Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 but I am going from surprise

Is this also the case for standard engines?

The standard smaller valve engine normally does not have this problem.

Laser metal recharging is performed.

That is more than a small crack between the valves, that is into the inlet port! Maybe a step too far with tuning mods?

Yes, the crack corresponds to the crack in the exhaust pipe. This is normal and is due to the temperature difference between the two intake and exhaust pipes and the temperature difference that can occur between full opening of the throttle and closing of the intake throttle. Once the crack is created, it no longer moves. I am not worried.

I started to reassemble the lower engine which is in good condition, the piston pins were difficult to disassemble so I went back through the reamer in the pistons to put clearances 0.015 mm to be able to push the pin with the finger, I made a template of the bottom cylinder seal to replace paper with aluminum seal series 1060 which does not pack and which can be reused to have a value on the protrusion of the pistons in relation to the cylinder, more than a year ago I put a complete crankshaft with new connecting rod in an engine whose connecting rod foot did not allow the entry of the piston pin I had to pass the reamer.
I regret not having taken the training course at S&S to learn everything that's wrong with the 132 cub, an engine that makes about 70 hp per liter.
Correct: The 121 cub was completely rebuilt after 120,000 km; it previously used a set of camshafts, head gaskets, base gasket, cylinder, oil pump, and piston on the last complete overhaul.










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Thank you so much for this article.
It is of great value for all of us, and gives hope how to repair our fragile engines.
I have a question
Does it make sense to drill a very tiny hole at the end of the crack?
Cracks do continue when the tension is still in the material with different temperatures.
A tiny drilled hole stops this. And at this place a tiny little hole will not make a difference in compression.
Same as with glass-windows.

Herrie
The small drill hole doesn't apply to this tiny crack. Once drilled, it allows for the metal to expand and contract and stabilizes. The only place I have to drill new holes is the cooling cylinders, which weren't designed to operate in the lateral direction of the three-wheeler's cooling. I had already done this when re-engining the 121.