| Author | Message | ||
| Bill Gerrie (Bill_gerrie)
Registered Member Username: Bill_gerrie Post Number: 193 Registered: 3-2006 Posted From: 166.90.247.59 Rating: N/A |
Has anyone experinced the use of a dimpled tube rad? Will a dimpled tube rad out perform a standard rad of equal size? Same number of tubes and fins per inch. I would like to run cooler and was told the dimpled tube rad would do but would like to hear from somebody that has used one as my rad is only a couple of years old and before I spend the money on a dimpled tube rad I would like to hear from somebody with first hand experience. Thanks. Bill | ||
| Luvrbus (Luvrbus)
Registered Member Username: Luvrbus Post Number: 551 Registered: 8-2006 Posted From: 74.33.57.23 Rating: N/A |
Bill, they do run cooler I was talked into the upgrade 4 years ago by Atlas the people that made the original rad for my Eagle best money I spent on the cooling system Good Luck | ||
| Keith Wood (Ft6)
Registered Member Username: Ft6 Post Number: 46 Registered: 8-2008 Posted From: 71.198.253.223 Rating: N/A |
Do you need a new radiator? How much more is this one than a standard type? Are you having cooling problems? If you aren't due for a new rad and not having problems, I wouldn't change it out. If you are having problems, I'd first increase the amount of oil and trans cooling and add scoops to increase airflow before changing out a good radiator. | ||
| Bill Gerrie (Bill_gerrie)
Registered Member Username: Bill_gerrie Post Number: 194 Registered: 3-2006 Posted From: 166.90.247.59 Rating: N/A |
Keith I don't need a new rad as mine is only 2 years old but I don't like running at 200 degrees if I have the truck on behind. I was told the dimpled tube rad would cure the problem. I have tried everything else and it all points to a better rad to cure the problem. Thank goodness for water misters sometimes. Luvrbus I have been told they are good. When I ordered the original rad it was supposed to be a dimpled tube and when the normal type rad came I was told it would do the job but I want to run cooler so I am willing to pay the piper and switch if it will work. Bill | ||
| Luvrbus (Luvrbus)
Registered Member Username: Luvrbus Post Number: 553 Registered: 8-2006 Posted From: 74.33.57.23 Rating: N/A |
Bill, the demo that Altas showed me was the dimples break the air and use the whole rad surface instead of just the area where the fan is located a normal tube rad has areas that air doesn't reach even with a shroud he did this by using regular flour and you could see the areas on the rad only the center showed up on the regular rad. Fwiw have you seen the mister system Hayden has for sale nice unit I don't use a mister but some others may need one good luck (Message edited by luvrbus on October 05, 2008) | ||
| Bill Gerrie (Bill_gerrie)
Registered Member Username: Bill_gerrie Post Number: 195 Registered: 3-2006 Posted From: 166.90.247.59 Rating: N/A |
Luvrbus Thanks for the info. I haven't seen Haydens mister system but they have a good reputation so I'm sure it is a good one. Bill | ||
| Jim Wilke (Jim Bob) (Pd41044039)
Registered Member Username: Pd41044039 Post Number: 316 Registered: 2-2001 Posted From: 69.77.156.190 Rating: |
Dimpled tubes also cause the water inside to mix around better & transmit more heat to the tube material. | ||
| David Lower (Dave_l)
Registered Member Username: Dave_l Post Number: 77 Registered: 11-2007 Posted From: 67.58.201.10  Rating: N/A |
I would like to know what is a dimpled tube rad as compaired to a regular rad? As I have never heard this phrase before. Thanks Dave Thanks Bill! (Message edited by dave l on October 06, 2008) | ||
| Bill Gerrie (Bill_gerrie)
Registered Member Username: Bill_gerrie Post Number: 196 Registered: 3-2006 Posted From: 166.90.247.59 Rating: |
Dave The tubes that form the rad core have indentations at regular intervals. I have heard that the water swirls around inside them just like Jim mentioned and causes the heat to disapate better. Bill | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 577 Registered: 8-2006 Posted From: 207.231.75.253 Rating: N/A |
