MGB & GT Forum

OK, The BW T35 was garbage and very few were made in MGs. If I wanted to keep the B series, how hard really would it be to mount an Asian OD automatic? Either Toyota or Volvo sourced.

First, a flex plate of the correct diameter. One could them fabricate a new center hub with the correct bolt pattern. Small differences could be made up in the starter mounting. Use the Toyota torque converter etc. Now, only problem is bolting up an adapter plate, trans cooler in the rad and shiftier. This does not seem impossible. Any thoughts from those with more experience than I in these matters? A Celica was not much heavier, so stall speed should not be an issue. Could a really good TIG welder just weld the Asian case to part of a old MG bellhousing?

My only other alternative is to junk a perfectly good Celica to get the 20R and trans to do a complete swap. Probably easier and cheaper, but it would pain me to trash a perfectly good Celica.

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Cogito ergo sum periculoso

I wondered why the Rivergate people didn't offer a Z car automatic conversion kit for the MGB.

If a 5 speed Z car transmission fits maybe a Z car auto would fit as well.

Probably because the market for such a conversion would be too small to justify the development expense...

Maybe it would, maybe not. With no viable choice, who knows. A lot of us are getting darn old.
It should not need much more than a new or modified rear plate. I don't know what trans Datsun used. If an older 3 speed or even 4 speed without a lockup, then it would not be a big advantage. The 42 and 43 series are long, but narrow. 700R or AOD are really fat. The Mazda uses a later version, so whoever is doing the Mazda conversion may also be a good starting place. A Microsquirt can me coded to control an electronic one, but I would guess most here woudl want hydraulic control.

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Cogito ergo sum periculoso

There is no flexplate option to fit a 280Z auto to the MGB. That's kind of where it starts and ends.

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jeff@advanceddistributors.com

Scott

when you say "BW T35 was garbage" what are you basing that upon?

I have a factory auto and it runs well. just installed a supercharger on it too.

i admit that gear changes may not be as smooth as a modern auto, but on a recent RR session, despite the fact there is no lock up clutch in the BW35 torque converter, the transmission held perfectly against the rollers. no slipping

I don't have a trasncooler. RR measured 140hp @ engine, so ~ 110-120 @ wheels. BW35 sat behind more powerful engine with no transcooler. i do look at my TQF fluid from time to time and looks very clean, no sign of burning.

I tend to drive mine like a clutchless manual and engine braking is effective too. kickdown has no more latency that my 200hp volvo.

it would for sure be great to have a 4 sped box with say a.75:1 top gear rather than 1:1 for cruising.

G

Graham,
Well, I had two of them, both failed. Not only this forum, but the Volvo forum is full of "complements" about how inefficient it is. The difference in my 99s with and without auto was huge. You are about the first person I know of who has ever been complementary. Your blower probably overcomes what it is sapping in HP.

Jeff,
Of course there is no off-the-shelf flex plate, but finding one about the correct diameter and fabricating a bolt ring for the hub and drilling holes for the torque converter does not look that difficult. If close, re-drilling the engine plate to tweak the starter location does not seem impossible. I am not expecting any bolt-on magic no one has discovered, only suggesting it may not be impossible. Considering we already have an engine plate to fit a miss-matched trans to the block, we are half way there.

I did just learn a lot of Rover SUVs were sold here in RWD only and the junk yard is full of them. There may be Rover V8s with OD autos available. Some research is in order. I have no idea what trans they used or how big it is.

My preference is still a 20R with already fit automatic, but no luck getting one yet. The B engine, considering it being a '50s water pump industrial engine, is not a bad bit of kit. It would be neat not to abandon it. Supercharger or turbo if power is needed. Not as cheap as displacement, but it is a mighty strong block. I have also been looking at the front cross-member, and if one re-routed the fresh air vents, maybe enough room for a Nissian engine as they need more rear clearance.

If one fit a blower on the B, put in the 3.5 rear end, maybe the BW would work OK. Can the valving be tightened up? Mod the vacuum servo? Better clutch disk and band materials? Then the little problem of them being just about non-existent over here.

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Cogito ergo sum periculoso

Ford Ranger A4ld for 4.0 V6 is very compact. Separate bellhousing. Used in Baja as a 6 speed manual with mods. The OD is in front of the C3 3 speed auto. Also the motor plate Dave Headly sells for the T5 conversion allows bolt up of GM 60 degree V6 bellhousing to stock MG 4 cylinder allowing the V6 S10/Camaro 700R4. You have to use the smaller 3 main flywheel ring gear on your flexplate. Simple spacers and crank pilot.



Edited 1 time(s). Last edit at 2017-05-02 05:46 PM by 260mgb.

I was not aware of the A4LD. Should be widely available. A MicroSquirt can be used as a controller if an electronic version. It looks like the Toyota being long and skinny. I'll read up on it. If they put it behind a Colone too, that might be a viable option, even though the 2.6 was not a great engine. It was small. I thought most used the AOD, which like the 700R4 has a big fat pan.

I sent Dave an e-mail about an automatic and got no answer. Same with the other guy up north that claimed to be working on it. The 700R4, obvious availability option, has a very wide pan. I know one car with a V6 and 700R4 in it and he had to modify the tunnel quite a bit.

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Cogito ergo sum periculoso

A combination I had not seen, the 3.0 Vulcan V6 with the A4LD, 86 Aerostar.
Getting away from the idea of a modern trans on the B engine though.

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Cogito ergo sum periculoso

Hank on this board did a 3.0 Vulcan V6 swap.

http://www.britishv8.org/MG/HankRonish.htm



Edited 1 time(s). Last edit at 2017-05-02 06:20 PM by 260mgb.

I think your best bet is a 200- 4R. It's narrower than a 700R4 and shorter as well. The pan is bigger but that's of no concern.

It has better, closer ratios and has a lot of aftermarket support. It can be built to handle far more power than you could ever dream of making.

My approach would be to make a new engine plate, modify a GM flexplate, and reposition the MG starter to match it. Similar aproach had been used on other antique engines.

Dave has a back plate for Chevy V8 and Ford V8 bellhousings also for his T5 conversion.



Edited 1 time(s). Last edit at 2017-05-02 06:24 PM by 260mgb.

Nope. All the Range Rovers and Discoverys were AWD with a transfer case. The ZF transmission is pretty big.
The only RWD Rovers that came over with autos were the P6B 3500 which used the BWT35 and the Rover SD1 which used the BWT65

Chasing the Asian connection is going to be more fruitful.

Width of the pan was what the guy with a 700R4 said was the problem. 200 looks slightly smaller. Can't find any reference if they came with lockup converters. I am pretty sure the 700 did.

What Jack said is my thought, but the Asian looks like a better fit.

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Cogito ergo sum periculoso