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TR2/3/3A Pist’n broke

Enjoyable video! Thanks for posting.
 
my Old Man was so cheap he drove a pickup with a small block Chevy for 30 years with a broken piston. When I final rebuilt it for him, it had 3 broken pistons and 9 broken rings. Still ran, but used almost as much oil as gas.
 
Looking at your pistons, I am reminded that there are no really good choices for pistons for TR's. I know the piston weight could reliably be cut in half from the big-ole' full skirt pistons we are forced to used. Were I racing, like you, I would be very tempted to machine a set down to more modern standards!
 
I had this dilemma when I had this engine built in 2021/22.
It wasn’t the lack of availability of top class parts. It was the cost.
I looked up a couple of uk suppliers and 1 cast piston was about £100.
A forged piston was between £250 to £370 each.
Same for matching conrods
And a billet crank £5 - 6000



There is a choice (for pistons and conrods ) between the cast that most of us use and mine are and forged that are the top class and rich racers option.
And not the overall weight.


You can look up the differences but basically forged stand the stresses far better. and with a billet crank can rev and provide power towards 8k rpm

All most of us can do is prepare the parts we can afford as best we can and balancing is the key here.
Have a look at the original build.
Nothing wrong with it, very good in fact. 3 seasons of very hard work.

 
I hope you re-assembled the engine with a greater end gap on the piston rings. The broken ring and ring land are typical of a ring "going solid." At some point on one of those long straights, the ring got hot enough to expand its end gap closed.
 
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