Not to get into a ******* contest, but think about how many Fords of the era are there out there without shrouds, and they run cool. I know well how a t-stat works, in my case with the 352 and 390 Fords, it worked. Bob
Just because it works doesn't make it a good idea to repeat. How many baby-daddys relied the pull out method? Another thing, is the temp sender in the head or manifold? Heads heat up pretty quick, but you may not REALLY be running hot. Fan shrouds help, they never hurt.
I'm proud of you guys for not recommending a ****py electric fan. Everyone running one(or contemplating it) should read this thread.
I have been wondering about this myself. In my 56 chevy the air can only go through the radiator. it cant go around. I have a 235 and the fan sits 1/2" or so from the radiator. I wonder if a shroud would lower my temps any. It never had a shroud from the factory Thoughts???
The air can only go through the radiator? I think not. If the car is not moving and relying only on the fan, without a shroud, do you think that all the air the fan is moving is coming thru the radiator. No, it is pulling some from within the engine compartment, it could be a substantial amount. The closer the fan the better, but without a shroud it will still be pulling some from the side. Path of least resistance.
"Im working on an idea for my fan shroud for my A right now..funny though how you see some pretty big muscle cars from the 60's without any shroud..my 68 Chargers (3 ) of them, and not one of them had a factory shroud..all 3 440 powered and never had any issues with over heating." A second on that. My 69 Charger 383 with no shroud runs cool, and it lives in Tucson. My two 32s in the SF bay area needed shrouds. One has an electric fan that works just Ok. My other one just does the solid fan on the water pump, and that seems the best setup, and that's with a chopped radiator.
Not trying to be a smart *** here, so bear that in mind. If the fan is pulling on the back side of the radiator, how in the world can air go backwards against the fan??? how is it pulling from the engine compartment if the fan is pushing away??
A thermostat is needed to restrict the flow when the engine is started to get to operating temperature as soon as possible. Keeping the the water in the radiator longer is one of those old wives tails. The faster you move it through the radiator, the more heat you dissapate. If it stays longer in the radiator, that means it stays longer in the engine and by that way of thinking, the coolant would absorb more heat while in the engine.
Yup, that's pretty much right. Since the water needs to both absorb heat from the engine and shed heat from the radiator, it needs to stay in both for a regulated period of time. If it doesn't spend enough time in the engine, it's not going to pull heat out of the block. If it doesn't spend enough time in the radiator, it's not going to transfer the heat to the fins. How can running the water through the radiator FASTER dissipate more heat? That makes no sense. If a t-stat was ONLY for when the engine first warms up, then why does changing from a 160-degree to a 185-degree change the reading on the gauge while you're driving down the road? The t-stat opens and closes at set points, and regulates/maintains the temperature of the coolant at all times, not just right after start-up. It doesn't stay full-open all the time--it opens and closes incrementally to maintain the temperature it's built for. -Brad
Exactly right. I find it funny that '55-'57 Chevy p***enger cars didn't have shrouds, but Buicks for those years did. I've seen factory shrouds on junk yard cars going back to the late '30s and '40s. They're rare today, I think because a lot of guys changed water pumps and would forget to put the shroud on before getting everything bolted back together. I know that's what I did on my first car! -Brad
Fluid dynamics... The air will be pulled from the perimeter of the fan, which will draw air from inside the engine compartment. The path will be from a large area behind the fan, and it'll flow to the edges of the fan, grabbed and forced through the fan, exiting behind it. If you don't believe me, take a standard house box-fan... one of the cheap ones from K-mart or something. The tall, narrow ones that fit in your window. Push it tight against the wall and turn it on. It draws from behind, but with it tight up against the wall, where is the air coming from? It still throws a breeze out the front. It's pulling air in from the sides of the fan blade, which will come from the front opening. It'll be inefficient as hell, but it'll still move air along the path of least resistance. -Brad
I remember reading that SBF's can have overheating problems if the head gaskets are put on wrong (backwards). Have you had the heads off lately? Is this vehicle new to you and it came with the problem or is this something that just started happening? Did it ever run cool for you? If it used to run cool but doesn't now then something has changed (rad getting plugged, thermostat sticking, block full of sludge etc). A shroud will definitely help (if built correctly) but IF you car used to run cool before then you need to find out why it doesn't now.
