I aquired a set of rotor housings in excellent shape and only a few thousand miles on them. What worries me is they came out of a motor that was overheated. Is there any way to tell if they are warped?

Factory service manual shows you how...

It requires a long straight-edge and measuring across several points on the rotor housing sides.





-Ted

thanks, didn't think to look there

how good of a micrometer do you need to do this?

I've seen it done in the atkins rebuild video. They use a thin feeler gauge and pull the flat edge across the irons face, if the feeler gauge slips, the housings is warped.

The service manual says to use a micrometer and to measure a few points on the rotor housing.

The micrometer is used to check differences on the face between the different wear areas, i.e. oil seal track, corner seal and side seal track. All that is required is a staight edge and thin feeler gauges.

More info on how to do this?

Rotary Engine Illustrated



Check on page C-51 for the side housings and on page C-54 and C-55 for the rotor housings.



Hope it helps. https://www.nopistons.com/forums/pub...#>/biggrin.png

Clean them up like new, and push the together. Check for gaps. Spin one around in the vertical axis, and press them together again. Check all 4 faces this way and then flip one housing to bottom up and repeat above. No gaps, good housings.



If you have some clean iron just lay the suspect housing on it and try to rock it side to side. Check along the outer edges for a little dent or a burr from foolish handling. This will cause a rocking housing.



Check the inside of housing for a bulged wear surface and cracks around the plug holes. Check the housing width across the plug area (hot side) for a difference from the intake (cold) side. Run without coolant, the hot side swells because it cannot get any wider. So when it cools it may be a bit thinner than the intake side.



If there is more than .001" difference (thinner) in just the hot side, think overheated. You can see this on a dial caliper. Or a micrometer, or make a "J" shaped tool with a point on the tip of the bottom of the "J" and clamp a dial indicator along the steel strap stock from Sears. Clip the tool onto a known good housing and adjust to zero. Clip it on the suspect housing and measure (compare).

Or, compare the hot side to the cold side.



Even if twisted slightly, a housing can still work fine. There are several tons of pressure pulling it up against the iron, and that can account for slight imperfections.



Lynn E. Hanover