Stihl 046 build…a little bit Frankenstein

[ManiacalMark]

Also a part of me wants to throw a 272 piston in it and finger ports.

 

[Loony661]

Also I can’t say I’m like over the moon with the results hard to tell so far. Burns more fuel than I thought it would for 72* intake.

I would think that with 3 ports on the muffler, it may not have enough back pressure to be “fuel efficient”. The less back pressure you have, the more fuel you will waste out the exhaust..

 

[ManiacalMark]

I have it running a tad fat right now, triple port isn’t overly extreme when all ports have OEM size screen. A muffler would have to be quite open to take away the entire exhaust pulse in the muffler to not force fresh mixture back into the cylinder. What could is higher case compression without an early release to ease the pressure off the incoming charge from the transfers. Runs good just doesn’t blow my johnson off yet.

Have to wash the muddy log off since it came from some loggers up on the hill.

Also, I’ve never cared about fuel consumption personally.

 

[ManiacalMark]

Looks like it cuts better in video than I thought? My cookie cutting skills aren’t the best haha

 

[ManiacalMark]

84dl Stihl full comp square, rakers are .035-.040”, 12.5” red oak

 

[Maintenance Chief]

Boy it sounds and cuts great Mark! Definitely faster..

 

[ManiacalMark]

It felt better, I really want to leave it alone because I haven’t given it the real test yet. If it can’t pull a 36” in hardwood good enough then time for piston #2

 

[ManiacalMark]

Ran out of fuel towards the end of the cut . Need to make a log mount I had to take it easier because the saw kept pulling the 200lb the chunk back.

 

[farminkarman]

Looks like it cuts better in video than I thought? My cookie cutting skills aren’t the best haha

Looks and sounds great to me. Nice job!

 

[ManiacalMark]

Thank you

 

[drf256]

Ran out of fuel towards the end of the cut . Need to make a log mount I had to take it easier because the saw kept pulling the 200lb the chunk back.

Very nice. What’s going on at the end of the video with the saw racing.

 

[Woodslasher]

Very nice. What’s going on at the end of the video with the saw racing.

Ran out of fuel towards the end of the cut .

 

[ManiacalMark]

Very nice. What’s going on at the end of the video with the saw racing.

Running out of fuel like an idiot

 

[ManiacalMark]

10 minutes later we’re here

 

[ManiacalMark]

Going to time a 372bb piston tomorrow. Wanted to use a 272 but made a felpro thick gasket and it threw timing way off and I can’t take much more off the squish band before I run out of plating.

 

[drf256]

I’ve done many 272 piston builds. Piston is very light and increases case capacity. I used a double metal gasket or the factory .035 gasket (hard to find) and took .040 off the piston crown (IIRC). There should be .140” of space between the top ring and the crown, so .040 will keep you at a safe .100 crown thickness.

You should time the ports accordingly. When I did hybrids with them, they acted more like 046 than hybrids.

I also went with the Hemi chambered jug to keep compression down.

 

[ManiacalMark]

Thanks, I didn’t even think to shave down the crown.

 

[ManiacalMark]

And so it begins…

 

[ManiacalMark]

One done now to make one match

 

[MemphisMechanic]

Oh damn. It just got interesting.