So I have a car that may have a few go fast parts on it and I have trouble in the summer keeping it cool. I made sure timing and everything is set properly and it was still getting hot. I have a huge radiator in it with 4000 cfm of fans pulling air through it. It doesn't get hot at a stop, just while under load. I can't reasonably put a bigger radiator in the thing but I could put 2 smaller roads in. I was wondering if I could hook 2 heater core to the water outlets on the heads of the 500 that the heater core would normally hook up to. My only concern would be disrupting the natural flow of coolant in the engine and making the issue worse. My second question would be where would that water then return. And would just looping the hoses to the place for the return help circulate water better and decrease my heat issue. The last thing is also my exhaust is a little restrictive for my engine but I don't know if that would be enough to make an engine run 230.
Do you have the proper thermostat with the lower valve on it? The proper stats have a different amount of open area than a typical stat plus they have that lower valve that blocks the bypass when fully open. That bypass is like a 3/4" hole so that's a decent amount of coolant to not go through the rad if its open all the time.
What sort of radiator are you running? There are a lot of pretty much crap radiators out there especially when you get into the all aluminum ones. They look pretty but have zero actual design going on.
For going down the road it sounds like maybe your fans are restricting things? I have seen setups with louvers that open up to allow more flow as well as some sort of active management of the fans so they are not also slowing things down. I don't think its as easy as not powering them.
What sort of car is this in? Stock cars have lots of seemingly unimportant little flaps and seals in various places to control the air flow. At higher speeds missing one of these features can really change the way the air flows so maybe you have something going on that just isn't allowing enough air to flow.
What compression ratio do you have?
Seems like 230 is about where these engines should run?
"It doesn't get hot at a stop, just while under load."
Under load is when you are actually doing some work and compression pressures and temperatures go up. As V-63 says, these motors were designed, for thermal efficiency, to run warm. 195-210 degrees is what they were intended to run at with 220-230 not being "worrisome" (to the engineers at least).
An issue with additional "radiator" devices might be exceeding the water pump's ability to pump effectively
Greg Surfas
One question I have is "is this engine in a Cadillac"?
What you are describing sounds to me like the engine bay where this motor is in does not have sufficient ability to allow the air to pass through, as in letting the used air out.
A build-up of air pressure within the engine confines will stop air passing through the Radiator, no matter how big the fan is. At idle, there might be enough outlets to get air flowing, but increasing speed, with more air trying to get in, if it cannot get out, then the pressure in the engine bay will stop the air from coming in through the Radiator.
This happens a lot when people do engine changes, like Hot Rodders and Custom Car Builders, then try to cover every hole or gap to make everything look neat and tidy. Sticking a larger engine in a place where a smaller engine came from, and not opening up the air-escape holes to allow for air to depart, is asking for trouble.
Bruce. >:D
So to start answering questions, it's a cadillac 500 in the 1970 body. There isnt a whole lot of air flow through the engine bay. It's a nice aluminum radiator with a shourd that has fans that pull enough air and has the little rubber flaps that let the air through once it up to speed. Most everything in the engine bay is still stock but I don't know how to get more air flow through that engine bay. My only thing that I will have to check is if the thermostat is the right one. I know I have a 180 in it but I have to make sure it's the right cadillac one.
William,n I might suggest you look for
There re "tens of thousands" of 1970 Cadillacs with standard radiators, correct fan shrouding, and a mechanically driven fan (7 blade is the best) running around successfully cooling in all climactic conditions.
I've got enough "go fast" parts in my (73) to make it almost UN-streetable, and I am using a stock (HD) radiator.
If you are unable to keep the coolant temperature in line (195-220 degrees F) then I might suggest you look for the source of the problem. If you are not using a Cadillac specific thermostat then the bypass circuit remains open recirculating hot coolant without it flowing through the radiator.
Greg Surfas
Quote from: wschimberg on July 18, 2022, 11:27:40 AMSo to start answering questions, it's a cadillac 500 in the 1970 body. There isnt a whole lot of air flow through the engine bay
The 1970 body? Meaning you have 1970 Cadillac that would have originally had a 472 that has been swapped for a 500? That should not really make a difference. Or is this 1970 body not a Cadillac?
