Post up your ported cylinder Artwork

[mettee]

Numbers as it sits

82 or 83 intake- It's 82.5 ish
110 exhaust
136 secondaries
140 primaries

Will end up

82 or 83
100
125 - 126 secondaries
128 - 130 primaries

Sumptin lik yat

Less like this:

125 - 126 secondaries
128 - 130 primaries

...and more like this:

125 - 126 primaries
128 - 130 secondaries

 

[Ketchup]

Trying some different stuff.

 

[Ketchup]

 

[Ketchup]

 

[MustangMike]

Care to share your theories for some of your changes?

 

[Ketchup]

Bigger carb may deliver less fuel and more air.
The stock transfers are overly complicated and restrictive.
The intake needs to stay high.
The exhaust needs to stay low.
It takes a lot to make compression in a jug this small.

Edit:
I think the stock piston skirt short circuits the final pulse of downstroke into the transfers.

 

[Mastermind]

Bigger carb may deliver less fuel and more air.

WILL deliver less fuel. Fact.

The stock transfers are overly complicated and restrictive.

With a 25cc displacement, direction of flow is probably more important than volume.

The intake needs to stay high.

Agreed.

The exhaust needs to stay low.

Agreed again.

It takes a lot to make compression in a jug this small.

I've not seen the need to add more compression to this model. I just lose the base gasket.

 

[Ketchup]

WILL deliver less fuel. Fact.



With a 25cc displacement, direction of flow is probably more important than volume.



Agreed.



Agreed again.



I've not seen the need to add more compression to this model. I just lose the base gasket.

It could be my imagination, but I feel like more compression allows me to lean on the saw more. This one has 0.053” off the base.

Aiming the transfers on these is a bugger. Sharp angles and tiny. Look at these burrs…



I’m not really going for more volume, just less turbulence. Trying more volume on the FW primary. I probably won’t be able to tell a difference.

I guess experimenting keeps it fun for me. I did a lot of BG deletes, but I’m well off in the weeds now.

I appreciate the feedback. Thank you!

 

[Mastermind]

I just look to make the saw better. I'm absolutely not interested in getting all I can from one of these. Dude up a tree on spurs ain't needing a saw that is tough to pull over. I lose the base gasket, and widen the intake and exhaust. I raise the edge of the lowers, and thin that insert. Then I spend quite a bit of time on the carb.

 

[Darryll]

I have not been here for a very long time and by far this is my favorite thread. Some of the work here is next level. I'd be very interested in your thoughts on how that cylinder runs Ketchup.

I have gone to the extent of setting up a CNC mill in my workshop and I'm using it to cut the squish and new combustion chamber profiles. It does a mint job and I'm able to go to the extreme of calculating my compression ratio biased on my ex port height. For sure I've improved my top end delivery, the saws feel happy and rev out to some extreme rpm's at times, my 395 hit 15600 the other day with a 99 EX roof (cringe). I find 9.5:1 to be a happy spot but just trying a 9.8:1 now and maybe a 10:1 next. Due to the restrictions of the existing chambers the squish band is typically around 40-43% by area with a minor radius of 5mm. I'd like to get that up to 50-60% to see if it will improve torque. But it seems I will need to build my own cylinder head to try that which is on the slow burner at the moment.

Anyhow just some observations so far I'd be interested to know if this lines up with some of your guys thinking.

 

[Ketchup]

I just look to make the saw better. I'm absolutely not interested in getting all I can from one of these. Dude up a tree on spurs ain't needing a saw that is tough to pull over. I lose the base gasket, and widen the intake and exhaust. I raise the edge of the lowers, and thin that insert. Then I spend quite a bit of time on the carb.

I thought the pull starts would be annoying, but it's barely noticeable. This one runs about like all the others. The one thing I was surprised by was how responsive to carb tuning the saw is now with the stock carb. Typically they won't lean out and it's very annoying to find the tune for an easy start. This one tunes so well I'm not messing with the bigger carb.

 

[huskihl]

Bump.
Lower it down a bunch. Raise them up a little

 

[srcarr52]

The best timed AM 660 jug I've ever tickled. Hopefully it will be a monster.

 

[MustangMike]

What make is it, and can I ask what your intake # is?

Looks like you did a good amount of work to it.

 

[srcarr52]

What make is it, and can I ask what your intake # is?

Looks like you did a good amount of work to it.

Unknown make, it's a Traverse Creek (SawSalvage.co) house brand.

I always do a lot of work to 066/660 cylinders, or any cylinder come to think about it.

Out of the box the intake was at 160 duration.

 

[Slumberjack]

My 371 husky nothing crazy

 

[Wolverine]

Bump.
Lower it down a bunch. Raise them up a little


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View attachment 344500

Your cross hatching?

 

[huskihl]

Your cross hatching?

Not mine. Newish saw. Couple tanks on it probably. The 5 series are like that. The camera also makes it look deeper than it is

 

[huskihl]

Your cross hatching?

Here’s another new one with 2 cuts on it. It’s more of a shadow than anything

 

[Slumberjack]

The old junk I like to play with for those who like dual ports. Machine work and port work.