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

[upstateamish]

What about the 55mm 390 piston?

the 390 wristpin is 13mm. I don't think they sell it seperately but I found this which is the needle bearing for it + multiple other models.

Husqvarna 181, 281, 288, 385, 390, 394, 395, K950, K960, K970 piston pin bearing

Husqvarna 181, 281, 288, 385, 390, 394, 395, K950, K960, K970Piston pin support bearingReplaces OEM 503 25 61-01

www.hlsproparts.com

If my crankrod swap idea works, then the 390 piston could be an option.

 

[Woodwackr]

the 390 wristpin is 13mm. I don't think they sell it seperately but I found this which is the needle bearing for it + multiple other models.

Husqvarna 181, 281, 288, 385, 390, 394, 395, K950, K960, K970 piston pin bearing

Husqvarna 181, 281, 288, 385, 390, 394, 395, K950, K960, K970Piston pin support bearingReplaces OEM 503 25 61-01

www.hlsproparts.com

If my crankrod swap idea works, then the 390 piston could be an option.

Those pins are all over the place I think I’ve given most of what I had away but others should have them. Very common size.

 

[Maintenance Chief]

@Ronie

 

[Ketchup]

385 is 54mm but 13mm pin. 660 is 54mm but 12mm pin. 365 crank is 12mm pin. No shenanigans with the crank. Only 82.45 cc, but that’s a bump more than XPW. Would probably run great on the HD12 as well.

 

[Rich Fife]

I was curious if I could attempt tig welding the intake ... of course then I wasn't sure if the plating would lift

I completely scrapped a 660 cylinder trying to tig the intake floor... I'm sure it's possible but, I lacked the skills to do so.

 

[upstateamish]

I completely scrapped a 660 cylinder trying to tig the intake floor... I'm sure it's possible but, I lacked the skills to do so.

Yeah, I guess I'll stick with Epoxy for now and test out my (nonexistant at the moment) tig skills on some scrap cylinders to experience what occurs.


Prototype #2

I started this out with the goal of building a few saws. I think it makes sense to keep it all in one thread.

The sacrificial crank I ordered for the "prototype number 2" should be showing this today. In preperation I tore down the new saw in preperation.
The goal was to extract the crank, to see if the hybrid idea works (if not I have a spare 372 shortblock inbound) but since I plan to clearance the case a bit to fit the cylinder, it made sense to tear it down.






Quality of the parts is more or less the same as the first

also have a pile of replacement build parts accumulating.

Most is from TheDuke, the rest is from HL Supply & Chainsawr (Mostly AM, but some OEM)
- 372 x-torq top cover
- 390 chrome cylinder (last one was Nikasil, it was what was in stock. not sure it'll matter much in this case.)
- 372 x-torq choke lever (OEM)
- 365 x-torq low top air filter horn (OEM)
- 395 carb
- filter (OEM)

 

[Ketchup]

If the crank mods don’t work out, cutting the caps for the wrist pin isn’t that bad. I scrapped my first attempt but the second one went pretty smooth. I had to trim 0.25mm off the 12mm pin on each end to get it all inside the circlip lands but it’s all together now.

Edit: I love the plastic bag that just says “SAW”.

 

[upstateamish]

If the crank mods don’t work out, cutting the caps for the wrist pin isn’t that bad. I scrapped my first attempt but the second one went pretty smooth. I had to trim 0.25mm off the 12mm pin on each end to get it all inside the circlip lands but it’s all together now.

excellent, having a plan B is a good thing!

Edit: I love the plastic bag that just says “SAW”.

I noticed that label as well, got a chuckle out of me.

 

[upstateamish]

Ok, 385/390 crank has arrived... I may have a 395 crank inbound as well but because it was delayed (I was impatient and curious... I ordered one too)

big end pin on the crank is ... well bigger.

15mm on the left, 18mm on the right


I guess we'll see what the 395 crank looks like.

I haven't given up yet (I am looking around at big end needle bearings which may be able to make up the difference) but Plan B might become more of a thing.

 

[Powerstroke Cowboy]

You could always just make a new pin since you have a lathe.

 

[Ketchup]

Plan C could be bore the small end of the 372 crank rod. Doesn’t solve the bore height difference, but that’s not a big thing on this build. Boring would be more durable than wrist pin caps.

