Hybrid clonesaw 365 with a 390 topend - aka the "86'r from youtube"

[Woodwackr]

I meant cutting some wood, but very cool.

O that’s just silly you expect this thing to cut wood like a regular saw?
Sheesh…

 

[upstateamish]

Rich hooked me up with a heck of a deal for some machine tooling (thanks man, I really appreciate it!)

I've also been digging around the interwebs and found this bearing that I think it may be an option/fit to bridge the gap between the 372 15mm pin & 395 large end crankrod.

I ordered a couple cheap ones off aliexpress to test my theory.

 

[Rich Fife]

Rich hooked me up with a heck of a deal for some machine tooling (thanks man, I really appreciate it!)

I've also been digging around the interwebs and found this bearing that I think it may be an option/fit to bridge the gap between the 372 15mm pin & 395 large end crankrod.

I ordered a couple cheap ones off aliexpress to test my theory.

Not a problem man.

 

[upstateamish]

I was out of pocket for a bit over the last couple weeks. Before I left I was having some issues pressing apart the 372 crank. I had ordered a cheap carbide set to turning down a wrist pinprior to @Rich Fife offering the set he's got to me. Now that I'm back, we'll have to sync up!

Pondering my options I had also ordered some SKF 6003 Bearingswhich are the right inner diameter (17) for the 385/390 crank I have& right outer diameter of the 6202 bearing (35mm) to fit in thecase. The 6003 bearing is just 1mm thinner than 6202.

I found a 1mm shim which has a 20mm inner hole, 35mm outerdiameter. So it'll need to be machined a little to clear the innerbearing race, but I think I could use these to get the 385/390 crankin the 372 case.

With bearings kind of figured out, fitting the 385/390 crank inthe case was next. I thought options might be

• machine the case (which would make it thinner than I'd like)
• machine the crank. (I now had the carbides)

Because I was having issues pressing the 372 crank apart & I thought the case would get pretty thin if i clearanced it for the 385/390 crank I gave machining the 385/390 crank a try. It was a learning experience, I did a bit of youtube watching to see how others may have approached doing it. So, what I did is probably not recommended. While I was successful on one side of the crank, I hit the crankrod on the second side (lesson learned, move and secure away next time) …




With the crank mostly machined and nothing to lose I revisited my press idea. I picked up a bearing splitter & some steel plates to better hold things, then successfully split the crank.


Finished machining of the counter weights. Then split the 395 crank, swapped over the longer 395 rod & pressed things back together



I need to look at balancing the crank now, but this is the current state on a stroker crankshaft with the larger crank rod wrist pin that can use a piston from a 390 & fit in the 372 case (hopefully)

 

[Rich Fife]

Ohhh Fuuuuuuuuudge... I totally forgot to send them out!!! I tossed them in a box and set the box on my shelf before I cleaned my lathe...
I'll send them out tomorrow!
My bad man!!!!

 

[upstateamish]

Ohhh Fuuuuuuuuudge... I totally forgot to send them out!!! I tossed them in a box and set the box on my shelf before I cleaned my lathe...
I'll send them out tomorrow!
My bad man!!!!

No worries man, I haven't been around to use them anyway! Still making some forward progress!

 

[Rich Fife]

No worries man, I haven't been around to use them anyway! Still making some forward progress!

Just got home, running out to the garage now.
I see the progress, definitely liking it!

 

[upstateamish]

so, a got a set of 6003 bearings from ebay (which is about 1mm thinner than a 6202) but has the 35x17 size we need for the crank I found a 35mm x 1mm shim with a 20mm bore from a thrust washer set on amazon.

Here's the bearing with the spacer & then I bored the two shims out to clear the inner race of the 6003 bearings. The theory is this should take up that extra space in the case.



While I hoped to not have to do anything with the case halves, I also have to clearance the case a bit to clear the larger crank rod end as it spins through (the counter weights fit without an issue but I don't want to weaken the crank rod.





I have a set of cheap 26x17 seals inbound (which in theory will fit the case) and but aren't rated for more than 212 degrees F. .. a higher temp seal can be ordered if these fail. But that should work on the flywheel side. There's some more challenges on the PTO side I need to figure out as the 372 uses a sleeve bushing that slides over the crank on the clutch side that the seal goes over. However the 385/390's larger crankshaft means it won't fit.

But, that is something I'm thinking about as I'm working on getting clearance in the case halves for the crank

 

[Shane¹]

so, a got a set of 6003 bearings from ebay (which is about 1mm thinner than a 6202) but has the 35x17 size we need for the crank I found a 35mm x 1mm shim with a 20mm bore from a thrust washer set on amazon.

Here's the bearing with the spacer & then I bored the two shims out to clear the inner race of the 6003 bearings. The theory is this should take up that extra space in the case.
View attachment 452162View attachment 452163


While I hoped to not have to do anything with the case halves, I also have to clearance the case a bit to clear the larger crank rod end as it spins through (the counter weights fit without an issue but I don't want to weaken the crank rod.

