Featured T120v On The Lift

@Iron: All the best for this project. It looks great.

 

Looking good so far mate

 

@Iron Same here mate. Good luck as if you need it. I have seen some of your rebuilds.

 

what kind of 750 barrels? T140?

is that why youre making up head steadies?

 

the 750 jugs on the long rod motors work really well

 

You can't beat a nice pair of jugs.

 

those appear more like an 850 kit

 

Built one for a mate years back, with porting, cam timing altering, and new carbs it did indeed, " work really well " !
I vaguely remember Americans not liking the 'short rod ' 750 for flattrack racing, for some reason ?

 

Built one for a mate years back, with porting, cam timing altering, and new carbs it did indeed, " work really well " !
I vaguely remember Americans not liking the 'short rod ' 750 for flattrack racing, for some reason ?

 

do you recall the cam timing you used?

 

Some note you might not have https://www.tioc.org/britbike/camshaft.pdf

 

https://www.thebonnevilleshop.com/c...cvl6vdaBZhMNXCHxPYOI2hy2VKvxcgLtnjsB-4zZ9fmYA

 

they list the 750 short rod motor with a very retarded intake cam lobe center-- 111 degrees, with a more typical 103 degrees on the exhaust. as i understand it, that retarded intake timing was intended to de-tune the 750 so it wouldnt destroy its . . . one-piece timing side main bearing? i forget.

normal timing is generally at lobe centers of 100/100, or 102/103, or in that range.

im curious because i run my land speed race bike at 106/109, very retarded lobe centers, and it has very good power at both upper and lower rpms. but the cams are 0.375 lift and 296.5 duration.

im interested in building a motor with a bias to low-rpm horsepower for a sidecar tug, so im thinking about what i might be doing there.

 

Ramp cams as fitted to pre unit Triumphs are a consideration or use dot to dot on inlet instead of dot to line.

 

was the dot-to-dot timing characteristic of milder triumph motors? that would advance the intake cam 7.2 degrees over dot-to-dash.

at any rate, super mild tuning is what im looking for. im not expecting more than about 45 mph out of that machine, especially with a 17-tooth gearbox sprocket, so any power over 4000 rpm is wasted.

 

Dot to dot was the Thunderbird tune