NWP MS260 Build

[drf256]

The transfers and ports in this jug were very nice, but still not OEM quality.

I'm at the point where I'm believing nothing beats OEM.

The jug was extremely easy to grind on and the plating did not chip at all. It was, however, either thinner or softer than OEM because my burr cut so easily through it.

One of the deals was that my Buddy has to give the Saw back in December, after his landscaping season is over, so I can pull it apart and see how the jug held up.

I used an OEM 44.7 piston in this build. Because the 44.7 saws OEM are so rare there are a surplus of OEM Pistons. I bought them on eBay for $11.99 shipped.

I have a 44mm OEM Saw done my usual way here. I plan on doing a cut to cut comparison in the next week or two.

It's got material removed around the spark plug in the chamber which will affect compression.

The upper on one side was almost 5* higher than the other side, but that was fixed.

Final timing is 102.5/119/77

 

[Deets066]

So you put sandpaper on an old piston, good idea. How did you spin it?

 

[drf256]

So you put sandpaper on an old piston, good idea. How did you spin it?

Old wrist pin and needle nose vise grips. Squish came out very even. Here's some more pics.

Back of deflector welds very cold because a had to fill a gap there.

 

[drf256]

Even .018

 

[drf256]

 

[drf256]

 

[drf256]

 

[paragonbuilder]

So you put sandpaper on an old piston, good idea. How did you spin it?

Old wrist pin and needle nose vise grips. Squish came out very even. Here's some more pics.

Back of deflector welds very cold because a had to fill a gap there.

I did my first one like that. Kinda wonky and slow.
Now I do this

Coarse

Than fine

This way I can hold the cylinder and press down, still no lathe... but it gets it done for me.
I get rolls of sticky back sandpaper on eBay.

 

[drf256]

Good idea Dan.

I like the variety of brews as well.

@Definitive Dave has these NWP jugs.

 

[Mastermind]

I just did a 260. Just cut a slight taper in the squish to match the crown. So many ways to do these saws.

 

[paragonbuilder]

Good idea Dan.

I like the variety of brews as well.

@Definitive Dave has these NWP jugs.

Yeah I like to mix it up [emoji6]
I'm interested how this works out. I wonder if they all have the ROD?

 

[paragonbuilder]

I just did a 260. Just cut a slight taper in the squish to match the crown. So many ways to do these saws.

Do you feel there is an advantage to the crowned piston? Or is it just better so the piston can be replaced without machine work?

 

[RI Chevy]

I thought @wcorey was working on something to cut the top out a little? His invention was pretty slick.

 

[Mastermind]

Do you feel there is an advantage to the crowned piston? Or is it just better so the piston can be replaced without machine work?

I think I can get a little more with a flat top because the exhaust can be dropped more. But even with a high exhaust, these saws can really run.

I do like the unaltered piston for simplicities sake though....

 

[drf256]

I think I can get a little more with a flat top because the exhaust can be dropped more. But even with a high exhaust, these saws can really run.

I do like the unaltered piston for simplicities sake though....

Couldn't agree more on the piston.

The flat cut I do buys me 3* more of exhaust roof, but its a ton more work.

The band match to the piston should bump the compression up more than a tapered band cut and keep the squish more symmetric. When I've cut on an angle, you get a tighter squish towards the chamber at a certain point.

More than one way to skin a cat for sure.

 

[drf256]

I think the domed piston and chamber increases surface area in the same size bore.

There's always some reason the engineers did something, even though we can't find it so apparent.

I think its for heat dissipation. An 026 has a very tiny jug for its bore.

 

[Moparmyway]

Back of deflector welds very cold because a had to fill a gap there.

Looks great Al !!
IMHO, thats a tough weld to make look good, especially on a well used muffler

 

[mdavlee]

If I get time or have to wait on parts I'll be building a head for one of these. Finally got a box of 26 stuff to play with.

 

[angelo c]

I did my first one like that. Kinda wonky and slow.
Now I do this

Coarse

Than fine

This way I can hold the cylinder and press down, still no lathe... but it gets it done for me.
I get rolls of sticky back sandpaper on eBay.

Im a strong supporter of the Shop-Rite brand of seltzer....

luv the Yuengling too....( support yer local brewery)

 

[RI Chevy]

Lol. What about Harpoon? Gotta show some love there. Lol