49SP and 70E Build From Scratch.......or Scratches!!

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HAHAHA!!! Hotshot, what you are seeing isn't an offset....I didn't even notice that until I looked at the pic too. All that is...is the outside top of the rough casting of the conrod was a tad light on that edge. The other side looks normal. I had to make a decision if it was good enough to use and decided if it hadn't been a problem in the saw that donated it, it would work ok in mine too. I'd just as soon it not be like that but the crank seemed to be one of the best used ones I had. Big end bearing on the conrod was real nice and tight. But it does look weird. Good question...hopefully a good answer...
 
Thanks Chris


Well after looking things over at the shop, I 've decided to change course a little. This thread wil go from a two saw build to a three saw build for a short time. I am going to be bead blasting the cyls for the 49sp and the 70E. The 49 because it is very crappy looking and needs it and the 70E because, though it is NOS it is somewhat dull looking from sitting so I am just going to freshen it up a bit. The third saw comes in because I have had a partially built 49SP on the bench from quite some time now waiting patiently for a NOS piston or NOS P&C kit to come along, which it/they have not. ( should someone reading this have or know where either one of these could be had....PM me!!!) So I do have two used P&Cs for the 49SP that are in real good shape and measure only 0.001" or so wear. If I am at the blaster I might as well do three as two. Then I will assemble all three and the latest 49SP will return to the shadows again with a new top end and the build on my original 49SP and the 70E will continue on to the end (hopefully).

The pics this time are of the new partial 49SP and the two chosen P&C units to be cleaned.

No need to itemize these other than to say the cyl on the left is from my saw. The piston for that is in front and in very good shape. The cyl on the right is from another donor saw and that piston looks funny in the pic but it's just discoloration that will clean up nicely. Not even minor scoring anywhere on any of these units. These will both get OEM NOS Jonsereds rings.:cheers:
 
Robin. I was away for a couple of days in Austria and the first thing I did when I got back was to boot up the computer and check your progress. Don't go and get yourself mixed up by doing three rebuilds. Seriously though, I am really enjoying this thread, so keep it coming.

geoff.

:cheers:
 
Good work and a nice shop! Thanks for taking the time to take pics, I know it's hard to stop when your on a roll. I have a mint 49sp and a decent 70E. Glad to see you reviving them. Are you going to do any transfer work on the 49sp? Have you ever done any port work on a 70E? I put a ring in mine and left the base gasket out. I left the cylinder stock but it looked like it would benefit from some grinding. Mainly just wanted to see how a 70E ran. I may open the 70's muffler baffles and and another port when I get time.
 
Hey Robin,
Great thread, love the pics and detailed explanations, not only about the rebuilds, but the Stove too! It truly is great to get non working saws off the shelf and back in the wood. Every time I pull my 49sp off the shelf and stick her in some wood you come to mind, the oiler pump part you sent brought her back to life.
:yourock:
:cheers:
 
Hey Robin,
Great thread, love the pics and detailed explanations, not only about the rebuilds, but the Stove too! It truly is great to get non working saws off the shelf and back in the wood. Every time I pull my 49sp off the shelf and stick her in some wood you come to mind, the oiler pump part you sent brought her back to life.
:yourock:
:cheers:

Well just thought I'd show off some of the shop stuff. Glad the 49SP is still running good for you. I find them truly pleasurable to run. Just sweet. LOL!! Glad you're enjoying the thread should be some more before the weekend is out. My better half has me on call today so I doubt there will be much progress until perhaps tomorrow.
 
Hey Lee... I figured you would have to see it sooner or later!! LOLOL! Are you back up here yet???:cheers:

Yeah, I am back up here. Got back late Wednesday night. We should get together sometime to swap some parts and kick back a couple Ballantine's.

:cheers:
 
Good work and a nice shop! Thanks for taking the time to take pics, I know it's hard to stop when your on a roll. I have a mint 49sp and a decent 70E. Glad to see you reviving them. Are you going to do any transfer work on the 49sp? Have you ever done any port work on a 70E? I put a ring in mine and left the base gasket out. I left the cylinder stock but it looked like it would benefit from some grinding. Mainly just wanted to see how a 70E ran. I may open the 70's muffler baffles and and another port when I get time.


Sorry Albert...I meant to answer your questions earlier but got sidetracked.

I think on the 49SP, I will probably just smooth the transfers as it is open port. I will be widening the exhaust port and straightening the sides. Probably doing some contour work on the intake and widen it as well. Not a lot but should help bring the RPM up a bit. I've never even heard of anyone porting a 49SP so we will just have to see how it goes.

On the 70E The transfers are rather small and pretty hard to enlarge much as the bottom part of the transfers that is built into the case is pretty limiting. Again I think the 70E as with the 49SP would benifit from basic intake and exhaust work. It will never turn like a 268XP or 670 as the cyl is just as not developed to produce max power from a 50MM bore.
The 70E also has 0.038" more stroke than the 670 and 268XP which is not earth shattering but does contribute to building more torque and less RPM. I have worked many hrs with a stock 70E...good saw...lots of brute power but a bit on the heavy side and not the fastest in the cut but that changes the larger the wood your cutting as the power does not fall off as quick as a lot of other saws this size.
 
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Made a bit more progress this afternoon and have a couple sets of pics. They are as follows;

052 This is the two 49SP cyl cleaned and prepped for the bead blaster. I install screws and bolts in all threaded holes to keep the glass beads from getting in the threads. For those that don't have experience with sand or bead blasting, all grease and oil must be cleaned from the work because if it isn't it will just absorb the media and will not allow the media to get to the surface and do it's job. I just cleaned these with gas and a stiff parts brush.

053 This is my cheepy-charley blast cabinet....works OK...but certainly not the best.

054 This is just a pic of one of the 49SP cyls in the blast cabinet.

055 All done with pistons. These cleaned up well and I put the pistons through at low pressure and didn't get very aggressive with them. But they cleaned up nicely too.

056 Is the same ..different angle.
 
The next set

057 Brand new NOS 70E piston....note the dome...this is an old school high performance piston. All these pistons in this thread are domed but the 70E is the most impressive. This is how they made high compression figures but not super high rpm like...say a 268XP or 670 with windowed, flat top pistons designed to run on the fuels available since the 80's. These saws were designed to run on the fuels of the day....leaded gas with octane ratings in the mid 90's. Not uncommon for a two ring 80 Jreds to pull 225-235 compression. With no decomp, you need to be committed when starting these types of saws.

058 This is the piston selected for my 49SP....HAHA note the fuzz from the rag I used to wipe it off!!! LOL!!

059 This is the piston for the other 49SP. Both of these pistons are used but measure real close to stock size. Just not glamor of the new 70E.

060 This looks much like a previous pic but the Ex ports are facing you this time.

061 This a shot across part of the shop...note the clutches ready and stacked up...

I also got the drive systems ready today...my 49 will have a new drum, bearing and .325 8 pin. The 70E has a new clutch, drum and 3/8 8 pin rim as well. These are the stock drive systems for both these saws. Of course the other 49SP also has a .325 8 pin too. Pics of this stuff and installation next time.
 
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