Big Old McCulloch Gear Drives ( Where is Al Smith When You Need Him)

[weimedog]

Have a couple....experimenting with Bar & Chain combo's. Was fortunate to have had help from Jacob. J in finding .404 sprockets...and have a virtually unlimited access to any bar that exists for those, can adapt anything modern or ancient... I also have some NOS 1/2 loops. SO asking those who actually know how to take advantage of the gear reduction with those old beasts (but low chain speed)..whats the best way to go for cutting speed in TWO conditions...a 32inch long bar and something in the 18-20 inch "limbing" range. Yup long and short. Have two 660's and want to set them up. I have a hard nose 20 with .404 on one. Had to tear the rakers down a lot to get cutting speed I expected. Really needed to take a "bite". So after...wondering there HAS to be a better approach not requiring all that file time. Looking for a direction...

[Al_Smith]

I haven't tried .404 sprockets but I have some .What I did do was adapt an 8 tooth 1/2" sprocket from a Homelite fit the Mac 650 gear drive I have .Keep in mind my saw  has a 2 to 1 reduction so with that it cuts pretty fast for a gear drive .
Conversely I have a David Bradley 360 that is slow as a snail also running half inch .In addition to that a Lombard with a float carb,most likely came over on the Mayflower .It's slower than the David Bradley .They both have Power Products AH 47 engines that were never noted for speed or power.
The McCulloch has an 87 cc engine and will wind up at over 9000 rpm about twice as fast as the AH 47's .About all I can tell you on the reed valve mac engine is just set it a tad bit rich on the high speed .
Gear drives are something that's fun to play with not something I'd care to run all the time .BTW in case you didn't know both these saws,650 and 660 are rated for a 60" bar . It would take half a day just to file the chain and at least a 12 pack of liquid refershment 

[starmac]

I had, may still have an old Mac. I want to say the model # was 56 or maybe 57. I left this beast at my place in New Mexico, and haven't cranked it in years. Anyway supposedly  a 60 inch two man bar was available for it back when. I know if I used it now, I would have to hire two good helpers to tote the thing all day.

[Al_Smith]

It sounds like maybe it could be a model 7-55 .7 horsepower, 55 pounds .I think it's 9.8 cubic inch ,bigun, heavy, slow . Better than a two man cross cut though .

[sawguy21]

My Mac 797 is heavy enough, I don't think I would want to pack one of those old gear drives. I have to question wanting to limb with .404 on a short bar, it is too aggresive and will grab. Save the big 'uns for the serious stuff.

[Al_Smith]

A big direct drive is made for one thing,big wood .They came from perhaps the last of an era of old growth logging  like coast redwoods and Douglas fir.I might add they do pretty good on Ohio oak which aren't as large .These are not your fire wood saws .My goodness they could wear out a young man swinging these old monsters in a full day . --still a hoot to run ,for a short period of time . 8)

[starmac]

Mine probably has a 24" or so bar, The one thing I remember the most of it was it sure made you respect what the old timers were made out of.

[weimedog]

My Mac 797 is heavy enough, I don't think I would want to pack one of those old gear drives. I have to question wanting to limb with .404 on a short bar, it is too aggresive and will grab. Save the big 'uns for the serious stuff.

All true. I have on video that setup and it actually wasn't bad, but I could tell there is more in the saw so looking to have a better setup...hence this post.
But ultimately, Its not about what makes sense...its about making them useful enough to have a GTG day. And pushing the "logical" boundaries is fun for me. There is some fellow on the YouTube channel now has written books worth of commentary on what I should and should not do.. If you want to have a little fun, go read the comments! Rips me all the time... Hard core logic would have me part them out on eBay. Or put them in with the scrap from the machining operations. But I just want to run them from time to time. While not practical in any sense of the word when I have a stable of saws that are much newer and more capable...its fun. And want to set one up with a long bar and one with a short bar. For chits & grins. No logic. But within those parameters getting real guidance from Al and folks like him can help make those hobby saws somewhat useful while we are having fun. I have several loops of NOS 1/2 semi chisel Oregon chain that need something to do as well. 78 and 84 links or something like that I think...I'll see if I can blend them into the equation maybe as well.

