Ported 026 Squish Check

[drf255]

I used mandrels to cut squish for a long while before I finally gave into using the lathe. After doing hundreds on the lathe, I can't imagine using a mandrel again. It's about a 15 minute job on the lathe.

I need to start doing this. I could cut an angled band as well. The stock piston arc may allow a tighter squish at the chamber edge of the SB as well.

 

[Mastermind]

The chamber and band on the 026 are an arc and not an angle. Adds to the complexity of the build and chamber geometry.

A small, angled band cut and a piston cut at the same angle may work well here.

The 026 is one saw that drove me nuts. I could never get any two of them exactly the same.

That is till I took Treemonkeys advice and started doing them like you are here. I'd stick with this method.

 

[jmssaws]

I still cut most cylinders by hand, old habits die hard.

 

[Mastermind]

I still cut most cylinders by hand, old habits die hard.

I was straight up afraid I would destroy a jug doing them on the lathe. I've not got any lies to tell. It was sorta spooky......you're working in a blind hole.

If anyone needs any setup advice, any tips, etc. Just let me know.....I'll give you my phone number and help you any way I can.

 

[drf255]

The 026 is one saw that drove me nuts. I could never get any two of them exactly the same.

That is till I took Treemonkeys advice and started doing them like you are here. I'd stick with this method.

All hobby for me, and I like experimenting.

Who knows if we will stumble upon a better mousetrap.

 

[drf255]

I was straight up afraid I would destroy a jug doing them on the lathe. I've not got any lies to tell. It was sorta spooky......you're working in a blind hole.

If anyone needs any setup advice, any tips, etc. Just let me know.....I'll give you my phone number and help you any way I can.

SOLID

 

[Mastermind]

All hobby for me, and I like experimenting.

Who knows if we will stumble upon a better mousetrap.

That is a very real possibility......

Wanna play with some aftermarket jugs?

 

[drf255]

Perhaps.

What about chamber cooling and SB surface area???

Any affect here?

 

[drf255]

I'd like to try to aluminum braze the exhaust roof next. I'm afraid that the heat from TIG will pop the plating or warp the cylinder.

I have that alum braze rod. May do the trick on combustion chamber and ports.

You know, the one you get at car shows at the "Weld aluminum with a propane torch" booth.

 

[Mastermind]

Perhaps.

What about chamber cooling and SB surface area???

Any affect here?

When it comes to squish band clearance, and shape, I just use what the old timers tell me. Some of these guys have been very helpful in steering me back when I get off track.

You can make more power than the unit will live with pretty easily......so finding that balance is key. Too tight on the squish will kill them........but too tight on the coil gap can too.

Experience is the great teacher, and I've got a lot yet to learn.

 

[Stihlofadeal64]

What's the exhaust from the factory on a 026/260? It's been years since I did one.

We need to somehow remedy that lack of involvement and get your "R&D" up to another level. I have a candidate that is a specimen for your knowledge base
This would be like one of those "clinical trials" where you volunteer yourself to be experimented upon with a reimbursement if you break out in hives or something
Let me know the ship to address.

 

[Mastermind]

We need to somehow remedy that lack of involvement and get your "R&D" up to another level. I have a candidate that is a specimen for your knowledge base
This would be like one of those "clinical trials" where you volunteer yourself to be experiment upon with a reimbursement if you break out in hives or something
Let me know the ship to address.

Repped.

 

[drf255]

I made the band wide in hopes of running the saw on Nitromethane at the next CT GTG.

I have to beat Mattyo's crappy little Hooskie.

 

[Moparmyway]

If you leave a small chamfer on the piston crown edge, you get a higher comp height. Certainly not ideal, but it helps the skirt issue.

At what point does one call it a pop-up ?

A small, angled band cut and a piston cut at the same angle may work well here.

Exactely !!

 

[Moparmyway]

I use a flexible rubber sanding mandrel to taper the edge of the band into the chamber. The harder you push, the more it flexes. That will allow you to bleed off some compression if you end up with too much. .

Do you have a link for this tool ?

 

[jmssaws]

Fear has kept me from chucking one up. I can I just dont.

 

[Red97]

Wonder how well putting the chamber in the crown of the piston would work? like a diesel piston. Some of these cut chambers get awfully small???

Seems if you cut a dish in the piston you could easily adjust squish band ratio?

 

[Trx250r180]

Absolutely. The hybrid for one can be a fantastic runner with no additional machine work. This one here has no machine work. I was going to offer to bump the compression for the owner until I ran it again, but it ran too good to mess with. As is, it will out cut most built 461s.

Saw sounds good ,what kind of wood is that ? Acts kind of like frozen wood does when i cut into it here ,it cuts but acts like the chain is not sharp when it is though .Is it some kind of dry hardwood ?

 

[Trx250r180]

Another question ,listening to the exhaust tone ,seems like the higher comp saws have a deeper tone to me .Am i hearing things ?

 

[Mastermind]

Do you have a link for this tool ?