Another 288 build

[mdavlee]

I got some time today to put the 288 case together and then get the degree wheel on the cylinder. I hope to get it together tomorrow after I go get the rest of the bolts I need.

 

[DexterDay]

Nice....

 

[fuzz1500]

Beautiful

 

[Adirondackstihl]

Subbin

 

[blsnelling]

I see fingers! That's something I've yet to try.

 

[mdavlee]

Thanks. Fingers seem to make some saws come alive. It give the last 288 a lot better throttle response. This one got the same thing with a little different numbers than the last.

 

[Grqnbech]

Can you show some more pictures of the finger ports...? How does a finger port effect the engine...?
I have never seen one

 

[mdavlee]

Here's a picture of the other cylinder. It just gives more transfer charge and directs it straight towards the exhaust trying to get more of the charge in and exhaust out.

 

[komatsuvarna]

They make the dual transfer port huskies come alive on the throttle response! Think 346 response in a 88cc saw.

 

[Grqnbech]

Very nice.... How deep in to the wall du you go....? This would be a good mod on one of mine 262xpg's

 

[mdavlee]

Very nice.... How deep in to the wall du you go....? This would be a good mod on one of mine 262xpg's

Those are around .100" deep.

 

[Adirondackstihl]

directs it straight towards the exhaust

You mean intake right?

 

[mdavlee]

You mean intake right?

Nope it's above the intake pushing charge across the piston towards the exhaust port. It's a poor mans boost port.

 

[tpope]

I'm loving this one. I can't wait to see it run. It looks great so far.

 

[mdavlee]

I wish the dealer would have come up with the parts today to finish it up. I've got mostly together now but missing a few wires and a nut to hold the flywheel on. That one is threaded crooked. I put it on finger tight to hold the flywheel to turn it over to degree it. Any one know the pitch so I can just go buy one?

 

[The Ripper]

Shouldn't the fingers be pointed towards the exhaust port to help aid the initial intake charge? Essentially the fingers create a low pressure draw don't they ,along with the squish turbulence. Or what am I missing and nice work too!

 

[HuskStihl]

ok, so this hasn't become super serious yet, so I'm just going to go ahead and ask you to do a teaching exercise. pretend for just a moment that i know nothing about two stroke engines, especially transfer ports, and explain using small words, what the **** finger ports do

 

[mdavlee]

ok, so this hasn't become super serious yet, so I'm just going to go ahead and ask you to do a teaching exercise. pretend for just a moment that i know nothing about two stroke engines, especially transfer ports, and explain using small words, what the **** finger ports do

It gives more transfer port timing and area. It will blow charge across the piston and gives more on the intake side. When the piston goes up intake lets the charge in. When the piston goes back down it forces everything under the piston into the transfer ports and then on top of the piston.

I'm getting a little closer now.

 

[HuskStihl]

so the finger ports are taking air/fuel mixture from the bottom of the transfers past the cylinder towards the intake port. is this basically making a dual port into a quad port, or is that way off

 

[ELECT6845]

Looking good Mike. I have an extra flywheel nut and a few extra parts if you need them let me know.