Cutting squish band

[Deets066]

There are very few saws with anything other than a flattop piston.

i see he had a wanted ad for an 026 KS cylinder

 

[srcarr52]

I use a lathe to cut squish bands. For a domed piston I'll match the initial angle of the piston plus 1-2 deg for the squish angle.

 

[drf256]

If you’re asking about an 026, you can scrape the factory band out on an angel to match the piston contour, then add varying grits of sandpaper to a piston dome to match it. Or you can cut the dome off the piston and machine the chamber flat.

Here’s a sanded band.

 

[drf256]

Here’s a flat band

 

[XP_Slinger]

Would any one be able to snap a pic of their mandrel for cutting by hand? I’ve got a good idea of how to secure the HSS but would like to see if I’m on the right track. Thanks.

 

[angelo c]

There are very few saws with anything other than a flattop piston.

There used to be a guy in OH that got a lot outta pop-up piston work....i just can't remember his screen name....it'll come to me...

 

[drf256]

Would any one be able to snap a pic of their mandrel for cutting by hand? I’ve got a good idea of how to secure the HSS but would like to see if I’m on the right track. Thanks.

Got em at home. I use a allen set screw put in on the load side of the cutter, so the the force pushes the cutter back against the slot in the mandrel and not the set screw.

Just mill a 1/4" slot tilted back 3*

 

[tree monkey]

 

[XP_Slinger]

Thanks gents...appreciate it

 

[Master Bud II]

If you’re asking about an 026, you can scrape the factory band out on an angel to match the piston contour, then add varying grits of sandpaper to a piston dome to match it. Or you can cut the dome off the piston and machine the chamber flat.

Here’s a sanded band.

View attachment 111874 View attachment 111875 View attachment 111876 View attachment 111877 View attachment 111878

That's Clever as *s-word !!!

 

[Al Smith]

It's all theory and a bit of experimental tinkering .I've never cut the band but if I did I'd just use a boring bar .
A pop up contrary to popular thinking does not increase the compression ,that is done by cutting the cylinder base .What two things they do is propagate the flame front and help sweep the area above the intake port .
You can increase the effectiveness with sweeps on the upper transfers or finger ports .What ever floats your boat ,they both work .On the other hand I've seen some hot runners with just a flat top piston .

 

[wcorey]

A pop up contrary to popular thinking does not increase the compression ,that is done by cutting the cylinder base.

A cut pop up will obviously decrease comp without lowering the cylinder but a welded pop up will certainly increase comp on it's own...

 

[wcorey]

Latest mods to my old adjustable cutter.
Added a depth stop and made some changes to the adjuster block, longer and a nested on 'range extender'.

 

[Al Smith]

A welded pop up would work providing you knew the actual alloy used .It's not pure aluminum and I might guess contains silicon and nickle . I'm reminded of the movie "the worlds fastest Indian "When good old Burt used two Chevy and one Lincoln piston for his home cast pistons .Must have worked,the worlds record might still have not been broken .Flying mile ,205 MPH.