STIHL 037 custom hybrid build pic heavy

[SawGarage]

Volks,

where did we end up on this???

:msp_blink::msp_drool:

 

[madhatte]

This is probably one of my favorite builds ever. I have pushed a stock 036 about as far as it will go on regular gas, and the very idea of slapping an 038 Mag topend on one opens up lots of possibilities. Sourcing parts still, but I will build an 037 myself eventually!

 

[bcorradi]

Ya I agree...it was a very cool and unique build. Good job Volks.

 

[SawGarage]

This is probably one of my favorite builds ever. I have pushed a stock 036 about as far as it will go on regular gas, and the very idea of slapping an 038 Mag topend on one opens up lots of possibilities. Sourcing parts still, but I will build an 037 myself eventually!

have you made a 2-piece head, and added boost ports?? oke:

I'm not doubting the COOLNESS.... i wanna know if we looked at the RPM limit issue, porting/port timing, mapping, fuel delivery issues, etc... I wanna see what makes sense!! lol

J

 

[ScottWojo]

This is what was thinking as I saw the thread. If he mapped the numbers I think he would see the reason for the low RPMS. But the 038 had tons of low end torq.

Scott.

 

[SawGarage]

This is what was thinking as I saw the thread. If he mapped the numbers I think he would see the reason for the low RPMS. But the 038 had tons of low end torq.

Scott.

How are ya Scott?


I can't see the case being TOO small... hell, if Ricky built a H50 SUPER saw, than I don't see why a 7cc (isn't the 036 65cc?) increase in displacement would HURT the performance of the saw... :dunno:

J

 

[Mad Professor]

The design started out as the 57cc 034 and was bumped to 62cc for the 034S/036

Overall would be a 26% increase in displacement from the 034 using a 52mm jug

 

[Mad Professor]

The design started out as the 57cc 034 and was bumped to 62cc for the 034S/036

Overall would be a 26% increase in displacement from the 034 using a 52mm jug

 

[madhatte]

have you made a 2-piece head, and added boost ports?? oke:

Geeze, I said stock! Though now you got me thinkin'...

 

[SawGarage]

This is probably one of my favorite builds ever. I have pushed a stock 036 about as far as it will go on regular gas, and the very idea of slapping an 038 Mag topend on one opens up lots of possibilities. Sourcing parts still, but I will build an 037 myself eventually!

Geeze, I said stock! Though now you got me thinkin'...

oke: you said " on regular gas..." 93 octane avail in your area?? 220psi (as you know) is not uncommon with an older j-red/husky... so...

The design started out as the 57cc 034 and was bumped to 62cc for the 034S/036

Overall would be a 26% increase in displacement from the 034 using a 52mm jug

Good point...I wonder if a 038S would be a better compromise... Course, the question is, is the 62cc cyl maxing out the bottom end...

cyl port mapping will tell us more, as well as some calculations in regards to optimum crankcase volume (which, I'll be honest, I'm still working on understanding.... )

Jay

 

[madhatte]

oke: you said " on regular gas..." 93 octane avail in your area?? 220psi (as you know) is not uncommon with an older j-red/husky... so...

Actually, there are a couple of airports nearby with the 110ll, as well as marinas with ethanol-free 93. I was really referring to not making the switch to nitrobenzene or any of the other exotic fuels. And a pop-up... see, now you got me thinkin' again.

This CAD is dangerous business!

 

[SawGarage]

Actually, there are a couple of airports nearby with the 110ll, as well as marinas with ethanol-free 93. I was really referring to not making the switch to nitrobenzene or any of the other exotic fuels. And a pop-up... see, now you got me thinkin' again.

This HPAD is dangerous business!

There, I fixed it for you

HorsePower Addiction Disorder

 

[volks-man]

Volks,

where did we end up on this???

