[Stan Weiss]

Originally Posted by PAUL K

I like your thinking. You still have an issue with lack of support for the piston skirt.

Wouldn't a 4.5" stroke 6.8" rod 1.2" compression height piston have the piston in about the same place ABDC as a 4.25" stroke 6.625" rod combination?

Stan

[PAUL K]

Originally Posted by Stan Weiss

Wouldn't a 4.5" stroke 6.8" rod 1.2" compression height piston have the piston in about the same place ABDC as a 4.25" stroke 6.625" rod combination?

Stan

The longer stroke is hard on everything. It's worse with a production block. 6.8 rod is a bunch better than a 6.625 rod as far as stressing the block.... I think you already know this.

We've made 850 with a factory block and 4.5 stroke. We made similar power with a 4.21, the later looked better everywhere when we freshened them. Other than a few applications I'm not seeing an upside to the longer arm other than bragging rights.


I could be wrong, I'm a simple head porter that got drafted into building engines I'd be happy to hear about others long and short stroke builds.

I should mention many years ago we were involved in three similar high end builds for the time. Two 4.25 and one 4.5 stroke engines. The 4.5 arm came up noticeably short compared to the smaller engines. Today those results would be different. My point is the odds are against you if you're going to order a "stroker kit" and go set the world on fire with a long stroke, stock block combination.