Miller Mod Saws and the Echo CS-500P

[blsnelling]

I may have missed it, but did you post before and after port timing? I saw that you raised the exhaust to 110, but what was it stock?

 

[MillerModSaws]

I may have missed it, but did you post before and after port timing? I saw that you raised the exhaust to 110, but what was it stock?

120/131/70-82.

 

[CoreyB]

I would like to request a video,
I wold like to see a 421 mm vs the 500 or 490 mm

 

[blsnelling]

120/131/70-82.

120?!!! Wow. That is amazingly low! And what are you at now after porting?

 

[MillerModSaws]

120?!!! Wow. That is amazingly low! And what are you at now after porting?

110/125/73-85.

 

[fordf150]

@fordf150 I'm told this saw and the new version the cs-490 are basically the same. Would you jump in here and gives us the low down and maybe the cost of a new one. Thanks my man.

Just a thread I read earlier tonight that someone has compared part number. It's basically the old 500p. I checked cylinder numbers awhile back and they are the same. $349 new.

 

[bikemike]

Is there a baffle plate in the canister?

 

[blsnelling]

120/131/70-82.

110/125/73-85.

With this not being a strato, I wonder if it would like a little more blowdown. That blowdown is like a 550XP, which has less blowdown than any other saw I've modded. I'm wondering how it might respond to 106/125/73-85.

Have you widened the transfers? Have you given it any timing advance yet? You've got the torque. I'm just wondering if you can find any more RPMs in there.

 

[bikemike]

in my recollection I have only seen about 32degrees max timing on any echo documentary that I have seen in the past. That's not much when looking for rpm

 

[MillerModSaws]

With this not being a strato, I wonder if it would like a little more blowdown. That blowdown is like a 550XP, which has less blowdown than any other saw I've modded. I'm wondering how it might respond to 106/125/73-85.

Have you widened the transfers? Have you given it any timing advance yet? You've got the torque. I'm just wondering if you can find any more RPMs in there.

We will fin out. One of these will end up that high. I just raised the trans. And they are widen kinda. The factory insert is narrower than the the cylinder openings. So you can see I've widened them a little. Theses trans are horrible to grind. And i have not tried timing. This was more first. Give it a shot and see what happens. Now to refine and see if I/we can get more.

 

[CapitaineHaddoc]

Great job, and nice pictures!

 

[wde_1978]

View attachment 479110

Funky intake!?

cs-500p muffler modded vs ported. 20" bar .325 in oak.

The saw sounds as if it would like the 14-16" bar area much more, 20" (not buried) seems to be asking too much of that saw.

How much rpm's are these ECHO's running WOT, they sound a little slow in that video - could be the cameras microphone though.

Nice build threat!

 

[hoskvarna]

I would like to request a video,
I wold like to see a 421 mm vs the 500 or 490 mm

I have a 421mm,if u come to the gtg this yr and somebody else would have a 500 u could run em.

 

[CoreyB]

I have a 421mm,if u come to the gtg this yr and somebody else would have a 500 u could run em.

Which gtg the iowa?
I am fearful I will find out I NEED more saws.

 

[hoskvarna]

Yes April 29&30


From the Hills

 

[fordf150]

The intake. Well it be weird. It was at 43% width when I started. I opened it up to 55% angling the top corners down to allow for plenty of ring end location cleareance. The main of the intake now opens at roughly 73° tapering quickly to 85°. I call it the superman intake. Lol.

How do you decide to widen the intake and exhaust? curious as to how you balance out straight out flow with the velocity...larger ports loose vleocity and velocity is king. velocity keeps your fuel charge atomized among other things. Nascar doesnt get to over 100%VE with large ports. They do it with velocity so that the air charge continues to flow even after the pressure has changed. I have wondered this on a couple of your builds..you always talk about widening the intake/exhaust to the max that is possible with ring ends and such but is this through trial and error or just the blanket thought that larger is better?

 

[MillerModSaws]

How do you decide to widen the intake and exhaust? curious as to how you balance out straight out flow with the velocity...larger ports loose vleocity and velocity is king. velocity keeps your fuel charge atomized among other things. Nascar doesnt get to over 100%VE with large ports. They do it with velocity so that the air charge continues to flow even after the pressure has changed. I have wondered this on a couple of your builds..you always talk about widening the intake/exhaust to the max that is possible with ring ends and such but is this through trial and error or just the blanket thought that larger is better?

Mostly it's trial and error. And you look at the carb. Rule of thumb for me. The smaller the carb the more time it needs to fill the cranckcase. The larger the carb. The faster you can shut the intake down and aim for case compression. Which the more case compression you have the more velocity your gonna produce. But pretty much trial and error.

 

[MillerModSaws]

Funky intake!?


The saw sounds as if it would like the 14-16" bar area much more, 20" (not buried) seems to be asking too much of that saw.

How much rpm's are these ECHO's running WOT, they sound a little slow in that video - could be the cameras microphone though.

Nice build threat!

I agree on the bar length buy long cuts like that will tell you a lot about a saw. And if I can get it to pull that buried nicely just imagine what it'll do with a good bar and chain length. Lol. The first ported one gives it up at 13k wot. I think it's rev limited there however it dosnt drive my tac crazy like a normal rev limiter. We will see.

 

[computeruser]

From the perspective of coming up with porting numbers and shaping ports, is there a difference in how you come up with a formula for a particular saw if you know in advance that a saw is being ported to increase short-bar versus long-bar performance?

For this saw, for example, would you approach it differently if it was being built to only ever run say 13"/.325"/8t versus only 20"/.325"/7t versus a variety of bar/chain/sprocket combos?

 

[fordf150]

What is your thoughts on the domed pistons? I am not a fan of popups....right or wrong i always thought a flat top piston promoted a better flame front than a popup but seems like echo uses allot of domed pistons in their saws and while they dont have the hinderance of the popup i still wonder if flat wouldnt be better. any chance of an easy piston swap to get a flat top so that the squish can be cut square? of maybe mill off the dome? piston thick enough for that idea? i doubt it as most of the flat tops are pretty thin in the center and i bet these are no different. seen a few of them with holes punched through from using metal piston stops

I think the 590/600/620 all use domed pistons and i have replaced rings on quite a few echo trimmers that ran a domed piston

Maybe a domed piston doesnt effect transfer flow as badly as a popup since its still a smooth transition and is actually directing the flow up into the chamber