Bill, The dimples do indeed cause swirls, turbulence, etc, which does provide better heat transfer. However, the dimples restrict the total amount of flow through the radiator, just because they intrude into the tube. The heating and air conditioning manufacturers have all made rifled tubing to increase heat transfer, and the tubing inside the coils is a thinner wall than the connecting tubing. Now we have to deal with the old wive's tale about water going thru the rad too fast to cool. The published data by all the radiator and A/C manufacturers shows that the more flow, the more total heat transfer, even though the increase thru the engine, and the decrease going thru the radiator(s) is less. When the flow decreases, the water will come out of the engine hotter, and out of the radiator cooler, but the total heat rejection is less. If you have the standard engine mounted dual oil cooler, (which just happens to put all of that heat load into the cooling water, and then the radiator,) Keith's advice on additional oil and trans cooling is top notch. At least, the hot trans oil can be run thru a fan forced oil-to-air cooler BEFORE it goes into the engine mouned dual cooler. This takes LOAD off the radiator, at a whole lot less cost than a new rad. BUT, I would put a mister on it first. You can make a trial rig easily with a garden sprayer, some hose stuck out a window, and a valve hooked into your fresh water system. Skip the scoop. In my opinion, a dimpled rad won't knock the temp down from 200 to 185 on a hot day, but some load reduction and a good mister system will come close, at a whole lot less cost. Good luck, HTH, FWIW, etc. George | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 1210 Registered: 10-2003 Posted From: 71.58.110.9  Rating: N/A |
I believe he said that he already has misters. | ||
| Bill Gerrie (Bill_gerrie)
Registered Member Username: Bill_gerrie Post Number: 197 Registered: 3-2006 Posted From: 166.90.247.59 Rating: N/A |
George Thanks for your expert comments. I have heard exactly what you are saying. It is a delicate balance between water flow and heat transfer. That is why I wanted to know if anyone had used a dimpled tube rad before I went for it. I use a water mister and it works well when needed but I was just trying to get rid of more heat when I tow my 5000 lb truck. I use a Hayden 2305 air to air cooler for the transmission so there is no heat transfer to the engine cooling system. I mounted it after the rad so not to transfer the heat to the engine. It is a larger cooler then needed to compensate for the postion. It is only 60% effectice in this postion according to Hayden literature. Bill | ||
| john w. roan (Chessie4905)
Registered Member Username: Chessie4905 Post Number: 1213 Registered: 10-2003 Posted From: 71.58.110.9 Rating: N/A |
I wonder if anyone makes an aluminum radiator to fit these coaches? | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 588 Registered: 8-2006 Posted From: 207.231.75.253 Rating: N/A |
Bill, You don't argue with success. Good greif, and I thought I was going to come up with an easy fix! Lets try a couple of more things before we buy a radiator. One thing is that thermostats start to open at their rating. So, a 180 degree thermostat won't be fully open until about 190. Adding more radiator won't lower the engine outlet temperature at all. In the same vein, lets think about this. You are running along on the flat, bus only, at cruising speed. The governor is holding the fuel rack at 60% for the sake of discussion. 60% fuel is being injected, and for the sake of discussion, the water pump, the oil pump, (spraying cooling oil on the bottom of the pistons) and the radiator fan are all being turned about 4 turns for each revolution of the engine. The actual ratio doesn't matter. The hot water comes out of the engine at the temp indicated on the temperature gauge, is cooled by the radiator to an unknown temp, and re-enters the engine. Now, we hang the toad, and go down the same road, same cruising speed, etc, but the gov now has to go to 80% fuel to maintain the same speed. Same number of engine, pumps, and fan turns, so what changes? The additional heat is brought out by hotter water. So now we need to ask a question. What is the radiator outlet/engine inlet water temp under these two conditions? Right now, we don't know, but we do need to know before we buy another radiator. If its 80 outside, and the water is coming back to the engine in the low 90s (without a mister,) the radiator is doing its job well. With the toad, if the engine inlet temp doesn't increase by nearly the same amount as the outlet temp does, changing the radiator won't lower the outlet temp on the gauge because the inlet temp is staying about the same, and the higher gauge temp is just the normal operation of the cooling system. The mister works well, because it lowers the air temperature well below the actual outdoor temp, and the inlet temp goes way down. So, if you can figure out a way to read bottom temperature easily, I would try that in both scenarios, before I bought another rad. KUTGW, George | ||
| Bill Gerrie (Bill_gerrie)
Registered Member Username: Bill_gerrie Post Number: 202 Registered: 3-2006 Posted From: 209.50.72.2 Rating: N/A |
George I have an infra red temperature gun so I will do more testing. I am out of camping for this year as I have too many things on the go now but will look into things later. Thanks for everything. Bill |
