Bob's Component Resto Part 35: The Engine Fan
Hello MoBros and MoSis'. Tonight's sleeping pill is my latest component resto project that I've just finished, so grab your milk and cookies and climb into bed - and off we go! Obviously, the engine fan isn't something that we deal very much. There's not really that much there - it's just a fan. I recently acquired a seven blade fan in excellent condition that came from a 1974 Dart 225 with air conditioning. I wasn't planning on using it, but later got to thinking that it might be a nice upgrade to my cooling system. Step one was to mock it up and see if everything fit right. I removed the existing fan and spacer, then compared both fans and their spacers to observe the difference. Here's what I learned: The seven blade fan is slightly larger than the stock four blade unit - 18" in diameter versus 17 1/2". The FSM specifies a 18" four blade fan for air conditioned slant six cars, and a 18" seven blade fan for slant six cars that came with the "Maximum Cooling" package. So the 1974 Dart that this came from had the Maximum Cooling option. The stock fan uses the 1 1/4" aluminum spacer (p/n 3730155), and the larger fan uses the 1" spacer (p/n 2863213). The first photo below is of the two fans side by side. As you can see, the blade pitch is the same for both. I then installed the larger fan using the original spacer. The Maximum Cooling spacer puts the fan too close to the engine, so I didn't use it. Once everything bolted together, I was satisfied that there were no interference issues and that everything worked well. So out came the larger fan and spacer. The second photo shows what the fan looked like prior to bead blasting, and the third photo is it in raw metal after it was blasted. One of the previous owners of the Dart decided to paint this fan at some point. Apparently he or she never took Painting 101, and proceeded to spray the wrong color (glossy black) over the surface rust on the fan - with predictable results. As an aside, I noted that the original yellow factory applied "engine side" stamp was still visible on the inside surface of the fan hub. To the blasting cabinet it went, and off came fifty years of rust and bad paint. As the awful, droopy and splotchy repaint came off, it revealed the factory paint before that too went away. The factory paint appeared to be a satiny black, definitely not glossy, and applied directly to the metal without any primer. When you observe this fan in bare metal, it really is a lovely piece of engineering - sturdy, well designed and carefully riveted together. I cleaned it up with alcohol and then hit it with three coats of Krylon Fusion #2732 Satin Black paint, which is identical to the original finish that I removed. By the way, am I the only one out there who finds bead blasting rusty metal intensely satisfying? I digress, sorry. With the fan now looking picture perfect I turned my attention to the spacer, which is an aluminum casting and is original to my Duster. It was sound mechanically but showed a lot of wear. After a thorough cleanup with Soft Scrub and a brass brush, I hit it with a steel wire wheel attached to my cordless drill. Finally, I polished it with Flitz metal polish to prevent any corrosion and it now looks great (sixth photo). I cleaned up the four factory original fan bolts, then installed the fan and spacer and re-checked clearances. All was well and the test drive went perfectly. The final photos are of the installed fan and two photos (inside and outside) of Dusty who loves her new fan. So here are my observations after driving with the new fan for awhile: The seven blade fan definitely moves a lot more air through the engine compartment than the stock four blade unit. It isn't any louder, and doesn't affect my gas mileage at all. The engine still stays right at 195 degrees, but that's because the thermostat is doing its job. I haven't had a chance to operate it in very hot weather yet, but I suspect that it will help out significantly keeping the motor cool in stop and go driving. It is a bit heavier that the four blade unit, although not that much. So why do it? Basically, because it was really fun and looks cool next to the slant six - and may actually help out a bit next summer. And yes, I know that this is a bit of "over restoration" for a car that isn't really worth that much. However, I love pouring TLC into old, abused components and getting them back to the way the factory intended. Finally thought: It was cold here today, but I had Dusty out on the highway and up to speed. The stout little slant six was just purring along at 70 mph with that lovely brand new fan on her nose keeping everything nice and cool. That's why we do this stuff - because of the happiness that it brings us. So that's it for now, kiddies. It's off to bed with you and your dreams of a wonderful drive in your Mopar. Night - night!
