I am performing an engine overhaul. The shaft turns smoothly and has end
play without binding before performing the eccentric end play check. The end
play is 0 and I have gone to a maximum spacer thickness of 8.12 mm spacer
stamp s which gives a slight end play clearance until tightening the bolt.
It still turns smoothly with a nice compression popping sound. The bearings
are properly mounted on the spacer and 2 thrust plates are installed per
procedures.

Any ideas on this ?

John P


I assume you have the shop manual.

One can download them from here free.

http://foxed.ca/index.php?page=rx7manual
                        

Paul Lamar



Just as there is no crying in baseball, there is no zero end play in rotary engines.


There is a very serious error in assembly. In measuring the end play it is best to use a magnetic base dial indicator and the engine in the horizontal.
Push the shaft to the rear by hand. Set the dial to zero. Push the shaft to the front by hand. Look at the dial. Should be .0025" to .0035"


The amount of free, or, unloaded lash, is to provide lots of room for lubricant, allow lower duty cycle for the needle bearings, and to prevent high spotting a bearing when you scream the engine (which of course you would never do) and get some crank flex that tips the bearing surfaces out of parallel.


Using a pry tool such as my long giant screw driver allows the trainee to flex the thrust plate and get a reading on the dial indicator that looks just like end play where there may be no end play at all. There should no no difficulty with getting a good free play feel with no side load on the crank other than the weight of the rotors.


Take it apart now or it will take itself apart later.


Assemble the thrust system with the nose up and lots of bearing grease to keep the spacer and bearings in place. You can also measure end play with the shaft in the vertical with practice.


Lynn E. Hanover