I'm putting a Solex on a 1.6 Kent with low boost, and I am fitting custom forged pistons for the build. This car will be for the street. The engine is stripped and I'm taking measurements to get the pistons ordered. I measured the bores as follows to get a feel for the starting condition:These measurements were performed without honing. If I remember correctly, the book "Engine Builder's Handbook" claims taper should be less than 0.0030 inch for a reasonable rebuild (though acknowledges if its not perfect it should be re-bored). The book does not contain guidance on out of round. Also, the book was not written for boosted applications. My question is, of course, are these reasonable measurements to continue with just a hone? I'm planning on using the ball flex-hone and doing it myself unless it is highly recommended otherwise. Possible a proper honing device would straighten the bores up some and be worth the while? Worse case, I can take it in to a shop for the whole 9 yards.
- I took an out-of-round measurement for each cylinder by measuring parallel to the crankshaft and perpendicular to the crank at the top of the worn-in area of the bore (beneath the ridge). Subtracting these two numbers, the max value obtained is 0.0019 inch (google says that's 0.04826mm).
- I measured bore taper at top, middle (taken just for reference), and bottom for each cylinder (I should note I eyeball-ed where top, middle, and bottom was) parallel to the crankshaft. Subtracting top and bottom values I obtained a max taper of 0.0010 inch (0.0254mm). For fun I also measured the taper perpendicular to the crank, also obtained a max of 0.0010 inch.
I will be sure to re-measure everything after the hone and use those numbers for the piston order form.
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