The "Throw Away 318"

rumblefish360 said

@Dale Davies


I have found that an engines rpm capability is limited to the pocket book of the builder and not the stroke size. While there are certainly advantageous ways to build and engine for one purpose over another, I haven’t really seen a long stroke engine not be able to perform and rpm really high.

The ability to have a long or short stroke engine run at a certain speed in the 1/8-1/4 or oval tracks isn’t dependent on there rpm capability.

Without a doubt more cycles created quicker will produce more power quicker. An advantageous thing not to be ignored. In the right arena.

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Remember my qualifier, displacement remains constant. In roundy round racing the displacement is tightly regulated. Short track have used smaller bore/longer stroke engines to get out of the corner quicker. They also will likely use a shorter conrod for that torque advantage. A long track restrictor plate engine will use the most bore allowed and the longest rods they can fit with high CR's. It is the combination that works for the application.
You are correct with RPM capability limited by the budget. That said, a short stroke and long rods stresses parts less. F1 engines rev 18,000 RPM or more and are required to last a few races. 3L displacement with about 1.5 inch stroke.. Deck heights are short to reduce weight. The pistons use only 1 compression ring as there is no room for 2, and cost £50,000. Berylium was banned as it is creates health concerns. They made the pistons out of this for a while. Cubic money supplies required to play in that game.