Experimenting on a Saw...

[czar800]

I've been playing with "turbo charging" this little Poulan and can't get it to run when I pressurize the intake.
Ill give everyone a few minutes to stop laughing and tell you what I've been trying to do.

 

[Warped5]

 

[czar800]

I've been wanting to try a few different thing and this is one of them.

I've taken my shop vac discharge and reduced it to the size of a sump pump discharge hose which is inch and a quarter and then I clamp it to the saw.

I can't even get it to start..... I understand I'm blowing excessive amounts air fuel mixture right straight out the exhaust.

I'm thinking the carburetor just can't supply enough fuel?

 

[Deets066]

Lol

 

[Deets066]

Don't believe you can charge one of these carbs

 

[Deets066]

Just like an updraft on a tractor, I looked into a turbo and it just don't work

 

[czar800]

My thoughts are to add a second carburetor???? I was going to tap the crankcase and add an inpulse line then stack another carburetor...

Now that everyone has spit out there coffee laughing let's discuss.

For some reason this idea has been rolling around in my head....

 

[T.Roller]

Just remove the jet from the carb. Should supply enough then lol

 

[Deets066]

You'd be overstuffing the case

 

[Deets066]

One carb, just bigger maybe

 

[Stihl working Hard]

 

[Stump Shot]

For the heck of it as long as yo have your set up there, try getting it running on its own than adding the "boost" and see what happens.

 

[XP_Slinger]

Can't pressurize it until the intake closes...you would have to run the boost directly into the crank case and time it to pressurize only when the intake is closed to prevent it from back feeding through the carb. It's the only way it would work and the carb would probably need to be tuned stupid rich and it will never idle. This is a fun conundrum...

 

[czar800]

For the heck of it as long as yo have your set up there, try getting it running on its own than adding the "boost" and see what happens.

That's what I have been doing it just kills it.

 

[Stihl working Hard]

That's what I have been doing it just kills it.

Is there a way of blowing fuel and air by adding a fuel line on your adapted intake manifold just a thought

 

[Stump Shot]

That's what I have been doing it just kills it.

Probably not going to happen then, there is a very delicate balance in what has to happen in order for these engines to run, obviously that balance was disrupted. I'm going to speculate here that the intake charge is being "blown" right out the exhaust. Also pressurizing a carburetor that works under a vacuum may render the charge useless. Normally a carburetor would sit on top of a blower so it can draw air in through the carburetor, not push it through. I do like that you tried though, never know when/where the next best thing will come from.

 

[Stihl working Hard]

You'd be overstuffing the case

If the saw was a rotary valve could this process work seeing its already in the crankcase or not

 

[czar800]

The funny thing is when I start to put the pressure to it it doesn't sound like it goes lien it just falls on its face.

 

[czar800]

Can't pressurize it until the intake closes...you would have to run the boost directly into the crank case and time it to pressurize only when the intake is closed to prevent it from back feeding through the carb. It's the only way it would work and the carb would probably need to be tuned stupid rich and it will never idle. This is a fun conundrum...

It's fun trying...

 

[TJ the Chainsaw Mechanic]

What you are basically doing NOW is Supercharging....Instant power. Notice super chargers use Huge carbs for Small cubes. I've seen 292 chevy I6's super charged with Twin 1100 CFM carbs! That is 2200 CFM! Right Now you'd need way more fuel as when you hit the trigger you are leaning it out to fast.....you might try turning the L mixture screw to like 4 turns out.
Turbos are Way different....boost comes on Gradually, and there is Still a need for more fuel.....what you Might try doing is cutting a large piece of wood with the saw to put it under a load....then try the boost....either it will explode, seize, or get an increase in power.