papak Posted December 15, 2014 Share Posted December 15, 2014 I understand that the major issue with using a Miata engine/transmission in a Birkin is that the transmission is a tight fit. Just how tight is it? Link to comment Share on other sites More sharing options...
BirkinBernie Posted December 15, 2014 Share Posted December 15, 2014 Hi Papak - I built a Birkin from the basic kit in 2000. It is chassis BIY 1877. I used a Zetec and a 1994 Miata transmission. It is indeed a tight fit, but works very well. Brian Anderson (constructor of the Ultralite) designed the engine adapter, and with some development work (well quite bit actually) it has become a nice reliable package. With Brian's guidance I fabricated the engine and transmission mounts. The only real touchy spot is getting clearance for the clutch release arm - there is a chassis member very close by. Not too long after my chassis was manufactured (in early 2000 most likely given that the car was delivered to the states in September of 2000) Birkin redesigned the fiberglass footboxes. They made them larger buy expanding them into the area surrounding the bell housing. I do not think you could get a Miata gearbox far enough into the transmission tunnel in one of the later cars without major surgery to the footboxes. Not impossible, just added work. I asked Dick Brink back in those days why Birkin didn't engineer a car around a Miata engine and gearbox. Seems an obvious solution vs the Brit gearbox and expensive adapter bell housing. He old me that Japan was a major market for Birkin, and the Japanese had no desire for a car with a Japanese engine/gearbox. They wanted something "British". Never mind that the Zetec, IIRC, was manufactured in Mexico.... I think the Miata would be a great package. Research the total height of the engine carefully to make sure you can end up with sufficient ground clearance. If you decide to try it let me know.... Bernie Long Keller, TX Link to comment Share on other sites More sharing options...
papak Posted December 15, 2014 Author Share Posted December 15, 2014 Bernie, Thanks for the explanation. I guess a concentric slave cylinder would help the clearance issue to some extent. I really prefer the Birkin chassis to the Westfield but building a Duratec is a pricey exercise relative to the Miata motor. The only reasonable part is the Suby diff. Kevin Link to comment Share on other sites More sharing options...
BirkinBernie Posted December 15, 2014 Share Posted December 15, 2014 Ah - you are talking about a much later IRS car. I have never worked on one of those, so I'm no so sure my comments would be relevant. Brian Anderson had built one Miata gearbox setup before I did my car, so he had shown that it would fit. Other things you will need to solve are: transmission tunnel (mine required some fiberglass work around the area of the shifter, though the shifter position is perfect) a custom driveshaft (used a driveshaft shop in Dallas for mine) likely a custom oil pan and pickup to get clearance (pan provided by Brian for my Zetec and I fab'd up the pickup) Fit of intake and exhaust (Brian modified a factory Birkin header for me as the engine sits a bit forward of the "stock" setup and the factory headers didn't fit). I had to slightly modify the stock plastic intake. There is a frame member on the earlier chassis that runs just below the bell housing area - it had to be made removable in order to get the gearbox in and out. There are probably some adventures I have forgotten about from the build, but it was very entertaining figuring out solutions to the issues that came up. At least until some later clutch related issues came up related to the adaptation of Ford to Mazda. But those are solved now. I'll be very interested in following your build if you head down that road! Bernie Link to comment Share on other sites More sharing options...
wemtd Posted December 15, 2014 Share Posted December 15, 2014 Call Tom carlin in Colorado I think he's got some of the new wide body frames on hand. Link to comment Share on other sites More sharing options...
mrmustang Posted December 15, 2014 Share Posted December 15, 2014 Speak with Skip Cannon here, he has a Miata powered 7 There is also a yellow Birkin running around with a Miata drivetrain installed. Link to comment Share on other sites More sharing options...
