One step closer to zero emission power equipment

[CH4Ohio]

Steppenwolfe:

Imagine this... In the future, only licensed professionals can buy, operate, and use gas powered tools, mowers, chainsaws... All under gubment scrutiny of course... Think it couldn't happen? Another big brother moment.

You forgot to mention that it would be managed by bureaucratic idiots totally indoctrinated in the idea that they know all and what is best for all.

And enforced using "hardware" that will be outlawed to the citizens and only available to the government agents.

 

[Snobdds]

I dont need a lesson on how to adjust a carb, it is running as well as it can. Idle, L, H are all tuned to mfg rpm spec. There is just no way to get around physics. A 35cc saw will loose about 1/3 of its raw power at 9000ft...no way to get that power back without a turbocharger. The smaller the engine displacement, the harder it is for it to compensate for the altitude.

I get the physics of the loss of o2 at altitude, but the carb is not an o2 dependent item, it's a flow and mixing thing. Air flow does not decrease at altitude and therefore you should be able to tune a carb, independent of altitude to run correctly. Besides, the % your loosing on a 35cc engine at altitude is maybe 4cc. That is not enough to notice any big decrease, and I can attest to not seeing any significant difference. On a larger engine, the % goes up proportionally, and that might be noticed a little more. I also run non turbo diesels at altitude and really don't notice a difference when I run the same machines at a few thousand feet lower.

I don't have the bogging that you seem to have, I want my two stokes to four stoke slightly out of the wood and clear up when in the wood. In other words, I richen it up a little more at idle and it leans out in the cut.

 

[Jchonline]

I get the physics of the loss of o2 at altitude, but the carb is not an o2 dependent item, it's a flow and mixing thing. Air flow does not decrease at altitude and therefore you should be able to tune a carb, independent of altitude to run correctly. Besides, the % your loosing on a 35cc engine at altitude is maybe 4cc. That is not enough to notice any big decrease, and I can attest to not seeing any significant difference. On a larger engine, the % goes up proportionally, and that might be noticed a little more. I also run non turbo diesels at altitude and really don't notice a difference when I run the same machines at a few thousand feet lower.

I don't have the bogging that you seem to have, I want my two stokes to four stoke slightly out of the wood and clear up when in the wood. In other words, I richen it up a little more at idle and it leans out in the cut.

Incorrect. You loose 3% for every 1000ft...look it up. It has been measured by engineers many times. At 10,000ft you loose 30%, which is 11cc, not 4cc.

Physics means less air is less air. There is no way to get more without something that controls air intake directly. The venturi on a carb wont do it. A turbocharger compresses the air (ie take thin air and make it dense again like at 1000ft), so it works. Adjusting the fuel makes it run smoother, but does not add power back to the engine....

I run a non-turbo diesel (RTV X1100C) and notice a significant difference. I drove it at 5000, and then at my place at 9000. There is a noticeable difference. Smokes way more, less power (especially hills). The M62 is turbocharged and runs much better. Maybe you arent going low enough to notice it?

That said I am glad you dont see a difference, we will have to agree to disagree. I agree about richening up the fuel at idle (L) to help it run smoother (but not more powerfully).

 

[Snobdds]

Incorrect. You loose 3% for every 1000ft...look it up. It has been measured by engineers many times. At 10,000ft you loose 30%, which is 11cc, not 4cc.

Physics means less air is less air. There is no way to get more without something that controls air intake directly. The venturi on a carb wont do it. A turbocharger compresses the air (ie take thin air and make it dense again like at 1000ft), so it works. Adjusting the fuel makes it run smoother, but does not add power back to the engine....

I run a non-turbo diesel (RTV X1100C) and notice a significant difference. I drove it at 5000, and then at my place. There is a noticeable difference. Smokes way more, less power (especially hills).

That said I am glad you dont see a difference, we will have to agree to disagree. I agree about richening up the fuel at idle (L) to help it run smoother (but not more powerfully).

No, that is for a 4 stroke engine. I knew you would pull out the 3% figure. Two stoke also have oil in the fuel that adds to a lower air fuel ratio, therfore they don't need as much air because the ratio is much different than a four stroke.

But again, carbs don't care about o2 density, they just want air flow and fuel to mix...

 

[Jchonline]

No, that is for a 4 stroke engine. I knew you would pull out the 3% figure. Two stoke also have oil in the fuel that adds to a lower air fuel ratio, therfore they don't need as much air because the ratio is much different than a four stroke.

But again, carbs don't care about o2 density, they just want air flow and fuel to mix...

I dont understand how an engine that requires oxygen to combust doesnt care about oxygen density.

Here is one article on 2 stroke engines at altitude...40% HP drop at 10000ft.

https://scholar.afit.edu/etd/1038/

Everything I am reading right now says you are just wrong. 2 cycle ICE still looses power. Can you reference something to the contrary? I am open to learning.

 

[Snobdds]

I dont understand how an engine that requires oxygen to combust doesnt care about oxygen density.

If you lean out an engine, the fuel air ratio goes up, If you richen an engine, the air fuel ratio goes down...all while the air remains a constant.

You can compensate for less air by changing the fuel. It's a ratio and one side of the equation is independent upon the other side. You can compensate for less 02 by leaning out the engine, but the ratio is still equal.

It's physics...

 

[Snobdds]

In other words, at sea level you need more fuel for the greater o2 in the air. At altitute, you lean out an engine for the less o2 density.

But like I said, carbs don't care, they just want flow and you adjust flow.

 

[Jchonline]

In other words, at sea level you need more fuel for the greater o2 in the air. At altitute, you lean out an engine for the less o2 density.

But like I said, carbs don't care, they just want flow and you adjust flow.

You can of course type what you want on a forum, I am looking for evidence. Do you have any references, documentation of tests, etc that back up your statements? I provided a study that looked at a 2 cycle 95hp engine and it lost 40% HP at 10,000ft. Do you have anything showing there is no HP loss at altitude?

 

[Snobdds]

You can of course type what you want on a forum, I am looking for evidence. Do you have any references, documentation of tests, etc that back up your statements? I provided a study that looked at a 2 cycle 95hp engine and it lost 40% HP at 10,000ft. Do you have anything showing there is no HP loss at altitude?

I never said there was no loss, I said it's less than you claim due to oil in the fuel and being able to lean a motor out to compensate for the lest dense air.

That article was weird, it was more of a summary than actual evidence with actual numbers. It seemed more about making a case for FI than anything else...

 

[Snobdds]

I guess I am relying upon those physics class I took in college. It's all in my head...