MillerModSaws plays with 440R/046D Hybrid

[gritz]

Looks like you've got a little bit of a fetish for twins, lol. First a pair of 7910's, now a pair of hybrids. What will the next set be? I know you've been talking about building your hybrid for awhile. Can't wait to see how they turn out.

 

[MillerModSaws]

Looks like you've got a little bit of a fetish for twins, lol. First a pair of 7910's, now a pair of hybrids. What will the next set be? I know you've been talking about building your hybrid for awhile. Can't wait to see how they turn out.

Me to. Goin for broke. Lol.

 

[MillerModSaws]

How thin are the cylinder bases now?

I'll try and remember to take a pic when I get home and send a measurment. But IIRC the ears were around 6 mm thick.

 

[cuttinties]

I'll try and remember to take a pic when I get home and send a measurment. But IIRC the ears were around 6 mm thick.

Weak link on the 440 and 460 is the cylinder base. I've seen stock cylinders break. It's more common than most would think.

 

[MillerModSaws]

Guys I laid in bed last night and was thinking man if somebody is looking to this thread for instructions. (WHAT IF ). So I thought i should add if I was building this saw for a customer it would not be quite so aggressive. I would have probably went .057-.062 off base and .025-.030 off squish. I have this saw maxed out and while I think it will be an awesome runner we will see. If your building a saw like this it might be smart to work up to this. Sorry I just don't want to mislead anyone or give bad advice. Thank you for following along.

 

[blsnelling]

Whatever they will give me!

You'll be north of 200 PSI.

 

[cuttinties]

You'll be north of 200 PSI.

Somewhere around 230 probably.

 

[KG441c]

Wonder if that much off the base and weak already and with that much compression will be a problem?? I bet it will be fine. Ive heard that most of them that break at the base are results of loose cylinder bolts?? The 6mm bolts should help secure her alil more?

 

[MillerModSaws]

You'll be north of 200 PSI.

I was hoping 210 to 215 but we'll see. I can always open the squish up a little. Most saws I build around .025 squish anyway. I'm not sure what the comp difference will be between the 046 and the 460 cylinder either. We will find out. Lol.

 

[Moparmyway]

Just a guess ........... but the "D" cylinder with .020 squish will yield 230# or more

 

[cuttinties]

Wonder if that much off the base and weak already and with that much compression will be a problem?? I bet it will be fine. Ive heard that most of them that break at the base are results of loose cylinder bolts?? The 6mm bolts should help secure her alil more?

Most I've seen break were under the exhaust port and I've not seen any loose stihl hardware. Look on the back of the mating surface side and you'll see why.

 

[Tractorsaw1]

When I went thru my 044, 1 cylinder bolt was missing, & 1 case half bolts was loose.

 

[mdavlee]

I think I only cut .038-040" off the base and whatever from the chamber to clear for squish. I didn't use a gasket either. I'm not at home with my notes right now to see though.

 

[cuttinties]

I was hoping 210 to 215 but we'll see. I can always open the squish up a little. Most saws I build around .025 squish anyway. I'm not sure what the comp difference will be between the 046 and the 460 cylinder either. We will find out. Lol.

Opening the squish up is going backwards on power.

 

[MillerModSaws]

I think I only cut .038-040" off the base and whatever from the chamber to clear for squish. I didn't use a gasket either. I'm not at home with my notes right now to see though.

I would say just seeing my numbers that's prob .022" off squish band. Or in that ball park.

 

[MillerModSaws]

Opening the squish up is going backwards on power.

You are correct but that's one way to bring your comp down a little if need be..

 

[mdavlee]

I would say just seeing my numbers that's prob .022" off squish band. Or in that ball park.

No gasket put back. I think it was .030-035".

 

[cuttinties]

You are correct but that's one way to bring your comp down a little if need be..

Dishing the piston works as well.

 

[MillerModSaws]

Most I've seen break were under the exhaust port and I've not seen any loose stihl hardware. Look on the back of the mating surface side and you'll see why.

I think this saw will be just fine. But if not I will be the first to tell ya what not to try. You never no till someone tries. There will be 2 of them running at this cut. If i feel that it's gonna be a problem I will pull it and put it on one of my not so nice 044s and put it to the test. Or I simply send it with one of my loggers. They'll test it. Lmao.

 

[Mastermind]

I take .030 out on these saws. At lower elevations I've seen 225psi on them.