Stihl 044 Oiler Performance?

[qurotro]

It’s a rare bird, but it exists. Was early OEM 1125.

Had one here on an 034S. It’s a multi-turn control bolt with no stop. The case acts as the stop so that the control bolt doesn’t get fully unthreaded and fall out.

My 1986 064 has the multi-turn. I don't know if it will stop if screw all the way out.

 

[SteveSr]

It would be interesting to know if an 046 HO piston and bolt would slide into an 044 pump body.

I can guarantee not. On the 046 pump they added an "axle" and a brass bushing to the non-pump end of the piston. This would greatly prevent wear on the pump bore. The previous (044) design had a 1/16" round section of the piston that rode in the soft aluminum bore.

I’ll add in that I believe modifying the groove at the tail end of the piston does nothing at all. The pump works via displacement. Making the area larger just makes it a larger displacement inside the bore, but the difference in the displacement between the piston being up and down will remain constant.

I think that you are probably right on that. The cutout area serves as a one-way valve preventing a straight shot through the pump... which makes them nearly impossible to clean without disassembly.

 

[SteveSr]

Maybe I need to restate this. Replacing the control bolt with another HO type will increase the oil flow a good bit. If you don't believe me try it yourself.

This would only work if there was extra "ramp" not being contacted when the control bolt was at "max" and the piston was fully retracted (out) of the pump bore. I would think that this would be easy enough to check with a caliper and the pump in hand. There may also be manufacturing tolerance in play here as well.

 

[Lightning Performance]

I can guarantee not. On the 046 pump they added an "axle" and a brass bushing to the non-pump end of the piston. This would greatly prevent wear on the pump bore. The previous (044) design had a 1/16" round section of the piston that rode in the soft aluminum bore.



I think that you are probably right on that. The cutout area serves as a one-way valve preventing a straight shot through the pump... which makes them nearly impossible to clean without disassembly.

So you actually tried installing an 1128 HO control bolt of the 460 type in an 044 pump?
I was planing on making this swap soon but not if you have tried it already.

Quoted the wrong post my bad.

 

[SteveSr]

So you actually tried installing an 1128 HO control bolt of the 460 type in an 044 pump? I was planing on making this swap soon but not if you have tried it already.

No, not yet. The saw got put back together after thoroughly cleaning the pump and the baked on crud on the control bolt and piston ramp. I want to see how this performs before I tear it all apart again.

 

[Lightning Performance]

No, not yet. The saw got put back together after thoroughly cleaning the pump and the baked on crud on the control bolt and piston ramp. I want to see how this performs before I tear it all apart again.

Okay then... I'm next. Have to dig in next week to see if a stock for stock will swap bolts. Or maybe a bolt from another Stihl pump. I have them all but 064.

 

[SteveSr]

Okay then... I'm next. Have to dig in next week to see if a stock for stock will swap bolts. Or maybe a bolt from another Stihl pump. I have them all but 064.

Before you start swapping stuff around check for any extra piston rotation without horizontal movement with the piston all the way out and the control bolt turned up to max oil. This should tell you if just a different bolt will have an increase in oil output.

 

[Lightning Performance]

Before you start swapping stuff around check for any extra piston rotation without horizontal movement with the piston all the way out and the control bolt turned up to max oil. This should tell you if just a different bolt will have an increase in oil output.

Or ask another builder first.

 

[dolmarkid]

You can modify the 044/ms440 oil pump to where it will oil a 32” bar no problem.