The correct thermostat will look like this, note the flange on the bottom that closes the bypass circuit. These thermostats only come in 185 and 195 degree iterations (not 160 or 180). Other "standard" type thermostats will fit but will not perform properly as Greg Surfas has pointed out. Cadillacs came with 195 degree thermostats form the factory, the 501 series engines (472/500/425) and their cooling systems were designed to run warmer than what some may be used to on older cars.
472-500 thermostat.jpg
There was a series of John Deere engines that used the same stat. I'm not sure what temps those were available in. At one time those were regarded as the best quality stats but I assume like most things what ever those fit got old enough that JD didn't care anymore so those too became junk.
I now do several test cycles on any stat I install in anything. I also don't ever replace one just because. I will test it if I suspect a problem and want to be sure its the problem.
If you have the correct thermostat, the shroud is designed specifically for the new radiator, and the timing is correct, one issue that hasn't been mentioned is the cooling passages in the engine block. Some guys on the ACCA forum recommend pouring a gallon or more of Evapo-Rust full strength in the radiator for weeks or months to dissolve deposits - even in antique cars that had been parked for decades.
These cars were designed to run well with the stock radiator and water pump. In fact, Cadillac overdesigned them to take just about any abuse an owner would throw at it. The only time I ever had an overheating issue on one of my Eldorados was with a failed thermostat or incorrect timing.
I have a friend with a Stock 500 ELDORADO that now has a "replacement" Direct fit ALUMINUM radiator.
With all other probables exhausted the aluminum radiator is simply NOT efficient enough. Ambient excessive at 110+ the engine Temperature getting to 250 and Then he shuts it down.
I just sourced an original (tested) used Harrison copper/brass radiator for it and anticipate that should resolve its issue.
Will advise
The reason I asked the question back in post No. 4, I was surmising that the car is not a Cadillac, but something a lot smaller, with a restricted engine bay.
He came back and said it was a 1970 Body, which sounds like he is trying to cover himself by not admitting what that 1970 body actually is.
Makes a whole lot of difference.
Bruce. >:D
Its a 1970 sedan Deville, so about one of the biggest cars that the engine could sit in, but then again it is still from fender to fender. I had the wrong thermostat in it so I took it out and the new one had the flange in the picture but it made the problems worse today. It looked like the water was moving slowly through the rad when I took the cap off of the rad, like dripping out. Would this be considered a low flow situation caused by the smaller hole in the thermostat? The Water pump looked fine when I did the engine rebuild about 20k ago so I don't think it is that. Do they sell a high flow thermostat with the Cadillac provisions on the bottom or am I just running in circles at this point, or do I need to do a water pump? Or with a stock pump and 4 core rad, will the water just flow through slower? My only other thought is that the stock exhaust is too resitctive being about 50 years old and not completely round in places anymore. It only get hot when it is about 70 out though so it isn't like my water pump gernaded or something, the system is working, just not to the best of its ability.
I asked about compression ratio and that's because if the engine is 10/1 then the problem becomes running the correct octane fuel that is no longer available at the pump.
So to correct the low octane pinging... the trick is to retard the timing but this also increases the running temperature.
Other issues could be a vacuum leak or a lien fuel mixture, improper carburation can cause over heating
Do you still have a mechanical fan on it ?
Im running at a 9.2 compression ration. It has about 20 degrees at idle(Not a small cam) 34 total and 8 degrees vacuum so it doesn't knock, as far as I can hear. So I don't think the timing is to far retarded. With the wide band I have on it, It runs at 13 at idle, 13-13.5 at part throttle, 14 at cruise and 11-12 at WOT. It is the stock Quadrajet and an edlebrock. Would the cross over not being blocked off in the intake cause an issue with summer driving? It has a derale fan shroud with 4000 Cfm of fans so I dont think air flow is an issue, Im more leaning towards flow. I don't have a lot of experience with cooling systems but it barely dripping, and I mean barely drip unless I rev it up. Maybe the 4 core is too much for the stock pump and a stock style thermostat.
Is the bottom radiator hose closing up when you rev it? This can cause flow restrictions.
You didn't say why you changed radiators, but Aluminium ones have to be larger to do the equivalent to the originals.
Have you tried reverse-flushing the coolant system?
