Piston wash patterns

[Wolverine]

Interesting comparing it to this 395 I found in the artwork thread
View attachment 308302

Same basic shape, but the carbon is concentrated in different locations.

I'm sure tune has something to do with that, as does mix. Millin' sure does heat things up too. I should pull mine apart again now that it's ported.

 

[Wilhelm]

PS-6400/DCS6401 47mm take-off P&C

 

[Nutball]

FT 660. The transfers I ported were not very symmetrical. 20-30 tanks of mostly RA @ 32:1

 

[huskyboy]

2021 372 xt stock wash. Not bad and it ran ok for stock. Squish was decent and the mahle cylinder was a good casting too.

 

[Ketchup]

201t V1. Giant muff mod, timing advance. Possible dying coil.

 

[MustangMike]

What oil is in the mix?

 

[deye223]

Hmmmm too much on the MM maybe

 

[huskyboy]

Those little saws don’t make much heat cutting twigs and can spooge up with carbon. The “giant muffler mod” + possibly too much oil in the mix aren’t helping the cause either.

 

[Ketchup]

50:1 Red Armor. MM is a 5/8” squareish hole and may be the only thing that saved it (though it’s definitely too big). Most of the fins are cindered over with old saw dust and bar oil.


None of that explains the FW dominated wash pattern.

Edit: Maybe just more heat on the PTO side transfer. The crust is thickest there.

 

[MustangMike]

I would guess the tune may have been way too rich.

 

[RI Chevy]

I'd venture to say just the opposite Mike. Red Armor running rich would wash that crown I would think.
But its a tough read.

 

[Wolverine]

I'd venture to say just the opposite Mike. Red Armor running rich would wash that crown I would think.
But its a tough read.

Maybe the saw never gets out of 4 strokin'?

 

[MustangMike]

If it was a dryer build up, I would guess lean, but it just looks too wet.

 

[huskyboy]

50:1 Red Armor. MM is a 5/8” squareish hole and may be the only thing that saved it (though it’s definitely too big). Most of the fins are cindered over with old saw dust and bar oil.
View attachment 314828

None of that explains the FW dominated wash pattern.

Edit: Maybe just more heat on the PTO side transfer. The crust is thickest there.

Im guessing he cut a lot of pine of some sort with it too. Most saws that looked like that when I took them apart cut a lot of pine. The pitch is nasty if you don’t clean it off it builds up a lot like that.

 

[huskihl]

I’m guessing the added heat from having the fins caked is what’s burning the oil on top of the piston

 

[Stump Shot]

I’m guessing the added heat from having the fins caked is what’s burning the oil on top of the piston

Black Armor?

#rename

 

[MG porting]

View attachment 314808
201t V1. Giant muff mod, timing advance. Possible dying coil.

Way to much oil.....

 

[Nutball]

2511t, polished piston, 1 tank of gas. I think it was 40:1 XP oil.







....... .

 

[Ketchup]

Love the in-cylinder pics. Way more info. Are the transfer uppers stock or modified?

 

[Nutball]

I blended the intake side toward the intake

Have you found any useful tweaks to the uppers? I've debated removing the roughness they leave there, but it seems intentional and only near the opening, not in the tubes.