I have posted in the past about my car tending to overheat at interstate speeds (especially behind 18 wheelers). Well over time I spoke to a lot of folks looking for opinions and suggestions and I believe I have come up with a solution to my car's problem that may offer benefits for others. After looking at the underside of the front of my car I concluded that it seemed possible that air flowing under the front bumper may actually flow under the radiator and UP behind it. The net result could be to reduce the air flow through the whole of the radiator. A friend had a C3 Vette and there was a lower "shroud" under the car beneath the radiator and his experience was that if this panel was removed his car would overheat at speed.
I took that information and designed two different plates to redirect airflow. After installing these, my car's temperature now actually drops at interstate speeds. One plate is similar to a front spoiler, it mounts vertically bolted to the radiator core support under the splash pan. The other is similar to a "skid" plate. It bolts to the front frame cross member. It is notched to clear the a-arms and the oil pan and has slight downward bends at the trailing edges. These 18 ga. plates were simple to make and all bends were done in a bench vice.
As further info, my car has a Griffith radiator (moved forward in the core support), a 16" Derale fan and shroud (holes with rubber flaps added at Derale's suggestion), a high volume aluminum water pump, and a 180 degree thermostat. The engine is a large FE (462 CI) that makes a LOT of heat. I changed from a 3.89 gear to a 3.25 to slow the engine down at speed.
Nice job on the fix. Keep us posted on how it works for you in summer heat.
Lynn, did you try these separately? Just curious as to which one provide the most "help". Could you post drawings with dimensions etc.?
John
Rich, I sorta tested the "fix" yesterday and while it wasn't all that hot (maybe 85) the result was the opposite of what was happening before. The car would run around 190 max in town but would start to creep up over 205 on the interstate. If I got off on an exit the temp would immediately start to drop. Yesterday the temp on the highway settled just below 185 at 65-70. Above 70 the temp actually seemed to come down a bit. When I exited to turn around the temp went up to 190. I have a SW 2 5/8" mechanical temp gauge that is pretty accurate and responsive.
John, I will post the dimensions of what I made. I bought the sheet metal at Home Depot so the pieces are not very large. I didn't try the parts separately, at first I was only planning on the lower plate but while looking at the car I could see that air could still go above the plate, hence the "spoiler". I think the "airfoil" shape of the front body mount on the frame contributes to the problem. The spoiler actually cleans up the look of the car a bit in the front.
My car actually runs a bit cooler than I'd like..regardless of outside temps, but with the reasoning why you did that in mind, I'm thinking it may solve the issue of my A/C not cold enough. If the oem setup was causing air to circumvent the radiator, it certainly would be the same effect on the condenser.
Quote from: KYBlueOval on 2020-04-07 05:45
Lynn, did you try these separately? Just curious as to which one provide the most "help". Could you post drawings with dimensions etc.?
John
Sorry it took a while to post these sketches of what I did. I made cardboard templates to make these parts and I had a 24" x 24" piece of 18 ga. steel.
Thanks Lynn !
John
Well, I have reported on this problem before so I thought I would offer the latest. As some of you may know I now have a A/C system that finally works very well. Almost as expected the A/C added to the heat load on the cooling system so my car began to overheat in stop and go traffic again. I spoke to Griffin Radiators and they convinced me that was my issue was all about the air flow through the radiator and they said that the Derale fan/shroud I was using was the problem. Their tests indicated that the best solution was the use of two Spal fans. They offered a VERY expensive dual 11" fan/shroud as a solution. Gary (gasman 826) helped me with direction and I decided to buy (2) 12" Spal fans and SHOE HORN them into my available space on a custom built shroud of my own design. The results were a dramatic improvement. My car will idle now with the A/C and hold below 185. On the interstate that temp will move up a little and when the engine is "heat soaked" it will creep up to 205 after exiting I-10. My engine doesn't like to run at that temp very well so I am adding an electric fuel pump with a recirculating pressure regulator in the belief that fuel temperature is the issue. That project involves installing a return fuel line and rerouting the supply line to keep it as cool as possible.... to be continued.
Nice job on the shroud. It's so nice when things eventually end up as hoped for.
Fuel pump.........are you adding an in-tank pump? If so let me/us know so I can provide some info on what NOT to do.
I am not doing an in tank pump yet. Just trying to get the carb to work thinking the fuel is too hot. I am thinking about a rotary vane pump and since the pump is low pressure I don't think overheating is an issue.
