Looking for M300 Radiator Shroud.

[The_Handier_Man1]

From: Coachmen1972  (Original Message)
Sent: 8/30/2006 12:55 PM

OK, one more time....new and improved.....

On the trip the temp reached the two-teens in uphill stop and go traffic. After discussion with various guru's I believe the fact that my radiator shroud is missing has a lot to do with that.

The radiator is the original M300...the engine a non standard 440, so I hope a "standard' shroud will fit, or can be modified to fit.

Anyone have one laying around? Or, does anyone know where to find one?

If not I guess I'll have to make one......



From: Slantsixness
Sent: 8/30/2006 6:16 PM

When you say it's a non-standard 440... what do you mean?
If it's not a 440-3, it's not really a big deal. But what radiator is in the Coachman? An original 318 radiator from 72? or a 413/ 440 motohome radiator (the were the same)?

How certain are you of this being a car 440?

The shroud, although it's a good thing to have, is common to both 318,413 and 440 for the correct model year radiator. For that matter, the motorhome shroud is the same for all standard radiators for specific years.  First what is the exact date you chassis was manufactured (on the dode VIN plate). Now this doesn't mean a 72 chassis radiator shroud fits a 71 chassis, but if you have a 71 radiator and 71 shroud, it fits. 72 is slightly different, 73 again different. 74 went to fiberglass shrouds, and almost all years after 71 have completely different mounting arrangement each year! (now I know you're completely confused... so am I...sorry...read on!)

You don't really need the shroud, at least not if you have the fan close enough to the radiator, and you have the standard firber-form motohome engine bay like Winnebago, Travco and Apollo used. (and I can't say for sure here, with yours being a Coachman...)

For arguments sake, what do you really have? Are the spark plugs above or below the exhaust manifold bodies?

If it's a Car 440, or stated as such on the block, it's possible it's only a 400?

Overheating? No matter which engine you have, 220 degrees is not so hot to be considered "overheating", but it will make you worry for sure! 190-195 is ideal, but if it's 100 degrees outside, 195 degrees is hard to maintain under load, especially on hills...

Be sure you have a cast iron water pump, and a "skirted" thermostat, a good fan clutch (yes... you should have a fan clutch) all of these are available at Napa and Performance Shops. Keeping these in good order will eliminate a lot of your temperature troubles.....

As far as using an original 2 core 318 radiator with a 440?
it's gonna run hot, but it won't kill it...

Ok... last but not least, there's 40 or 50 posts here about overheating, engine temperature, the thermostat dilemma and the water pump identification...
But.....
don't forget.....

The original dash gauges run off of a 5V regulator, which is housed inside the Fuel gauge on 64-73 model intrument clusters (the rectangular dash) and the regulator is a little 1"X1/2" tin box plugged into the back of the newer (round gauges) dashes, all the way to 1993 Mopar trucks and 1997 in B series Vans...
To make a longer story even shorter... when these regulators (you only have one in any dash) are the root cause of inaccurate guage displays, erratic gauge operation and even burning smells under the dash when they are bad. Check it out.

Ok.. now I've been on the soap box too long... pictures would be helpful... I haven't checked your photos yet but I'll get back to you if they're already there and helpful.

Long-winded-Tom



From: Slantsixness
Sent: 8/30/2006 6:18 PM

oh yeah, and if it turns out a standard 1971 shroud works, I have one you can have... I'm in Central Virginia.

Tom



From: ClydesdaleKevin
Sent: 8/31/2006 5:37 AM

As Tom said, make sure you check your guage accuracy...lol!  The guage on the Ark last year was spiking, so I thought I was overheating.  I recored the radiator, replaced the missing thermostat with a skirted 160 from Summit Racing, replaced the water pump, replaced the fan clutch...and the guage said I was still overheating!  So I added a mechanical guage just to see what the real temp was:  My average running temperature, pulling the fullsize Dodge Ram van, uphills and in traffic, is just above 180 degrees.  On really hot days it can get up to around 195, but never exceeds that temp, and then drops back down to 180 when driving on the highway.

Kev



From: Coachmen1972
Sent: 8/31/2006 7:06 AM

Tom,

Thanks for your complete and comprehensive response. A few answers.....The chassis is 1972. Originally came with a 413. It was replaced with a car 440. The way cooling hoses run and a few other pieces of "evidence" point to this. The radiator is original. (ie motorhome 413) The temperature gauge in the dash is inop. There is a mechanical aftermarket gauge installed, I believe it to be accurate as it normally runs around 190-195, except for the one little episode of stop and go uphill traffic in hot weather. As soon as we got above 25mph the temp went back down to 195. I have the correct thermostat. There is no fan clutch......the fan is bolted on to the (cast iron) waterpump and turns, period.

I'd love to take you up on your offer of a shroud. Look for an e-mail.

Oscar.



From: denisondc
Sent: 8/31/2006 3:15 PM

If you dont have a fan clutch on the water pump, no wonder the engine sounds likes its turning fast at 60 mph. The viscous drive in the fan clutch slips more at higher engine speeds, allowing the fan to run at perhaps 2000 rpm, no matter how much faster the engine turns.
If your engine runs at 195 normally, you could install a 180°f thermostat, and see if the temperature excursions dropped by about 15°f. I use a 160° thermostat in mine, but it spends nearly all of its operating life in summer weather. On long uphill climbs my water temp gauge (the mechanical one that has degrees marked on it) will go from 160 to 180 or a little higher, then back down again on the level.



From: ClydesdaleKevin
Sent: 9/1/2006 5:39 AM

I wonder why my rig runs at 180-185 all the time, Dave?  I also have a 160 thermostat, and would think with all the new cooling parts and recored radiator it would run at the 160...ah well, 180 is still pretty darn good!

Kev



From: denisondc
Sent: 9/1/2006 8:05 AM

I think your results could depend on several things. 1. Where is the temperature pickup for your added gauge? 2. What is the error % for that gauge? I dont think most automotive gauges are very accurate from gauge to gauge. I imagine that being 10 degrees off is common. 3. What is the opearating tolerance for the thermostat?
When I drive ours (with the 160°f thermostat) in hot weather it will read 170 on the level; perhaps 180 on hot sunny days driving on black pavement, and up to 190 on steep hills in W. Virginia. In cold weather, when its below 50°f outside it will read maybe 150°f, even lower in a chilly rain. I think the percentage of antifreeze in your coolant mixture can even be a minor factor. Glycol doesnt conduct heat as well as water. I use about a 20% mixture, unless we were going to use it in freezing weather.
The pickup for my mechanical temp gauge is on the drivers side back on the water pump housing. The original mopar sender on a 413 is located in the midder of one engine head, close to the valve cover.



From: ClydesdaleKevin
Sent: 9/6/2006 7:12 AM

That sounds about right, Dave!  Thanks!  My added guage pickup is threaded into a spare plug on the water pump housing.  I have no idea what the error % for my mechanical guage is...it wasn't a very expensive one, so who knows?  Other than the fact that I'm almost always at 180 degrees with a 160 thermostat, it looks like our temperature variances based on conditions seem about the same...although even on a chilly day she reads a solid 160 and never dropped below it yet.

Kev