Test your two stroke knowledge

[Keith Salyer]

How many of you two stroke guru's know what this little item is? Manbearpig and 42Isles excluded from this trivia question.213450

[redsox]

im a two stroke moron, not a two stroke guru. its a flow restrictor from the exhaust of something, i'd guess.

[nd4speed]

It's a Chevrolet canooter valve.

[TecateDan]

I'm going with a base plate spacer for a stroked crankshaft

[Keith Salyer]

Oh Tecate Dan you mighty warm. Hard to tell by the pic but it is not flat. It has some curve (concave) to it.213451

[3 Wheel Drive]

Every 2 stroke mechanic needs one of those to calibrate their machine properly - a beer bottle opener! Duh...:beer

[bansheekx]

It's a crank case stuffer to reduce the crank case volume.

[Billy Golightly]

It does look like a stuffer but its not very thick...Something to do with turbulence or something from the crank perhaps? The rod fits through the slot.

[ironchop]

its like an oil shield goes between cylinder base and engine lower to direct oil from cylinder walls down into the valley to direct it toward the crank pin (if you flip it over so the concave side is up)?????

That's my very best guess

my second guess is it`s something for a Chevrolet like nd4spd said....maybe a really crappy homemade grill badge lol

[atc300r]

Its a crank case stuffer it helps increase crankcase pressure on the down stroke of the piston to increase the charge threw the transfer ports.There was a snowmobile company back in the 60-70s that had a system like this but was part of the crank case.

[Keith Salyer]

Wow, I'm impressed you guys. Calvin at Cammex put these stuffer plates in all the 81-84 airfoolers . These motors did not have full circle cranks so this plate helped fill that void but if I remember right it also directed the flow through the transfer ports more efficiently. It is made out of thin alum plate and I used to help Calvin build them for the motors. I don't remember if we sold them to the public or if it was for the team trikes only. Mine had them, Kirby Stanislaus ran them, Mike Park, Jay Spradling, Jimbo Eubanks and Robby Owl all had them. I don't know if Glen Isles had an air fooler at the time.

[atc300r]

I read an article about Rob Selvy welding pieces onto the 81-84 250r crank and then machines it into a full circle crank and destrokes it for the liquid R 200 kit.There also used to be a company that made a full circle crank for the air-fooler.Is this piece a bolt in deal or is there some machining to do . Id like to try one of these in one of my air-foolers.

[Billy Golightly]

Keith I had a bit of an unfair advantage...I've had this (And a few other) pictures saved from some posts and comments Calvin had made at www.planetsand.com probably 10 years ago. I knew it looked familiar, just wasn't sure about the thickness of it really working that much as a stuffer moreso than a deflector of the sorts.

213460

(This was posted by Calvin as a precursor and something he worked on during the development of the 500cc Sabre 250r engines)

[Keith Salyer]

He made a lot of cool stuff in the three years I worked/rode for him.

[onformula1]

How many of you two stroke guru's know what this little item is? Manbearpig and 42Isles excluded from this trivia question.213450

Thank goodness, I knew what is was.

Next time you may want to rename the picture. :lol:

I miss- Calvin

[Keith Salyer]

Billy that spacer looks like it is cast out of the plastic mold material.

[Billy Golightly]

Yes. I believe from memory, that was a pattern piece for a casted part of that in his foundry that was past of the Sabre 500 kits.

[onformula1]

Besides Billy did anyone here read his work on plantsand? He was on there a lot at one point he talked about crank stuffing in a very long thread.

[TrikeGarage]

Can someone explain how this go's. Into a crankcase for me. Thanks.how many cc of crank case volume is lost by adding this peice.

[barnett468]

.
.
Looks like atc300r wins the steak knives, good job.



Can someone explain how this go's. Into a crankcase for me. Thanks.how many cc of crank case volume is lost by adding this peice.

That’s an easy one . . Looks like it rested on the step in the cases that is around 1 inch below the top . . Looks like the two tabs went toward the front to keep the plate from rotating in the cylinder . . The base of the cylinder would have kept it from lifting . . The cyl base may have had to be machined slightly to do this . . Looks like the convex portion would face up to clear the crank.

http://www.3wheelerworld.com/attachment.php?attachmentid=213451&d=1427899374

.......................http://www.3wheelerworld.com/attachment.php?attachmentid=213450&d=1427894542

http://i.ebayimg.com/00/s/MTE5NVgxNjAw/z/5pwAAOSwNSxU61HX/$_57.JPG

[barnett468]

.

how many cc of crank case volume is lost by adding this peice.

I had to guestimate at the approximate size, which is pretty easy to do, then guestimate what it would be as a rectangle instead of the square, then subtract the open area in the center from the estimated overall width, then add the thickness.

This is what I used

a. 3.5" long minus 1/4" to estimate it being square = 3.0".

b. Width of each side .75" x 2 = 1.5"

c. .060" thick but it's more likely at least .080"


The volume is:

0.0000044245 cubic meters
4.4245 cubic centimeters
0.000005787 cubic yards
0.00015625 cubic feet
0.27 cubic inches
0.0011688 U.S. gallons
0.0044245 liters
.