Hi dogge, this is about where I was in 1988, at the start of the slippery tuning slope (which ended with a full drag race spec 850 weslake motor) My standard T120 ran low 14s over the quarter. With the Morgo kit, skimmed head and the T140 inlet cam it ran high 12s. Other T140 cam numbers to look out for are 70-7016 and M20416.
It's a good mod which will give an increase in performance and still be OK on the road.
I'm going to send you an article off line, written by a top sprinter, which has a few more ideas. As I recall, even when the article was written and published in "the Sprinter" Triumphs had fallen from favour as 1/4 mile bikes.
The lift and duration of the T140 camshaft requires the use of STD tappets (3/4"radius). The T120 or T140 exhaust can use the R tappets, but using the STD items softens the tune and extends the life of the cam and tappet, with little reduction in performance. The T140 inlet camshaft does NOT have the holes for the timed crankcase breather which the 69 uses, you will have to vent the crankcase some other way. The IN T140/EX. T120 set up works very well in either the T120 or the T140 by installing a nitride-hardened exhaust cam from a 69-72 650. The Kenny Harmon/JOMO 15 is now made by Megacycle as the 51015. Good cams for either short or long rod street 750 with at least 9.5CR and relatively free flowing exhaust. I run the JOMO 15s with a Routt kit on a 68 bonneville converted to a TR6 with 32mm carb. Best bike I've ever owned. Dead reliable.
What, me worry?
Re: T140 Camshaft on a T120#88050 12/16/072:55 am12/16/072:55 am
I'm reading this with interest, I have a t120 exhaust cam waiting the day (may be a while) to be fitted whenever the engine gets worn enough to be stripped down on the t140. (hopefully I've plenty of time yet to collect nice bits to fit)
I do like a nice burst of accelleration (and noise) every now & then to put the hot hatch drivers in their place
I have just finished building a T140 engine, and I have fitted T120 inlet and exhaust cams (along with timing-side roller). I was advised that the inlet would provide better torque than the 'race' T140 inlet. Everyone knows the story about the de-tuned exhaust, which is usually changed on its own. I used the same timing set-up as the standard T140, which if I remember right, is the same as 'Steve in Tulsa' suggested. It runs great, but I haven't taken it on the road yet. Will report back when I have. So far (touch wood) it is the first time in the 20 years I've had the bike that it isn't leaking oil!
76/78 T140 Bonnie, Suzuki B-King and Kawasaki ZZ-R1400.
Re: T140 Camshaft on a T120#88053 12/17/072:30 pm12/17/072:30 pm
Excellent stuff Bobsimmo, glad to hear it's going well. I have the same cams lined up for my rebuild too, so I'm really interested in your comments on the bike when you ride it. I am also interested in whether it stays oil tight and what sealant you use!
Dog - I had a very similar setup once, spitfire inlet and 3134 exhaust with morgo on a T120, good spread of power and quite a bit better in the higher revs for sure.
Re: T140 Camshaft on a T120#88054 12/18/0712:56 am12/18/0712:56 am
Mele Kalikimaka Tiger....How you doin', mate? Same to you all, enjoy the holidays. I just got my prezzie....a 67 T120 bottom end on eBay with light crank, Carrillo rods, some sort of new hot rod cams, new bearings, complete gear set, timing cover, and a new Aerco Big Bore cylinder sans pistons. I guess I should wait until it gets here and I get a look at it to get all revved up.
What, me worry?
Re: T140 Camshaft on a T120#88055 12/18/071:06 pm12/18/071:06 pm