cooling

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mopar373

mopar373

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I have no only a restrictor plate in my t-stat housing (small block). Would it tend to run cooler with the bypass plugged off? Thanks AL:prayer:
 
I have blocked or removed them before and never seen one bit of difference in running temps.
 
I've always wondered why there is such a humongous bypass on SB's (must be an engineering good reason). I think a person could restrict that "some" but not all the way unless a person is running no stat like in circle tracks so that that amt is cooled but a functioning system cools OK with it operational so lets find the problem. Did you say you are or are not running a restrictor? I'm with cooling guru Sanborn who says emphatically NO restrictors. People have said that the coolant can flow thru too fast to be cooled, well consider this: if one block of coolant moves thru the rad faster (& gets cooled less) then the next block arrives faster (& starts getting cooled sooner!) so it balances out. Al are you having an overheating issue? high speed or around town? shroud or no shroud? fan distance from rad or into schroud? recent issue? any recent tuning or part changes? happened all of a sudden?
 
It should cool properly with the bypass and a 180 thermostat. If it doesn't, you have other problems. My car can stay under 205 even when it's 98 degrees out with a 26" 3-row aluminum radiator and the contour fans even in the Woodward dream cruise which is the world's coolest insane traffic jam.
 
Rapid Robert said:
I've always wondered why there is such a humongous bypass on SB's (must be an engineering good reason). I think a person could restrict that "some" but not all the way unless a person is running no stat like in circle tracks so that that amt is cooled but a functioning system cools OK with it operational so lets find the problem. Did you say you are or are not running a restrictor? I'm with cooling guru Sanborn who says emphatically NO restrictors. People have said that the coolant can flow thru too fast to be cooled, well consider this: if one block of coolant moves thru the rad faster (& gets cooled less) then the next block arrives faster (& starts getting cooled sooner!) so it balances out. Al are you having an overheating issue? high speed or around town? shroud or no shroud? fan distance from rad or into schroud? recent issue? any recent tuning or part changes? happened all of a sudden?
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I have to disagree on two points.

1. I have blocked the bypass completely and it made zero difference in running temps, idling or under a load.

2. It's not just that unrestricted coolant gets cooled less, but that it carries less heat away from the motor because of not staying in there longer. (they work together)
Some engines will run cold all the time without restriction, and others will gradually get hotter and hotter.
 
Keep in mind that a restriction in the flow is a designed-for factor. The restriction in the t'stat area makes sure that the the pump outlet pressure builds up the pressure in the block and head to a level greater than the overall system pressure. I.e, the operating pressure in the block and heads is higher than that in the radiator by many pounds. This helps to reduce localized boiling in the heads in particular.

When people see higher temps in the engine when they remove the t'stat, this is really what is happening: they are lowering the pressure in the block and heads and that lets more localized boiling, more gases in the coolant in the head, and thus less heat transfer. The idea that the faster coolant flow is the cause is a natural, but likely erroneous, conclusion. I've researched this a few times, and have yet to find that the flow is so fast at to effect heat transfer; but I'll keep looking.....Edit to add: But all I have ever found is that the heat transfer is weakly effected by flow velocities, and actually, high flow velocities are slightly better, as the coolant is spending less time by the hot spots in the head, and so has less chance for localized boiling.
 
I am running a restrictor and a three row Champion radiator, twin cooling fans, electric t-stat, cooling fan on trans cooler, hi volume water pump, rear intake cooling lines to t-stat housing, and it still wants to head towards 200* at a traffic light. 340 bored .040 over with a 360 trunk crank. Edelbrock heads 11.7 C.R. Easy EFI app 500 HP. For your argument about the restrictor, it was worse with out it, so it does help!
 
It seems that the bypass puts some of the already cooled water back through the t-stat housing instead of back through the motor ??????????????
 
mopar373 said:
I am running a restrictor and a three row Champion radiator, twin cooling fans, electric t-stat, cooling fan on trans cooler, hi volume water pump, rear intake cooling lines to t-stat housing, and it still wants to head towards 200* at a traffic light. 340 bored .040 over with a 360 trunk crank. Edelbrock heads 11.7 C.R. Easy EFI app 500 HP. For your argument about the restrictor, it was worse with out it, so it does help!
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Your overheat problem would likely be cured by reverting back to clutch fan.. Many are,, there are several threads related,, do a search for "overheat" under the " heating/cooling" forum,, there are numerous posts...

mopar373 said:
It seems that the bypass puts some of the already cooled water back through the t-stat housing instead of back through the motor ??????????????
Click to expand...

