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Sikryd, something went wrong when you made your changes from iron heads to aluminum heads. There is no reason that should have happened. Likewise nad427's electric fans, something was wrong and is wasn't because he chose electric fans.

Unfortunately, you described everything as I would do it - I have no suggestions other than this one - check your timing to be sure that it's what you think it is.
I will recheck the timing this weekend, it's still deathly hot here in Vegas but should be cooling down a bit soon.
 

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I have an off-the wall suggestion for your cooling system. Have you considered pulling the electric fans, installing a 5 or 6 blade mechanical fan on, and one of the aftermarket shrouds, and see if that doesn't solve your problem? I prefer electric fans, but with the smaller surface area of the tri-five radiator I'm wondering if you wouldn't pull a lot more cfm with a properly shrouded HD mechanical fan.

Also, for general engine bay temperatures, if you don't want to lose your headers you could always consider ceramic coating them, maybe even wrapping them.
 
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I have an off-the wall suggestion for your cooling system. Have you considered pulling the electric fans, installing a 5 or 6 blade mechanical fan on, and one of the aftermarket shrouds, and see if that doesn't solve your problem? I prefer electric fans, but with the smaller surface area of the tri-five radiator I'm wondering if you wouldn't pull a lot more cfm with a properly shrouded HD mechanical fan.

Also, for general engine bay temperatures, if you don't want to lose your headers you could always consider ceramic coating them, maybe even wrapping them.
My brother has been trying to get me to put a mechanical fan on it, but I can sit there and idle for a long time and temps seem to be fine which tells me it's not an airflow issue. I think it's either a capacity issue or more likely an issue with heat in the engine compartment that cant escape. My headers are not ceramic coated, but they are painted with that Eastwood header paint. At idle the tubes just outside of the head are around 315 degrees. I could pull them and get them coated, but I am afraid that when they get blasted in prep to get coated, they will fall apart, lol. I looked into having headers made once and $2,500 for mild steel or $4,000 stainless made me say all kinds of nope. The problem with my car is that it's a manual trans, it's a big block, and the motor is not pushed forward. I have not found a pair of off-the-shelf headers that say it will fit, and I am not willing to spend $1,000 to find out that they don't, scratch them, and not be able to return them. Most off-the-shelf headers for a '56 with a big block are for an auto trans, the Z bar gets in the way. These current ones are a royal pain in the ass to get in and out of the car let alone get them bolted in. Put it this way, it's such a pain, when I needed to change my starter, I chose to drop my oil pan in the car to get the clearance instead of dropping the passenger side header. lol, yeah, it's that bad, and the passenger side is the easy side. I'm going to call around to see what it will cost here in Vegas to get them ceramic coated. Header wrap kills headers in my experience, I've seen way too many fall apart a few years after being wrapped. I just don't have the money for that these days.
Maybe once my extortion payments stop to my ex-wife 4 years from now, I can look into new headers. Remember kids, marriage is the leading cause of divorce. You want to know what marriage and then divorce is like, go take half your stuff and throw it out into the street, this includes your bank account and retirement account. If anyone has a time machine, please go back to March 31st, 2012, and punch me in the face to bring me to my senses. My past and future self thank you in advance.
 

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It's been 50+ years ago since I had a BB tri five but back then headers were common for a BB in the stock position with mechanical clutch linkage pretty sure mine were Headman back then I remember swapping to a set of Doug headers then having to modify the clutch linkage. That I'll never forget the reason the day I bought the Doug's I was supposed to have bought my wife a engagement ring.We have now been married 51 years but it was touch & go for a few weeks & she tells that story on me to this day. Sorry that has nothing to do with your heating problem
 

