having just bought a hanger 9 twist 40 I was thinking of the Jen56 wt 1 lb 3.8 oz mvvs 40 wt 1lb 0,4 oz I have decided to go with the
mvvs 40 about 3 oz lighter (both with dieselheads the jen 56 AJs the mvvs davis head. so on to the bench with the mvvs
13x5 wood zinger 8200 13x6 wood zinger 8100 11x7 gray graupner 9500 idle on all quite good 2000 average. then disaster then engine
booged and squeeked to a halt IT did it again the wrist pin c clip came off (this may have been my error in installation l just e mailed
paul at JE to send a new liner piston and rod (having him install the c clips) the groove for the c- clip does look a little more shallow
then the one on the other side which may have been the problem they were installed so the c was vertical and it was humming so good
martin
There is good news Turkey and ham only a hr from now

Slightly used piston and liner mvvs available with the latest cooling grooves on both

Martin,


The MVVS overhaul sets now come fully assembled. Paul is not the one who does it....

They come from the factory with the con-rod, wrist-pin, piston and retainers all assembled in place.
All left for you to do, is to hook the con-rod bottom end on the crank-pin and to slide the sleeve over the piston.

Just make sure that the rod is the right way around and that the sleeve ports, are aligned with those of the cylinder block.


The con-rod, the retainers and the wrist-pin can also be ordered separately, but the piston+sleeve now come only in this unified, ready-to-use package, for all MVVS ABC engines (all .12-.91).

They probably found the retainers are very easy to fumble and lose... so they send them assembled in place...

Dar putting the liner in so its lines up no problem . How can you tell the front from the back of the piston/rod assembly??

Martin, one side of the rod should have a small chamfer or relief cut on the bushing to match the radius where the crankpin meets the flywheel, the other side of the rod should be completely flat. On occasion there are rods that are offset and will only fit one way, some have an oil hole that needs to be toward the crank.

Martin,


I don't have such a rod on hand, but some con-rods also have a relief, or a larger relief, on the side, which faces the front of the engine (to provide more clearance for the crankshaft counter-weight).

I am not sure the MVVS .40 rod is like that.

Dar looks like a self resolving problem if it now comes pre- assembled the arc cut on the bottom of the piston must face the crank
for clearance,just as a point the rod is symmetrical {crankpin end) on both sides and an oil hole on each side of it