The by-pass hose goes to the suction side of the pump, as does the heater hose..
The function of the b/pass hose is to keep water circulating in the block while the t/stat is closed, preventing potential localized hotspots,, this also helps warm and circulate water to the heater sooner, before the t/stat opens, and all the cold stagnant coolant (rad) is warmed..

hope it helps
 
200*F at the top of the rad, is NOT too hot. 220* would be a little dicey, unless it never ran over that.
My math puts your displacement at 374 cubes, and with 11.5Scr, and with aluminum heads. I hope your TB is getting fresh cold air.
And you have a high-flo pump, and a stat restrictor,and a nice new rad.
----------------------
Well my combo is a little tamer than yours, for sure. Probably 430ish hp.
I have the pump and heads, and 10.7 Scr. I also have a 42 year old pos rad, and a 7 blade all steel fan, mounted on a FORD thermostatic clutch, a 205 Stat,a 7 pound cap,a shroud, and fresh cold air.
My combo cares not a bit what the outside temperature is, or what the engine is doing, or how hard I'm pushing it. The temp gauge behaves exactly correctly, and once warmed up, it never moves.
Besides 70 WOT horsepower, and a hair more cr, what's different? A part-answer is in post #10.
On a lighter note; maybe your pistons or rings are too tight.....
Sometimes you have to lose to win, back-up to go forward, say nothing to speak volumes....
 
inertia said:
Your overheat problem would likely be cured by reverting back to clutch fan.. Many are,, there are several threads related,, do a search for "overheat" under the " heating/cooling" forum,, there are numerous posts...



The by-pass hose goes to the suction side of the pump, as does the heater hose..
The function of the b/pass hose is to keep water circulating in the block while the t/stat is closed, preventing potential localized hotspots,, this also helps warm and circulate water to the heater sooner, before the t/stat opens, and all the cold stagnant coolant (rad) is warmed..

hope it helps
Click to expand...

200 is not overheat by any means. There will be absolutely zero issue with running the engine at this temp. My car cools much better with the contour fans then it did with any clutch fan. You need to look at the setpoint for when they turn on if you want it to run cooler.

My opinion is that you want the engine to run between 180 and 190, which the 180 thermostat helps with. You'll get complete combustion and not be wearing the bores out with unburnt/unatomized fuel. If the engine pings, you have too low octane gas for your compression.

In a newer car, they pretty much all run at at least 200 all the time...and allow up to 230 in some cases when sitting in traffic.
 
goldduster318 said:
200 is not overheat by any means. There will be absolutely zero issue with running the engine at this temp. My car cools much better with the contour fans then it did with any clutch fan. You need to look at the setpoint for when they turn on if you want it to run cooler.

My opinion is that you want the engine to run between 180 and 190, which the 180 thermostat helps with. You'll get complete combustion and not be wearing the bores out with unburnt/unatomized fuel. If the engine pings, you have too low octane gas for your compression.

In a newer car, they pretty much all run at at least 200 all the time...and allow up to 230 in some cases when sitting in traffic.
Click to expand...

The fan switch on a lotta new cars triggers at 230*..

I'm not refering to 200* being overheating,, my reference was to the heat building at a traffic light..

If all was well,, and is equiped with a thermostat of any temp, the fact the vehicle comes to a stop,, shouldn't cause the engine temp to rise significantly. The thermostat should be partially closed at normal temp,, and will open to increase coolant flow to compenate for building heat at idle, all things working as they should..

If the thermostat is totally open at normal temp,, and can't open farther when extra load is put on the cooling ststem,, then something is deficient,,
 
The hotter you run it the more power it will make, until the oil cooks. That would be too-hot...
The stat trys to set the minimum temp. It has nothing to do with the maximum. The maximum is set by the ability of the rest of the system to shed heat. If the only time you are over heating, or think you are overheating,is with the car stopped and the engine idling, that speaks to the inability of the system to shed heat.Since you are stopped, the job goes to the fans and rad. Since everybody who runs that rad and a mechanical fan, has no problem keeping cool......that would point to the fans.

In post 12, you said "clutch fan".
In post 11, I said "Ford thermostatic clutch". I should have said- Ford Truck thermostatic clutch
Was yours a thermostatic clutch fan? or a viscous clutch fan?
Yeah, Chrysler makes thermostatics too; for stock engines. The Ford truck T-clutch works.; and keeps on working.And keeps on keeping on.
 
