36 FORD SBC MECHANICAL FAN WITH STOCK FIREWALL. Setup as in lengthy discussion on other post. Car originally a/c with condenser in front of new Walker Radiator with 15" steel 4 blade fan and shroud. Radiator was shoved forward for fan clearance ruining grill and hood alignment. Removed a/c , installed stock grille and hood in proper position but had to use a Marflex 15 nylon low clearance fan. Fan blades still extend into shroud opening. Engine now heats in slow traffic even with condenser removed from front of radiator and 5 blade fan. Will run 190-200 at speed but heats in slow traffic to 220+ . Checked for vacuum leaks, checked hoses for restriction. Overcammed ? Will a steel 5 blade help ? Don't have 2" to go 17" fan. Don't mind pulling sheet metal again if I could figure out what to correct. Whats the risk of pulling out thermostat ? Cloth over grille shows suction but not enough to hold it there. Any help appreciated, I will try anything that will get this Phx. drivable again. Large Electric Puller ? Pusher ?
Use a high quality steel fan,they are available in different sizes,gut after many problems with cars overheating I have come to the conclusion the aluminum or nylon fans just don't work. HRP I tried one of these and my car that was running hot actually heated up quicker with this fan.
You mentioned so many guesses, but many on fan type. What I always do for air flow, is just hold your hand at back of fan/radiator safely, as many places as safe Next is temp gun, that helps gets your bearings, knowing temps going up into top tank, and coming out at bottom. Intake front scan at front water channel and T-stat area, ....also different spots on core, but you say it's new...but it could show corners way too hot that are not catching the fan flow if fan is way too close to core I doubt closed hood is causing low air flow, but does it still heat up while testing things with them up.?
I would have thought cloth should have stayed on the grill, will newspaper stay there? If newspaper won't stay there at light rpm then you certainly have a problem. Is it possible the fan is on backwards?
With me, anything is possible, these mardayne nylon fans are basically flat on front and all blade curve to the back, so much so water pump housing clearance can be an issue. I hope thats correct.
^^^ this is important piece and you need one more piece to solve the question. >>>Did it run hot before all of the things were changed in this list above? If it only ran hot after the mods, the fan is the most likely thing, rather than the baffle etc
Most fans are clearly labeled engine side like the top fan in the post above by HRP. The second one should have a sticker but I can't see it. If yours is on backwards like this above your problem should be solved when you put it on as a puller fan instead of a pusher forward .Good luck.
add a pusher fan to the front of the radiator. get a quality fan, like a spal. please know that in electric fans, amps is work. a good 16-18 inch fan should draw 12+amps when running. if you get one and it only draws 5-7 amps its not moving any air. cfm ratings are fudged to make the fan look better then it is. running amps is the only true numbers that matter. also you should be able to get a 160 degree t-stat for the sbc. DO NOT run with out a t-stat, it is needed to slow the water down to stay in the radiator long enough to give up it's heat. uummm, just a thought, try running without the shroud. some times they are not deep enough to allow air to get pulled through the radiator or can cause a "dead head" of air at the engine block because they force all the air to bottle up at the engine and it can't get out of the way fast enough to allow more air in. good luck with this.( by the way, i'm running a 16 in. pusher in the car that's pictured in my avatar. it pulls 15 amps when running. and the car runs at 185 in 90 degree heat with 90% humidity at idle.) best of luck.
Bottom line is, a SBC in a 36 Ford should not run hot or need any band aids like extra front mounted electric fans. If the block is clean and the radiator is clean, the pump is o.k. and there are no obstructions to flow, all should be good with what you have. But something must not be right. Please post pictures so we can really see what you have and the relationship of all the pieces. This too: I've seen shrouds which are more of a hindrance than help.
Perhaps a pic of the set up would be good to see. You said that the fan still extends into the shroud area. It has always been said that the fan should extend only into the shroud 50% to avoid a vortex which will prohibit the transfer of the air. Can you clarify this?
I also have a 36 Cabriolet Same set up S/B Chevy 350 LT1 350 hp A/C also I was worried with cooling problems I put in a Walker radiator Z line with A/c Condenser in front ( sounds like you have the same ) I had very limited room for fan What I did was ordered a Sidewinder fan from the fan man in California It has been in for 9 years now no problems with cooling Sat in traffic at the Back to the 50's for over a 1/2 hour getting in the last 2 years & no problems with over heating Cooling componets is also making a fan shroud combination for a 36 that tapers towards the bottom for clearance to fit If you want picture's or anything PM me & I will send them to you Ron
^^ When we ask guys who ran a sbc in a 35/36 back in 1965, and they had no problems...they were forced to re-use the original radiator prior to modern repro. Repro radiators today are thicker, 32 thru 36 hotrods built back then with original radiator and sbc fan had just enough room, but in later years the old radiator just could not be repaired anymore, and the repro radiator may cool better, but the old very efficient GM fan won't fit. So, I would look into the fan that was suggested by nor6304 .
Not to sound ignorant,but what is the problem with 220 degrees in traffic? If it doesn't boil over and cools down when you are moving-I wouldn't worry about it.
my `36 with a SBC and Walker Z-line radiator barely gets over 180 degrees even on a hot day. i have a 15" mechanical fan on the front of the motor with no shroud. stock firewall and that inner lower grille/baffle installed. something is wrong with your setup...pictures?
Are you sure your temperature gauge is accurate ? I have the original radiator in my '36 with a flat-front nylon fan and no shroud with a SBC and have no problems with temperature being too high, even on the hottest days.
That looks like a big ass water pump pulley? You could have 2 or 3 small problems instead of one big one.......................... Could someone post a pic of a Walker Z for a '36, wanna see the top tank over hang.........................
With new Z radiator walker added to back, not front of radiator. Now have 3/4 inch between flat nylon fan and radiator with less at water pump shaft. Only that nylon will fit, no others, tried them all. Will have to resort to pusher if this doesn't work. Any recommendations on pusher electric of high quality ? No room for puller. thanks
Am running two small pushers on my 37 with an 8ba. Tight fit inside those small grilles. Has worked great for 13 years.
Thanks kind of what I am thinking. not wide but plenty of room for stacking two small ones. Are you still running the fan with the pushers ? thank you
No just the pushers. No room for a puller fan. If you feel you need a pusher plus a puller you need to review other issues not related to the fan.
I would check to see if the distributor is setup correctly. Too much total advance will make the engine work harder & overheat.
One manufacturer said you must remove the mechanical fan before using a pusher(s) otherwise it will defeat the electric fan flow.
I can only think that having a mechanical fan will help the air flow through the radiator by creating a low pressure area behind the radiator and help pull the air flow from the electric fans.
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