New designed Hyway 660 cylinder

[GlocknStihl]

I requested one of their new ones to try. It looks like cast as ported. I'm sure most of you won't like it because its aftermarket, but I just thought I'd share it. The new one is 56mm and has a popup piston with it.

 

[Chainsaw Jim]

I'm sure most of you won't like it because its aftermarket, but I just thought I'd share it.

The only things we don't like around here are limiter caps and jms.

 

[LBracing]

How is the compression ?

Where did you buy it ?

Numbers # ?

You got my interest .

 

[GlocknStihl]

How is the compression ?

Where did you buy it ?

Numbers # ?

You got my interest .

I'll have to get the numbers. I test for them.

 

[Dub11]

What does a Crossman MMWS head look like inside?

 

[GlocknStihl]

How is the compression ?

Where did you buy it ?

Numbers # ?

You got my interest .

I was just told this version is not in mass production yet. I'll keep this thread updated.

 

[JonCraig]

Subbed...

 

[GlocknStihl]

Subbed...

I may have 4 more on the way. I've promised this first one to a friend already.

 

[LBracing]

If you would be interested to have one turned into a race build put me on the list !$

 

[GlocknStihl]

If you would be interested to have one turned into a race build put me on the list !$

Done! I've been testing for durability, and I cant think of a better test for this purpose.

 

[Dub11]

Done! I've been testing for durability, and I cant think of a better test for this purpose.

Got any timing numbers?

 

[RI Chevy]

I wonder why they decided to go with a pop up?

 

[JonCraig]

I may have 4 more on the way. I've promised this first one to a friend already.

Dang... wish I had a 660 to give one a whirl. My only 1122 saw is an 064, all original.

 

[GlocknStihl]

Got any timing numbers?

I dont currently have a saw to test it. So I'm passing them to guys who can answer that for you.

 

[Dub11]

I dont currently have a saw to test it. So I'm passing them to guys who can answer that for you.

Cool

 

[Chainsaw Jim]

I have saws to test these on. I'd enjoy getting into an 1122 jug that has a leg up on the rest...one good skinny leg.

 

[Poleman]

I recieved one also and thought it looked ported already in the intake and exhaust. Transfers don’t look huge.
The casting and finish is quit good. Very little slag and roughness. Fines are straight, finish looks really good. Pop up piston look good, rings look like good quality.
Excited to do some prelims on this to see where numbers are at, squish and compression numbers. Then get it in some wood.

 

[wcorey]

I received one also and thought it looked ported already in the intake and exhaust.

Could be partly the photo angles but the exhaust port on this one looks quite noticeably different than the op's, flatter on the roof and more radius on the floor.
Again could be the photo angles but the upper transfers don't appear to be very 'directionally orientated' toward the intake wall, particularly on the primary side.

And looks like the 'cross sectional thickness' of the bridges are even front to back, rather than tapered to match the trans tunnels as on the oem and mmws cross. I'd guess that's likely a byproduct of the 2mm overbore.
Can't tell from any of the pics if the trans tunnels are angled in toward the exhaust like oem or straight and following the bridges.

Will be interesting to see some timing numbers...

 

[drf256]

Could be partly the photo angles but the exhaust port on this one looks quite noticeably different than the op's, flatter on the roof and more radius on the floor.
Again could be the photo angles but the upper transfers don't appear to be very 'directionally orientated' toward the intake wall, particularly on the primary side.

And looks like the 'cross sectional thickness' of the bridges are even front to back, rather than tapered to match the trans tunnels as on the oem and mmws cross. I'd guess that's likely a byproduct of the 2mm overbore.
Can't tell from any of the pics if the trans tunnels are angled in toward the exhaust like oem or straight and following the bridges.

Will be interesting to see some timing numbers...

I see the same. That’s what’s annoying about AM, they always fail at some part.

I don’t hate something just because it’s AM, quality AM is tough to find though. I bet in a few years, the market will change and there will be some very fine pieces out there.

Thanks for Posting. Very interesting.

 

[Brewz]

I have been sent a few of these for testing as well, but I'm more working with them with the 660 to try and get the damn port timing right.
Firstly, these cylinders are not yet available for sale.
The stock cylinders are about the 96/126/86 mark
I got a regular big bore as well and it was 97/127/87. No free porting either.
Then they sent me the revised port size big bore and it was same timing, but I told them the exhaust was pointlessly oversize, the fragile little gasket wont last 3 minutes and its all undone as soon as you bolt a muffler on that has not been modified to suit. It also free ports slightly at the bottom
They then sent me a big bore with revised port sizing and revised port timing. When I told them they had successfully made the worst timed 660 cylinder on earth they rang me to discuss. It was 86/123/90.
I told them if they could create a cylinder that has factory timing around the 98/120/80 mark, they would sell them by the truckload as they are actually very good quality.
We discussed the transfers flow etc and I said they are fine for the general market and those that want more can grind it themselves. I also told them it cant freeport so they need to keep that in mind.
All the cylinders I got had pretty much bang on .020" squish with the gasket fitted under the cylinder.
They are now going to make a cylinder with timing I asked for (or try to) and will get back to me.
Fingers crossed they can get it right

I have given the original 54 and 56mm cylinders to a mate who is learning to port to mess with and test as he cuts firewood full time.
I dont cut enough to do durability testing