AJ/FormS said:
The hotter you run it the more power it will make, until the oil cooks. That would be too-hot...
The stat trys to set the minimum temp. It has nothing to do with the maximum. The maximum is set by the ability of the rest of the system to shed heat. If the only time you are over heating, or think you are overheating,is with the car stopped and the engine idling, that speaks to the inability of the system to shed heat.Since you are stopped, the job goes to the fans and rad. Since everybody who runs that rad and a mechanical fan, has no problem keeping cool......that would point to the fans.
Click to expand...

Zackly.. assuming the rad 100%
 
And everyone who switched out the E-fans, for a mechanical fan stops having problems.
Well almost everyone. There was this one guy......
One guy even switched to one of those (almost pos) aluminum flex-til-it-throws-a-blade fans, and reported success.
 
AJ/FormS said:
The hotter you run it the more power it will make, until the oil cooks. That would be too-hot...
The stat trys to set the minimum temp. It has nothing to do with the maximum. The maximum is set by the ability of the rest of the system to shed heat. If the only time you are over heating, or think you are overheating,is with the car stopped and the engine idling, that speaks to the inability of the system to shed heat.Since you are stopped, the job goes to the fans and rad. Since everybody who runs that rad and a mechanical fan, has no problem keeping cool......that would point to the fans.

In post 12, you said "clutch fan".
In post 11, I said "Ford thermostatic clutch". I should have said- Ford Truck thermostatic clutch
Was yours a thermostatic clutch fan? or a viscous clutch fan?
Yeah, Chrysler makes thermostatics too; for stock engines. The Ford truck T-clutch works.; and keeps on working.And keeps on keeping on.
Click to expand...

I had an OE Chrysler Thermostatic clutch fan. It was from some late 1970s truck IIRC.

The Contour Electric fan moves more air than that does by a lot, even on low speed. The OP probably has some much weaker aftermarket fans (CFM and shrouds vary greatly) so I'm not disagreeing with you that the fans aren't working, and yes, I know the thermostat controls the minimum temp...and we both agree that taking it out does not control the maximum temp, so there really should be one there.

They make full size trucks now with Electric fans, if you have good ones, they work. Why would you want to go back to an engine driven fan to loose power to "fix" a problem that doesn't seem to exist in the first place? If the OP never hits 210 degrees under any circumstance, why worry? We don't know that yet.
 
VG info, I will say that I thought I was at the top of my game till I wandered over here from Moparts. The guys here are taking me up a level (or two)! Parts for sale section is a candy store also. All I need to do to progress is find an early A body close by for sale that ain't gold plated
 
goldduster318 said:
They make full size trucks now with Electric fans, if you have good ones, they work. Why would you want to go back to an engine driven fan to loose power to "fix" a problem that doesn't seem to exist in the first place? If the OP never hits 210 degrees under any circumstance, why worry? We don't know that yet.
Click to expand...

The big trucks and motorhomes I've worked on and noticed,, that big elec fan is an auxillary fan,, and there's still a motor mounted fan on the inside.. My Motorhome also has both, with the electic seldom coming on except under long heavy loads, (N Cal mountains in summer, and that long (17mi) grade on I-15 into Vegas)..
 
inertia said:
The big trucks and motorhomes I've worked on and noticed,, that big elec fan is an auxillary fan,, and there's still a motor mounted fan on the inside.. My Motorhome also has both, with the electic seldom coming on except under long heavy loads, (N Cal mountains in summer, and that long (17mi) grade on I-15 into Vegas)..
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Right, if they believed that they needed both based on testing, they can (and may have to) do that. In that application you can certainly create ridiculous amounts of heat, which is also the same reason they drop compression on really HD gas engines. Since this is a light A-body we should be able to use one or the other provided it's well sorted. A friend of mine has a Chevelle with 11.7:1 468 that runs low 10's and it stays cool with basically a 4-row radiator about the size of a 26", good dual electric fans, and a stock water pump.
 
I speak from having read yrs of posts here,, and 2 springs ago, I noticed a trend and searched "overheat" and to no surprise,, IIRC 12 of the first 14 posts were about folks trying to get all kindsa designs of elec fans/shroud combinations to keep the engine cool,, especially when stopped.. It quickly became obvious to me, and others, including the OP'S that returning to the original fan/clutch (?) whatever cured their prob.

Since then , there's been a gazillion similar posts,, there was a post recently of a gent declaring "I finally fixed my overheating prob.."" He had been the electric path in everyway,, and went back..