scannon Posted December 15, 2014 Share Posted December 15, 2014 Speak with Skip Cannon here, he has a Miata powered 7 There is also a yellow Birkin running around with a Miata drivetrain installed. From what I am seeing above the Caterham was more accommodating of the Miata transmission than the Birkin. I did have to remove the large boss for the power plate Frame (PPF) on the tailshaft housing and some metal from the main case to get it to fit in the tunnel. I used a sawzall and die grinder to rough out a sacrificial transmission then turned the tailshaft housing over to a machinist friend along with the tailshaft housing I was going to use in the car. He removed the excess metal from the tailshaft housing and machined a mount for the factory Caterham transmission mount. I used a sander and files to trim the main case and it all fit with 1/8" clearance and the shifter came up through the factory location in the tunnel cover. In the picture the stock tailshaft housing is on the left, finished product in the middle and the sacrificial housing on the right. The other picture shows the new mount designed to take the Caterham factory mount. Link to comment Share on other sites More sharing options...
papak Posted December 15, 2014 Author Share Posted December 15, 2014 So you had to shave the right side and bottom of the case? Was this a 5 speed or 6 speed? Link to comment Share on other sites More sharing options...
scannon Posted December 15, 2014 Share Posted December 15, 2014 So you had to shave the right side and bottom of the case? Was this a 5 speed or 6 speed? It has a 5 speed. Turbos don't work well with the gear spacing of the Miata 6 speed and the 5 speed is a much nicer shifting transmission. The pictures only show the tailshaft which is shaved on the right side and bottom, the main case needed some shaving on both sides as well. No problem with the throwout arm, it came out well forward of the foot boxes. Link to comment Share on other sites More sharing options...
rzempel Posted December 16, 2014 Share Posted December 16, 2014 FWIW, I've seen an early Birkin ("88-ish IIRC) here is SoCal (don't know where it is now) that was equipped with Miata engine and transmission. Link to comment Share on other sites More sharing options...
papak Posted December 16, 2014 Author Share Posted December 16, 2014 I would imagine that I could achieve the same clearance with a few (?) carbide disks if I wasn't concerned about esthetics. Hmmmm. Sawzall? Link to comment Share on other sites More sharing options...
mrmustang Posted December 16, 2014 Share Posted December 16, 2014 FWIW, I've seen an early Birkin ("88-ish IIRC) here is SoCal (don't know where it is now) that was equipped with Miata engine and transmission. Yellow body, dual windshields (along with a 1 piece unit), sold for 15K, then turned around a year later and sold again for 16,2K Last heard to be in Florida and for sale at 18K. Bill S. Link to comment Share on other sites More sharing options...
Croc Posted December 16, 2014 Share Posted December 16, 2014 Yes Bill's memory is spot on - it was complete Miata drivetrain in a yellow Birkin. Was sold by Chequered Flag in Sth CA and went to FL and I last heard of it being in Tampa. Link to comment Share on other sites More sharing options...
mrmustang Posted December 16, 2014 Share Posted December 16, 2014 (edited) Yes Bill's memory is spot on - it was complete Miata drivetrain in a yellow Birkin. Was sold by Chequered Flag in Sth CA and went to FL and I last heard of it being in Tampa. Found my old post on it Older discussion thread from 2011 when it was for sale at a California car dealership on Ebay: [/url]http://usa7s.com/vb/showthread.php?t=6656 The car sold for $16,600. :blush: to one of our own who then had customs and logistics problems and it ended up back at the selling dealer (which still shows today): http://www.econpch.com/inventory_detail.aspx?@page_inv_id=10057 Believe it sold for $17,500 several weeks later. Current seller states "my reserve is set ultra low and 21K and it will sell for that" Bill S. Description link still active http://www.econpch.com/inventory_detail.aspx?@page_inv_id=10057 Edited December 16, 2014 by mrmustang Link to comment Share on other sites More sharing options...
Croc Posted December 17, 2014 Share Posted December 17, 2014 Interesting - I did not realize it also went through European Collectibles in CA. I know it was sold by Chequered Flag in late 2012 as I have it on my handwritten list of Birkin/Caterham sales that I write down to keep track of values over time. Just a note - while the ad listing kindly posted by Bill is still live it is listed under the "sold" page on the website. Link to comment Share on other sites More sharing options...
