Old British Sports Cars as Donors?

[trials_man]

While I was working, driving my route through Southern Indiana, I saw a Spridget that was pretty forlorn and likely for sale, and it got me to thinking about using MG's, Triumphs, and Sprigets to harvest for components. I'm interested in a "historic" or "period" at this point. I'm quite open to Ford stuff, but I did a little cursory research for an updated Series One/Two style Seven:

 

Ford Crossflow

MG/Triumph gearbox with Laycock OD, or Pinto 4-speed

BM/BL sports car rear axle, brakes, and spindles

Wire wheels, 13-15 in.

 

I know the Spifire's pretty attractive for this sort of thing, and I reckon the Spridget's track dimension wiukd likely work against it.

 

Thoughts?

 

Dennis

[MHKflyer52]

I built my 7 clone and used an MGB as a donor for the drive train and it works very well.

[notakit]

The MG's bushings at the frame can not handle the torsional forces of the Lotus 7's anti-sway bar/upper arm design. You'll need to build a true "a-arm" with a seperate anti-swayback like the Caterhams and clones.

[notakit]

"swaybar" not swayback. lol!

[DeanG]

A spridget would work well for engine, transmission, rear end but there isn't much power.

 

If you were to go with a Ford engine I would go with a Ford transmission. It is rare to hear of transmission problems with Elan's which use the Lotus twin cam on a Ford base along with the transmission.

 

Starting with good parts is important. It is easy to drop $6K on a spridget engine rebuild.

[trials_man]

I've been looking into the spridget option this weekend, it's become a bit more appealing and interesting. I have to look into the abilities of the 1098/1275 A-series, I figure a 948 is too rare. I also read where you can use a Datsun 5-speed in one. Sounds plausible, since Nissan license built Austins that used the A-series.

 

I've got a copy of Tony Weale's book on the way, that might answer some things...

[HankMauel]

When rebuilding my 7, I used a 1275 BMC engine and transmission. The rebuilt engine was taken .010 overbore and a mild cam added. Reckon it produces 90 hp, give or take. The rear end in my car was a 3.90 so the extra oomph from the 1275 is useful and I get about 18.5 mph per 1000 rpm, so it's not revving it's guts out. Acceleration is still brisk and if I'm not careful, it's easy to chirp the tires.

1275 BMC engines started in 1968, if I recall, and were used for quite a while. They mount up just like the old 948's in the 7 Americas and look good in the engine bay. Good low end torque, parts availability and gas mileage make them nice motors for the 7.

[trials_man]

I'm leaning more and more toward using a Spridget donor. I'm liking the idea of a series 1 type replica and much from a spridget wiukd drop right in. They are a nit more plentiful, oddly it seems than a 1.6 Pinto which at the outset I thought might be tops. Anyway I've got David Viziers tuning.book on the A series coming so I'll be intereste in that..

 

I'm thinking a tuned Spridget drive train would make a quick Series 1 copy.

 

I looked at the car that gave me this idea, looks like it wiukd have what I need from the outside. I couldntt check it as to engine, etc, though. No one answered the door when i knicked. I do know it would have to have an A series in it.....

[escondidoron]

I can assure you that an A-series 1275 / Datsun 5-speed combination can deliver adequate power for a Seven if tuned properly:

http://farm5.staticflickr.com/4054/4207506042_2467a2b616_b.jpg

http://farm8.staticflickr.com/7018/6698312017_53b86110d3_b.jpg

Edited June 26, 2012 by escondidoron

[trials_man]

Good lord! Is that a GMC suoercharger in the Bugeye?

 

 

Vizard's book arrived today, it'll be priority reading for a while. 140HP from and A series???? I doubt I'll do that, but the tuning potential is pretty nice.....

[DavidL]

David Vizard's book is awesome... it is genuinely scientific, meaning he shows the data behind his modification ideas. Not just wild claims, but solid conclusions based on experimental data he collected.

 

---David (scientist and 7 owner)

[escondidoron]

Good lord! Is that a GMC suoercharger in the Bugeye?

 

 

No. It's an Eaton.

[trials_man]

I'd assume if I went for a 1275cc, I shiukd try and find the high compression variant?

The 1098 is interesting as well, especially since it is a pre-emission controls engine. Vizard states it can use a longer duration can than a 998, being a stroke version of that engine.

 

That plan at this point is to roam the yards, survey and get things as is where is. The stuff wiukd then be rebuilt/remain with quality performance stuuf with a view toward the finished product being "new" and tuned.

[danilo]

BMC A series motors were Fun.. back in 69/70. The blocks are 'mostly' the same , basically the Cranks and bore differ. Cooper S variants were a bit improved.

Remember these are/were Cast iron lumps with 3! main bearing cranks and siamesed intake ports. Being dead simple, there are lotsa blacksmith DIY mods possible, many being crap, but some are very good, the fabled 8 port cyl head (gasp! one intake and ex hole per cyl And Cross flow too.. how moderne can you get?) being the best(?) development.

Believe there are still (?) a few D Sports Spridgets buzzing about race tracks with their $20,000 engines :-)

Many retrofit Honda D series engine units into their Minis though.