Best All-Around Camshaft Set-Up For Triumph 650's
So your rebuilding your Triumph 650 twin and your in the market for a new set of camshafts to replace your old cams but your not 100% sure of exactly what you need.
Camshafts especially for vintage Triumph's are confusing as there are so many variations and brands to choose from.I've seen many posts on Britbike forum asking other members "what is the best all around camshaft for a Triumph 650 twin?" The short answer is it depends on your application and what you expect to get out the engine.
Recently I rebuilt my 1968 Triumph TR6R and I needed to replace both inlet and exhaust camshafts. I also was in the same boat as many of the forum members trying to find good replacement camshafts to replace the stock units.
My engine was 100% stock and original. My inlet camshaft was the E3134 variety while my exhaust was the 70-5047 variety. This set up was stock from the factory which provided much power and reliability for typically on and off-road use applications.
Since my exhaust camshaft was not being reproduced under the 70-5047 part number I had to search elsewhere until I ran across a cam called the E9979 or 70-9979 "half race camshaft". This 70-9979 camshaft was a stock profile cam exactly like my original exhaust 70-5047 camshaft that was no longer available.
I would be using my Triumph TR6R for standard road use so I figure I better replace my cams with the stock set-up. For the unaware the E3134 camshaft profile is known as Triumph's most popular and "famous" grind that was designed.
I wanted to keep my Triumph TR6R as original as possible so I went ahead and installed the E3134 and E9989 camshafts imported from England by L.F. Harris. Harris make exclent vintage Triumph parts - I have had nothing but excellent results using L.F. Harris camshafts; the power and mid-range is exactly what I was looking for.
Below is a comprehensive chart that will cover everything that you need to know about the best all around camshaft set-up for Triumph 650 twins. You will also find the lifters that should be used in conjunction with the E3134 and E9979 cams.
All L.F. camshafts are affordable and manufactured from forged blanks (hardened) in Taiwan but ground and machined in England from a reputable camshaft grinder
|L.F. Harris||Taiwan||E3134 (70-3134)||Inlet|
|L.F. Harris||Taiwan||E9989 (70-9989)||
*Exhaust camshaft can accept a tach drive and also features a locating dowel for the advance unit.
|Part number||Application||Lift||Base Circle||Open / Close||Journal Diameter|
|E3134 (70-3134)||Inlet||.310"||.819"||34° BTDC - 58° ABDC @.020||.809" & .872"|
|E9989 (70-9989)||Exhaust||.310"||.819"||58° BBDC - 34° ATDC @.020||.809" & .872"|
As far as timing goes, I went ahead and used a dial indicator and took measurements off the lifters using the figures @.020" (or as close as I could get it).
I am almost certain you can run these camshafts using the stock timing marks and be fine. I went away from using the stock timing marks and made my own just to be safe and accurate.
You can use this camshaft set-up on all Triumph 650 twins from 1963-1972 with great results. I would imagine that you could also use this same set-up on Triumph 750 twins.
Give this set-up a shot...
If you are in the market (like we where) for cams I would recommend that you give this set-up a shot. For road use and even for other applications where you want your Triumph to have power but also be reliable (and tameable) then this may be what you want.
I have compiled a complete list below in which you can use to obtain the same set-up that we discussed in this post. Click on the parts in the list to be taken directly to the listing.
If you have any questions please feel free to send us an email or drop us a line at any time. You can also leave comments and questions using the comment box below and we will get back to you as soon as possible.
Thanks for reading and ride safe!