026 build running a bit lackluster

[NateSaw]

I don't believe there are any limited coils on this chassis.
My lower transfers aren't quite as big as yours, but I can see that causing an issue on a 44.7. You have to remember that an 026 is a big bore, and a stroker on this chassis. 44mm stuff is finicky about case volume, and doesn't like any case mods at all. Idle quality and low end power suffers.
I have not built a 44.7, but everything I have ever read says ported a 44 will always outrun a 44.7.

My upper transfers are completely untouched on this particular saw, they were where I wanted them, and I built the saw a few months after a fire where we lost damn near anything, so I didn't have a 90 degree grinder at the time.

View attachment 369578

View attachment 369577
Yes, the lower ring is missing, the supporting area for the gap got in the way of my intake port.

This was a super simple build, and it just plain runs.






Hardwood, softwood, short bar, long bar, it doesn't care, just don't open up the muffler, then it falls on its face.
This is a stock carb WT194 build.

The fire... That's horrible man. Were you able to rebuild? Or did you have to relocate?

 

[drf256]

Hate to be THAT guy, but I’m gonna be. You need an OEM cylinder for any real performance.

Your transfer tunnels and lowers are too big and lack direction, which is what it’s all about. Almost every single AM jug I’ve encountered has those shítty transfer tunnels with almost no intake side hump and a centered upper over lower (as opposed to and upper that’s shifted towards the intake side).

Here are a few pics of my opinion of what an upper should look like on an 1121. A few of the intake/exhaust ports as well.

 

[drf256]

This is an 034S jug, but it illustrates the intake side tunnel “hump”

 

[82f100swb]

The fire... That's horrible man. Were you able to rebuild? Or did you have to relocate?

We relocated, it was the best option for the situation, fire was 5 years ago next week.

I'm actually pretty conservative with the H screw on that saw as well. Mostly because it's not a play saw, it's the truck/quad saw and gets run more than anything else.
I recently had it out after a pretty big temp swing and didn't have a screwdriver with me. Lean is mean, and it loved it, I just don't trust running it this lean:



The more RPM going into the cut, the more it held in the cut.

 

[NateSaw]

We relocated, it was the best option for the situation, fire was 5 years ago next week.

I'm actually pretty conservative with the H screw on that saw as well. Mostly because it's not a play saw, it's the truck/quad saw and gets run more than anything else.
I recently had it out after a pretty big temp swing and didn't have a screwdriver with me. Lean is mean, and it loved it, I just don't trust running it this lean:



The more RPM going into the cut, the more it held in the cut.

That's how mine runs. I suppose I've just been way to cautious leaning it out. Way too cautious. I bet I haven't even put ten tanks through this thing, and the muffler cover is sooty. And that's saying something with HP2. I'm looking forward to getting it back into some wood with it screaming a bit more. I have a Chineseum stock muffler cover to try. I'm interested in seeing how having back pressure again will affect it. Was your relocation far?

 

[NateSaw]

This is an 034S jug, but it illustrates the intake side tunnel “hump”

View attachment 369596

By all means, please, be THAT guy. Your porting is beautiful. I see and understand what your showing me...
... And that's why I keep tearing it down for evidence... When I saw this, I could see the charge flow wasn't aimed hard enough toward the intake, or even... So an oem ms260 jug is not in my reach at the moment... But, if I get a piston, I can go back to 44mm...

 

[NateSaw]

@drf256 , I imagine you've created a low pressure (turbulent?) swirl above your "hump", and that ramps up the velocity on the intake side of the upper?

 

[huskihl]

By all means, please, be THAT guy. Your porting is beautiful. I see and understand what your showing me... View attachment 369665
... And that's why I keep tearing it down for evidence... When I saw this, I could see the charge flow wasn't aimed hard enough toward the intake, or even... So an oem ms260 jug is not in my reach at the moment... But, if I get a piston, I can go back to 44mm...

It’s also likely that the charge is blowing upwards and not flat across the top of the piston. Hence the lack of much of a wash pattern

 

[NateSaw]

@drf256 , I imagine you've created a low pressure (turbulent?) swirl above your "hump", and that ramps up the velocity on the intake side of the upper?

It also appears you're doing alot with intake timing, duration, and even width?

 

[NateSaw]

It’s also likely that the charge is blowing upwards and not flat across the top of the piston. Hence the lack of much of a wash pattern

Indeed. I feel oddly relieved that I've essentially trashed trash lol. It's almost as if I can now freely poke the goo in the petri dish, and see what happens. It's not unusable. Yet... Anyone have luck with epoxy?

 

[huskihl]

Indeed. I feel oddly relieved that I've essentially trashed trash lol. It's almost as if I can now freely poke the goo in the petri dish, and see what happens. It's not unusable. Yet... Anyone have luck with epoxy?

JB Weld would likely be fine in the lowers if you wanted to experiment. Need to degrease and then rough it up again afterwards before the epoxy

 

[NateSaw]

JB Weld would likely be fine in the lowers if you wanted to experiment. Need to degrease and then rough it up again afterwards before the epoxy

You knew where I was going lol.

 

[Mastermind]

Too much blowdown.

 

[NateSaw]

Too much blowdown.

What if I raised the uppers on a slant, uphill towards the intake? Just a smidge... Kill two birds..

 

[Mastermind]

What if I raised the uppers on a slant, uphill towards the intake? Just a smidge... Kill two birds..

Keep them flat. 118

 

[NateSaw]

Too much blowdown.

So I'm not scavenging enough...

 

[NateSaw]

Keep them flat. 118

Flat equals hard pop from uppers?

 

[Mastermind]

So I'm not scavenging enough...

Two port transfers are lazy. Open them sooner to give them a head start.

 

[NateSaw]

You guys are throwing me some tasty nuggets here.

 

[Mastermind]

You guys are throwing me some tasty nuggets here.

I usually don't chime in. So many ways to skin a cat....