Plan Delta could be machine cases and install 390 crank. More displacement for more work.

What happened with the 7900 rod?

 

[upstateamish]

You could always just make a new pin since you have a lathe.

true, I guess ordering the carbide tooling has to go on the list.

Plan C could be bore the small end of the 372 crank rod. Doesn’t solve the bore height difference, but that’s not a big thing on this build. Boring would be more durable than wrist pin caps.

Plan Delta could be machine cases and install 390 crank. More displacement for more work.

Good points on the plan C/D. as noted, both will need some addtional tooling on my part... any good places to get some decent stuff or will cheap ebay tooling work?

395 crank has arrived. Big end bearing is the same 18mm pin size. (longer connecting rod)

372: connecting rod length: 90.63mm (rough measurement)


385/390: connecting rod length: 91.70 mm (rough measurement)


395: connecting rod length: 96.92mm (rough measurement)

What happened with the 7900 rod?

the 7900 crank was from a failed bottom end I got from ebay, not sure how it got cracked... But the small/big end of the crank rod match up to the exiting 372 crank rod (the 7900 crank rod is 3mm shorter length wise)

 

[Rich Fife]

Any good places to get some decent stuff or will cheap ebay tooling work?

I order and use Shars tooling... (its honestly pretty good stuff) but, I purchase good carbide from Sandvik, Kennametal, Iscar and Valenite.
What tooling do you need? I have a lot of stuff that I'm not using and it's starting to rust... let me know what you need and I'll see if I have it... if so, I'll toss them in some rust stop, clean them up and send them to you.

 

[upstateamish]

I order and use Shars tooling... (its honestly pretty good stuff) but, I purchase good carbide from Sandvik, Kennametal, Iscar and Valenite.
What tooling do you need? I have a lot of stuff that I'm not using and it's starting to rust... let me know what you need and I'll see if I have it... if so, I'll toss them in some rust stop, clean them up and send them to you.

Nice, I've got some old manual iron, I'll drop a direct message and we can sync up to see what may fit!

 

[Ketchup]

the 7900 crank was from a failed bottom end I got from ebay, not sure how it got cracked... But the small/big end of the crank rod match up to the exiting 372 crank rod (the 7900 crank rod is 3mm shorter length wise)

Darn. Shorter rod on a shorter stroke is the wrong direction.

Ebay is a fair place to get metal stock and I get junker burrs there for stuff like mufflers, but mostly the budget stuff is junk and the used equipment is both overpriced and of questionable condition. I’ve had a lot better luck at machine auctions. Gotten burned there plenty as well but lots of things like HSS tooling, chucks, indicators, calipers, hardware tend to be fair deals if you know how to weed through the junk. Stuff like lubricants, paint, adhesives, abrasives, bearings, belts, fixtures etc. usually go dirt cheap. However, auctioning is a terrible addiction.

Carbide is hard to get a deal on if you don’t work in the machine world. Sometimes you can find it at auction, but there’s often a lot of interested parties. Fixed carbide is a lot easier to buy second hand than inserts.

Simplest to just buy what you need.

 

[Rich Fife]

Carbide is hard to get a deal on if you don’t work in the machine world. Sometimes you can find it at auction, but there’s often a lot of interested parties. Fixed carbide is a lot easier to buy second hand than inserts.

Simplest to just buy what you need.

Facts.

 

[Maintenance Chief]

Is there a video of the saw you already built?

 

[upstateamish]

Is there a video of the saw you already built?

Yup, earlier in the thread. This should drop you to the post

U

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

Jan 19, 2025

Ok, figured out some youtube stuff. I don't have any of the fancy things everyone uses to make nice videos so you just get my phone in the hand videos that i've taken for now

1st runs:

Added the echo exhaust deflector

• upstateamish

• 

 

[Maintenance Chief]

Yup, earlier in the thread. This should drop you to the post

U

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

Jan 19, 2025

Ok, figured out some youtube stuff. I don't have any of the fancy things everyone uses to make nice videos so you just get my phone in the hand videos that i've taken for now

1st runs:

Added the echo exhaust deflector

• upstateamish

• 

I meant cutting some wood, but very cool.

 

[upstateamish]

Ah, sorry. Unfortunately I don't. I'll work on getting a tripod/phone holder to get some cutting vids