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My brother has been trying to get me to put a mechanical fan on it, but I can sit there and idle for a long time and temps seem to be fine which tells me it's not an airflow issue. I think it's either a capacity issue or more likely an issue with heat in the engine compartment that cant escape. My headers are not ceramic coated, but they are painted with that Eastwood header paint. At idle the tubes just outside of the head are around 315 degrees. I could pull them and get them coated, but I am afraid that when they get blasted in prep to get coated, they will fall apart, lol. I looked into having headers made once and $2,500 for mild steel or $4,000 stainless made me say all kinds of nope. The problem with my car is that it's a manual trans, it's a big block, and the motor is not pushed forward. I have not found a pair of off-the-shelf headers that say it will fit, and I am not willing to spend $1,000 to find out that they don't, scratch them, and not be able to return them. Most off-the-shelf headers for a '56 with a big block are for an auto trans, the Z bar gets in the way. These current ones are a royal pain in the ass to get in and out of the car let alone get them bolted in. Put it this way, it's such a pain, when I needed to change my starter, I chose to drop my oil pan in the car to get the clearance instead of dropping the passenger side header. lol, yeah, it's that bad, and the passenger side is the easy side. I'm going to call around to see what it will cost here in Vegas to get them ceramic coated. Header wrap kills headers in my experience, I've seen way too many fall apart a few years after being wrapped. I just don't have the money for that these days.
Maybe once my extortion payments stop to my ex-wife 4 years from now, I can look into new headers. Remember kids, marriage is the leading cause of divorce. You want to know what marriage and then divorce is like, go take half your stuff and throw it out into the street, this includes your bank account and retirement account. If anyone has a time machine, please go back to March 31st, 2012, and punch me in the face to bring me to my senses. My past and future self thank you in advance.

Earl Williams is THE header for your car. 2 1/4" primary 3 1/2" collector designed for manuals and or Autos.

Automotive lighting Motor vehicle Crankset Hood Auto part


Least amount of claarance issues
Tire Wheel Car Motor vehicle Vehicle


Car Automotive lighting Vehicle Automotive tire Motor vehicle


These were Jet Hot coated by Earl and he tig welded the V Band clamps on as that is the only connection I will uses on exhaust systems.
 

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Earl Williams is THE header for your car. 2 1/4" primary 3 1/2" collector designed for manuals and or Autos.

View attachment 346977

Least amount of claarance issues View attachment 346978

View attachment 346979

These were Jet Hot coated by Earl and he tig welded the V Band clamps on as that is the only connection I will uses on exhaust systems.
I just spoke to Earl, his headers require the 3/4" forward mount of the engine, so they will not work in my application. I am pretty sure my motor is in the stock position because my firewall is definitely cut. Back to the drawing board..

 

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Back to the OP, you mentioned having A/C. Your fan should always be running when the a/c in on, no matter what the engine temp is.
 

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I just spoke to Earl, his headers require the 3/4" forward mount of the engine, so they will not work in my application. I am pretty sure my motor is in the stock position because my firewall is definitely cut. Back to the drawing board..

Mine is in the stock location. Firewall mods done with the Earl Williams panels
 

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If this were my issue: Key on = fan on = done deal.
Luck
If you're doing that though, you might as well just run a mechanical. The whole point of electric is to easily have the fan on only when you need it.
 

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If you're doing that though, you might as well just run a mechanical. The whole point of electric is to easily have the fan on only when you need it.
^^^^^^^^^^^^^
Think about it --- your mechanical fan runs all the time even when you don't need it. They rob HP, they are noisy & dangerous I have had a factory mechanical fan loose a blade @ +7K rpm the blade went through the hood = new hood + paint.

For some inexplicable reason darn near everyone here is adverse to running an electric fan or think it should only run when absolutely necessary its like y'all have to shell out greenbacks every time the E-fan comes on. Your DD's with E-fans run the fan(s) all the time with AC use it does not cost anything to run an E-fan.
 

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^^^^^^^^^^^^^
Think about it --- your mechanical fan runs all the time even when you don't need it. They rob HP, they are noisy & dangerous I have had a factory mechanical fan loose a blade @ +7K rpm the blade went through the hood = new hood + paint.
I did think about it.

A decent mechanical fan setup (read: not what the factories did 60+ years ago) has a fan clutch on it. Also, yeah you shouldn't spin 60 year old junk mechanical fans to 7000rpm.