I'm not saying elec fans won't work,, there are a few successes involving very large OEM Ferd fansI believe,, and a few others,, but they also went down a long path to get there..

It's not just a matter of zap-stapping a coupla Walmart elec fans, and away you go,, there have been some truly magnificent, and ingenious designs of expensive hi-flow fans and custom shrouds,, guess what,, they didn't work,, a shame really,, cuz some were very very appealing, and truly demonstrated skill and talent..

I would encourage anyone thinking "electric" to spend a lotta time researching on the web, but mainly here, to find a sucessful way to make it work...

I just wonder why electric..?? If you think your saving horsepower,, you're not,, cuz the drag/draw the fans put on the alternator will likely equal or be more than a de-clutched fan.. and not be as efficient.. For racing,, pull the alternator field wire off, (or have a manual switch) loosen the fan belt so it slips down the 1/4 mile, same as turning off the fans,. my .02

hope it helps
 
inertia said:
I speak from having read yrs of posts here,, and 2 springs ago, I noticed a trend and searched "overheat" and to no surprise,, IIRC 12 of the first 14 posts were about folks trying to get all kindsa designs of elec fans/shroud combinations to keep the engine cool,, especially when stopped.. It quickly became obvious to me, and others, including the OP'S that returning to the original fan/clutch (?) whatever cured their prob.

Since then , there's been a gazillion similar posts,, there was a post recently of a gent declaring "I finally fixed my overheating prob.."" He had been the electric path in everyway,, and went back..

I'm not saying elec fans won't work,, there are a few successes involving very large OEM Ferd fansI believe,, and a few others,, but they also went down a long path to get there..

It's not just a matter of zap-stapping a coupla Walmart elec fans, and away you go,, there have been some truly magnificent, and ingenious designs of expensive hi-flow fans and custom shrouds,, guess what,, they didn't work,, a shame really,, cuz some were very very appealing, and truly demonstrated skill and talent..

I would encourage anyone thinking "electric" to spend a lotta time researching on the web, but mainly here, to find a sucessful way to make it work...

I just wonder why electric..?? If you think your saving horsepower,, you're not,, cuz the drag/draw the fans put on the alternator will likely equal or be more than a de-clutched fan.. and not be as efficient.. For racing,, pull the alternator field wire off, (or have a manual switch) loosen the fan belt so it slips down the 1/4 mile, same as turning off the fans,. my .02

hope it helps
Click to expand...

Right, yes, you need a good electric fan setup that works if you are gonna run one. A lot of them are utter crap. Most OE setups are better than the aftermarket ones short of a few that I have seen.

You will save HP with an electric fan if it's set up correctly because it basically won't even be on while you are moving most of the time. Mine usually shut off completely by the time you hit 20 mph because it's cooled well enough. Also even if they are on, let's say it's using 25A of electricity at 13.6V. Power (in Watts)= I(current)* V (Voltage). and let's say the alternator is about 50% efficient, so P=(25*13.6)/.5 which is 680W. That's basically 0.91hp. So, even a terribly high current draw fan setup would be about 2hp to power. The Ford Contour setup I have is fused for 60A from the factory so it's maybe 40A draw at worst on high and less on low. Of course that can keep a 2.5V6 with A/C and a single row radiator cool in Death Valley in an engine bay that would be claustrophobic for an ant, and look, it fits great on a 26" radiator:
20130518_155146_2_zpsadda91cf.jpg




Car Craft did this test about 15 years ago, and here's the comparison.

No fan = 496hp
Electric = 494hp
Thermal clutch = 487hp
Nonthermal clutch = 485hp
HD thermal = 476hp
HP flex fan = 476hp
Stock 4 blade = 473hp
Low-profile flex = 466hp
One piece plastic flex = 460hp
OE replacement 6 blade = 449hp
 
Someone is not reading my post right. TWIN ELECTRIC FANS WITH SHROUD> no engine fan at all. I'm aware that 200* is not an over heat condition, but fluctuating between 160* and 200* wears out rings and other parts too.

With a good operating 5 blade clutch fan and high flow 160* t-stat it would go to 220 *.
Bypass is not suction side, it is pressure because it is designed to blow bubbles off of cylinders and heads.
With a restrictor and no t-stat the bypass should be more of a hinderance than an asset ???
All Parts in this cooling system are new!
 
I'll bet if you had a thermostat it would regulate your temp swings. That's what thermostat's do. (or at least help it) And yes, 200° is not overheating.
 
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