handling balance and interior on the BGT, so best of both worlds.

Frankly, i wish I had one of each but the wife won't allow it :)

irish44j wrote: funny, I was just today reading some old '07 GRM mags in my garage that were when they were doing the MGBGT Miata drivetrain setup....

Do you remember which issues? I would like to dig them out of my 'archives' to see what's actually involved in the swap...

Forget the Miata swap:wrong engine for this car as far as bang for the buck. The GM 60 degree V6s are a well established swap and will provide both better initial power and good potential. The Miata is just going to get more high strung as you squeeze it for power.

ford 302 is a better way to go and also well documented. The one negative tot he GT is that it does get hot in the summer, a swap is not going to help.

Really fringe individuals put LS1s into these cars. At least until they let their editors or agents get in the way ;->

I thought that the original car was designed for a HEAVY engine, so a miata drivetrain isn't the best idea. Somebody correct me if I'm wrong, but isn't the weight distribution better with a heavier (read bigger) engine?

One question you should ask. Is this an MGBGT? If you answer Yes, then you should take it home.

NOHOME wrote: Forget the Miata swap:wrong engine for this car as far as bang for the buck. The GM 60 degree V6s are a well established swap and will provide both better initial power and good potential. The Miata is just going to get more high strung as you squeeze it for power. ford 302 is a better way to go and also well documented. The one negative tot he GT is that it does get hot in the summer, a swap is not going to help. Really fringe individuals put LS1s into these cars. At least until they let their editors or agents get in the way ;->

I assume you aren't including the the fact that a Miata engine is an easy 200+whp dead nuts reliable diy turbocharged beast in that statement?

I'm pretty hell bent on the Miata drivetrain swap. I already have the donor car and I'm toying with the idea of making a DD out of a Miata-swapped MGB GT.

I did a 302 conversion on a GT. I think there's only about 5 parts that are still original MG. About any 35 year old car is likely to have rust issues - for mgb, floors are easy. Sills are more complicated - but the fix is well documented. Vulnerable areas - sills, floors, dogleg (in front of rear wheel), lower front fenders and wheel arches. Wiring - it's lucas...I went aftermarket. Just about every body part is available - aftermarket fenders are spendy. Somebody has done about every engine swap you can think of from ford 460s to turbo nissans. The v6 and v8 conversions are more documented/more support, but a good twin-cam conversion is pretty intriquing. My conversion was on a challenge budget - now the challenge has come & gone I've thrown the checkbook at it. Like a lot of stuff - start with the best donor you can come up with - it will speed things up a lot. It's a pretty good platform for playing with - overbuilt unibody. Looks good - not rare enough to worry about carving one up - bonus points for annoying MG purists. 6-7k gets a pretty good driver -3-4k should be very usable. Mine was $150 (bad motor, floors and front fenders)

btw a 302 weighs 80lbs more than the stock motor - IIRC the GT has a 52/48 weight dist

I have fond memories of my father's 68 GT. I think the Miata drivetrain is perfect for these cars. People forget how little HP they had new

NOHOME wrote: Really fringe individuals put LS1s into these cars. At least until they let their editors or agents get in the way ;->

The book's done, I'll be working on the B again this week. And the check from writing the book will help fund the MG!

I think a Miata engine and transmission would be a great match to the chassis. For someone else, obviously But it looks right, it'll fit well and it'll have performance similar to the Miata the engine came out of. The GT is a really pretty little coupe. My "parts car" is parked outside so I see it every day, and I'm appreciating the shape more and more.

I love the MGB GT. One of the all time great shapes.

Have a look for a preview of what you are getting into. http://www.eclecticmotorworks.com/miatab7.html

I drove a Miata for 13 years and have nothing but respect for that car. I have had my GT since 1978 and it has been in a non-stop evolution to become the perfect car.

Putting the Miata engine in the B will make a better B, but it still will not be the perfect car that the Miata is. You will achieve 90%of the results of doing a Miata swap by bolting a 5 speed behind a fresh B engine with a fresh engine and a ported head.

If memory serves, the Miata had a 4.10 rear gear. the B has a 3.9. The Miata does not have a lot of torque down low, so the gears are working against you. There is a 4.11 MG gear, but it wont be cheap by the time it is in.

Swaps are never cheap and you are going to end up with more money in the swap than you would buying a nice Miata

Maybe take a page from the civette book and drop the GT shell over a Miata frame? http://carscoop.blogspot.com/2007/06/civette-honda-civic-with-corvette-ls1.html

Regardless, you will have an adventure if you do this swap. Make sure you post it somewhere so we can follow along.

I am surprised the B has a 3.9 rear. I am used to my Fiat's with the 4.40

If you've got a 3.9 rear, stick a Miata 6-speed in. That's the rear Mazda used with that transmission. You can't look at the rear end ratios without taking the transmission ratios into account.

Miatas and Bs don't have separate frames of course and the Miata is about 4" wider, so it's probably easier to simply swap the drivetrain. Maybe that's what I'll do with my "parts car", it's a complete car with no engine or transmission.

For those that are doing an engine swap, my local fiberglass shop does bodykits for the MGB - Including a bulged hood:

I dont know how much of the rear quarters match between B & GT, but here is the SCCA bodykit:

Kendall

A 1.8 MeOtter would make a good swap when used with the stock 3.89 B rear axle. I'd definitely upgrade the front suspension and brakes; it wouldn't be that hard to adapt Miata uprights and brakes, then redrill the B rear axles and drums for 4x100 mm (so your wheels would match front and rear) add A/C since GT's do get toasty inside and then have a good ol' time.

I question stuffing a cast iron V8 in there. Sure, lots of people have done it but the front of engine sits right over the front axle centerline, meaning some of its weight hangs out front, boogering up the PMOI. The amount of chopping to move the engine back a decent amount to keep things balanced would lead to the heater box going away, which may or may not be important.

B's are already sort of porky to begin with, the extra 80-100 pounds would do no real good. I'd seriously consider a Taurus SHO V6 or a Nissan VG swap before I'd do a big horkin' cast iron lump.

The Miata-swap issues are in the store. Look under "collections".

A 302 (with aluminum heads) only adds 50 pounds.

If you want a swap that likely is 1) easy, and 2) plenty of performance parts support, you might want to look into a Toyota 4AGE.... 112hp stock , but with room to build it to 160 and still keep it full street...

One reason for a 4AGE... they sound WONDERFUL, and cruising down the back woods in an MG touring with a wonderful twin cam note to the engine...... pure music... no radio needed

If you need torque, you can look into a supercharged 4AGZE, 145#/ft at 2000 rpm

MG Experience

This was my go-to site for the 5 years or so I've been running mine. You will find all the 'experts' on the subject there at some point or another, and I think there are write ups on swaps if i remember correctly.

I was looking into MGB GT's a week ago as a swap candidate, and everything in this thread went through my mind. Was sparked by my dad sending me a link to a 4AGE powered MGA.

Not sure if they fit well, but a sr20 has a really nice personality.

Plenty of swap info at British V8 not just V8

My dream BGT has a 3.8L Ford V6 from a 1999 - 2004 Ford Mustang