GSL #186 (General Service Letter) dated May 2, 1955 to all dealers states

para 1.

Radiator Air Upper Deflector - 4 Barrel Carburetor Units - 1955 cars



As you know, recently we advised that to minimize the possibility of icing in 4 barrel carburetors used on 272 Special and Police interceptor engines, a radiator deflector was going to be incorporated in production. The air deflector, part number B5A-8327-A will be effective in production approximately May 1,1955. Service parts will not be available until approximately June 1, 1955.



Use of the radiator air upper deflector increases the under hood temperatures. This, of course, is desirable in ambient temperatures below approximately 58 deg F to prevent carburetor icing. The increase in under hood temperatures, however, may have a slight detrimental effect on engine performance during the warm summer months in most areas. However, in areas of extremely high summer temperatures, it will be desirable to remove the air deflector to prevent possible detonation and loss of performance.



marv

I have a very late 55 that originally had a 272 4 bbl that had one,I removed it when I had 6 cylinder brackets put on the radiator when installing the 351 to gain some clearance for the longer water pump,its going back on when I put the 292 in.

Butchering up everything I can get my hands on in Dayton Ohio

Rick:

Could you post a pic as that is interesting.

marv

That service information that Marvh posted has given me something to try.I have the deflector on mine with nice repro seal so it closes against the hood.I am getting a rough idle when hot.Vacuum gauge is steady so I am thinking the underhood temp is causing fuel to become hot and vapourizing a bit.Going to remove the deflector and see what happens.I was under the impression the deflector was to keep air moving through the rad but it appears it was meant to raise underhood temp to prevent carb icing which wont happen when its 70+ in the summer.Thanks Marvh!

  

Just wanted to update my last post.I took the deflector off this morning.Took it for a ride so it got good and hot.Without the deflector on it idles just about perfectly smooth.Seems to have a little more power on acceleration too.All that hot air trapped under the hood WITH the deflector on was causing my idle problem I think.Thanks for the info Marvh.I think you solved my problem.

  

Your welcome Mark; Do you have the under pan removed as I have found the engines run much cooler if that is removed.



I would like to see the mod Rick has done to his car to force the air through the rad. This could also help as I think he is onto something. Could you post a picture Rick if possible.

thanks

marv

Hi Marv! I bought the splash pans and never did install them.I would like to see Rick's mod too.Anything that helps keep engine cooler is of interest to many I think.

  

I hope this works - these are pictures of the deflectors I use fitted to a Customline fitted with a 351 Cleveland.

This car was always hard to keep cool and these along with a seven blade fan plus a thermo did the job well.

This car would idle all day in any temperature in traffic and never get above 190 degrees with a 180 degree thermostat using a standard cusso radiator header tanks fitted with a four core radiator from a Toyota four wheel drive.



I have sold this car so can't get any clearer photos.

For some reason I haven't done this to my Mainline utility though I have owned it for 17 years.

As you can see, I have a plate (about 16g sheetmetal) bolted underneath the opening in front of the radiator. I have two sections of 1/8" insertion rubber siliconed into place in the two other openings in the support panel. This means that all air hitting the grille opening must pass through the radiator.

Regards

Rick - West Australia
Do Y Blocks Downunder run upside down? Gravity Sucks!!

Sorry about that it didn't work so I have uploaded them to Photobucket to view. Here we go again.





I hope this works.

Regards

Rick - West Australia
Do Y Blocks Downunder run upside down? Gravity Sucks!!

Rick! Pics not opening.Not working second time you tried either.