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Vitesse 6?
Anything and everything Vitesse.
Section : Gearbox
Clutch, gearbox, overdrive, propeller shaft.
Posted By : Tim Bell, 19-Sep-2005,
12:27pm
My pal Jon (I'm getting him to join the TSSC) has recently bought a Vitesse 6 convertible (1964 vintage) and wants to put an overdrive in it. He asks,
"what type of overdrive gear box fits the 1600 Vitesse. I think its all Herald size stuff, ie main shaft is same spline, so I guess spitfire 1300 or 1500
o/d box will fit but not sure about bell housing and clutch. Would be nice to know what does work so I can try and get one.
Car definitely need s o/d as it gets up to about 70 really quick and is doing about 3500+ on revs and an O/D would reduce this to a more acceptable
level".
Can anyone advise on the best approach?
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Posted By : Colin Wake, 19-Sep-2005,
12:52pm
it certainly won't be a spitfire gearbox that is required, the ratios will be wrong.
Canley Classics list a Vit 1600 box as a unique p/n, so I guess it's a 1 off.
Chances are that a Vit 2litre or GT box will fit.
Cheers
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Posted By : Chris Taylor, 22-Sep-2005,
02:18pm
Any Vitesse or GT6 overdrive gearbox will fit a Vitesse 6. While the clutch plate is unique, it has the same splines as a 2 litre Vitesse.
Depending on what the overdrive and propshaft have come from, you may need to change the flange on the propshaft to match the overdrive output flange,
(Vitesse 6 and Spitfire overdrives had a smaller flange than the 2 litre) but that's not a big job.
You will need of course a shorter propshaft, the correct mounting plate, operating switch, relay, right-angle speedo drive and maybe a longer speedo
cable, but that's the case for any overdrive conversion (and perhaps why it was not a particularly cheap option from the factory).
A 1600 running on its correct diff will be revving to nearly 4400 rpm at 70, so assuming your car does not have a different diffm the speedo is
overreading. Overdrive will bring revs at 70mph down to 3500. Well worth the effort!
If you've any experience in rebuilding gearboxes, you can rebuild the 1600 gearset in a Spitfire 3 synchro (ie Mk1 - Mk3) overdrive gearbox as the
mainshaft is the same. You should use the 1600 gearbox case so you have the springs preloading the layshaft thrust washers, and you must use a 1600
layshaft as the 1600 uses needle rollers rather than the bronze bushes of the Spitfire/Herald.
Taking all the above into account, it's probably easiest to get a 2 litre overdrive gearbox, but note that the higher 1st gear ratio will make hill
starts on steep hills a bit trickier.
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Posted By : Tim Bell, 27-Sep-2005,
10:34am
Cheers guys for your detailed feedback. Greatly appreciate your taking the time. Many thanks for the invaluable info.
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Posted By : Tim Bell, 27-Sep-2005,
10:54am
Chris - re your comments, Jon says, "Having just bought a 3.6.3:1 Diff from a 1500 Spit, I removed the Diff from the Vitesse 6 only to find that on
counting IP to OP rotations, the ratio was already a 3.6.3:1!
Strangely enough, an earlier speed check indicated 60mph at 3500. I presume this to be expected if 70 comes up at 4000.
Although it has been said that a 3.27:1 ratio diff would be too long, I can't help feling that with the lower first gear in the Vit 6 box, it would
cope with this final ratio perfectly well considering the satisfactory power output the engine is supplying.
Any experience or comments gratefully received. Ideally I think the next step is an O/D box from a Vit 6 - IF I CAN FIND ONE!"
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Posted By : Colin Wake,
27-Sep-2005, 07:49pm
Tim
having been traiterous just now, I noticed that there is a guy on the Club triumph messageboard who has 2, he might be pursuaded to sell to
fund the right box he needs for his 2L vitesse!
Look under Vitesse/Herald.....
Colin
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Posted By : Tim Bell,
27-Sep-2005, 11:28pm
Colin - I've been and had a look and have spent an hour looking but can't find any reference to the guy who has two and a 2L Vitesse. Is it
in the Forum section? I've looked in the classifieds too just in case but no joy. I'm probably blind, but can you give any more info?
Thanks
Tim