For some inexplicable reason darn near everyone here is adverse to running an electric fan
I prefer electric in most applications, but you can't deny even a mild mechanical fan setup outflows most electric fans. All but the most high end electric fans can't touch the flow of a mechanical. Now, look at the radiator in a tri-five compared to a modern car. Modern stuff has 2-3x the surface area ie. lots of room for great big electric fans. The narrow width of the stock tri-five radiator means if you're going to go electric, you've got to get a good one, it's going to spin fast, draw lots of current, and be loud. Also, the vintage look is why some people prefer mechanical fans on cars like these.

Anyways, my point wasn't that mechanical is better, it was that if you're going to wire it like you suggest, you're losing out on one of the main benefits of an e-fan, the ability to control it. Zero manufacturers do it this way because it makes absolutely zero sense.

or think it should only run when absolutely necessary its like y'all have to shell out greenbacks every time the E-fan comes on. Your DD's with E-fans run the fan(s) all the time with AC use it does not cost anything to run an E-fan.
Temperature switches work fine if you select the proper location and the proper temperature given the location. There is no reason not to use a temperature switch. OEMs will often turn one fan on with the AC, and some of the latest stuff has variable speed fans. A decent e-fan has a high current draw, and running it at full speed when the engine is cold doesn't make sense. And of course it costs power to run an e-fan, electricity isn't magically beamed to it. If we set up an actual experiment, the same fan blade, diameter, pitch etc. running the same rpm would take the same power to run whether you do it mechanically or electrically. The electric would actually use a touch more because of the conversion losses going from mechanical to electric to mechanical again. That's why OEMs have fans turn on and off as needed. And you're telling me to think about it...
 
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I did think about it.

A decent mechanical fan setup (read: not what the factories did 60+ years ago) has a fan clutch on it. Also, yeah you shouldn't spin 60 year old junk mechanical fans to 7000rpm.



I prefer electric in most applications, but you can't deny even a mild mechanical fan setup outflows most electric fans. All but the most high end electric fans can't touch the flow of a mechanical. Now, look at the radiator in a tri-five compared to a modern car. Modern stuff has 2-3x the surface area ie. lots of room for great big electric fans. The narrow width of the stock tri-five radiator means if you're going to go electric, you've got to get a good one, it's going to spin fast, draw lots of current, and be loud. Also, the vintage look is why some people prefer mechanical fans on cars like these.

Anyways, my point wasn't that mechanical is better, it was that if you're going to wire it like you suggest, you're losing out on one of the main benefits of an e-fan, the ability to control it. Zero manufacturers do it this way because it makes absolutely zero sense.



Temperature switches work fine if you select the proper location and the proper temperature given the location. There is no reason not to use a temperature switch. OEMs will often turn one fan on with the AC, and some of the latest stuff has variable speed fans. A decent e-fan has a high current draw, and running it at full speed when the engine is cold doesn't make sense. And of course it costs power to run an e-fan, electricity isn't magically beamed to it. If we set up an actual experiment, the same fan blade, diameter, pitch etc. running the same rpm would take the same power to run whether you do it mechanically or electrically. The electric would actually use a touch more because of the conversion losses going from mechanical to electric to mechanical again. That's why OEMs have fans turn on and off as needed. And you're telling me to think about it...
With all due respect. Mechanical do not out flow electric at the engine speeds that airflow matters most. In Fact mechanicals normally turn at near engine speeds. So at low speed low RPM maximum air flow is required. Not gonna happen with a mechanical fan turning 1500 RPM
 

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With all due respect. Mechanical do not out flow electric at the engine speeds that airflow matters most. In Fact mechanicals normally turn at near engine speeds. So at low speed low RPM maximum air flow is required. Not gonna happen with a mechanical fan turning 1500 RPM
I'd absolutely agree with that. Of course the mechanical is going to work on a curve and the electric you can have running at full speed with the engine at idle if you want. A great advantage of electric fans for sure. Mechanicals tend to outflow all but the most ludicrously expensive electric fans at highway speed, but you're right, going back to the very original problem I believe the concern was lower speed airflow, not highway. I was just balking at the idea of having the electric fan on 100% of the time, it sounds like a real band-aid.
 

