Z320 Posted February 27 Report Share Posted February 27 (edited) Hi there, I need two measurements on the TR6 flywheel, please. On my TR4A the diameter is 280 mm. It reaches 45 mm deep in the gearbox bell. Is this different from my TR4A to the TR6, while the clutch cover still ist the same? + I know the fixing of the flywheel on the crankshaft changed while the TR6 was on the market. Does this change this dimensions? I need this information to be shure my MX5 gearbox #1 will fit a TR6, and to make a limited number of adapter rings for other TR drivers. The problem is this area in the MX5 bell, the TR4A flywheel does not touch it with my adapter ring, hopefully also not the TR6 flywheel. Thanks for help in advance. Ciao, Marco Edited February 28 by Z320 Quote Link to post Share on other sites
Malbaby Posted February 27 Report Share Posted February 27 Hi Marco.....My 6 cyl flywheel diameter is 269mm. Flywheel is not on the engine ATM...The second measurement you wanted would be very close to 47mm from the face of the gearbox mount plate...I have the long back crankshaft. Quote Link to post Share on other sites
Z320 Posted February 28 Author Report Share Posted February 28 Good morning Melcolm, thank you very much for your measurement, that seems to fit! Ciao, Marco Quote Link to post Share on other sites
Z320 Posted February 28 Author Report Share Posted February 28 Uuups, Malcolm, looking at photos of TR6 flywheel, the TR6 starter ring looks wider, compared with the TR4 starter ring! Or it only looks like because the flywheel is slightly smaller? The outside diameter of the 4 cylinder starter ring is 292 mm, could you measure on your flywheel again, please. Ciao, Marco Quote Link to post Share on other sites
AJAS Posted February 28 Report Share Posted February 28 Hiya. My tr6 flywheel is also 269mm Tony Quote Link to post Share on other sites
BlueTR3A-5EKT Posted February 28 Report Share Posted February 28 (edited) 3 hours ago, Z320 said: Uuups, Malcolm, looking at photos of TR6 flywheel, the TR6 starter ring looks wider, compared with the TR4 starter ring! Or it only looks like because the flywheel is slightly smaller? The outside diameter of the 4 cylinder starter ring is 292 mm, could you measure on your flywheel again, please. Ciao, Marco You are measuring the bolt on type starter ring gear used on TR4/4A and some TR3A. There is an earlier starter ring gear. I will measure it and let you know. The depth of the flywheel face to fear of cylinder block did not change on the 4 cyl as far as I know. Edited February 28 by BlueTR3A-5EKT Quote Link to post Share on other sites
Z320 Posted February 28 Author Report Share Posted February 28 7 minutes ago, BlueTR3A-5EKT said: You are measuring the bolt on type starter ring gear used on TR4/4A and some TR3A. There is an earlier starter ring gear. I will measure it and let you know. Yes, I measured the bolt on typ. Isn‘t this the same dimensions all 4 cylinders? Thank you fir your offer. Is the TR6 starter ring shrinked on the flywheel? Quote Link to post Share on other sites
Malbaby Posted February 28 Report Share Posted February 28 (edited) 5 hours ago, Z320 said: Uuups, Malcolm, looking at photos of TR6 flywheel, the TR6 starter ring looks wider, compared with the TR4 starter ring! Or it only looks like because the flywheel is slightly smaller? The outside diameter of the 4 cylinder starter ring is 292 mm, could you measure on your flywheel again, please. Ciao, Marco Mine has a new ring gear...300mm overall....and is heat/shrink fitted. I will measure the diameter of the starter motor gear later this morning, plus the measurement from centre of crankshaft to the centre of the hole in the gearbox mount plate. Edited February 28 by Malbaby Quote Link to post Share on other sites
Z320 Posted February 28 Author Report Share Posted February 28 Malcolm, thank you, sadly there is a problem: 300 mm is exactly the diameter of the MX5 gearbox bell housing! Could you please measure how deep the starter ring reaches in the gearbox bell? For example 20 mm —>anadapter ring d 305 mm x 25 mm would be needed Ciao, Marco Quote Link to post Share on other sites
Malbaby Posted February 29 Report Share Posted February 29 (edited) Centre of crank to center of starter 161-2...On my aftermarket hi torque starter, gear diameter 29mm...front edge of starter gear when installed is out 14mm from the mount plate [into the bell] at rest, 26mm extended. [12mm of travel]. Then there is the length of the input shaft to consider, [custom made long spigot bush?]...Perhaps use the TR4 flywheel and clutch with a modified gearbox/engine mount plate to bring the starter in closer to the flywheel? Anything is possible, miracles take a little longer Edited February 29 by Malbaby Quote Link to post Share on other sites
Z320 Posted February 29 Author Report Share Posted February 29 Hi Malcolm, thank you very much for your help, the adapter and gearbox bell is 300 mm and with the starter in a different position my gb #1 has to go to a 4 cylinder TR. To create a TR6 solution (slightly different adapter, cut the bell 5 mm wider) must be the challenge for a 6 cylinder owner. I report on my MX5 gb thread later. Well, from time to time I count together the benefits and disadvantages of my TR4A IRS and finally I‘m convinced this is the best TR model anybody can buy. Ciao, Marco Quote Link to post Share on other sites
