McCulloch Chain Saws

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It cost me a bit but I had a .pdf file of the paper so I could print it out. The SAE folks know how to protect their property so I could not actually save the file. Mostly the article discussed the low vibration nature of the BP design. The folks at McCulloch did know how to get their ideas out there.

I also bought a copy of the 1970 Popular Science magazine that discussed the BP series engines. I tend to collect stuff...


Mark
 

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Mark, what's in that filing cabinet? Vellum prints?

Brian
 
Jerry - the big seal goes in the bearing, I find it easier to install that seal with the saw apart. The small seal is pretty hard to slide in place if it is square to the shaft, I prefer t put those on with a little "rock/roll" over the step on the shaft then assemble the crankcase halves. Saws with the bearing insert on the PTO side are more challenging, I like to put those in with the saw assembled. Be sure to buy good quality seals (6119) as some cheap one have such a thin steel body that you can't get them pressed into the housing without damaging it.

The 10 Series have pinned rings, keep that in mind when reassembling. I use Threebond 1194 on the housing when they go back together.

Mark
 
heimannm said:
They are, of course, drawing files but I use them for gaskets, gasket stock, oversize advertisements, etc.

Mark
Click to expand...
Good idea. I should have grabbed the cabinet like that at work when they dumped it.

Brian
 
heimannm said:
Jerry - the big seal goes in the bearing, I find it easier to install that seal with the saw apart. The small seal is pretty hard to slide in place if it is square to the shaft, I prefer t put those on with a little "rock/roll" over the step on the shaft then assemble the crankcase halves. Saws with the bearing insert on the PTO side are more challenging, I like to put those in with the saw assembled. Be sure to buy good quality seals (6119) as some cheap one have such a thin steel body that you can't get them pressed into the housing without damaging it.

The 10 Series have pinned rings, keep that in mind when reassembling. I use Threebond 1194 on the housing when they go back together.

Mark
Click to expand...
Thanks mark. I've got the case split but haven't pulled the crank yet. Going real deliberate so as to not be totally surprised and make things more difficult ( not that I've ever done that). I'm guessing there used to be threads on this but guessing also that the pix disappeared. Anyone got any pix
Pistons don't seem to have pins. Like I said, seems to be real early model
 
Mark,

Most know the back story on the BP chainsaw, but what is the back story on these motors?

Ron

heimannm said:
It cost me a bit but I had a .pdf file of the paper so I could print it out. The SAE folks know how to protect their property so I could not actually save the file. Mostly the article discussed the low vibration nature of the BP design. The folks at McCulloch did know how to get their ideas out there.

I also bought a copy of the 1970 Popular Science magazine that discussed the BP series engines. I tend to collect stuff...


Mark
Click to expand...
 
heimannm said:
Jerry - the big seal goes in the bearing, I find it easier to install that seal with the saw apart. The small seal is pretty hard to slide in place if it is square to the shaft, I prefer t put those on with a little "rock/roll" over the step on the shaft then assemble the crankcase halves. Saws with the bearing insert on the PTO side are more challenging, I like to put those in with the saw assembled. Be sure to buy good quality seals (6119) as some cheap one have such a thin steel body that you can't get them pressed into the housing without damaging it.

The 10 Series have pinned rings, keep that in mind when reassembling. I use Threebond 1194 on the housing when they go back together.

Mark
Click to expand...
Thinking of using three bond on all the gasket surfaces. Good, bad, or no biggie idea? Never worked on one of these unique older saws before hence the newbie level questions. Better to have asked and be deemed a DA rather than not to have asked and truly be one
does anyone know what aftermarket seals would work on the flywheel side?
 
Ron - McCulloch was interested in getting into the snowmobile/ATV/personal RV type business and had a number of BP engines on the drawing board. There was a run of the 399T's built (50 units?) and some got out and around. There was a single cylinder version in prototype (I gather from the photos) and discussion about 4 and 6 cylinder versions as well. Robert P. McCulloch never did anything half way.

In searching other forums, it seems the high output of the BP engine design also lead to high fuel consumption and higher emissions that eventually put them out of consideration.

During one series of threads on AS a couple of years back I was contacted by M. Jackson in California who's father Robert V. Jackson had been an Engineer at McCulloch for many years and had been able to gather up a few things when McCulloch was moving from L.A. to AZ. Unfortunately I was never able to make it to CA to meet with Mike and his dad. Among the things I received from the Jackson's was copies of a number of patents RV Jackson had received while working for McCulloch as an Electrical Engineer, two of the most significant were the fast charger for the 10E saws (McCulloch sold the patent to HP since their technology allowed rapid charging of batteries that was not heard of before) and the 17o Welder. The BP399T engines, PM 850 Super, 3-10E, plus the McCulloch Shop Vac and air compressor were all personally delivered to me in Iowa along with a great collection of other McCulloch paraphernalia.

pic066.jpg

Mark
 
Jerry - I am not sure how much it helps but here is a photo of an SP60 apart, crankcase halves are coated with three bond as it is going back together. On this one the PTO side bearing and seal go in an "insert", basically a housing to help spread the load on the crankcase bore.

DSC06638.JPG

The 4 larger screws that hold the case together are 12-24, clean the threads on the screws and the tapped holes in the block before reassembling, I like to put a dab of three bond on the threads as I am reassembling to insure a good seal and to secure the screws in place.

The 4 smaller external screws are 8-32 and can be hard to get to for proper tightening, I will substitute socket head cap screws if the hex head on the originals are questionable.

If you have any specific questions let me know and I will try to find a photo. I do have the 10 Series workshop manual, PM with your e-mail address if you are interested.

FWIW I don't put three bond on anything other than the crankcase halves and the carb gasket to the airbox as I don't want it moving around when I try to put the carburetor back on. The insulator is normally stuck on as shown in the photo above.

Mark
 
nice stuff mark.
any vids of the BP399T's running ? hint
BTW- got my cp-55 running with a sp-60 boot that fit like you said it would. runs sweet, thanks again.
 


See if the link works, otherwise try McCulloch BP399T in youtube or google and it should come up. I am in the red, white and blue sweat shirt, Joey Taylor in the brown carhart jeans, and Mitch Weber taking the video. Everyone is wearing hearing protection...

Since I have a spare again, I will try to start taking my runner with me to GTG's in the coming year so others can appreciate it as well.

Mark
 
At approximately 60#s for the powerhead, it would take a stout fellow to run. Probably more than 60#. 59# minus 4# starter plus X# for tanks, oiler, bar mount and handles. I'm thinking with two BP399Ts, the pair would make a fast and simple rear drive buggy. Ron
 
pulled the seals last night. the dimensions I get with my HF caliper are:
1.564" x 0.564" x 0.257"
spent couple hours doing on-line search and nothing. i'm guessing the huge OD might have something to do with that. looks like i'm stuck buying a NOS seal. what is the collective judgement concerning the "health" of NOS seals?
 
The measurements I've seen published on the flywheel side seal are: 1.563 OD x 0.557 ID x 0.255 thick
The clutch side seal, which is the same as the PM 800 series, part number 110260, cross references to a National part number 253747. The needle bearing has a cross reference to Koyo BH 108.
I haven't seen anyone come up with an alternate part number for the flywheel side on the 10-10 series.

Eric
 

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