Play time?

[huskihl]

Chop chop you have hybrids to build. There will be no popcorn

 

[Red97]

Chop chop you have hybrids to build. There will be no popcorn

Ooof you right..


Ate it all...

 

[huskihl]

Ooof you right..
View attachment 227616

Ate it all...

That looks like the living room, not a bright chainsaw shop with a shiny stainless bench

 

[Red97]

That looks like the living room, not a bright chainsaw shop with a shiny stainless bench

Ya Got me...

Relaxing, trying to get the ideas flowing...

Everyone must just be watching the thread. Was hoping for some input, like the good ol days lol.

 

[huskihl]

Ya Got me...

Relaxing, trying to get the ideas flowing...

Everyone must just be watching the thread. Was hoping for some input, like the good ol days lol.

I don’t know my Echoes too well, Joe. Otherwise I might be piping up a little bit.
I’d try getting your bigger carburetor and better air filter on and see what you think. And then If it needs livened up a little bit, maybe raise the primaries up a little like we talked about and see if it helps out. If it goes backwards, you could raise the exhaust up 2 degrees to get some blow down back. And if it helps, you could raise transfers up a couple degrees

 

[huskihl]

trying to get the ideas flowing...

I understand this theory. That’s why I had @dall ’s piped 026 here for 2 years. Sometimes you just need to sit back and let some ideas happen

 

[Red97]

I don’t know my Echoes too well, Joe. Otherwise I might be piping up a little bit.
I’d try getting your bigger carburetor and better air filter on and see what you think. And then If it needs livened up a little bit, maybe raise the primaries up a little like we talked about and see if it helps out. If it goes backwards, you could raise the exhaust up 2 degrees to get some blow down back. And if it helps, you could raise all 4 transfers up a couple degrees

But can you really call it an echo still?

This is where I like the conversation.

I think this would work well with numbers between the 046 and 7900...

I plan to get the cs 8611 up and going before making any changes to the 7985.

I can see the maxflo, and wj making a big difference.

 

[huskihl]

But can you really call it an echo still?

This is where I like the conversation.

I think this would work well with numbers between the 046 and 7900...

I plan to get the cs 8611 up and going before making any changes to the 7985.

I can see the maxflo, and wj making a big difference.

Could check case capacity of an 046 and the Echo. I don’t know if there are any other deciding factors on blow down and transfer duration or not

 

[Red97]

Could check case capacity of an 046 and the Echo. I don’t know if there are any other deciding factors on blow down and transfer duration or not

Have heard the dolmar likes blow down. But I believe the 046 transfers can move more bulk flow than the dolmar..

Leads me to believe less bd than the dolmar may be liked.

 

[Junk Meister]

I don’t know my Echoes too well, Joe. Otherwise I might be piping up a little bit.
I’d try getting your bigger carburetor and better air filter on and see what you think. And then If it needs livened up a little bit, maybe raise the primaries up a little like we talked about and see if it helps out. If it goes backwards, you could raise the exhaust up 2 degrees to get some blow down back. And if it helps, you could raise transfers up a couple degrees

Least little much mo better!
But what do I know(My way of saying I am confused).

 

[drf256]

046/460 generally like little blowdown, like 14-18*. Even with the area you carved out, I’d venture to say you have less case capacity than an 046.

How was the original jug on the saw timed Joe?

Shooting from the hip, I’d say to start at 25* BD and go from there. Can use a cheap piston with a ridge carved at the transfer edge, ala TreeMonkey, and see if it wants the transfers higher.

 

[mdavlee]

I like 22-24 in a 460. They run good like that and some cylinders liked short blowdown. I’d say with the smaller case and faster piston speed with the extra stroke you could try that for a starting point.

 

[Red97]

046/460 generally like little blowdown, like 14-18*. Even with the area you carved out, I’d venture to say you have less case capacity than an 046.

How was the original jug on the saw timed Joe?

Shooting from the hip, I’d say to start at 25* BD and go from there. Can use a cheap piston with a ridge carved at the transfer edge, ala TreeMonkey, and see if it wants the transfers higher.

The 620 (45mm bore) is 77,105,125 those are not exact but in the ball park and around where I like my ported 590's. Again a 45mm bore.

Trimming the piston was my plan once I get the 54mm running.

If the case is indeed tighter that means higher pressure. Typically the higher the pressure the more peaky an engine becomes....
I don't really feel a peak in the saw yet. Could the little carb and restrictive filter be mellowing out the powerband.

I plan on testing lots of things, I just thoroughly enjoy the discussion.

I like 22-24 in a 460. They run good like that and some cylinders liked short blowdown. I’d say with the smaller case and faster piston speed with the extra stroke you could try that for a starting point.

I didn't realize I hadn't posted any numbers.

It has been a while, butbibreally need to look at the 7910 ports.. Don't they have a smaller ex than the 046? Could that along with the long stright trans play a role in why they like the longer be?

I've never messed with the short bd. But even the shorter bd would be more piston travel vs the 046.



I raised the ex to 100 intake and ex are 65%

Upper trans are untouched.

 

[MG porting]

But can you really call it an echo still?

This is where I like the conversation.

I think this would work well with numbers between the 046 and 7900...

I plan to get the cs 8611 up and going before making any changes to the 7985.

I can see the maxflo, and wj making a big difference.

It's a Stihlecho now.

 

[MG porting]

Have heard the dolmar likes blow down. But I believe the 046 transfers can move more bulk flow than the dolmar..

Leads me to believe less bd than the dolmar may be liked.

The ms460 that I built the exhaust is right at 103 it likes it has a ton of low-end and still has lots of speed even though I drilled the jet to big oops but do your build the way it soots you you definitely impressed me big time.

 

[Red97]

Dolmar 7910 is the one on the left/ clean one. 046 on right/ dirty

It appears as if the 046 has larger intake and exhaust ports, a lot more 'swoop" to the transfer tunnels.

Looking side by side, the dolmar transfer tunnels will hold more volume without adding the piston/case into the mix.

 

[Red97]

Grins and giggles here are the transfers the saw/case was designed for. At 45mm bore.

 

[smokey7]

Joe I've thinking of alk the hybrids you have done and am kind of lost on what the actual cylinder piston crankcase combos you have actually running. Didn't you cast or have someone else some jugs? Can you list what you have going for other slow folks like myself?

 

[Red97]

Joe I've thinking of alk the hybrids you have done and am kind of lost on what the actual cylinder piston crankcase combos you have actually running. Didn't you cast or have someone else some jugs? Can you list what you have going for other slow folks like myself?

Yes I have had a few different combos, but this thread is about these 2 saws.

The first one (52mm 046 cyl) that is currently running.

And the other is just a big bore (54mm) 046 cylinder.

The dolmar talk comes about because the dolmar shares a long stroke with the echo.

 

[P.M.P.]

Yes I have had a few different combos, but this thread is about these 2 saws.

The first one (52mm 046 cyl) that is currently running.

And the other is just a big bore (54mm) 046 cylinder.

The dolmar talk comes about because the dolmar shares a long stroke with the echo.

Would you would have to do a popup on the hood of that badboy to get that Dolmar to fit?
That would be cool