Testing time

[windy]

On Sunday had my first chance of 2013 to see if the lighter piston was a success on the steamer.
First and second runs were frustrating as the engine stopped on the second lap.
It seems the engine is now running hotter and steam inlet poppet valve needed more clearance.
Stripped engine and re-shimmed the cam follower.
My last run of the day had the tethered hydroplane do an average speed of 120.9mph over 500metres with one lap at 122mph.
The valve clearance is very critical as with the high-pressure steam (1000lbs plus?) on the valve head it gives the cam follower a hard time.
On stripping the engine at home one of the hairpin valve springs fractured guess they only have a limited life span and was fortunate it lasted for that final run.
Another month to go before my next attempts to go faster.
It keeps the brain cells working.

Paul

 

[Lakc]

Sounds good, was that appreciably better or worse?

 

[windy]

At the moment it's hard to tell if there was an improvement with the redesigned piston as the tappet clearance was a bit too much as it affects the valve timing.
Will reduce the clearance but set it 0.002" more than last years to compensate for the extra expansion of the poppet valve and also try to reduce weight on the hydroplane.
Back to my little heaven the workshop.

Paul