MPG Posted December 17, 2014 Share Posted December 17, 2014 > I would imagine that I could achieve the same clearance with a > few (?) carbide disks if I wasn't concerned about esthetics. > Hmmmm. Sawzall? > That's exactly how I did mine. It was quite quick & easy. It looks like the Birkin might require a bit more cutting than my Westfield though. Link to comment Share on other sites More sharing options...
BirkinBernie Posted December 17, 2014 Share Posted December 17, 2014 That is an early Birkin. Note that the a-arms are round tubing instead of the "aero" tubing on the later cars. It has one brake master cylinder rather than dual masters with a balance bar. Also note the heater core where we normally see the passenger foot well. So that car was manufactured before Dick Brink took over as importer sometime in 1999 or 2000. There may be other detail differences in the frame and footboxes compared to the more common (in the U.S.) later cars, so it may not be a good indication that the Miata will fit well in a later car. A friend here has a Birkin of the same general vintage that has a Peugeot engine and unknown transmission. It was built in South Africa years back and imported fairly recently. Bottom line, an enterprising soul with sufficient skill and patience could make just about any 4 cylinder fit..... Bernie Link to comment Share on other sites More sharing options...
Croc Posted January 4, 2015 Share Posted January 4, 2015 Last heard to be in Florida and for sale at 18K. Bill S. Well look what turned up for sale this week - I bet this is the same Birkin we discussed above. http://honolulu.craigslist.org/oah/cto/4831652080.html For sale is my Lotus Birkin Super 7. The car was imported as a rolling chassis and body from South Africa in the early 1990s by a builder of Porsche Speedster replicas who planned to expand his business to include the Super 7. The car is titled as a 1973 Lotus 7. The builder also actually has attached what appears to be an original lotus seven VIN plate to the firewall. I am not sure why this was done but I suspect it had something to do with California DMV rules. In any event, the car has a clean and clear Florida title at present, soon to be Hawaii titled. The new owner wanted a low maintenance, reliable twin-cam four-cylinder engine that had been designed for use in a rear wheel drive car, so a 1.8L Mazda Miata engine and gearbox were considered the best fit. He purchased the Miata drive train out of a nearly new Miata with 1000 documented miles. Thus, a nearly new drivetrain was obtained. Wilwood disc brakes were installed up front and the solid rear axle received brand new drums. High quality Fly Yellow paint was applied to the aluminum and fiberglass body and the interior was trimmed in black leatherette/vinyl. The car is complete with both a full windshield and the Brooklands screen included. A top, full tonneau and side curtains are included as well. The yellow paint and black interior are in great condition. This Birkin had traveled just 583 Kms when I purchased it two years ago and now has 1400 Kms on chassis and remains in excellent condition throughout. It is extremely fast and very well set-up. I have owned dozens and dozens of sports cars and this by far has been the most fun car I have ever owned. This statement is made having owned numerous Porsches, Ferraris etc etc. I was excited about this car in the fact that it could sit for months on a trickle charger and you can hit the start toggle switch and instant idle. . .no lotus twin cam head gaskets issues etc etc. If you want a really nicely prepared lotus seven that has Japanese-like reliability and low maintenance then this is the 7 for you. It has literally been sitting in my garage and not being driven. I am a busy professional with a family and frankly it needs to be in the ownership of someone who can enjoy her and drive her as she needs. My asking price is less than what a new Birkin kit costs. If you have any questions please feel free to email and I will respond asap. I'd consider a trade for a 4 door Pickup truck or land cruiser Asking $19000 If the original poster wants photos maybe contact the seller and ask nicely to get some photos of the critical installation aspects. Link to comment Share on other sites More sharing options...
mrmustang Posted January 4, 2015 Share Posted January 4, 2015 Looks like a straight cut and paste of the original (private) sellers ebay ad. Bill S. Well look what turned up for sale this week - I bet this is the same Birkin we discussed above. http://honolulu.craigslist.org/oah/cto/4831652080.html Asking $19000 If the original poster wants photos maybe contact the seller and ask nicely to get some photos of the critical installation aspects. Link to comment Share on other sites More sharing options...
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