Compression Plate Side Cover

[kartjockey]

Runs well now. Can't wait to see how it runs with one! Being that I restored the running clearance of the rotary valve via all of the machine work must be the trick.

[Ed Steele]

I have a 52, and mine does not have the inner piece, just the cover, now i am wondering if it is going to run correctly after i get the crank back in it?

[Ricks]

Before Tom said his ran without one, I would have bet money on NO.  Now, I guess it can!

[Mike Sal]

I would think it would have to run better with the plate.  I wonder how much the gas mixture has to be adjusted from with and without the plate in place?
Mike Sal

[kartjockey]

My servi-cycle went under the knife today. I am making the crankcase insert. I have taken all the dimensions I need but the ones pictured look alot deeper than mine will be. It will be inserted 7/8". Does this sound about right. I just wonder if earlier blocks were shallower and didn't require one so intensively. Maybe when I get to Portland I will ask Wayne. None the less it can't hurt and one is in the works!

[kartjockey]

I noticed that the picture of the compression plate Mike Sal posted has 12 bolt holes where as mine has 8 bolt holes.

[Mike Sal]

The depth of my plate is 1.062 inches.  I never noticed that the older crankcases were 8 holers.  I wonder if they added the extra bolts when they made the bigger crankcase to accommodate the bigger crank?
Mike Sal

[rldebuse]

Crankcase stuffers were not uncommon on early 2 stroke engines.  Many racers increased the volume of the stuffer to get better fuel-air intake.  Wayne promoted his stuffers as greatly improving starting due to the incresed volume.

[admin]

Crankcase stuffers were not uncommon on early 2 stroke engines.  Many racers increased the volume of the stuffer to get better fuel-air intake.  Wayne promoted his stuffers as greatly improving starting due to the incresed volume.

  I spoke with Bob Kerr, and he does not think this does anything at all.  The compression takes place above the piston, and the amount of air drawn in is determined by piston travel. 

[Mike Sal]

I would think that by reducing the volume of the crank case, it would servce to make sure more oil had the chance to "fall out" of the air and onto the crank bearing & cylinder surfaces where it's needed and not on surfaces (addtional crankcase wall surface area) where it's not needed.
Mike Sal

[bjm]

in waynes defence, they dont come polished. i have 10 that i had waterjet made. you have to polish them yourselves. the cost would be alot more if they came polished. 

[kartjockey]

I know mine starts way better with it.  Went with out it for years AND there is a difference.  Being of the third port design is is necessary to have base Pressure to charge the cylinder and it would stand to reason that if the case volume was larger than the cylinder volume it may caause is issues. recalling the 2-strokes I have worked on seems like there was just enough room for the crank to spin.  Waynes experience told him that a model M wouldn't "hardly run at all" without one and the early blocks will but run better with it.