Hello MoBros and MoSis'. Tonight's sleeping pill is my latest component resto project that I've just finished, so grab your milk and cookies and climb into bed - and off we go! Obviously, the engine fan isn't something that we deal very much. There's not really that much there - it's just a fan. I recently acquired a seven blade fan in excellent condition that came from a 1974 Dart 225 with air conditioning. I wasn't planning on using it, but later got to thinking that it might be a nice upgrade to my cooling system. Step one was to mock it up and see if everything fit right. I removed the existing fan and spacer, then compared both fans and their spacers to observe the difference. Here's what I learned: The seven blade fan is slightly larger than the stock four blade unit - 18" in diameter versus 17 1/2". The FSM specifies a 18" four blade fan for air conditioned slant six cars, and a 18" seven blade fan for slant six cars that came with the "Maximum Cooling" package. So the 1974 Dart that this came from had the Maximum Cooling option. The stock fan uses the 1 1/4" aluminum spacer (p/n 3730155), and the larger fan uses the 1" spacer (p/n 2863213). The first photo below is of the two fans side by side. As you can see, the blade pitch is the same for both. I then installed the larger fan using the original spacer. The Maximum Cooling spacer puts the fan too close to the engine, so I didn't use it. Once everything bolted together, I was satisfied that there were no interference issues and that everything worked well. So out came the larger fan and spacer. The second photo shows what the fan looked like prior to bead blasting, and the third photo is it in raw metal after it was blasted. One of the previous owners of the Dart decided to paint this fan at some point. Apparently he or she never took Painting 101, and proceeded to spray the wrong color (glossy black) over the surface rust on the fan - with predictable results. As an aside, I noted that the original yellow factory applied "engine side" stamp was still visible on the inside surface of the fan hub. To the blasting cabinet it went, and off came fifty years of rust and bad paint. As the awful, droopy and splotchy repaint came off, it revealed the factory paint before that too went away. The factory paint appeared to be a satiny black, definitely not glossy, and applied directly to the metal without any primer. When you observe this fan in bare metal, it really is a lovely piece of engineering - sturdy, well designed and carefully riveted together. I cleaned it up with alcohol and then hit it with three coats of Krylon Fusion #2732 Satin Black paint, which is identical to the original finish that I removed. By the way, am I the only one out there who finds bead blasting rusty metal intensely satisfying? I digress, sorry. With the fan now looking picture perfect I turned my attention to the spacer, which is an aluminum casting and is original to my Duster. It was sound mechanically but showed a lot of wear. After a thorough cleanup with Soft Scrub and a brass brush, I hit it with a steel wire wheel attached to my cordless drill. Finally, I polished it with Flitz metal polish to prevent any corrosion and it now looks great (sixth photo). I cleaned up the four factory original fan bolts, then installed the fan and spacer and re-checked clearances. All was well and the test drive went perfectly. The final photos are of the installed fan and two photos (inside and outside) of Dusty who loves her new fan. So here are my observations after driving with the new fan for awhile: The seven blade fan definitely moves a lot more air through the engine compartment than the stock four blade unit. It isn't any louder, and doesn't affect my gas mileage at all. The engine still stays right at 195 degrees, but that's because the thermostat is doing its job. I haven't had a chance to operate it in very hot weather yet, but I suspect that it will help out significantly keeping the motor cool in stop and go driving. It is a bit heavier that the four blade unit, although not that much. So why do it? Basically, because it was really fun and looks cool next to the slant six - and may actually help out a bit next summer. And yes, I know that this is a bit of "over restoration" for a car that isn't really worth that much. However, I love pouring TLC into old, abused components and getting them back to the way the factory intended. Finally thought: It was cold here today, but I had Dusty out on the highway and up to speed. The stout little slant six was just purring along at 70 mph with that lovely brand new fan on her nose keeping everything nice and cool. That's why we do this stuff - because of the happiness that it brings us. So that's it for now, kiddies. It's off to bed with you and your dreams of a wonderful drive in your Mopar. Night - night!
