Community Forums

leadman · 10-04-2010, 11:28 PM

My MH has a radiator that is showing its' age and is seeping at the tubes.
I am thinking on replacing it with an aluminum radiator which should help cooling.
I know someone posted here quite awhile ago that they were installing electric fans on their MH to replace the engine driven fan but I did a search and can't find it.
There are 2 small fans on the bottom of the a/c condensor in front of the radiator that I have wired to a switch in the cab, but these seem to have no effect on engine temperature.
I would also like to install electric fans to replace the fan clutch but don't know if it will work or not. Really tired of listening to the fan roar.
I found a fan rated at 3,300 cfm but I don't know how much air flow the engine fan moves. I can mount 2 fans for 6,600 cfm.
I also want to move the engine oil cooler from in front of radiator and use a small fan on it with an air scoop to direct air to it when the vehicle is moving.
I have also thought about installing a rooftop a/c condenser with electric fans to allow more air through the radiator. This might be more money than I want to spent though, have to check current price on this condenser, the labor I can do.
Has anyone tried any of these modifications?

JimElliott · 10-05-2010, 04:47 PM

There are NO electric fans on the market that will out pull a stock 7 blade fan period...
Clean out the clutter in front of the radiator and allow clean air to flow through and you mechanical fan will work better without coming on rapidly..

Jim

leadman · 10-05-2010, 07:13 PM

I'll call GM and hopefully find out what cfm the engine fan pulls. If nothing else maybe I can use an electric fan in front of the radiator that comes on 10 to 15 degrees before the fan clutch engages. This may reduce the time the fan clutch is engaged.

I think moving the a/c condenser is a very good idea. We just completed a 2,700 miles trip from Az. to Wyoming and back and when it was cool enough that we did not need the a/c the fan clutch would only engage when the thermostat would open.
Fuel mileage increased up to 2 miles per gallon.
I am going to look for a thermostat that is not the poppet style that opens fully all at once but opens a little at a time. Might also drop down to a 175', now have a 180'.
I need to move the aftermarket temp gauge as I am not getting accurate readings and can't tell the exact temp the fan clutch is engaging at.
Looks like I may have to have a radiator custom made if I want to go with aluminum. Price will be a factor but as it will be $500 to $600 for a new 4 core standard brass radiator with the 20% to 30% increased cooling claimed with alum. it might be worth the extra money.
More investigation is in order.

JimElliott · 10-06-2010, 11:36 AM

Leadman, On my 454 I have (2) threaded ports on the thermostat housing and one of them is for the digital temp readout...
Both dash & digital (Autometer) follow each other very close which satisfies me....
The center line on the dash temp gauge is 212º and for some unknown reason getting out of town last Wed mine exceeded 220º so gotta check that out....
I do have a 2 row Aluminum rad on my race car but it don't cool as good as my old 4 row brass one BUT cuts down some weight.
Going to bump up the ignition timing another 2º and clean up the mechanical weights in the distributer (might be hanging up a dab) cuz NO pinging was going on while traveling.....

leadman · 10-07-2010, 09:01 PM

My t-stat housing doesn't have any ports available, but I'll look at a parts catalog to find one that does. If I can't find one I'll buy a new housing and have a boss welded on it so I can drill and tap it.
The aluminum radiators I found don't have the pipe on the radiator for the hose that leads to the cap and they have 2 large tubes, think they were about 1" or 1 1/2" wide. I may end up with a brass 4 core unless I have an alum rad. built.
We went to Wyoming and back to Az. last month and the fuel mileage was low climbing the mountains and/or the wind (5.6 to 7), but the last day it was fairly level and no wind, got over 9 mpg at 58 mph.

bachler · 10-16-2010, 08:18 AM

When you stated A mid 1980 motorhome That rad is near 25 years old. and on a motorhome should replaced. And it should be a 4 row Copper/brass stock one. They are pricie but you blow ti apart on a long up hill climb Have a tow truck pull you to shop then you will see what the deffanition of pricie really is.. In 20 years a lot of water/coolent has passed thought them cores;; Don't you think ??

leadman · 10-23-2010, 08:27 PM

bachler, might try reading the whole post.

