Starter/ Generator- How Hot Should It Get????

[LesH]

Can anyone give me any idea of how hot the starter/ generator should get?? Mine is on an old Big 10 AC. The bearings are not bad. After running for 5 minutes I can barely touch it. No smoke yet!!! She always turns over. Any electrical tests I can do?? Battery is new and connections are clean. Thanks.

[Roy]

They run hot normally. Don't know how they survive all the heat but they do. Might also run too hot if the generator is overcharging. My experience.

[BLT]

Well it is a sealed unit and that is why they only have an 8-10 amp charge rate. If that same frame size had a fan and open end frames, you could easily pack away 25-30 amps worth of charge. Mine gets hot to the touch also but has never created any blisters.

[Ketchamized]

BLT, I wonder if anybody has tried putting CPU cooling gel on the generator/engine head...

[HubbardRA]

Erick, I am not sure what you are talking about with the cooling gel. I am familiar with conductive greases and epoxies that are used when mounting electronic components to circuit boards, and expecially to aluminum heat sinks. Increasing the conduction to the engine block will likely make the S-G hotter, since the engine can get hot enough to burn you. I am not aware of any material that can be put on the outside of a component to enhance the convective cooing to the air. Most gels or greases act more like an insulator and hold the heat in the unit. If someone is truly worried about cooling, they might try mounting a large piece of finned aluminum heat sink to the generator with screw clamps, and use the conductive gel/epoxy between the S-G and heat sink. They would need to evaluate this method carefully, because in bright sunlight it might take on more radiant heat than it is giving off by convection. Without doing some careful evaluations it is difficult to determine what methods are better than the factory design.

[BLT]

I am also inclined to think that there would be more insulation then radiation as you would still need some mediam to draw away the heat out of the cooling gel.

[Ketchamized]

Rod, The gel I am referring to is usually applied between a computer's central processing unit and the cooling fan in high-end custom-built computers. In my computer, I have noticed a 12 degree difference. With the gel, the temperature drops 12 degrees (which is great for the computer) I do know that this gel lasts the lifetime of the computer, more or less. It's kind of expensive, though. Here's an example of this stuff on ebay: http://cgi.ebay.com/SPECTRA-COOL-SC1-THERMAL-COMPOUND-grease-4-OVERCLOCKING_W0QQitemZ280012145062QQihZ018QQcategoryZ46322QQrdZ1QQcmdZViewItem I would suspect it's similar to the gel and epoxies that you're familiar with, or perhaps even the same thing. That's interesting in regards to greases holding in heat. It makes total sense... Although, wouldn't there be some kind of gel that could be applied that would draw heat out of it, rather than hold it in? (or be forced to have something else mounted to transfer the heat) I agree with both you and BLT in regards to the heatsink and having something to transfer the heat. If somebody really is concerned about heat, then best thing to do is to machine a head that has a bigger fins, possibly coupled with another method, such as oil cooling, or water cooling. Once, I saw a moped that didn't have heating fins at all. Instead, it was an enclosed system with water cooling. It was odd looking, but that moped had great reviews. Pretty much from that conclusion, the best thing we can do is keep our cooling fins as clean as possible, and harness our wires very neatly so that air circulation is good. In addition to that, would be the use of better oils. That aside... I've heard about Marvel Mystery Oil. [url]http://www.autobarn.net/chmm013.html[/url] Would this stuff help or hurt our tractors? I tried some of it in my Craftsman tractor, and it seemed to be a little bit harder to start, but runs smoother.

[HubbardRA]

Erick, I was talking about cooling the Starter-Generator. Yes larger fins on the head, or more fan area on the flywheel will cool the engine more. Just like the thermostat determines the temperature of a water cooled engine, the size of the cooling fins on the cylinder and head, combined with the volume of air blown over those fins will determine the temperature the air engine runs at. The benefit of water cooling is that they can be designed to over-cool then the thermostat controls the water flow to hold the engine at a precise temperature. These air cooled engines are designed to operate within a specific temperature range depending on outside air temperature. There is no thermostat on the air flow.

[Ketchamized]

Rod, I brought the engine head/fins up, so that in theory, it would apply to the original question of cooling the starter-generator. I wouldn't think that the starter-generator would need any cooling. But if it did, aluminum cooling fins could be fabricated for the starter-generator and wrapped around it via a hose clamp and heat transference gel between the fins and the starter generator. I'd leave things stock, though... If it lasted 30+ years, it stands to reason that it could last another 30+ years with proper maintenance and care. The starter-generator seems to be built similiar to older model drills were built in the sense that the magnets can be replaced via the slot screws on the either sides of the generator. If that's the case... I have restored old drills, and I found they run better if I cleaned the magnet contacts as well as the copper spinning disc where the magnet touches. Also, clean out the ball bearings and remove gunk and replenish the grease. If you decide to go this avenue- the cleaning of the magnets, and if it is indeed built like an older drill, watch out for the spring that's immediately under the screw cover. (That is- if that's the case) It's under tension and can pop out, never to be found. Another thing that might help is if the belt tension wasn't too tight. If it was very tight, it'd put more pressure on one side of the bearings, and run harder... More friction. A good cleaning would help too. I'd rebuild the starter-generator if heat was an issue. My Allis B-210's starter-generator is a little bit hot, but not hot enough to cook say, meat. :o) Hope this helps.