Different, not necessarily superior. I think this is what you're failing to understand. Your correlation is erroneous.
Should you get a heavy duty fan clutch?
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Different, not necessarily superior. I think this is what you're failing to understand. Your correlation is erroneous.
Yes, to you, specifically. But to my point, it is not technically superior in reality, simply different. I believe what you mean to say is that you think it suits your specific needs for your vehicle better, and therefore a superior choice for you.
What I find odd is that it feels like you're trying to convince everyone else here that you're correct about something that has more than one answer, to the point of arguing with people about it. Surely there's a better use of your time...I know there is of mine, which is why I'm done now with this exchange.
Most of my arguing has been in relation to Zorba's incorrect assertions about a 2771 being engaged at all times below 3,200 rpm and how that convinced someone else to buy a 2771 because it "moves more air". The facts are that both are **thermal** fan clutches so they engage and disengage based off of engine temperature and not RPM, the 2791 moves slightly more air when the engine is hot and you want it moving air, it moves slightly less air when the engine isn't hot and most people don't want it moving more air, and it should also last longer overall because it's a more robustly bit part.
If, after knowing all that, someone wants to use the 2771 then it is what it is. It's also almost certainly not worth it to take if a working 2771 to put on a 2791. I'm not going to argue with their decision. But if they are basing their decision on bullshit I'll argue with them about the bullshit.
Technically they all respond to the air temp in the space between the radiator and fan clutch where the bi-metal thermostat lives, not directly to engine or coolant temps.
When moving fast, that space will drop below the activation temp and reduce fan output to the "unlocked" state of 20-35% input shaft speed. When slowed in traffic, that space gets hotter causing the clutch to engage, and lock into the 70-90% state.
Based on what I read, an individual clutch will have fixed percentages in it's unlocked and locked state such as 27% unlocked, 86% locked. I believe the ranges refer to the variability between individual clutches deemed in tolerance for that model, not partial locked or unlocked states. It would take some testing and data logging to know with absolute certainty and ain't nobody got time for that. In theory you could get a straight answer from the company if they'd let the engineer/designer answer, but you'd undoubtedly get bullshit answer from "Joe in Sales". And with that, it would be impossible to know whether a 2771 or 2791 was moving more air unless you logged data on both and even then you'd probably have to sample many of each. I honestly think the difference between them would be pretty marginal. But having a clutch with higher engagement unlocked would be significantly worse for performance. To get one that was sitting on the high end of 30-35% drawing 14hp unlocked at 3000rpm would suck. Literally - more sucking. Sucking the gas out of your tank and power from your motor.
I personally made the decision to "exit this conversation" and go electric. The parts are here when I have the time. I wanted to have a better understanding of the operation of a mechanical fan clutch to determine whether the conversion made sense for me.
When moving fast, that space will drop below the activation temp and reduce fan output to the "unlocked" state of 20-35% input shaft speed. When slowed in traffic, that space gets hotter causing the clutch to engage, and lock into the 70-90% state.
Based on what I read, an individual clutch will have fixed percentages in it's unlocked and locked state such as 27% unlocked, 86% locked. I believe the ranges refer to the variability between individual clutches deemed in tolerance for that model, not partial locked or unlocked states. It would take some testing and data logging to know with absolute certainty and ain't nobody got time for that. In theory you could get a straight answer from the company if they'd let the engineer/designer answer, but you'd undoubtedly get bullshit answer from "Joe in Sales". And with that, it would be impossible to know whether a 2771 or 2791 was moving more air unless you logged data on both and even then you'd probably have to sample many of each. I honestly think the difference between them would be pretty marginal. But having a clutch with higher engagement unlocked would be significantly worse for performance. To get one that was sitting on the high end of 30-35% drawing 14hp unlocked at 3000rpm would suck. Literally - more sucking. Sucking the gas out of your tank and power from your motor.
I personally made the decision to "exit this conversation" and go electric. The parts are here when I have the time. I wanted to have a better understanding of the operation of a mechanical fan clutch to determine whether the conversion made sense for me.
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Sure, but there are fan clutches that engage and disengage based on engine RPM via centrifugal force. A thermal fan clutch won't be engaged "100% of the time under 3,200 RPM" like he claimed because it's not RPM dependant. When I'm cruising 75 mph at 2,300 RPM in 40° F winter air I guarantee my fan clutch isn't engaged and his 2771 wouldn't be either no matter what he believes.
If you are referring to our skirt wearing token weirdo, quit now because there is nothing you can do to change or stop the amount of bullshit you'll have to counter, forever. Even if you make a compelling and fact based series of assertions and convince him to change his point of view for that small bit of discussion, the very next time the subject is broached again, he will revert right back to every declaration he made previous. It is almost as bad as trying to have a coherent discussion with Jerry. It is a never ending game of whack-a-mole and unless you make it your personal quest to follow him around and correct him each and every time, nothing changes.
Stay in context, it is better for everyone. Our fan clutches are of the viscous type.