MCCULLOCH The official McCulloch thread

[Lightning Performance]

All great ideas I'm sure.

Having a machine shop next door and diamond tooling makes this an easy conversion for me. I've got plenty of diamond burrs to make oil holes. His carbon drill bits took a beating last time just like mine always do. I know for sure he melted two carbide cutters working on the Sabre bar I sent over. Also have a few bars that were sent out be straightened that came back in about the same condition. The first use moved around the steel on one of them. Going back to my old school hammer and eyes method. They need to be set with impact on the steel because the press work does not stay put.

 

[Al Smith]

For the Stihl bars I just basically machine like thick washers to take up the slop .Fact the Stihl 066 size I have for big Homelite the driver count remained the same .10 series Mac bars depends on who made them ,For example some bars have enough adjustment to able to run either a 7 tooth rim or 8 tooth with a standard driver count of 70 on a 20" 3/8" chain . Some you about need to add another driver or cut the slot .Too tight for a 70 driver and not enough for a 72 driver .Then you hang it on a nail and get it confused with a standard loop .
.

 

[Dream]

0.045" are in fact the thick rings. Thin rings are tool steel and 0.022" thick. 92517 are the correct rings if there are no locating pins. You have the correct seal numbers, let me know if you can't find them elsewhere.

Mark

So I finally got back from work.
This piston DOES have locating pins.
Rings are not notched for them.
Ring end gap is .055".
The pins are .043" if my calipers are getting in there. Both pins measured the same, so maybe?
That would leave .012" for wear indication, but it doesnt seem right to me to have that much gap.
Would think it would be losing a lot of compression there.
Any insight or helpful hints appreciated.

 

[Steve]

So I finally got back from work.
This piston DOES have locating pins.
Rings are not notched for them.
Ring end gap is .055".
The pins are .043" if my calipers are getting in there. Both pins measured the same, so maybe?
That would leave .012" for wear indication, but it doesnt seem right to me to have that much gap.
Would think it would be losing a lot of compression there.
Any insight or helpful hints appreciated.

My steel ring 6-10 will hang from the rope all day long. Has pins and ring gaps just as yours.

 

[Lightning Performance]

So I finally got back from work.
This piston DOES have locating pins.
Rings are not notched for them.
Ring end gap is .055".
The pins are .043" if my calipers are getting in there. Both pins measured the same, so maybe?
That would leave .012" for wear indication, but it doesnt seem right to me to have that much gap.
Would think it would be losing a lot of compression there.
Any insight or helpful hints appreciated.

Run it.

I won't go tighter than 0.008 on a 2" bore or under. Bigger saw should have 9-10 minimum imo. Thick rings or thin rings.

 

[Dream]

Run it.

I won't go tighter than 0.008 on a 2" bore or under. Bigger saw should have 9-10 minimum imo. Thick rings or thin rings.

Just to be clear. Total ring end gap is .055", not .0055"

 

[Lightning Performance]

Just to be clear. Total ring end gap is .055", not .0055"

0.055 - 0.043 for the ring pin?

 

[Steve]

Just to be clear. Total ring end gap is .055", not .0055"

Correct!

 

[Al Smith]

My steel ring 6-10 will hang from the rope all day long. Has pins and ring gaps just as yours.

Since you mentioned it believe it or not because I advanced the timing my 6-10 will wind up to over 15,000 . It's the best running 10 series saw I have over cants .It's also the loudest . It's put the look of amazement on the faces of a lot of people including myself . There's more to it though than just a bump in timing .That's one saw I spent a lot of time on ,more than any other I've ever done . I'm done with it because if I'd have kept on tweeking eventually it would be time bomb .I have no desire to have a saw engine come apart like a dollar watch .

 

[PogoInTheWoods]

Any insight or helpful hints appreciated.

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Regardless of the type of ring, and when considering the pin, you should be fine in the lower end of the ballpark described above. .097 on the other hand is getting up there and may actually be a typo.

 

[Al Smith]

I can't put my finger on it, have no idea why or how it happens .Never the less on iron bore Mac saws reeders or piston ported the rings and the bearings plus the seals seem to last forever .I've pulled them down and even showing eccentricity they still run quite nicely .It's not the oil because todays mix oil is much better .It's not the age because I've got several dating back to the late 50's that still run like they were factory fresh .One such is a Super 44A which morphed into the MC 10 kart engine that still owns records after all these years .Maybe R.P. McCulloch had secrets he took to the grave with him ?

 

[Definitive Dave]

Since you mentioned it believe it or not because I advanced the timing my 6-10 will wind up to over 15,000 . It's the best running 10 series saw I have over cants .It's also the loudest . It's put the look of amazement on the faces of a lot of people including myself . There's more to it though than just a bump in timing .That's one saw I spent a lot of time on ,more than any other I've ever done . I'm done with it because if I'd have kept on tweeking eventually it would be time bomb .I have no desire to have a saw engine come apart like a dollar watch .

I wanna see this saw someday sir

 

[Al Smith]

If this lock down ever ends and some day another GTG is planned I'll bring a truck load many people have never seen before including the hot rod Mac 6-10 .The avatar saw being another one .Few have seen one of those antique PNW redwood slayers that ran correctly . I myself have only seen three of them in my life time .How about a gear drive Mac 650 with a 2 to 1 reduction unit .Fewer have ever seen one of those running or static display .

 

[Steve]

If this lock down ever ends and some day another GTG is planned I'll bring a truck load many people have never seen before including the hot rod Mac 6-10 .The avatar saw being another one .Few have seen one of those antique PNW redwood slayers that ran correctly . I myself have only seen three of them in my life time .How about a gear drive Mac 650 with a 2 to 1 reduction unit .Fewer have ever seen one of those running or static display .

Lockdowns are over Al. GTG are happening as we speak. You load them up and I'll be there!

 

[Dream]

View attachment 302495
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Regardless of the type of ring, and when considering the pin, you should be fine in the lower end of the ballpark described above. .097 on the other hand is getting up there and may actually be a typo.

Well there you go.
Straight from Robbie Mac himself.
Thats good info.
Not that I dont trust all of you guys.
I just wanted to make sure everyone understood what I was working with.
Thanks to everyone for the help!

 

[Dream]

0.055 - 0.043 for the ring pin?

Correct.

 

[Steve]

I dont trust ALL of you guys.

We know.

 

[Al Smith]

Lockdowns are over Al. GTG are happening as we speak. You load them up and I'll be there!

Perhaps but none I know near this area .I refuse to go to A-site for any info or any other reason .

 

[jacob j.]

Perhaps but none I know near this area .I refuse to go to A-site for any info or any other reason .

There was a reason McBob called it "Abortist.com".

 

[Steve]

Perhaps but none I know near this area .I refuse to go to A-site for any info or any other reason .

Don't worry, I'll have to travel several hours and get a hotel to any gtg I attend. It's worth it though.