calling Stihl hybrid builders

[mdavlee]

036

 

[drf256]

I’m planning on the swap. I can tell you all I’ve come to learn.

The 036 crank is longer in width than the 044 crank. I compared the 2 a few weeks ago with the same idea in mind. The 044 PTO side will be too short. The 036 PTO side is like an inch longer than the 044 crank.

The jugs are externally a very similar size.

The bearings are the same.

It’s been done a few times before.

Like @Chainsaw Jim said, the jug base gets too thin for the swap. You really need to mill the case (@Mattyo @trooney) so that you can keep the jug base thick enough. Jim is saying to take .080, remember that’s with an unported jug. You’ll be pushing less volume into the same chamber, so you’ll need to cut the band or the compression will be piss poor. So you’re looking at dropping the jug almost .120 in most cases.

The 10mm oem slug will have pin placement that’s too narrow for many 10mm cylinders. Plus, why ruin one. The meteor 10mm slug is a 12mm one with a 10mm hole. The rest of it is the same, including pin boss placement unfortunately. I should be able to snap a pic in a moment. The skirts are wider than an OEM 10mm piston. This should allow use of any 12mm jug, including an AM for experimentation.

I’ve got the estimated connecting rod length written down somewhere. It’s just an estimate, as it’s tough to measure precisely. It’s accurate enough to plug into the Torquesoft program for numbers

 

[drf256]

Conn rods

036 = 60mm

044/046 = 62mm

Base to band with .020 squish

036 = 2.467”

044 = N/A

 

[drf256]

It’s appears that the ring pin info I’ve read on the 10mm vs 12mm pistons is wrong or off very little.

The meteors have wings and offer much more stability in the cylinder. Port coverage is about the same though.

 

[drf256]

 

[drf256]

This is where the 10mm meteor fails. The 12mm small rod end is wider than the 10mm rod end. The inner pin boss width is smaller on the oem 10mm slug, but it’s the same on the 10mm and 12mm Meteor. This allows the pin bearing to slip sideways.

People don’t like this, but no ones heard of any actual failures.

 

[Definitive Dave]

I’ll throw some random detritus in here for mastication by the collective brain trust.
First work saws are dumb - all that matters is speed

Plenty of race saws have sloppy pin bosses and/or shims/bushings/spacer bearings.

@bulletpruf asked me about a new old stock 048 cylinder kit yesterday and when I looked it is actually an 042AV kit 49mm, with a d-shaped combustion chamber and domed piston

Fits up to the base of an 034 pretty nicely so maybe with a tiny base clearance and a two piece for making the 2mm extra stroke happy and a shim to fix the piston pin difference 10mm vs. 13mm this could be a badass sneaky cheater 034.

If I show up and smoke ya’ll with an 034 next year remember I ain’t cheatin’ I’m Innovating!!!

 

[drf256]

A 2 piece changes the whole game Dave.

Port geometry with the shorter stroke will get interesting.

I bought a few titanium 12mm Dominant pins to machine as 10mm pin end caps. Should be able to get 3 caps from each.

This will allow up to a 54mm big bore 046 cylinder to mate up to the 034 case with an 066 piston. Vibration city I guess.

Only 8mm bigger bore than the original case was meant for. No biggie.

Case to swept volume ratio sh0uld be ridiculous. Uppers will likely need to be in da 130* range to prevent over scavenging.

Or one can add a 52mm 461 jug to the case with some JB weld, a dollar, and a dream.

Lots of mental masturbation here. Remember what happens to 044/6 hybrids when the bigger jug goes on the smaller case. More rpm and less low end ass. 18k+ possible before the crank falls apart.

Let’s keep this thread going with ideas and projects. Around 8 more saws for me, then I’ll be free to play again.

 

[Deets066]

Around 8 more saws for me, then I’ll be free to play again.

I didn't think you were taking anymore saws Doc?
Lol

 

[J_M____]

Can the pin be pressed out of the crank and the longer 044 rod be used on the 036 crank? That should solve the issue with the stroke.

 

[Red97]

Does a 12mm pin bearing fit the 036 rod?

If so a 268xp piston is about 2mm taller than the s tihl iirc.

 

[Stump Shot]

Does a 12mm pin bearing fit the 036 rod?

If so a 268xp piston is about 2mm taller than the s tihl iirc.

From what I can tell, no this won't fit up, also the pin to dome measurement of the 266/268 and 044/440 piston are the same. So no gain here. Measured an 036 and 044 cylinder and found that the difference in height is closer to 1.5mm.

Don't know if that helps you guys or not.

 

[Backtroller]

I think you'd have to run some sort of velocity stack to make it reach its full potential. The filters aren't so great in that series.

I just ran my metal filter mofo 034Super vs my Mofo 036pro with the oem flocked airfilter. Its a huge difference power wise .

 

[EvilRoySlade]

Can the pin be pressed out of the crank and the longer 044 rod be used on the 036 crank? That should solve the issue with the stroke.

I would say probably. I would guess they used similar big end bearings across multiple models. I wish I had the tooling to try this. My mechanical mind thinks setting the lobe width and squared up would be the hardest part.

 

[J_M____]

I would say probably. I would guess they used similar big end bearings across multiple models. I wish I had the tooling to try this. My mechanical mind thinks setting the lobe width and squared up would be the hardest part.

I wonder how the factory does it

 

[RI Chevy]

I think you'd have to run some sort of velocity stack to make it reach its full potential. The filters aren't so great in that series.

I just ran my metal filter mofo 034Super vs my Mofo 036pro with the oem flocked airfilter. Its a huge difference power wise .

So was the 034S metal mesh filter better or the 036 flocked filter better?

 

[Backtroller]

Sorry, the metal 034Super or early 036 flows much better.

There doesn't seem to be too many options for the 036/360 pro filter. I'm going to make my own mesh one for that saw

 

[Backtroller]

This one

 

[RI Chevy]

OK. That's what I thought.
I actually went backwards on my 036 Pro and put the older metal mesh filter on it and bought an older air filter cover to fit the filter. They do flow lots of air! Much much more than the flocked filters.
Saw runs much stronger too.

 

[J_M____]

I’m using a 036pro/ms360 nylon mesh/winter filter, seems to flow much better than the flocked. Similar to the metal mesh