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That's why I'm going back to a flex fan. Rated to 10,000 rpm.

On the fan that threw a blade at 7,000 rpm, was that the engine rpm or the fan? Either way, I don't think GM intended for the fan or the motor to go 7,000 rpm.

Also the flex fan I used and have a new one sitting here blows a hell of a lot of air at idle, possibly more than the 18" Derale electric that is in it now. And it makes a LOT LESS noise doing it! I suppose I tried the electric for more HP, but I'm not looking at hundredths of a second anymore.
 

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Nothing in this life is free, and everything has a cost. Electric fans take power to turn, just like mechanical. This is provided by the engine itself on both accounts. It’s just which is more desirable?

One thing to note is that the electric fan assembly blocks airflow through the radiator at some speeds. A mechanical doesn’t. Yeah a mechanical doesn’t need to spin much at highway speed, but that’s at least partially why a clutch was employed.

Then there’s the noise. Electric fans spinning wild at idle are obnoxious to those that like engine songs. Some mechanical fans are obnoxious at higher engine speeds too though. Watching and listening to a cool hotrod pulling into a show with electric fans howling isn’t the most pleasurable, most any time. Plus, in case of power failure like a fried alternator you know for sure the mechanical fan car is going to make it far further to get help than an electric.

I don’t hold it against those that like electric, but me and others like me can’t tolerate them, and some engines with certain cooling systems can’t either. It’s all a matter of personal and reasonable choice, plus what’s best for the treasured engine.
 

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Nothing in this life is free, and everything has a cost. Electric fans take power to turn, just like mechanical. This is provided by the engine itself on both accounts. It’s just which is more desirable?
The added power needs of an electric fan placed on an alternator can not exceed the power consumed by a manual engine fan. If HP is your goal, a mechanical fan would not be the choice. Of course, if the mechanical fan did indeed cool the engine and the electric did not, then this point is null. This Engine Masters episode shows mechanical fans take up to 30HP.

One thing to note is that the electric fan assembly blocks airflow through the radiator at some speeds. A mechanical doesn’t. Yeah a mechanical doesn’t need to spin much at highway speed, but that’s at least partially why a clutch was employed.
A good electric fan should have a shroud that has rubber flaps that open at higher speeds to let air through so it does not stack up and become a restriction.

Then there’s the noise. Electric fans spinning wild at idle are obnoxious to those that like engine songs. Some mechanical fans are obnoxious at higher engine speeds too though. Watching and listening to a cool hotrod pulling into a show with electric fans howling isn’t the most pleasurable, most any time. Plus, in case of power failure like a fried alternator you know for sure the mechanical fan car is going to make it far further to get help than an electric.
I can't hear my fans over my exhaust, but then my car has a big block through long tubes, Super 40 mufflers through 3" pipes that dump out the side of the car through 4" tips.

I don’t hold it against those that like electric, but me and others like me can’t tolerate them, and some engines with certain cooling systems can’t either. It’s all a matter of personal and reasonable choice, plus what’s best for the treasured engine.
My car cooled just fine with cast iron heads, a copper/brass radiator, a Moroso water pump, and twin 11" SPAL fans in Hawaii. I could drive my car all day, never got above 185 degrees. I move here to Las Vegas and it runs hot, 220+ after say 20 minutes of driving. I get farther on the surface streets than I do on the freeway because of the gearing in my rear end. I avoid the freeway like it's the plague. If I do jump on the freeway, my temps rise fast, as soon as I jump off, they will drop a good amount. I changed to Edelbrock aluminum heads, a Dewitt aluminum radiator, FlowKooler water pump, same 11" SPAL fans. The radiator and the water pump made 0 difference in the temps, it's still hot.

