If you can get a copy of "Sportbike Performance Handbook" by Kevin Cameron there are whole chapters on intake and exhaust port design, air flow and a multitude of other subjects. You may already have the the best head for your bike if I remember what Healy said. You may just be in need of a "proper" valve job. I know my old 56 T110 could run circles around any Bonneville I've owned. The book is written in plain English and is a good read on a cold winters night.
Last edited by desco; 05/29/125:46 pm. Reason: addition
1968 T120R 1972 T120RV Any advice given is without a warranty expressed or implied.
Morgo were known at one time for possibly not being bored true. Square to the barrel/crankcase flange I'm talking about. That causes side thrusting on the gudgeon pin circlips. I'd be carefully checking.
The most practical head would be '69 -'70. You get UNC threads holding the rocker-boxes,and UNF threads holding the carbs.
I wouldn't worry about the intake ports being slightly too big for a 650.You'll still get good results with these heads,and they were recommended by Shenton in "Triumph Tuning".
I'm not a big fan of drop-on big bore kits.The cylinder walls are thin where they enter the crankcase.They work,but they always look fragile. There is/was a kit made by Routt,that required opening up the crankcase and it had thicker walls.There may be others like that.Routt did also offer a drop-on kit.
You should be happy enough with the Morgo kit.The engine won't feel as revvy as a 650 with the same cams and carbs.Low and mid-range torque will feel good.
If you plan to make good use of the potential power increase,it could be wothwhile to crack-test and tuftride the crank.I'd balance the crank to 71% balance-factor.I think a '62 frame will still vibrate with any balance factor.
IMO Morgos are quite aesthetically pleasing as they follow the line of the cylinder head, but go easy on the centre head bolt. As Pete R says, the walls are thin, and even with the correct torque setting, after running you can still see a polished section near the centre bolt hole on the bore where it has belled out slightly .
my 62 is mostly stock. I think I will just keep it a 650 with a 9 bolt cyl and head. I have a nice 63 tr6 head that i can use. One thing I do want to add is a oil cooler. With the FL heat and traffic, anything will help.
John Healy said once that the earlier 9 stud unit 650s with smaller valves (up to 1965?) went over the ton a lot more easily than the later bikes. Maybe he will chime in on this point. My 67 TR6R is fitted with an earlier head with small valves and it certainly bombs along! It does still have the 67 1 3/16" carb and 67 cams. Dave
Now, that's a cool ride. Duplex framed Triumphs are my all-time favorites. There's a lot of nonsense floating around how bad they vibrate and handle. Nonsense. The absolute smoothest Triumph I ever rode was a '62 Bonnie. Smoother than my Commando at 70mph. It handled fine. As long as you don't chop throttle at the apex you shouldn't have any problems there. The front brake is probably the best mod you can do to that bike. I've been doing that for many years on my bikes. The 2 into 1 exhaust is stock for that year, but it does rob power. My T-bird ran much better with twin exhaust and sounded better also. You can make a 9 bolt top end look very stock if you grind off the rocker box fins and re-profile the head fins. Almost no-one would even know. If your bike vibrates too much, a simple mod to try is to replace the two front motor mount bolts with one long one and a spacer between the front down tubes. Sometimes this transforms a duplex bike. Cheers, Bill
Bikes 1974 Commando 1985 Honda Nighthawk 650 1957 Thunderbird/T110 "Flying Tiger" Antique Fans: Loads of Emersons (Two six wingers) plus gyros and orbiters.
#437445 - 05/30/128:08 pmRe: best year Triumph 650 head & advantages of a morgo