Community Forums

William Willard · 06-08-2012, 01:34 PM

Has anyone changed their rear radiator to the side -- I`m going to try it this week-end, & with the help of Harry Martin (Happycarz), I think we can do it in a day or so - Any suggestions will be helpful, since neither of us have tackled a mod such as this -- Bill Willard

Gordon66 · 06-08-2012, 02:02 PM

Good luck. Post pictures of progress.

sgtjoe · 06-08-2012, 02:12 PM

X2 on the pics. Good luck. This has my interest.

mdc99 · 06-08-2012, 04:26 PM

Please educate me on why. I understand it would make the engine more accesible, but is that worth the work involved? Or are there other advantages? Thanks, Mark

dennis45 · 06-08-2012, 04:47 PM

OOOH, Have you heard of the term "Can of Worms"?

Mr_D · 06-08-2012, 05:03 PM

Quote:

Originally Posted by dennis45

OOOH, Have you heard of the term "Can of Worms"?

Yep, I have!!!!!!!

dennis45 · 06-08-2012, 05:25 PM

Any chance I could get that pic? I can think of a number of places it would come in handy.

EngineerMike · 06-08-2012, 05:47 PM

A well planned move would be a nice upgrade. Side radiators (to answer mdc99's question) are way less prone to holes due to thrown rocks, and essentially impervious to engine blow-by that will later collect road dirt & de-rate the cooling capacity of the radiator, perhaps to the point of plugging it up.

Make sure the radiator, which is quite heavy when full of coolant, is well supported structurally, isolated from vibration using fat bushings, and sealed well to positively direct airflow thru the fins. Its easy to crack a radiator that is too free to wiggle, and inefficient on cooling if its not well sealed. On my rig the radiator stack is outrigged off heavy .375 steel arms that Grade-8-bolt onto the frame rails. Additionally, they are back-stayed at the bottom using 1/2" threaded rods, also to the frame (or maybe its a bracket off the frame) to keep the bottom from vibrating laterally. Fat rubber bushing on top mounts and on back stay struts so the mount is firm but not rock hard.

Curious about airflow. Are you doing some kind of ram air setup, going to electric fans, or what for positive airflow?
My rig uses maybe 30hp for full fan flow, which is supplied by the engine's hydraulic system from a PTO on the transmission (my rig is 31,000# rolling, and makes serious heat staying up w/traffic on hills). Its tough to get in that ball park w/electric fans. Based on some assumptions so you can't quite take this to the bank, I'm moving 8-10,000 cfm, might be closer to 15k. Best setups I've seen w/electric fans are topping out around 5,000 cfm, but a much lighter rig might be able to get by w/that.

Also, you have several items in the stack for cooling. Depending on rig, you can have:
~ air conditioning condenser
~ tranny oil cooler
~ hydraulic oil cooler
~ charge air cooler (intercooler)
The more stuff you have in the stack, the more drag on the air column being forced thru the coolers, so the more raw CFM capacity you need. I can see you getting rid of the direct drive or clutch fan off the motor, but you need some H.P. to move the air needed for all that stuff. Anxious to see the pics x3.

Drifter · 06-08-2012, 06:03 PM

Mr. Willard you have a side Rad. Is it not your coach?

ga traveler · 06-08-2012, 06:08 PM

Rear radiators are in the vacuum area. The vacuum created at the rear of the coach helps pull the air through the radiator. The side radiator is in the slipstream. It is much harder to move the air through it. you are going to need a large fan to keep from having a cooling issue.

moisheh · 06-08-2012, 06:08 PM

Nothing like going where no man has gone before! I too wonder how you are going to power the fan. I have never seen any side rads that used an electric fan and doubt you could push enough air. Are you buying a complete setup from one of the MH wreckers? Otherwise the cost could be prohibitive: Hydraulic pump, hydraulic motor, hydraulic hoses, mounts,rad hoses ( both metal and rubber) some sort of fan controller , actual fan and of course a grill. Are you using the same rad? Sure hope you will post a play by play.

jauguston · 06-08-2012, 06:12 PM

Are you prepared to design and install all the hydraulic system needed to power the new hydraulic driven fan you will need? Seems like a lot of expense and work to get rid of a system that with proper maintainance has done fine on thousands of motorhomes for many years.

Jim

Wizard · 06-08-2012, 06:24 PM

Quote:

Originally Posted by dennis45

Any chance I could get that pic? I can think of a number of places it would come in handy.

I just did a right click, copy image and it was in my download file. From there I copied it to my pictures.

Thanks Mr. D

EngineerMike · 06-08-2012, 08:00 PM

I'm currently puzzling my way through "re-programming" my fan controller. Here's some discussion as food for thought, might be useful to the OP
.
I have 2 fan speeds, fast and way-the-hell-fast. I know I can reclaim some mileage by slowing the fan speed, and I know I've got slack in the cooling as my rig runs 10-15 degrees cooler than all my ISL buddies. You can get temp probes that are programmable for a window (basically an On/Off switch), then stack them via relays & some form of modulator circuitry to control fan speed. For electric fans it'd be a snap.

For hydraulic its more complicated. You can get a PMW solenoid controlled spill valve that spills or bypasses fluid flow past the fan motor. I have such a circuit internal to a hydraulic block called a hydraulic integrated circuit, but it isn't being driven PWM, the chassis mfgr set it to On/Off only (hence two speeds). I have some options.
1) get a better PMW bypass valve (higher capacity for slower fan speed), and drive it w/PWM step-wise using the window type temp sensors. Maybe get 3 or 4 speeds depending on how many sensors I want to buy at $180 ea.
2) drop the initial fans speed by installing a small bypass line between fan input line and return line; this would bleed off some of the flow and lower fan speed overall.
3) leave the existing On/Off solenoid config, add a bypass like like #2, but put its own PWM valve on the new bypass to trim bypass as engine heat builds; use same temp sensors for trim logic (relay w/in-line resistor for each temp sensor so that the sum of active relays determines the PWM signal.

for any of the PWM drivers above, I need to add a PWModulator, but there is a decent one that takes voltage in as signal for PWM% out for about $40 in a DIY kit form from Vellman. The rest is just wiring.