JimElliott · 10-25-2010, 01:45 PM

Quote:

Originally Posted by leadman

My t-stat housing doesn't have any ports available, but I'll look at a parts catalog to find one that does. If I can't find one I'll buy a new housing and have a boss welded on it so I can drill and tap it.
The aluminum radiators I found don't have the pipe on the radiator for the hose that leads to the cap and they have 2 large tubes, think they were about 1" or 1 1/2" wide. I may end up with a brass 4 core unless I have an alum rad. built.
We went to Wyoming and back to Az. last month and the fuel mileage was low climbing the mountains and/or the wind (5.6 to 7), but the last day it was fairly level and no wind, got over 9 mpg at 58 mph.

Leadman, The fuel consumption on the level is very good (over 9 MPG).

Most of the thermostat housings are made from cast and should have at least one threaded port, I had the machine shop add another port with the pipe threads for 1/8.....Just screw in the sensor and away you go...

How about a salvage yard in your area?...Chebby parts are just about the same on the thermostat housings.

Jim

leadman · 10-25-2010, 11:08 PM

Jim, I am going to pull the thermostat and check the area of the intake to see if I can drill and tap it for the temp sensor. The is already a vac. switch in the thermostat housing.
I have been thinking about moving the a/c condensor to the roof. I have done alot of a/c installs and repairs over the years so this is actually pretty easy and I think it would make a big difference in the cooling of the engine. The fan clutch is on most of the time when the a/c is on and this really affects the fuel mileage.
When we got over 9mpg the a/c was off and the fan clutch would cycle on and off.

JimElliott · 10-26-2010, 09:25 AM

Quote:

Originally Posted by leadman

Jim, I am going to pull the thermostat and check the area of the intake to see if I can drill and tap it for the temp sensor. The is already a vac. switch in the thermostat housing.
I have been thinking about moving the a/c condensor to the roof. I have done alot of a/c installs and repairs over the years so this is actually pretty easy and I think it would make a big difference in the cooling of the engine. The fan clutch is on most of the time when the a/c is on and this really affects the fuel mileage.
When we got over 9mpg the a/c was off and the fan clutch would cycle on and off.

I know we have read the arguements about the amount of "H.P." a 7 blade fan takes to turn and even playing on a dyno it's hard to determine...
Best guess at the moment is 20 or so horses and that is placing a propane torch in front of the clutch since the water temps vary and NOTHING hot in front of the engine, I don't like to stand around a new engine with a high RPM pull.
One thing that helped me was to clean up the airflow going through both coolers (A.C. & radiator) by moving the horns to the bottom (below the rad) and the water over flow to the extreme passenger side plus moving small items out of the way also.....
On the drivers side I had a 3 inch gap and the air would slide around the radiator and on the passenger side it was a 4 inch gap so a nice long thin piece of rubber on both sides solved that problem, Along the top a 3 inch rubber (long) stretched along the entire bay area for another way to force more air through everything....
Along the bottom the "V" shaped air gap (3 inch) was allowing air to escape prior to hitting the radiator's..........
Custom built the "air dam" and bolted it to the bumper all of the way across, Found the "tuff" rubberized material (5 inches wide) at Home Depot in the garden dept.....Might just add another 4 foot piece directly below the radiator this winter just to create a much lower air pressure in the engine dept....
Since our temps where we both live seem to be in lockstep year round this should be a very interesting series of test and see what next years summer ~heat~ does to us

Jim

JimElliott · 10-26-2010, 09:31 AM

Leadman, Forgot one item....
On the way over the hill (September into October) it was plenty hot on the day I left and yes the engine heat got up there.....
I turned on the generator and turned on both A.Cs. to relieve the stress on the engine componets, Once out of the Coachella valley (Palm Springs) ALL temps returned to normal.

Jim

leadman · 10-27-2010, 10:07 AM

I did use rubber shower pan material from Home Depot to fill the gaps around the radiator after reading it on here awhile back. Think you may have posted it.
Got alot going on right now but when I get time I am going to see if I can buy a roofmount a/c condensor at a decent price. If not I will fabricate one from the condensor and fans that I have.
I do want to make an air scoop to mount to the bumper to funnel air to the radiator also. I am going to do one thing at a time so I will be able to post what I feel is most effective.
First thing is a new core or radiator. Just need time and money.