PT Radiator Air Scoop

[Leroy Eckert]

First the scoop will not cool the radiator any quicker or cooler or reduce the fan on off sequence because the water temp is controlled by an instrument *Alarmstat* designated by BB. It the radiator is plugged up it ain't gonna cool, scoop, extra fans or anything else. On most coaches through 1994 there is an Alarmstat which senses the water temp and activates the fan to high mode and back to idle mode constantly if the fan override and the chassis a/c is off. It cycles between -+ 8 degrees. It was specified by BB at 195 degrees. Accordingly, the fan in idle mode spins between 200 and 600 rpm at engine rpm values 800-2100 rpm according to my BB manuals. So, if the radiator is not clean and good massive amounts of air will do not good the result being the fan will cycle more often. In high mode, chassis a/c on; or fan override on; the fan runs at approx. 1800 rpm. The only thing that will stop the fan high/idle mode sequence timing is a new radiator. It makes a lot of sense. Bad radiator, no air flow, no efficient cooling. A scoop is not going to help a bad radiator. It is that simple. Of course it may help for a bit if you remove the Alarmstat, let the fan run constantly and you may see some reduced temps. I have jacked with my bus using VMSpc for quite some time and I cannot prove the old wife's tale that the fan reduces mileage. I have documents with lots of numbers on them that support my opinion. I realize opinions are like a$$holes, everyone has one. However, my numbers prove my statement. I long ago changed my Alarmstat to 190 degrees after talking to BB and Detroit Diesel mechanics. I have seen a 7% decrease in overall temps without a decrease in mileage. I have a good radiator. My conclusion is, the Birds did not have a problem when they were built or there would have been a recall. 15-20 year old radiators need a good going over and all will be well. No scoop needed. Think of an Alarmstat as a forced high temp thermostat, because that is what it is. Leroy Eckert 1990 WB-40 Smoke N Mirrors Dahlonega, GA Royale Conversion --- On Wed, 8/6/08, Scott Forman <scottforman75@...> wrote: From: Scott Forman <scottforman75@...> Subject: [WanderlodgeForum] Re: PT Radiator Air Scoop To: WanderlodgeForum@yahoogroups.com Date: Wednesday, August 6, 2008, 8:07 PM I do not have a cooling problem, in fact I just re-cored my radiator. Just wondering if the scoop could give me the 5 degrees I need to keep the fan from kicking on...which as we all know saps fuel economy...during hot weather. Scott --- In "WanderlodgeForum%40yahoogroups.com", "Gregory OConnor" wrote: > > Scott, when the engineered systems will no longer control the heat, > there is issue with the systems. to make things run cooler at more > stress, can only prove to allow more stress than engineered. I pust it > to the limits of heat befor I back off stress. A mod to help overcome > ambient temp influence like the radiator evaporative cooler MikeH uses > is one mod I would like to try. > > GregoryO'Connor > 94ptRomolandCa > > > > --- In "WanderlodgeForum%40yahoogroups.com", "Scott Forman" > <scottforman75@ > wrote: > > > > There was some talk a while back about fabricating an air scoop for > the > > radiator grill on a PT to increase air flow through the radiator. > Did > > anyone install one? Does it seem to make a difference? How did you > > build it? > > > > Scott Forman > > 86 PT38 > > Memphis > > >