I'm not saying you are not wrong, I'm just saying that my car cooled fine with the same setup except for the difference in heads and geographic location and now it does not. I don't have a head gasket issue, I do not believe I have any air pockets in the cooling system. I do believe that the aluminum heads are putting more heat into the engine compartment that is not being extracted, and my engine is also consuming this excess heat via the open air cleaner in the engine compartment. I have let the car idle for a long time with the hood open, no issues with overheating, but then this is obvious, no hood always cures overheating problems unless you have issues like a head gasket problem, a collapsed hose, a clogged radiator, or a non-functioning fan. Obvious things.

Since you do not like electric fans, you are going to hate this. I have 2 - 7" electric fans that I will be mounting to push fresh air into my engine compartment to see if it helps to push any hot air out. I'm not positive this will work, but they are laying around and available, and does not cost me anything but time to test this out. I have a pair of old radiator side panels that I will mount them to, this may work against me by stealing available air from the radiator and/or creating excess pressure in the engine compartment that may work against the radiator electric fans. Only one way to find out.

What I hate the most is throwing money at a problem and not knowing for sure it will cure the issue. I don't want to buy a mechanical fan and shroud not knowing that it will fix my issue, the same thing goes with a cross-flow radiator.
 

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No way that the added power needs of an electric fan placed on an alternator exceed the power consumed by a manual engine fan. This Engine Masters episode shows mechanical fans take up to 30HP.
You're kind of right, but kind of wrong at the same time. Mechanical and electric fans can't be compared like that as the airflow is so drastically different. On tests like that, notice the power the fan uses goes up with the rpm, just like you'd expect. The fans they test on the dyno at 5000-6000+ rpm are using an obscene amount of power (20-30+hp), way more than any electric out there. They're also flowing many times more air than any automotive electric fan on the planet. An electric motor that could drive those fans at that speed would be huge and use hundreds of amps @ 12v.

What people like myself and nad are saying when we say there is no free lunch, that your fan costs energy either way is this. If you think about a certain fan with a certain design, number of blades, pitch etc. it's going to take the exact same energy to turn a given rpm whether it's being driven by your engine, electricity, steam, or hamsters. There is no way the exact same fan at the exact same speed will use less energy being driven electrically than mechanically, that's just not how physics works. "But the dyno!" you say. Yes, the mechanical fans are WAY more aggressive than the electrics, more aggressive pitch, and in the case of your dyno test, way more RPM than your electric fans which are limited by the amperage they can draw. It's really an apples vs. potatoes test.

Look at your dual 11" Spals, a real nice setup, top end fans, great choice. 30 amps each, so 60a total, rough maths 2.4hp draw on your alternator, not bad! (~25w/hp) but they flow only 2720cfm for the pair, on high (not published but probably ~4000rpm). A good shrouded mechanical fan setup can often be 4000-5000cfm @ 2500rpm. I don't even know the kind of CFM a mechanical would be pulling at the dyno speeds in your video, but off the charts compared to electric. See why the mechanical uses a lot more power? Flow costs power.

So why does everyone switch to electrics? The first driving force was FWD cars, but aside from that, you can control them! They don't need to run when you don't need more airflow, which saves fuel. Referring back to your dyno video, drag racers love electric fans, since it's not drawing that 30+hp at 7000rpm! The electrics can run for longer to make up for less cfm, not a problem. Electric fans are also better than mechanical in the regard that you can have full airflow at idle speed if needed, which you cannot do with a mechanical. Neither drag racers nor daily drivers produce ridiculous amounts of waste heat over long periods of time, so electrics are great. Sure, they flow less, but run them for longer to shed the BTUs, perfect solution.

If electrics are so great, why do modern heavy duty pickups still use mechanical fans? Because they flow a TON more air than any bank of high dollar electrics you could stuff behind your rad, they're cheap, and stupidly reliable. They have the airflow for heavy towing on hot days, situations with prolonged shedding of a lot of BTUs to the cooling system where electrics just couldn't keep up. Also, the truck engines don't tend to get spun to the speeds in your dyno video, and owners aren't concerned about eking out every last hp and mpg.

Hope this makes some sense.
 
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