WTB Mc 49 or 5 crank

steveohara · Post by **steveohara** » Mon Sep 05, 2011 9:52 pm

Anyone have a 49 or 5 crank they can spare? Will buy or trade.
To be used as a runner so needs to be in decent shape.

BTW.. I have two 49 cranks that are nice cosmetically but the rod journals are ruined from decay where the needles sat for years and rusted. If anyone needs them for display motors let me know. I have cleaned them up and sanded the journals to look pretty good but they are about .005 undersize now and still have flaws.
Steve O'Hara

Scott Kneisel · Post by **Scott Kneisel** » Tue Sep 06, 2011 6:36 pm

Hi Steve,
49/Mc5 cranks are really getting hard to find, everyone is scooping them up.

I use the stubby saw cranks, cut a keyway in the 5/8" portion, make a 1"long 5/8"Dia extension with a 7/16-14 LH internal thread on one end and a 5/16-24 LH thread in the outboard end. I install and tighten the extension piece then turn it down to 9/16" from the back side so it tightens when I machine it.

Then the crank is ready to install a west bend clutch, rev grip or Max torque, they fit perfectly and work great. I have many hours on the 49 that I run at events without a problem. It is worth the work.

I do use an outboard bearing on the crank (needle bearing area) when I machine the extension so I can maintain 0.001" TIR.

See the pic. This one has a 3/16 keyway because that is the way I get the clutches from Jim. I use 4 flute carbide end mils and usually end and usually end up chipping a tooth or two on the first few cuts. The crank is so hard I have to make several passes on my small mill to get a good keyway.

Have fun,
Scott

9T Crank 001.jpg: (155.16 KiB) Not downloaded yet

steve miller · Post by **steve miller** » Tue Sep 06, 2011 7:53 pm

scott and steve ..how do i id. a 49 crank ..?? i have a box with kinda alot of cranks i been saving ..there all taper shaft s ..the only mac crank i can id useally is a 6 because of the grove machined in counter weight ..i have put together few 49s lately they all run..?? but i just crab a crank and if it turns over with out stopping i use it ..

steveohara · Post by **steveohara** » Wed Sep 07, 2011 3:40 am

Scott,

Great post... nice work. I am working on some ideas for using the saw cranks as well since they are so easy to find and usually in great shape. I will let you know how my project works out after I test.
Regards,
Steve O'Hara

Scott Kneisel · Post by **Scott Kneisel** » Wed Sep 07, 2011 7:19 am

Thanks Steve, I would love to see what you are cooking up on those saw cranks.
Mr Miller.............
The older 49 cranks are more difficult to ID because the pretty much look like every other standard Mac Crank. I usually just measure the stroke on a flat stone.

The 49E cranks are easier...the have a LH thread and no keyway and the rod journal sits lower between the counter weights, it is very obvious. I don't have one here or I would post a pic.

There are part numbers that are stamped on the side of the counter weight on the flywheel side. Don't know them off the top of my head.
Those numbers seem to be elusive.

Scott

steve miller · Post by **steve miller** » Wed Sep 07, 2011 9:29 am

Ohhhh so thats what them cranks are for ..ill look i no i have a couple ...also what cranks will fit in a 49 block ...jeeez i think i just been using anything that messures 1.375 .??? i wondered why some my motors have straight ,tapered and stepped cranks ..its kinda a pain in the butt because i have to have seperate clutches for everyone ..

WTB Mc 49 or 5 crank

WTB Mc 49 or 5 crank

Re: WTB Mc 49 or 5 crank

Re: WTB Mc 49 or 5 crank

Re: WTB Mc 49 or 5 crank

Re: WTB Mc 49 or 5 crank

Re: WTB Mc 49 or 5 crank