Ported 036 Squish

[drf256]

So I had some case and piston variation between my builder case and the actual saw I'm building.

Using my builder case, I got a perfect 020 squish, but there were no rings on the piston.

The jug has .040 out of the band. Exhaust is 103.

I'm using .023 solder for measurements.

I'm at .015-.017 across the band right now. I'm using a caliper and my mic usually reads .001 bigger, so maybe I'm at .016 minimum.

Run it, or sand the band?

 

[drf256]

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[Ironworker]

That's probably the smallest I would run. I like my 60cc saws around .020.

 

[Savage Saws]

I found this little formula on the other site long ago and has worked well for me. (Stroke x .0125 ÷ 25.4) gives you the minimum squish clerance for that stroke. I.e 395xp has 38mm stroke: 38 × .0125 = .0475 ÷ 25.4 =.0187. So .018 is closest you should safely go. Could be absolute hokum but, i haven't built a head slapper yet! (Prbably means i'm not pushing the envelope far enough)

 

[drf256]

Sounds like it's coming apart for a sanding.

Was my plan anyway, do it right once.

Figured I'd throw it out there.

 

[Keith Gandy]

I found this little formula on the other site long ago and has worked well for me. (Stroke x .0125 ÷ 25.4) gives you the minimum squish clerance for that stroke. I.e 395xp has 38mm stroke: 38 × .0125 = .0475 ÷ 25.4 =.0187. So .018 is closest you should safely go. Could be absolute hokum but, i haven't built a head slapper yet! (Prbably means i'm not pushing the envelope far enough)

What was the source of this formula? Thats interesting and would be nice to calculate from if it has a creditable source?

 

[Keith Gandy]

Sounds like it's coming apart for a sanding.

Was my plan anyway, do it right once.

Figured I'd throw it out there.

I like .018 to . 022. Ive seen alota ported saws Ive been in around .026 but I think that will also depend on the amount taken out of the top as to whether u need a tighter squish?

 

[Savage Saws]

I honestly can't remember Keith??? Its probably lost in the waste land of the pre-linkbuks A.S.

I'm sure it was a side note from one of the old time builders. Posibly Romeo, used to build bike saws i think.

 

[Keith Gandy]

I guess if the port timing was near where it needed to be from factory ,taking more out the top and deleting gasket and lil off base would make more sense than cutting the base first then the squish? I may be wrong but taking more out of the top will require less of a tight squish to gain psi?

 

[Keith Gandy]

I honestly can't remember Keith??? Its probably lost in the waste land of the pre-linkbuks A.S.

I'm sure it was a side note from one of the old time builders. Posibly Romeo, used to build bike saws i think.

Ya there was a load of info lost as well as pics. Discouraging when a man starts using the search function

 

[Keith Gandy]

View attachment 8108


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From the looks of that 036 video u posted awhile back Id do the same in this one!!!

 

[Moparmyway]

So I had some case and piston variation between my builder case and the actual saw I'm building.

Using my builder case, I got a perfect 020 squish, but there were no rings on the piston.

The jug has .040 out of the band. Exhaust is 103.

I'm using .023 solder for measurements.

I'm at .015-.017 across the band right now. I'm using a caliper and my mic usually reads .001 bigger, so maybe I'm at .016 minimum.

Run it, or sand the band?

With that tiny chamber, it probably is best to sand a little. Youre going to have pretty high compression anyway

 

[mdavlee]

Sand a little and you'll be fine.

 

[Brush Ape]

What was the source of this formula?

It was conceived by Ischlem Bimba as he meditated upon an ice boulder on the planet Relius during the epoch of Nordch.

 

[Keith Gandy]

It was concieved by Ischlem Bimba as he meditated upon an ice boulder on the planet Relius during the epoch of Nordch.

Lmao!! Only from u Ole Ape!!!

 

[drf256]

I have the ability to sand it, plus, I actually enjoy working on saws.

The extra work, as strange as it may sound, gives me more playtime to hone my skills.

 

[Milkman31]

It was conceived by Ischlem Bimba as he meditated upon an ice boulder on the planet Relius during the epoch of Nordch.

I don't care who you are that's funny!!