[TR] Sticking Valves?

[Tony Drews]

The valve guide clearance is a key factor in our engines.  With too 
small clearance, we have stuck valves in racing conditions - 
especially when the engine starts running hot.  With a high lift cam 
so the valve can potentially hit the piston, the result is 
disastrous.  With the stock lift, there shouldn't be interference, so 
the result is much less catastrophic.  The #4 cylinder is more prone 
to run hot than the other cylinders.  So, your theory is 
plausible.  BTW, we specify 0.004" with new guides.

Normally I would suspect a fuel delivery problem, but the "valve 
train clatter" is suspicious.

- Tony Drews

At 11:32 AM 9/19/2009, Michael Lang wrote:
>I have now got about 2000 miles on my freshly rebuilt TR3 engine and am
>having a sporadic problem. I drive a lot of hilly back roads on the way
>to and from work. When I climb one particularly long hill at about
>65mph, the engine starts missing on one cylinder and I begin to hear a
>lot of valve train clatter. If I back off a bit, it stops missing and
>runs fine. It continues for such a short time after reducing load that I
>have never been able to stop and diagnose the problem.
>
>When I rebuilt the engine, I had the head done with new valves, bronze
>guides and hardened seats. I think that I have a valve that is sticking
>when running hot under load. Is this a common problem with these
>engines? Any other thoughts an what might be happening?
>
>Thanks,
>
>Mike