1608 piston-bore clearance

[dom]

Hi guys,

I had my 1608 rebored to .4mm over. The .4 oversize pistons seem tight in the bore. I have no way of checking bore size. I installed a new set of oversize rings in the bore to measure end gap. There is none. Now i am assuming that the rings have to be filed to fit but I was expecting at least some gap. Any other way to guage if the bores are too small without using proper instruments. Pistons move kinda freely up and down but i have not installed them on the crank yet. I am worried about heat expansion. Just being careful. I did tell him the clearance in the manual which was .0025 to .0033 inches.
Thanks
Dom

[LIQUIDLOUNGE]

Well, you'll definitley need ring end gap or you'll ruin those nice new bores in short order. As far as PTW (piston to wall) you should consult the piston manufacturer, instead of your factory repair manual because pistons have changed in several areas over the years that could affect the desired PTW. For instance, the newer hyperutectic designs require less PTW than the older cast pistons. If the pistons are forged, they might need more PTW than the originals. Pretty much PTW has reduced as technology has advanced.