Has anyone ever seen this weird factory exist port ?

[gary55]

I believe the older snowmobile, chain saws, ice auger, and most had a bridge in the port. Performance was not a problem as far as i know. Oh yes even the old go-karts had MC. engines, some 2 or 3..................Curt

OK gotcha. Seen them but not in china girls. This one is definitely a odd ball.

 

[curtisfox]

Yep all 2 stroke, I would try it and see got to be better then china engine, especially if it had the tuner on. Maybe a old kart motor......................Curt

 

[FurryOnTheInside]

Hey, here are some more pictures and details.

There are a few other unique elements, aside from the bridged exhaust port, that make it different from the cylinder that came on my $90 shipped ebay engine.

1. Overall surface finish is much nicer than the one on my new ebay engine, it's actually very nice. There is no pebbly rough surface, it's very smooth. I'm not sure but I suspect it is heavier too.

2. There are some round casting marks on the one side of the fins (shown in one of the pictures)

3. Rectangular intake port with studs 40mm apart. My eBay engine is 35mm

4. Larger casting/mounting surface for exhaust port, larger port too... and bridged of course

5. Also, Not positive but I think it's a few mm shorter

Sorry! I haven't cleaned it yet View attachment 79696 View attachment 79697 View attachment 79698 View attachment 79699

Where did you get the cylinder?
I would love to try one of these if I can find one. It looks like it has potential!
Although the exhaust side of the transfer definitely looks like it needs some redirecting, that mod should be very easy to do with the transfers being open.
Do the piston ring ends clear the intake side of the transfers?

 

[Street Ryderz]

Look at the size of the intake port it's huge,The bridged transfers are easily correctable and also well sized.I would deffinately be trying it out,The casting doesn't match those original Russian engines at all look at the port flange area on the Russian ones totaly different as are the transfers.

 

[Street Ryderz]

here is a D series engine from Russia one of the latest versions

here is the earlier pre 60's version.

Notice the exhaust port does not use studs it's a colleted fitting and the intake is in the case on all these models.

 

[machanic]

Looks like rotary valve induction, cool stuff,very trick.

 

[Street Ryderz]

Looks like rotary valve induction, cool stuff,very trick.

That's a crank induction system. There is a hole and bore through the shaft and a windage cut simmular to those used in R/C engines.

 

[machanic]

Not familiar with that induction system, would be like breathing through a straw.

 

[curtisfox]

here is a D series engine from Russia one of the latest versions

here is the earlier pre 60's version.

Notice the exhaust port does not use studs it's a colleted fitting and the intake is in the case on all these models.

Angled carbs so float is level, looks like a lot better engine,. Can you still by these engines? I know the little R/C engine really rev............Curt

 

[Street Ryderz]

Not familiar with that induction system, would be like breathing through a straw.

The nice part of this style induction is there is no blow back through the carb,The window in the crank is timmed and as the piston decends the window is closed unlike our piston port version.Breathing through a straw not really accurate remember we're dealing with a pulsed vacume wave not a constant vacume and it works quite well.