View attachment 452164

View attachment 452165
View attachment 452166
I have a set of cheap 26x17 seals inbound (which in theory will fit the case) and but aren't rated for more than 212 degrees F. .. a higher temp seal can be ordered if these fail. But that should work on the flywheel side. There's some more challenges on the PTO side I need to figure out as the 372 uses a sleeve bushing that slides over the crank on the clutch side that the seal goes over. However the 385/390's larger crankshaft means it won't fit.

But, that is something I'm thinking about as I'm working on getting clearance in the case halves for the crank

Could you just bore the case halves where the seals go and use the 390 seals? They are 17x28x5 which is not too much bigger and that in theory would just make both sides the same seal and be done

 

[upstateamish]

Could you just bore the case halves where the seals go and use the 390 seals? They are 17x28x5 which is not too much bigger and that in theory would just make both sides the same seal and be done

Yup, Initially I had hoped to do no (or minimal case work) in order use as many stock 372 / off the shelf parts as I could. Boring the pockets for the seals is definately an option and I do have a set of 390 seals inbound. If the 17x26 seals are a no go I'll research how to bore out the bearing pockets.

 

[Ketchup]

Just some random questions:

Would the 390 rod clear where the 394 rod doesn’t?

Can the 372 top-hat bushing be bored to fit?

Are the shims necessary with the 6002 bearings?

 

[upstateamish]

Just some random questions:

Would the 390 rod clear where the 394 rod doesn’t?

I don't believe so, large connecting rod end hole is 24mm on both (I'll confirm)

Can the 372 top-hat bushing be bored to fit?

perhaps? This might be the easiest option, not sure how thin it'd end up being though. I'll take a closer look

Are the shims necessary with the 6002 bearings?

Good question (as I was wondering if they'd be needed as well.) I'll have to measure case width & see where things will end up on the new crank to se if the shims are actually needed or not.

 

[upstateamish]

Connecting rod size (Large Connecting rod end width)
- 372 = 28.75mm
- 385/390/395 = 30mm so about 1mm case clearancing will be required for this to clear not a ton, but more than zero.

Top Hat:
So, looking closer at the way this works I think cutting down/boring out the bushing that the ring rides on could work. It would fit the 17mm shaft and then the 372 seal "should" be able to be used. (although there would be a 1mm difference where the bushing rides on the inner race not sure how big of a deal this might be)





Shim question:
- measuring of the case distance between bearing pockets is "about" 60mm. The shims are needed with the 6003 bearings to match up with that width

I'll continue my case clearancing later today & taking into account the cylinder modifications I'll need to do to make it fit

 

[upstateamish]

I was able to bore down the the top hat and while it wasn't pretty (in theory) this might work.


Turned down some aluminum rod and plugged the bolt holes in the cylinder then spun it up on the lathe and took the skirts down a bit / clearanceed the case so things sit flush.

 

[upstateamish]

Tonight I continued to clearance the case for the crank.


(I think its going to be close, I don't want to grind to much off as I'm not sure how much stress happens here. I guess we'll find out if it's too thin)

Also cut the gasket to match between the cylinder and case and cylinder holes drilled.


The cylinder will need more work to flow with the case ( gotta cut the skirts down where they're blocking the transers in the case as well as open up the lower transfers in the cylinder) but it's coming together


All bolts line up and snug sit down nicely without any issues

 

[Ketchup]

Looking sharp! I’m really enjoying this build!

 

[Rich Fife]

How much clearance do you have between the larger end of the rod and the case?

 

[upstateamish]

here comes my learning experience of the day

How much clearance do you have between the larger end of the rod and the case?

"just enough' (aka, unfortunately I didn't measure ) but after taking things apart and putting them together ... multiple times today I'll have to measure next round.

Why did I take things apart and put them back together multiple times? ... well...

1st time putting things together I had interferance and thought it was my shim on the clutch side. So pulled things apart and removed that shim.

2nd time I still had interferance and realized the crank was hitting the flywheel side of the case and it needed to be clearanced.



so clearanced that with some sandpaper on a mandrel (you can see where I dinged up things getting a seal out)


3rd round I put two 1mm shims on the flywheel side (but it probably could use another... I'm debating if I want to pull things apart again or just send it.) also its kinda hard to get a picture of that but I tried


but it's together and spins freely (which I consider a success)


I also matched up the cylinder to the case halves (I'll pics in a bit)

 

[Rich Fife]

It's a custom build... its normal to assemble and disassemble multiple times. Unkess, you do all of the calculations prior... but, Setup bearings make it a relatively painless process.

 

[Woodwackr]

It's a custom build... its normal to assemble and disassemble multiple times. Unkess, you do all of the calculations prior... but, Setup bearings make it a relatively painless process.

With your piston choice, where are things going to sit, timing wise?
I have a Shindaiwa frankinsaw project and things don’t really line up well