I have two PM700's that I'm struggling with what appears to be a fuel starvation issue. And a 650 & 660 gear drives that I want to blend into a work day like Bob & did with the 562's last week. Al mentioned the different gear reductions....I'll see if I have both a 2-1 and 3-1....put the short bar on the 2-1 and a longer bar on the 3-1 I guess. Probably will use them on one of the many over mature maples we have on the farm. I've been taking them down to get the canopy open for new growth. Some of those trees are upwards of 4ft across. Perfect for those old saws....if I have enough left in me to actually do that work anymore!

[Al_Smith]

Big old saws certainly aren't for the weak at heart .Often times they could have set unused for decades .So with that in mind it could be a daunting task to just get them running let alone use them .I like to tinker with them so as I have time,which is not often that's what I do .Some I soup up ,some I totally restore to about new looking condition .Some I may never do a thing to ,they might set on the shelf a long time before anything gets done .
The newest saws I own are a pair  of Stihl MS 200T's and one of them I did a bit of enhancement ,my little hot rod  8).The oldest goes back to 1956-57 ,old Lombard gear drive .Cantankerous old thing that reminds me of my first wife .Does what ever it wants to,I never know if it will start or not .More times not . 

[Iwawoodwork]

When I worked in the woods for Weyerhaeuser, during the middle 1970's  I spent a short time on the cutting crew, during that time they were phasing out the big Mac's and Homelites, for Stihl's. We had both the gear drive and direct drive Mac's The gear drives usually ran a 5 foot bar or longer, the direct drives (125) was usually used for bucking and smaller timber with a 36" bar and we ran the 404 chain on both. can not imagine a gear drive  with less than a 36" bar.  The short bars you mention could be a wild grabby ride.

[Al_Smith]

The longest I have I think is a 32" which was originally on a Mac super 44a which is 87 cc direct drive .Even with 1/2" chain I don't find it grabby on the 650 but you have to hook the dog because it gets a big bite .Not something you want to make an up cut with for sure .
As I said before these things are just a part of history ,worth restoring for some .The 650 I think is circa 1966 ,the year I graduated from high school and most likely about the end of the gear drive era .

[LeeB]

How well would those old monsters work for ripping/slabbing

[mad murdock]

Great for breakdown saws. I recently parted with my Stihl O75 it was a great one for some serious quick ripping. Would rather have an old Mac. Weimdog, when you get one of the PM700's going, do some side by side comparison cuts with a 372XP. I have both and have used both, I think the PM700 on Big Crosscuts is quicker than the husky, seems to pull harder/more torque. The PM700 is a lot smaller package too as the configuration allows for a more compact saw, weight I would guess is within ounces on either. Sure wish the 10 series macs we're still being produced. Would be awesome to see someone with modern CNC capability turn out some kit saws and new parts for the hard core CAD folks!

[weimedog]

Great for breakdown saws. I recently parted with my Stihl O75 it was a great one for some serious quick ripping. Would rather have an old Mac. Weimdog, when you get one of the PM700's going, do some side by side comparison cuts with a 372XP. I have both and have used both, I think the PM700 on Big Crosscuts is quicker than the husky, seems to pull harder/more torque. The PM700 is a lot smaller package too as the configuration allows for a more compact saw, weight I would guess is within ounces on either. Sure wish the 10 series macs we're still being produced. Would be awesome to see someone with modern CNC capability turn out some kit saws and new parts for the hard core CAD folks!

That is "when" as I haven't been able to get them right. Spend a 1/2 hour another there. Seems like a fuel starvation issue on both...:( Guessing its a carb issue. I'll probably have to soak them and pull welch plugs to get to the heart of it. But have two pretty clean one, one ALL NOS built. Neither run.

[mad murdock]

not to hijack your geared saw thread, just a comment on the PM700, those are sweet saws, when you get them going, you will like them.  Mine starts easy every time, and has plenty of power! I like it almost better than the 372XPW, as it is nimble and handles real nice!

[Al_Smith]

The problem with ripping with a gear drive  is first they are a tad slow as a rule .Two with those big old cutters on 1/2" chain and slower chain speed you'd spent as much time clearing the noodles as you would trying to rip .They can make a rat's nest in your chain guard in a hurry .

[Al_Smith]

Now 700 McCulloch against a 372 Husky . I 've never timed my 700,never tached it just ran it .However in my pile of goodies I have a 6-10 not to be confused with PM 610 .It's 70 cc's right hand start older version of  a 700 .It's been massaged a bit and will usually cut right even with a bone stock 372 .If the Husky has been tweaked the Vikings win the day .