Richard,Good info. I found a temperature control that I'd lke to order but that link appears to be several years old and more importantly does not provide a place / phone number to order from. Do you have that info?ThanksJim
Richard,Without starting the disparaging rants that Twodogs received last year on BNO about replacing the engine driven fans with electric, I'm curious. I went to the Hayden site and found the biggest fans they had #226216, 16"x16" mounting platform, 1300 cfm. I could clip 4 of these to the front of my radiator on my eagle 10 and use them to supplement the airflow through it when needed, ie. over those big mountains I climb in Colorado. I don't expect to get 1300 X4 the cfms through my radiator, but I would get a lot more than I'm getting now, wouldn't I? The fans could be controlled by t-stat or manually from the cockpit as needed. My alternator can handle the cumulative 80 amp total. My reason for considering this is that I had a long conversation with the design engineer at Atlas Radiator Mfg inCorpus Christi Tx. His company manufactured most of the radiators for EagleMfg Co. in the mid 80's thus the radiator in my coach probably came fromthem.He told me they were sized to unload about 10k btu's of heat from theDD6v92. I failed to ask if that was per minute or per hour. I assume perminute and assume this is under a near full power loading. Even with thisengineering he said the eagles still had some heating issues.The 41" OEM radiator in my 10 has 8.33 sqft of surface area to scavenge its air flow.The requirement for proper btu removal is 2000 cfm of air per minute,roughly 24mph according to him. These are optimum amounts. The cfm beginsto fall if the fan is too close to the core, shroud problems, etc., and a number of the other things. His take on the larger 46" radiator that is available will not be any more effectivewithout a larger fan. The 46" requires 2700cfm for optimum heat removal. Anything less reduces the efficiency, thus the heat load of the engine overcomes the radiator's ability to remove the heat load.He recommended 2 smaller hydraulic high speed fans which could really movesome air. This may not be practical in this setting because of the framingetc., not to mention the cost. Probably why Eagle never did it that way.Your last post really intrigued me. All I need is a supplement to get over the high altitude pass without the nagging heat gain and my problem is fixed. This idea may be workable.What do you guys think?David
Hmmm....Let's say that your main engine-driven fan is moving air thru the radiator at 10 miles per hour. If you then stick a small electric on there as well that is only capable of moving air at 5 miles per hour, it may not help much- in fact it could turn into a generator or simply freewheel, and actually make things worse.If, on the other hand, your little electric is capable of moving air as fast as the main fan, or faster, it will help airflow to increase somewhat. There's a lot of leeway depending on how it's motor is designed... usually it will act like a kid helping a bunch of big men to push someting- every little bit helps....A simple way to tell if anything's being gained would be to measure the current in the electric fan with the main engine fan not running, and then measure that current with the engine fan running at full tilt. Some DC motors are built so that they go faster under a lesser load, and if your electric does this, there's a good chance that it will be able to help as Richard found.So if you see, for example 10 amps with the engine off and 8 amps with the engine on, there's a good chance it's helping... if you see 10 amps engine off and 1 amp engine on, there's a good chance it's hindering...
Richard and Tom,I value your advice and experience greatly. Tom, I've done everything I could possibly do to get this OEM radiator as efficient as possible based on advice from you guys and professional help from high priced radiator shops. I cannot stay below 200 in any protracted climb in triple digit ambient temps above 2000' msl without misting. It doesn't matter what speed, what gear, or what rpm the coach runs, I cannot do it. If the temps are 85 or below I can run Colorado or the Nevada desert without the misters until the fuel runs dry.According to Atlas radiator in Corpus Christi, this coach was designed to run the Houston freeway, flat and level, in up to 99 degree temps. It performs as engineered.With Richard's positive experience with this in DML, I sort of feel like I now have somewhat of a choice. I can throw $500 at 4 easily installed pusher fans or about $3000 for a 46" radiator, fan, shroud and all the ancillary goodies that may be needed to get the beast in it. I guess if I do it and it fails, you may see 4 fans on Ebay in the future. LOLDavid