Topic: Nova (Dyson) transmission question

[NickO]

Just getting all the parts together for the race motor I'm having built and the guys over at Nova transmissions are asking if I need a 43 tooth or a 48 tooth type?

Me being a complete novice on these motors (amongst other things) , and not yet having stripped-down the "donor" F1 engines I have, is this query to do with the difference of the F2 cases/final drive set-up, or something totally different?

Apparently the Nova 43T gear meshes with a 50T gear on one type, (and the Honda part no. of this 50T gear is 23511-392-000)? but I don't know any more info.

The guy at Nova said it was because they sold a CB750 transmission recently and the customer had to have the 43T gear changed for a 48T one (or vice-versa), as it wouldn't fit. They had never had this request before!

[lordmoonpie]

That's dead right Nick - the output gear on your shorter output shaft next to first gear has a 43 tooth gear normally but the nova box needs this to be a 50 tooth to work properly so you have to buy the additional part mentioned. Your part number is correct and you should be able to get it from David Silver. I'm surprised that someone needed a 48 tooth gear instead though - maybe they didn't count up to 50 very well as I can't see it meshing with anything other than a 50 tooth?!

Incidentally I had a number of issues fitting my nova box, this being just one of them. I also found that I had to leave out the final standard thrust washer to avoid the gearbox locking up when torqueing the cases together. Works OK until you put the final torque into the case bolts then locked the box solid. I haven't had any issues in leaving this washer out but it shows the origins of the nova box being developed for one donor engine and that doesn't account for the many small variances Honda built into the model series over the years.

Still, the 750 box is better than the 450 box - I could write a book on the issues I had to overcome fitting their box on the 450! 

[NickO]

Lord Moonpie,

PM sent, thanks for the info.

Nick