288 Piston in a 660

[NateSaw]

That saw is like a good marriage counselor. It's bringing you and the log closer together.

 

[huskihl]

Nice ass

 

[jacob j.]

Nice ass

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That's Dr. Al's specialty.

 

[farminkarman]

Nice ass

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Way to go…now he’s gonna be self conscious.

 

[drf256]

Nice ass

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The ass shots were for @Canadian farm boy

 

[drf256]

Update. I sent saw to the Dyno and wasn’t happy with the results. Only 8.9 hp. Went back in 4 times. Saw gained with each mod.

Interestingly enough, saw kept gaining with more intake. I had to bring the floor up again with more epoxy so it wasn’t a hog.

I’m not sure I like the coating on the Duke’s slugs. I’m sure it’s doing its job, but it looks like Dog Shít. Saw’s had probably 5 full tanks through it, so I would claim the piston to be a success.

The crown pattern appears ok.

 

[drf256]

Here is the saw when I got it back from the Dyno.

There are successive video’s, but I won’t bore you with them. This is the saw after 4th mod with a modified carb. The line was loose to the carb so I zip tied it. It didn’t do the trick and was leaking. The carb had no choke and a slightly enlarged venturi.

And here is the saw with a standard unmodified WJ69. Keeping saw this way.

I think I’m done with it. The 066/660 seems to be an enigma. The cylinder geometry and the huge upper transfers seem to present the biggest problems. Many builders (that know a lot more than me) claim they can make more power from the 52mm 064 jug than the 54mm jug. It has to be the huge uppers on the 52mm jug that are creating the issue. The 660 seems to respond quite differently than to mods any other Stihl I’ve been in.

 

[trooney]

Nice ass

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Thats why his wife married him...

 

[NateSaw]

Here is the saw when I got it back from the Dyno.

There are successive video’s, but I won’t bore you with them. This is the saw after 4th mod with a modified carb. The line was loose to the carb so I zip tied it. It didn’t do the trick and was leaking. The carb had no choke and a slightly enlarged venturi.

And here is the saw with a standard unmodified WJ69. Keeping saw this way.

I think I’m done with it. The 066/660 seems to be an enigma. The cylinder geometry and the huge upper transfers seem to present the biggest problems. Many builders (that know a lot more than me) claim they can make more power from the 52mm 064 jug than the 54mm jug. It has to be the huge uppers on the 52mm jug that are creating the issue. The 660 seems to respond quite differently than to mods any other Stihl I’ve been in.

To clarify, for my future shopping list , the 52mm jigs have the tight uppers?

 

[srcarr52]

Update. I sent saw to the Dyno and wasn’t happy with the results. Only 8.9 hp. Went back in 4 times. Saw gained with each mod.

Interestingly enough, saw kept gaining with more intake. I had to bring the floor up again with more epoxy so it wasn’t a hog.

I’m not sure I like the coating on the Duke’s slugs. I’m sure it’s doing its job, but it looks like Dog Shít. Saw’s had probably 5 full tanks through it, so I would claim the piston to be a success.

The crown pattern appears ok.

View attachment 400100View attachment 400101View attachment 400102View attachment 400103

The coating is supposed to wear off pretty quick. It's more to prevent the chance of scoring during break in and some of the coating does get transferred into rough areas of the cylinder on a microscopic level.