Jump to content

Suddenly have a large trove of Spridget parts, 7 S2 build?


Recommended Posts

The only real 7 I ever got to drive was Sprite powered so I think an S2, even had wire wheels.

Just lucked into a ton of Spridget parts and so interested in recreating the nifty little 7 I drove all those years (Decades!) ago.

1275 Engine and rib-case trans are obvious, along with the wire wheels.

What other parts may be used from a Spridget?

And where to find original dimension drawings so it all looks right when done?

 

This has to follow on after my current 442/Kent 1600 build.

But I need to plan now so that I keep the correct parts on hand.

 

Link to comment
Share on other sites

The rear axle on most of the series 1 models were derived from Nash Metropolitan or the A40 model but with 15 inch wire wheels. I understand this is essentially the same as the early bugeye Sprite 948 axle but of course has some plates welded on just inboard of the brakes to attach the trailing arm suspension bits. The Sprite engined 7 America model apparently started as a series 1 but had series 2 looking fiberglass "clamshell" front fenders to comply with USA requirements since cycle fenders were not allowed. I think the early ones (1960?) did not have that "A frame" attachment to the bottom of the center like series 2 ( I understand that move caused a lot of problems as the attachment to the rear housing caused the TR-10 housing to crack unless you welded on a reinforcing plate to carry the suspension load). Instead they had upper and lower trailing arms just inboard of the brakes. But the early 7s had a small Ford side valve motor usually and skinny 15 inch tires so not all that much loading on the various axle parts. Not sure about the ones that were fitted with the Coventry Climax motors for racing as they were probably also treated to various trick parts derived from the Lotus 11 racing experiences. My series 1 , number 475 (so the 75th built) was originally built with an A40 rear axle and a 1300 twin cam Alfa engine so was an oddball but survived quite a few owners, per the official UK paperwork I have, before I shipped it to the USA in 1978 and finally installed a 1500 early Cortina type motor ( dual 40 DCOE etc). All those years with the 1300 seemed to be fine for the axle as it looked perfect inside and out. i understand the somewhat newer Sprite/Midget axle shafts were made with a better heat treatment or alloy and are even less prone to failure than the older bugeye types. Racers usually install a dual bearing set-up for Sprites so  you could consider that while you have it all apart. It should be a great drive with a 1275 so good luck.

Link to comment
Share on other sites

I have some photos and a drawing of the A-series engine mount bracket that I can post for you when I get home.  I'm not sure what else was specific from a Spridget-powered Seven.  I have a S2 replica vintage racing chassis that is set up for a Ford X-flow that I could send you some photos if you were interested.  

Link to comment
Share on other sites

There are several S2 chassis drawing sets floating around out there on the internet, some "original", others with various modifications from DSK, Pat Prince, and a few others. They've been handed down through various internet forums and such, so no guarantees as to provenance (or copyrights). I've done a full scale layered version to compare them for my own version, an original looking slightly enlarged S2/3 to fit long legs and big feet. If you're interested, let me know.

Link to comment
Share on other sites

I have several Spridet axles including wire wheel.

Need to confirm correct track width, Spridget is only about 50".

Also wondering if Spridget front suspension parts are of any use?

I know the gauges can work.

Link to comment
Share on other sites

6 minutes ago, anduril3019 said:

There are several S2 chassis drawing sets floating around out there on the internet, some "original", others with various modifications from DSK, Pat Prince, and a few others. They've been handed down through various internet forums and such, so no guarantees as to provenance (or copyrights). I've done a full scale layered version to compare them for my own version, an original looking slightly enlarged S2/3 to fit long legs and big feet. If you're interested, let me know.

 

Very interested.

I have the 44 and 442 drawings but they are large enough to hold a V8 so certainly poor dimensions for a 1275 Sprite engine.

I am no taller than when I drove that original so long ago, just a bit thicker, so this may be as much a diet plan as automobile build. :classic_laugh:

Link to comment
Share on other sites

Do you have graphic or technical drawing skills and or software? If not, I can make you some scaled PDFs. My drawings are in Illustrator (an odd platform for technical drawings, but it works for me!)

