TR2/3/3A Rebuilt TR3 Engine....how many miles before ...

[karls59tr]

readjusting the valves? I think the manual recommends a 1000 mi but a Triumph club member here recommends 300 mi. Any advice?

 

[MDCanaday]

As soon as the cam has been properly broken in....most cam guys say 25 or 30 minutes at 2500rpm.I would doubt that 300 would be severely too long but INMHO it should happen in the first 100mi. Sick dog that I am, I will also change the oil at that time.Big waste of money?? Or cheap insurance??
My experience is that you will never be sorry you gave your TR motor that little extra to make it live a long and happy life.
MD(mad dog)

 

[karls59tr]

I had a lot of problems when starting up my rebuilt engine so I dont think it had a good run for 25min at 2400 rpm. Plugged fuel filter was the culprit. So with all the starting and stalling and rough running I'm wondering if I prematurely wore out the cam lobes ...it is a mild street cam. The TR3 seems to pull OK when I'm on the throttle but idles rough when I back off on the throttle. I know that performance cams cause a rougher idle as a matter of course but what about off the throttle? The other possibilty is the tube header....could this be causing the problem. Karl

 

[TRTEL]

Karl, What rpm is your normal idle, and how much are you backing off on deceleration. If it's not smooth to begin with when ticking over at idle then often gets magnified coming off higher rpm's. Could just be a number of minor problems, throttle balance, mixture, etc.

Tom Lains
TS8651 & 58107

 

[karls59tr]

I think idle on a stock engine is around 800. With a street cam isnt the idle supposed to be higher? Correct me if I'm wrong on that. My idle is around 1100 rpm....seem to remember it stalling out any lower. I think your right about throttle balance and mixture. It may run better in the Spring when I get that dialed in.

 

[YankeeTR]

I usually break-in a cam at 1500 RPM....although I've read anywhere between 1500 and 2500 will work.

The theory is that a cam gets mostly splash lubrication and the higher RPM's during break-in allow more lube to reach the lifter faces and also promotes lifter rotation to evenly break-in the lobes.

You don't have to do it all at once....there are always interruptions when first starting up the engine...leaks, noises, things that need to be tightened, etc. So starting and stopping the engine is no big deal. Just don't let it idle...and don't rev the crap outta it trying to impress your friends!