:msp_blink::msp_drool:

sorry for the late reply guys..............
i didn't even know this thread was revived again............
i'm laying tile at my house and have been working on that more than surfing the web.

well....
theres another thread of mine with a back to back comparo of the 037 and 038m with same bar/chain/sprocket/log.
the 038m is stock with slightly tightened squish. in 14" square white oak cant the 038 was about 1 second quicker than the 037.
http://www.arboristsite.com/chainsaw/158355.htm

i have aquired an 044 carb and intake boot. one day i will tear it down and get some timing numbers.
my idea is to adjust the port timing to get it to run better with the current carb setup.
if i still feel it isn't performing to it's full potential i will cut out the rear of the carb box, fab up an aluminum plate to replace it without the impulse hole, and shift the carb/intake to one side a bit to alleviate the dogleg in the current 036 boot. easy-peasy.

 

[volks-man]

This is what was thinking as I saw the thread. If he mapped the numbers I think he would see the reason for the low RPMS. But the 038 had tons of low end torq.

Scott.

i agree.
and
the intake boot is crooked. as a result it kinda pinches down a little.
it is certainly a bottleneck.

 

[volks-man]

The design started out as the 57cc 034 and was bumped to 62cc for the 034S/036

Overall would be a 26% increase in displacement from the 034 using a 52mm jug

i calculated the 037 @ 70cc after taking a bit off the bottom of the cylinder to account for the deck height difference in the 036 and 038.

 

[blsnelling]

i calculated the 037 @ 70cc after taking a bit off the bottom of the cylinder to account for the deck height difference in the 036 and 038.

That will not change the displacement at all. That is solely a funcion of bore and stroke. You did not change the stroke when you tightened the squish.

 

[Mad Professor]

Besides where you opened up the case to clears the piston skirts, I think it would benefit from opening up the whole case to match the 52mm diameter of the cylinder bore. This could just be blended in to provide a smooth flow for the gases where you do not need the clearance for the skirts.

E.g. right now you have ridge where the 48mm case meets the 52mm bore

 

[SawGarage]

sorry for the late reply guys..............
i didn't even know this thread was revived again............
i'm laying tile at my house and have been working on that more than surfing the web.

well....
theres another thread of mine with a back to back comparo of the 037 and 038m with same bar/chain/sprocket/log.
the 038m is stock with slightly tightened squish. in 14" square white oak cant the 038 was about 1 second quicker than the 037.
http://www.arboristsite.com/chainsaw/158355.htm

i have aquired an 044 carb and intake boot. one day i will tear it down and get some timing numbers.
my idea is to adjust the port timing to get it to run better with the current carb setup.
if i still feel it isn't performing to it's full potential i will cut out the rear of the carb box, fab up an aluminum plate to replace it without the impulse hole, and shift the carb/intake to one side a bit to alleviate the dogleg in the current 036 boot. easy-peasy.

Tile....mmmm...good fun.

i agree.
and
the intake boot is crooked. as a result it kinda pinches down a little.
it is certainly a bottleneck.

hmm...that may HAVE SOMETHING to do with it...

Had you ever checked timing #'s after the piston mod/jug mod? I'm wondering if exh timing is way low, or the transfers might be restricted...

That will not change the displacement at all. That is solely a funcion of bore and stroke. You did not change the stroke when you tightened the squish.

+1

 

[volks-man]

Tile....mmmm...good fun.




hmm...that may HAVE SOMETHING to do with it...

Had you ever checked timing #'s after the piston mod/jug mod? I'm wondering if exh timing is way low, or the transfers might be restricted...



+1

the pinch is nearly a third of the cross section of the boot.
it has a lot to do with the rpm limiting.

i have never checked timing numbers on the 037. one day i will...

 

[parrisw]

normally i would agree.
but...
other things are at play here.
the 036 must have more of that stroke below the cylinder flange/case deck or i wouldn't have had to lower the cylinder to get a useable squish. we are talking close to 2mm here not .001.

look at it like this... hypothetically if you lowered the center point of the crankshaft 10mm and took 10mm off the cylinder flange the stroke would still be the same but there would be less of that stroke happening in the cylinder. more of it would be in the case and that is no longer 'displacing' volume in the cylinder.

am i wrong? why?

Unless you changed the crank throw, the stroke remains the same.