I find it interesting that you car runs hotter on the highway, than in town. I have had my 59 on the road for 5 weeks now, have put almost 700 miles on it so far. It has a fresh 428 Cobra Jet, with a mildish solid lifter cam, headers, Performer RPM intake, and stock iron CJ heads. I have an aluminum 2 row radiator from Auto City Classics, and a 18" Flexalite stainless steel flex fan, run by factory stock sized steel pullies. The rad is in the factory V8 location, so it has a fairly short (3/4"?) spacer between the fan and water pump. There is no shroud of any kind. I am running a 160 degree thermostat, and while on the freeway, or moving at 30 MPH, the Autometer mechanical gauge stays between 160 and 170. If I`m idling for several minutes on a warm day, the temp gauge does slowly start to rise, but never over 200, and once you start moving again, it drops back down quite quickly. On a 59, the grill is rather short, maybe 6" tall, and the hood drops down quite a bit more than a 57 or 58, so not a really large opening for the radiator, between the front bumper and hood. For yours to run warmer at highway speeds, would seem to me , point towards not enough airflow thru the radiator. I wonder if the electric fans and shroud, in addition to the A/C condenser may be restricting the amount of air able to flow through the radiator. Whenever I tried using just electric fans on an older vehicle, I always ended up going back to a belt driven fan. I know most modern cars use them, but modern EFI computer controlled engines tend to run quite a bit warmer than I would like for my old, carbed FEs.JMO. Since my car only warms up, and not badly, I am looking at trying a fan shroud for my engine driven fan, but to be honest, I don`t really think I have an issue. Maybe if I let it idle on a 95 degree day for an hour or so, it might overheat, but I really can`t imagine a situation where I would need to do that.
Maybe part of the issue is climate related? In the summer the heat index gets over 100 almost everyday here. Temps in the mid 90's, lows in the upper 70's. I had an 18" Flexalite fan but I felt it really needed a shroud to work. The highway speed overheating was happening then too. I attributed that to too many RPM with the 3.89 rear end in the car. I agree that modern cars run a lot hotter than our cars were meant too. Perhaps moving the radiator forward affected airflow but it was in the original position with the Flexalite fan. I moved it forward to accommodate the power steering and A/C additions and decided to use the 8v belts for that. I still have room to put the mechanical fan back on. As of now I feel the highway overheating is resolved but the car runs a little too hot to run right after a long road trip. I am not sure there is room for what I would like to have... a car that runs at the thermostat temp a 100 percent of the time. I love solving problems so..... I appreciate your thoughts on this. I saw a old rule of thumb somewhere, hotter at idle means airflow issue, hotter on the highway means radiator size.
Lynn, I had a similar problem when I installed air on my 60 truck, it heated more at hiway speed. When I talked to Vintage Air they told me to only have a max gap between condenser and radiator of 1/4", I had a bout 1". They said more then 1/4 " disturbs the air flow. After changing the gap I never had a problem again.. Just a thought
Appreciate the input. My condenser is about a 1/4"from the radiator.
Big FE engines can be tough to cool but sounds like you have got it under control.
Another trick I like to use is to install a smaller water pump pulley, this will speed up the water pump . This is especially helpful for keeping things cool around town.
For some reason most of the 50's Fords had larger water pump pulleys that ran the water pump slower than the crankshaft speed.
There is a 289 water pump pulley from a 65 / 66 Mustang that I have used with great results , in fact I have one on my 57 Country Sedan and my 62 406 Galaxie.
If somebody is interested I'll dig up the part number.
BEAUTIFUL FABRICATION!
Any chance of a frontal shot showing the chin spoiler on the car?
During this past summer, I had an overheating problem with the 312 in my recently acquired 57 Skyliner. It was OK in all circumstances except when I went over about 55 mph, cool or hot days. The car has an upgraded water pump and rad and fan.I tried installing the main deflector described here that goes up to and around a bit of the pan. It didn't make any difference but I was very impressed with the design , drawings and instructions. That piece fit perfectly like a glove. In the end the problem was caused by a bad thermostat. I removed the thermostat and I couldn't get the gauge to rise above the cold end of the dial. I installed a new 160 thermostat and the heat gauge went to center and stayed there. I put the old thermostat in boiling water and it didn't move. I am used to seeing them fail either open or closed but not like this.