Z320 Posted February 29 Author Report Share Posted February 29 Hallo Tony and Peter, also a thank you too you! Ciao, Marco Quote Link to post Share on other sites
Malbaby Posted March 1 Report Share Posted March 1 I think the MX5 conversion is a good idea for TR5-6 and saloons, and relatively cost efficient. Toyota W58 gearboxes are getting scarce, parts are not readily avalable, and the bellhousing with associated parts are expensive. Using the slightly smaller TR4 flywheel and clutch would not bother me....I presume you have a dedicated clutch disc in mind for use with the Mazda GB, and have solved the possible input shaft length problem.. Quote Link to post Share on other sites
Z320 Posted March 1 Author Report Share Posted March 1 I will do some measurements tomorrow and perhaps a TR4 A flywheel, drilled for a modern diaphragm clutch cover, will fit a TR6 engine. very likely the different starter ring diameter will need a different position of the stater. Anyway - to design the adapter ring to 305 mm and grind the bell particular out 2.5 mm should be no problem. Ciao, Marco Quote Link to post Share on other sites
BlueTR3A-5EKT Posted March 1 Report Share Posted March 1 (edited) 10 hours ago, Z320 said: I will do some measurements tomorrow and perhaps a TR4 A flywheel, drilled for a modern diaphragm clutch cover, will fit a TR6 engine. very likely the different starter ring diameter will need a different position of the stater. Anyway - to design the adapter ring to 305 mm and grind the bell particular out 2.5 mm should be no problem. Ciao, Marco The TR250/5/6 ring gear fits a TR2/3 flywheel that is shrink on type. The TR4/4A flywheel with bolt on ring gear fits a TR2/3/3A The gearbox bell housing bolt positions for the starter do not change from TR2-6. The only thing that changes is the starter motor gear size and quantity of teeth the bendix drive gear has. What you are after is an accurate dimension for the ring gear and the flywheel as you stated at the beginning of this thread. Peter W Edited March 2 by BlueTR3A-5EKT Quote Link to post Share on other sites
Z320 Posted March 2 Author Report Share Posted March 2 (edited) Hi Peter, thank you very much! Indeed I had my spare TR4A engine AND a TR6 engine plate AND a gearbox housing to check the positions of the bolts to fix the gearbox on the engine. The bolts for the starter must be the same! —> They go through the TR gearbox flange, and the gearbox fitts all TRs Do you know a TR4/A flywheel fits a TR6 crankshaft? Ciao, Marco Edited March 2 by Z320 Quote Link to post Share on other sites
BlueTR3A-5EKT Posted March 2 Report Share Posted March 2 The rear part of the TR6 crank shaft where the flywheel fits is 73 mm diameter. It is a plain straight shaft that the oil seal runs on, so the rear crank oil seal can be changed by ?simply? removing gearbox and flywheel. 73 mm is the speedi sleeve size suggested to repair the rear crank oil seal area. Quote Link to post Share on other sites
BlueTR3A-5EKT Posted March 2 Report Share Posted March 2 (edited) Here is internet image of TR6 flywheel fitted. Marco, I think how far the ring gear of TR 6 is from the rear engine plate is the question also. It is the biggest diameter you need to get into the MX5 gearbox bell housing. An accurate measurement is needed. We know the MX5 gearbox goes in Vitesse as someone gave photos of it in your article about fitting the replacement gearbox. Vitesses uses a flywheel the same ring gear as TR6. It was YOW500 who posted the images in here regarding gearstick position. Edited March 2 by BlueTR3A-5EKT Quote Link to post Share on other sites
Z320 Posted March 2 Author Report Share Posted March 2 (edited) Hi Peter, the flange on the TR4A crankshaft is 101.6 mm (4"), the TR6 flywheel will not fit The gap between the starter ring and the engine flange is 9 mm, it reaches 21 mm in the bell The ring spins 1 mm in the 10 mm adapter, the inside diameter is now 300 mm for the 292 mm flywheel, it must be about 305 mm for a TR6 The talented TR6 owner only has to grind out 2.5 mm from the MX5 gearbox housing, about 12-13 mm deep (?), this only on about 1/3 - 1/2 of the circumference. Bing - and ready is the issue Photo will follow. Ciao, Marco Edited March 3 by Z320 Quote Link to post Share on other sites
BlueTR3A-5EKT Posted March 2 Report Share Posted March 2 (edited) Marco, I have just received a TR2/3 flywheel with the original shrink on ring gear for a 'bomb' starter. The ring gear is 296 mm diameter. It is positioned in the same place as the later bolt on ring gear. Edited March 2 by BlueTR3A-5EKT Quote Link to post Share on other sites
Z320 Posted March 3 Author Report Share Posted March 3 Peter, that‘s great to hear. So „only“ the TR6 has one more challenge with the MX5 gearbox. From Nick Jones’ thread I know it also „not fits“ with the GT6 ring starter gear, pretty shure on 6 cylinder Saloons too. Ciao, Marco Quote Link to post Share on other sites
Z320 Posted March 3 Author Report Share Posted March 3 Okay, the pink with chalk marked area is some more than 1/2 of the circumference where 2 mm deep x about 13 mm wide has to be grinded out to give space for the TR6 flywheel. Ciao, Marco Quote Link to post Share on other sites
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