Spitfire An automatic for a Spitfire

[Coastalman]

I have an opportunity to get a Spitfire with a blown motor, but with a very nice body. My wife has ridden many miles with me in my Healeys so I thought this might be a chance to do something good for her. She would drive a Spitfire if it was automatic drive.
Do any of you on the forum know of a small engine with automatic transmission that could be installed in a Spitfire without a major modification of the existing body work/engine bay?
If I could make this work without a big hassle it would be fun and make my wife happy to have a LBC that she could drive.
Thanks,
Charlie

 

[HealeyRick]

There's a few conversions with autos here: https://www.britishv8.org/Photos-Triumph-Conversions.htm

 

[dklawson]

Hey Charlie! I've been wondering how you were doing. Will you be up here for the show this year?

For the gearbox conversion are you thinking of staying with the Triumph engine or changing that at the same time? I don't know how hard it is to find an automatic Miata but I would imagine a complete Mazda engine/gearbox transplant might be a good choice. See the link below.
https://jalopnik.com/5691898/for-6000-the-spitiata-is-the-lee-majors-of-sportscars

If keeping the Triumph engine, you'll want to look for a gearbox no longer than the Triumph single rail gearbox with overdrive. You might have to modify the transmission tunnel (of the tub) if this is an early Spit. That would give you a fair amount of length to work with. Unlike the BE or Spridget, the Spitfire has a removable transmission tunnel which is fairly wide. Originals were made in a cardboard-like material and I have seen aftermarket ones in fiberglass and some form of plastic. Tunnels of the later two materials could be customized to work with larger (wider) gearboxes if necessary.

Some of the larger Triumph sedans could use a Borg-Warner (35?) automatic but I think those all bolted up to the larger 6 cylinder engines and fit cars with wider tunnels. I think some of the Triumph Dolomites had automatics but you aren't going to find those as donors in the U.S.

 

[number6]

I believe the Sunbeam Alpine used a Borg Warner type 35 auto unit coupled to the 1725 engine, not sure that it will fit a Spitfire however. I had that unit in a Rover 2000 SC and as I remember it,
it was quite wide in dimension. I have heard that Mazda rotary's are a fit for a spitfire. You might try the British V8 website for information. They cover a lot of conversions that do fit the car.

 

[HealeyRick]

I wonder if a Miata motor and automatic would fit? https://jalopnik.com/5691898/for-6000-the-spitiata-is-the-lee-majors-of-sportscars

 

[Andrew Mace]

Unfortunately, the BW35 is incredibly wide, likely necessitating major surgery to a Spitfire type chassis, since the rear part of it would sit where the main rails have tapered in to little more than a "backbone"! Even the experimental TR3 with the BW35 sacrificed a good bit of foot and leg room. Plus, by today's standards, it's a pretty inefficient three-speed box.

I like the suggestion of a Miata drivetrain, in part because they're probably not hard to come by nor outrageously expensive. Otherwise, small RWD engine/tranny combos are pretty scarce these days (thinking to the days of RWD Corollas, Chevettes, Datsun B-210s and the like).

 

[Coastalman]

Hi to all and Doug, I was thinking about a full motor/transmission conversion. The Miata sounds good. I will check out the link. In fact, a neighbor with an automatic Miata was just telling me today that she was thinking about selling her Miata. I would probably get a better deal from a salvage yard. If I get the Spitfire I will keep everyone updated on the build.
Doug, I will not be at any of the shows in the near future. I am having back surgery on next Monday and I will not be doing any events or car work for about 4 weeks or maybe more. I am hosting the Ice Cream Social for classic British cars again in August on the 19th if you can make it down. Email lf you want details.
Now I will have time to figure out how to make the Spitfire an automatic.
Charlie

 

[dklawson]

I'm sorry I won't see you at the show. It's been a few years since we've met face to face.

I did not read all of the article I sent you a link to. However, they did mention the Miata drivetrain weighed less than the Spitfire engine and gearbox... with more power. It sounds promising. Let us know if you pursue it.

 

[Coastalman]

By the way Doug, Ed sold his big Healey and has now bought an Aston Martin DB9. It is a rocket!

 

[HealeyRick]

One thing about the Miata motor is that it's tall. You'll probably have to cut a hole in the hood and cover it with a scoop. Usually, the problem with a swap using an automatic is the tranny width. I have no idea what size the Miata auto is, so probably something you want to check out first.

 

[martx-5]

... However, they did mention the Miata drivetrain weighed less than the Spitfire engine and gearbox...

The article mentioned that the Miata engine had both aluminum head and block. Not so, the NA, NB 1.6 and 1.8 engines have cast iron blocks with aluminum heads. The gearbox is larger also. I doubt it is lighter then the Spit engine and gearbox.

Edit: I just looked up the weights of the Miata 1.8 engine and gearbox. Engine with head, intake, flywheel, clutch & ancillaries comes in a close to 300 lbs., gearbox with TO brg etc at about 85 lbs.

What's the Spit engine weigh??

 

[dklawson]

Edit: I just looked up the weights of the Miata 1.8 engine and gearbox. Engine with head, intake, flywheel, clutch & ancillaries comes in a close to 300 lbs., gearbox with TO brg etc at about 85 lbs.

What's the Spit engine weigh??

The reference pages at the Spitfire & GT6 magazine site say the weight of a stripped Spitfire engine is 220 lbs (without the flywheel or ancillaries). They did not say which displacement engine that weight was for. The folks at Triumphexperience use that 220 lb figure for the 1500.

Paul Tegler has a page where he discusses alternate engines and their weights. Link below.
https://www.teglerizer.com/triumphstuff/performancedata/III_whichengine.htm

Paul lists the Triumph 4 speed gearbox as 42kg. Paul lists the weight of the Spitfire engine as 125kg... presumably with flywheel and some ancillaries. Adding Paul's figures a basic Spit engine should be close to 167kg (as much as 368 lb).

The article on the Miata swap may have underestimated the weight of the Mazda engine but the total drivetrain weight might still be slightly less than the standard Spitfire parts.

Charlie, be sure to look at the page I linked above for other possible engine swaps.

 

[Coastalman]

Thanks Art, Rick and Doug. I will do a bit of research before I jump into a project like this. I also have a local Sprite, not BE, as a possible buy, but that would not be automatic. My thinking on this is to provide a LBC that my wife can drive. I remember a BE that was at the 50th party in Pa. that I attended that had a Chevette engine with automatic in it. It was a very nice fit and worked very well. I don't know if there are any Chevettes around anymore. It was nice though.
Charlie