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Fan for Sunstar?


heron

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I've read and now experienced how the Sunstar with the 20Hp Kohler gets hot.. Engine is clean and everything clear of grass etc...still seems to run hot to me. No problems..it's not running lean...I just think they could have designed a better ventilated hood to compensate for this motor. Can I add an electric fan to the bottom of the hood over the cooling fins? I assume I'd want it pulling out. Has anyone done this...is there a certain fan to use..low profile, weather/UV resistant, mounting options etc... would be appreciated. One more thing... I looked at pulling the rollers off. There is one key at the right side but it seem like the rod is welded on both sides. How does the rod come apart...?
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Okay, how does the collar work..I removed the screw and tapped on the collar but it would not budge. There does seem to be some weld on both sides but it's factory, not aftermarket. I can take pics later.
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You have both heat of engine and muffler being blown thru the grill about as as far from each other as you can get. Unless you have instrumentation to measure, intake air temperature, out flow temperature and ambient temperature, along with air flow gauges both in and out, it is hard to determine what is really hot. You could have, in theory, 210 degrees coming out of radiator grill on a 90 degree day and pass the engine manufacturer's cooling requirements. I agree that it get pretty warn out the front end as I have a 20HP version also and I run the snot out of it and it is real warm, but not to blister you hands. You will need a fan that is greater in flow capacity then what is happening now or the engine stands a chance to heat up more. Before you do anything, try removing the grill and see if it is less warmer to thre touch.
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I agree. It probably is fine but I thought how easy it would be to fabricate up some brackets and put a nice electric radiator fan just under the holes in the hood to help pull air thru the grill and out the top of the hood... Might change it over to synthetic oil also...it drops temps in my modded duramax motor significantly.
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If you were to add a fan it would need to go in the front and blow out. The airflow is in through the holes in the top of the hood and out the front of the grill. I know mine seems to get hot also but I think a lot of it is from the muffler. I repowered it with a 27hp and it ran just as hot brand new out of the box so must just be the nature of it.
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Wow, I would have thought air flows thru the front and over the engine then out the top..heat rises...? The fan on the front would be easier for sure. I've got an extra 12v fan I pulled off my rv that may work except I'm not sure how it would tolerate the heat.I suppose an auto radiator fan would be better. I'm certain any cooling would help the engine in the long run.
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Cooling air enters through the top in an effort to collect less debree and to pass through the hydro cooling coil before picking up the engine heat. I have had a couple with over 1000 hrs. with no ill effects from the heat. As long as you keep the cooling fins clean, and with dino oil. Here is an exploded view of your roller bar assembly. http://www.partstree.com/parts/?lc=simplicity&mn=1692136+-+SunStar+20P%2C+Hydro+and+60%22+Mower+Deck&dn=12579 This is how I have saved three roller bars. http://simpletractors.com/club2/topic.asp?TOPIC_ID=111304
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Comet, yes, I've been on partstree lots so far and will be looking up some seals for the front axles next. Great idea on the roller bar. I'll go that route when my bar is shot. So far I've got some time left on it. But, how do you release that collar once you back the set screw out? I couldn't get anything to move. I was wanting to pull the rollers and straighten out the washers but I gave up when I messed with the collar and didn't know what I was doing. I do agree about the fins...what about the dino oil vs the synthetic. I've found the syn drops my temps in what ever I use it in...? Is it not the case with an air cooled motor? I may just see what I can fasten to the front grille. An electric fan is an easy install. I'd think having a few hundred extra CFM's of air passing thru the system wouldn't hurt it. I don't think it would cool it off too much and create other issues. Can you tell me the correct cross over battery I need for this tractor. The original owner dumped in a Batteries Plus 600CCA battery and had to put a wood shim under the bracket so the oil cooler cover hole would line up with the hold down stud. I'm not sure what height/size battery I should have in there..as far as a new one. I know I can get the original off partstree but I'd rather go local. Do you know if there is some overflow hole in the fitting on top of the hydro unit? When I changed the hydro fluid I got to about 5.5 qts in and noticed oil coming down the side of the hydro unit. I removed the back plate and sure enough right there where the fill tube connects to the 90 fitting there is oil coming out. Oozing out right above the threaded part of the fitting. Once it weeped out a good bit it leaked no more. I put a wrench on the fitting but could not budge it so it's definitely tight. Should I replace the fitting?
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Hi, I know Simplicity did some work with a fan on the front clutch like the Legacy uses. It did nothing worth while for cooling like it worked on the Legacy. The problem was that the side panels are tight and there is no path for cool air to come in. One could use the little round louvers that they use in house siding. Just use a hole saw and cut a series of holes in a row and glue them with silicone on the back side. Like a 50 Buick with 8 port holes instead of 3 or 4. Any air inlet back in the side panels would let a fan work more efficiently. Question? How many remember the 3 hole and 4 hole Buicks especially the Roadmasters? Al Eden
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The fan I am going to use will pull 1250cfm so I'm hoping it will do something as far as drawing air down thru the top and around the engine. I know it won't be much but if it expels the heat of the muffler that I'd think would do something for cooling it down. Good idea on the holes but I'm not sure I'm ready to chop up the hood...yet. I'd probably just use a good quality screen or something if I did that. it would be easy enough to fasten on to the hood down the sides. Total cost of fan and parts probably $20. Worth a try.
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As Al indicates, the sides are closed off, and it is doubtful you can move anymore air through the plenum and engine than the engine fan already provides. Which would leave the only source of additional air supply to your new fan to be from under the tractor, around the front of the deck. (Notice the engineered air intake) These decks have a lot of blow back and clipping collection on top of the deck. This may cause the front screen to clog up and actually diminish your cooling. The way the system is designed it keeps this area pressurized and allows very little collection of clippings. If you should try this I suggest you keep a close eye on this condition. The primary cause of the heat under the hood of these tractors is the muffler. The heat from which is never introduced into the cooling stream. It is blown out the front of the hood and dissipated through the hood itself. Therefor I don't think it has any large impact on the engine. I am not an engineer and YMMV...02
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It is the muffler/exhaust. Compare my stock 917 with our 920 gas pulling tractor. The pulling tractor has dual vertical straight pipes. The 917 hood is way too hot to touch, the grill is too hot to touch, but the pulling tractor hood and grill barely get warm.
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I mounted a small, 12" automotive fan in my grille. Have it hooked up to a three position switch that I installed in the dash. "Up" pulls hot air out of the engine compartment. "Middle" is off. "Down" reverses the fan to suck grass clippings and crap off the grille that got sucked through the fan. I have no idea how much good it does, but I figured it sure can't hurt. The air coming through that grill is blistering hot on a warm day, but a lot of the heat could be from the muffler too. I also cut and installed some thick foam cushion type material to the underside of the hood to help seal off the engine compartment from the air intake plenum - idea to to help prevent the engine from drawing hot air into the cooling system. This seals off what was a pretty good gap where it would potentially be drawing hot air into itself.
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WI Tom: yes, I'm with you, I can see lots of heat coming out the front from the muffler but I figure if I can help get the heat out it's less the engine has to cope with. I'm putting in a 7", says it moves 1250cfm. Not sure how I'd wire it to go both ways...? I'm running mine thru a relay and tapping into the red extra wire that comes off the harness right by the battery. I'm running the keyed ign to a simple on off switch which will turn on the relay once the tractor is started. Do you find having it go in reverse really works? I usually blow off the tractor once I'm done, just figured I'd blow off the fan also? Have you ever done a front seal on your tractor? Mine is leaking and I've got the seal on the way. Another member says it's an easy job. Not sure how tricky it is to remove the clutch assembly.
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