ms 462

[tree monkey]

Thanks. That is an excellent explanation Scott. Also the longest post I’ve ever seen you make, lol.

Never thought a lot about the Stoich difference. That is certainly interesting to me.

I know one good builder here speaks of “equalizing the stratos” and builds a mean ass 562. I believe that’s where many of the questions emanate from.

My question is why not try to use them, even with the understanding that they are a fresh air pump. Seems like air flow is the rate limiting step in power production. The carb usually can supply all the fuel ever needed.

yes and no, it depends on what can be done to the intake as a whole, intake and strato port combined. not gutted, but the combined volume of each. the only function of the intake is to fill the case. the faster we fill the case the faster the engine runs. but we need to empty the case as well, the shorter the intake dur the better we can empty the case. in other words move more air. this is why I want the dur to be about the same for each. if we can increase air flow before the port window, then it should be done. but we are limited buy what can be done to a rubber manifold and keep it reliable.

 

[drf256]

But don’t the stratos fill the case as well?

It’s just stratified.

 

[tree monkey]

Maybe we can bring a chalkboard to Randy’s and you could give a lecture.

Just kidding, but that would be pretty awesome.

I will be bringing the cutaway cylinder with, i'll talk with anyone on this subject

 

[tree monkey]

But don’t the stratos fill the case as well?

It’s just stratified.

yes, it's part of the intake

 

[drf256]

I’ll be bothering u, again.

Don’t have a jug in my hand, but my recollecton is that the piston moves up, creates case vac, then pulls air in through the intake port and back down through the stratos. So the case gets a nice wet intake charge which is great for lower end lubrication also, but it does mix with fresh strato air.

 

[drf256]

I’ve thought about a finger from the intake port to the uppers. Haven’t tried it.

Case vac as piston rises possibly pulls charged air through fingers into uppers as well as case.

The kinda mod I just have to try in an AM jug to see if it makes any difference.

 

[tree monkey]

the stratos fill the case by back stuffing the tr's

 

[drf256]

I remember now. Yes.

Its the transfers that pull the air outa the stratos. All just little blips at WOT.

Fascinating stuff.

At TDC on non strato saws, uppers are open to case anyhow, more with certain piston geometry than others.

 

[tree monkey]

I’ve thought about a finger from the intake port to the uppers. Haven’t tried it.

Case vac as piston rises possibly pulls charged air through fingers into uppers as well as case.

The kinda mod I just have to try in an AM jug to see if it makes any difference.

won't that push tr charge out the intake?

 

[drf256]

I do wonder if uppers opening under lowest ring land as piston moves up has more to do with performance than meets the eye.

It’s at least part of why I’ve tried different pistons in saws.

 

[drf256]

won't that push tr charge out the intake?

Least resistance shouldn’t allow that.

I’m just thinking about flow.

Your MS261 made me think a lot. And drink a lot.

I’m fairly certain I drank a lot before I ran it.

 

[drf256]

Are Strato saws more affected by carb Venturi size than others?

I know some have a separate butterfly for the stratos.

 

[drf256]

Sorry for the brain pic. I’d like to see that cutaway at Randy’s.

 

[tree monkey]

the charge is under pressure before the tr's open

 

[GCJenks204]

Least resistance shouldn’t allow that.

I’m just thinking about flow.

Your MS261 made me think a lot. And drink a lot.

I’m fairly certain I drank a lot before I ran it.

As the owner of said 261, I love that video. I still watch it regularly.

 

[sawmikaze]

You guys make me feel dumber than I already am.

 

[tree monkey]

Are Strato saws more affected by carb Venturi size than others?

I know some have a separate butterfly for the stratos.

I don't get to far into carbs or part swapping on work saws, if I was building a race saw out of a strato I would gut it, add a carb block, and large carb. but that's not what we're doing here

 

[Hinerman]

You guys make me feel dumber than I already am.

Don't feel alone. How is the weather your way? Coolest morning since last winter here....50 degrees.

 

[Stihl working Hard]

Iam impressed Scott

 

[sawmikaze]

Don't feel alone. How is the weather your way? Coolest morning since last winter here....50 degrees.

Same-o Same-o here..my favorite weather to work in.