Henry and his engineers didn't seem to think that one was necessary when they built it. That tells me that you have something wrong or you have changed something to cause the problem. Where do you have the vacuum advance hooked up? For it to idle cool it should be hooked up to manifold vacuum. There is a lot of misinformation out there. There is nothing wrong with building a shroud but I'd want to know why I suddenly needed one after working fine for 40 years.
The cars that didn't come with shrouds had good seals around the radiator (on the top of the front bulkhead to under the hood, the sides of the radiator and most likely a pan under the bottom) If the fan was turning when the car is stopped the path of least resistance for air was through the radiator and it worked. Lots of those seals get discarded as the car get olded because they are in the way for working on it. I love the comment about a shroud directs the air on to the engine!! That's the best.
Exactly! How dare we second guess Henry Ford? I've either been the luckiest S.O.B. in the world or been blessed with cars that only overheated for a reason that I found quickly. I simply will not put up with a car that runs hot. I don't piss around with old radiators, I buy a new one if its available. For water pumps, they get pitched at the first sign of trouble and I buy new ones. Bob
Are you running an automatic ******, that utilizes the radiator to cool the trans fluid? If so, perhaps the problem can be helped by going with a separate trans cooler. Just a thought.
considering how many people here flip out over their older engines, with flat tappet cams running zinc free oil, it's hard to imagine how many want to speed the process of flat cam death. 160 thermostats aren't a cooling solution- if it's gonna get hot, fix the system, dont start it sooner. if it does run that cool-great, you're now producing oval cylinder walls, decreasing ring seal, building up more blowby to add to the varnishes and acids in the crankcase. That plus all the moisture in there (how's it gonna boil off if you're 160 thermostat actually keeps it to 160?) will kill your bearings and ruin the oil sooner. if there's dew on the yard, there's dew in the mill- blowby adds more moisture. i like the bores round, the bearings smooth, and the cam bumpy. just get a properly sized radiator, fan, and shroud in whatever ride you happen to have... (yes some cars had no shrouds from the factory, but you know they had the bay and components sized right...) rick
I drum type thing around the fan is not a shroud in any sense of the imagination. The only thing it does is keep fingers away from the fan blades. Does nothing for air flow.
I ***ume that you have throughly flushed the block and had the radiator professionally cleaned. Make sure the fan is close to the radiator, within one inch
My 2 cents worth Background: Late 1970s some of the first reproduction parts we made was 4 different radiator shrouds for the GTO. Original AC GTOs al had shrouds....other than that seemed to be an option or dealer installed. All good advice on this thread bottom line is, a shroud will help but if you have another issue you need to correct it also. If you use a clutch fan be sure it is working properly... rev motor up, shut it off fan should only do a few more cycles and then stop, if it free wheels the clutch unit is bad.... The shroud opening needs to be positioned so your fan blade is half in and half out... obviousily go with the biggest lade you can in the diameter shroud you go with. The GTO shrouds we made for over 15 years was a huge seller for us...because most owners that restored GTO developed more heat more power and heat is not something owners wanted..... Today they make the GTO shrouds in the correct metal we did them in fibergl***. Air current is a funny thing look at some of the cars and trucks some have a small deflector under the front end to draw air to the radiator... Cars like I am very familar with turbo buicks have shields off to the sides so incoming air focuses on the radiator..... denniskirban@yahoo.com
Actually, the guys at Griffin just told me that, surprisingly, the drum-style shrouds on '58-'64 Chevy cars and pick-up trucks are very efficient, as they pull a ton of air through the center of the radiator core. They were surprised, but had data to back it up. As for cars not coming with a shroud from the factory, like Tri-5 Chevys, I wouldn't be surprised if a lot of that came down to bean-counters pinching pennies and not putting a shroud on low-end cars to keep prices down and profits up. Finally, to the question of "why is it suddenly doing it now but hasn't in 40 years?" I was shocked when I pulled the 283 out of my '62 Suburban... I pulled the plugs out of the water jackets, and it was so built up with sludge that the water wouldn't drain--I had to keep poking into it with an ice pick to move the sediment out of the way. The block was .060-over, which means it'd been hot-tanked at least twice in its life. When they were new, they didn't have four pounds of mud and **** in the water p***ages. -Brad
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