 

Front end on the 7 is Triumph Spitfire and Herald, Steering Rack, Uprights, Brakes. You could probably make the Spridget parts work, depends on how authentic you are trying to make it. You'd have to work out A arms and associated geometry. Spridgets use lever shocks, with the lever acting as the upper locating arm. With the Spridget stuff, you'd still have a period correct "special," just not quite original.

 

Have you visited the Locost USA forums? (http://locostusa.com/forums/) Tons of build information there, and as many opinions. The main thing you might run into in discussions regarding building something kind of original is, "Why bother?" There are better, cheaper, easier to find components, as well as easier ways to build and complete your project. Personally, I'm taking a similar route to yours. Why? Why not! It won't be a "real" 7, and it won't be the fastest 7, but it will be fun, and it will be mine, that's reason enough.

 

Message me about drawings and what file formats you can work with.

 

Link to comment
Share on other sites

Not sure, but you may want to be cautious about using a Sprite rear with series 2 type suspension. As I mentioned, the series 2 had that "A frame" under the Triumph TR-10 rear for lateral location and that puts a huge load (twisting I think) on the center of the housing and may crack it. Not sure if you do this, just how to best reinforce the axle housing. I think some builders have adapted the Ford Cortina axle which may be a bit wide or some early Toyota Corolla maybe. You could alternatively use a series 1 type setup like I have. That has upper and lower trailing arms with the lower right having a tube for lateral axle control welded to it that runs at an angle from the rear of the arm to connect to the frame with a bushing pivoting on a stud coming out from the 1 inch square frame that surrounds the rear of the driveshaft tunnel. If you want to try that I can take some measurements and send them. Alternative I guess is fabricating some sort of Panhard rod to locate the rear housing. I am not qualified to design that approach however.

Link to comment
Share on other sites

I have been on Locost USA for a long time.

But that site seems to have little enthusiasm for the original 7 concept or use of a "mere" Sprite engine.

Lots of excess HP there, up to and including blown or turbo big-block v8's. 

Most builds have lost the "Simplify" concept as well with EFI and Turbo, plus digital gauges, in nearly every build.

What I am after will not be a real 7 no matter what I do, and with no intent to sell no reason to not make it to suit only myself.

Link to comment
Share on other sites

Agree with you on Locost USA, but I have come across some good fabrication tips there. I actually considered using a Spridget drivetrain on mine but finally settled on a Cortina rear end, transmission, and pre-crossflow 1500. Keeping it simple and old school.

 

I’ll send you the S2 drawings in a few days, I also have a pretty detailed parts list I’ll share with you, it may or may not help. Hope it goes well, I’d love to see your progress as it comes together. 

Link to comment
Share on other sites

Hope to use as many Spridget parts as possible since I have them in such abundance.

TR10, Metropolitan, and even Morris Minor rears are now hard to find.

Even a TR7 rear is not easy and they are fairly recent.

Have not seen a Cortina being parted out in decades.

Link to comment
Share on other sites

Would be nice to use as many of your Sprite parts as appropriate. Watching out for suspension attachment points might be important as it possibly changes the roll center for front and rear. That could make for a very ill handling car and after all, superb handling is why all of us are attracted to Lotus designs in the first place. That said, the Sprite rear and series 1 suspension design works ( no suspension attachment point at bottom center of the rear housing like series 2). Works  for sure as far as handling goes and I suspect would handle the torque you are liable to apply with a 1275 given how light the car should be. Or are you planning to go all out with the motor and use slicks for some competition? Not so sure about the front as that Sprite suspension is way different from Lotus practice. Staying with the lever shocks means using your wire wheels is easy. If you use a more Lotus 7 approach on the front then the wire wheels might require some sort of adapter? Others may have experience on how to fit AH wire wheel hubs to Triumph Herald/Spitfire uprights/hubs. Maybe simple but I never tried it. I understand that Mike Brotherwood in the UK makes complete frames and might be good to contact. Just another thought-- watch your clearance, rear wheels to frame and trailing arms, as the Sprite rear is fairly narrow.

Link to comment
Share on other sites

Unfortunately I couldn't find the drawing of the engine mount for the A-series.  It must have been saved on my previous PC and didn't get moved to my new one.  I did find this photo from a BAT auction which shows the mount pretty clearly.

1965_lotus_seven_1558657045cd20849207307.jpg

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...