I don't suppose you have the fans turning in the wrong direction?
What is your timing with the Vacuum Advance off and plugged?
I have the crossover in my '72 completely blocked off, as I like cool petrol to gain the best combustion.
What is the actual temperature of the radiator? Using a good IR gauge? These things run hot. Hotter than most, but are designed to run hot.
What is your Pressure Cap on the Radiator?
Being an aftermarket radiator, is it designed for recovering excess coolant? And if so, is the radiator cap the correct type, and pressure?
The size of the radiator will have very little bearing on the cooling system, so long as it isn't too small. The proper thermostat will regulate the coolant flow.
One question though, is the Edelbrock Manifold designed to take the Factory Thermostat, or a basic one? If the Factory one is not working, then this could bring up another problem.
Lots of questions.
Bruce. >:D
Just a note. When I was having heating problems with my "warmed over" 500 I was looking into electric fans. I tried a couple of set-ups and they did not seem to do the job. I called and talked directly with the Tech dept at one of the major electric fan companies and his response was interesting. He said that ANY electric fans you could behind (r in front) of a standard sized radiator would not have the capacity as far as air flow was concerned that a properly cowled, 7 bladed mechanically driven fan would. Interesting.
Greg Surfas
Step one on any car here is have a premium 4 row
brass and copper radiator made, minor mounting mods
may be required. The old radiators never seem to
have 4 rows, and they do lose capacity with age.
No aluminum experience here, I keep reading they
are not as good. I will not have one, to begin
with I cannot solder up any aluminum rad leak.
Some belt driven fans have deeper blades for moving
air. They might use 5hp when the clutch engages,
no electric fan setup can claim that. If they
could, it would draw some 250A, the alternator with
losses would use close to 10hp. Anyway they are
for dealing with minimum speeds, road speed can
handle air flow. Bruce Roe
Also consider the impeller in the water pump has deteriorated where it does not move sufficient coolant.
This is just my .02
I did some research prior to converting over to a 16" 3000CFM electric fan on my 365. They come with a 40Amp relay and 30amp breaker. If you want to get down to how much HP loss you will have, consider you'll always have loss with a mechanical fan compared to electric since the electric fan will cycle on and off when there is a demand for it. You cannot deny that electric fans move more air at idle (mine will blow the leaves out from under the car when it comes on) compared to a belt driven fan, but electric loses its efficiency compared to belt at high engine RPM. As long as I am driving down the road and air is hitting my radiator, my electric fan never comes on until I am stopped for a few minutes.
As much as I am all for the electric fan, there are times and engines to use them on, they are not for all, and I would certainly avoid one with the 500 engine. I would absolutely stick a 7 blade belt fan on it with the proper shroud/rubber and original radiator recored. If while driving, the combined air from the fan pulling and the air hitting the radiator at speed isn't enough to keep things cool, you have bigger things going on such as the already mentioned dirty block/water jacket or an impeller that has rusted down to nothing. You already know you have a flow restriction, it's time to start taking things apart to find out why.
So with the new correct thermostat, it gets up to 230 climbing hills but is much better but still if I was to get the ac working it would definitely still get hot. The timing could be slightly retarded still but 34 total without vacuum advance seems fine. It doesn't get hot at a stop, just under a load at speed so I don't think it's the electric fans I have on it. They seem to be moving air properly too. The rad sits at 185 at idle while the gauge sits right at 195. That could be the gauge sitting in the block compared to the in the rad. I was under the car today and the exhaust seems to be crushed a little and could very well be a restriction. Would the restrictions lead to normal temperatures at idle but higher temperatures under load?
If the exhaust was restricted enough to cause increased engine temps, pretty sure that would be accompanied by some loss of power. Have you checked temps at the upper and lower radiator hoses with a laser thermometer, should be at least 20 degrees difference.
"The timing could be slightly retarded still but 34 total without vacuum advance seems fine."
Maybe I am misinterpreting this, but the maximum centrifugal advance (without vacuum advance) for '73 472 engine should be 11-13 degrees. Your 500 (depending on the year) might be a little different, the later 500s were less.
Maximum vacuum advance should be 12.75 degrees for a total of vacuum and centrifugal advance (under some conditions) of about 25 degrees.
It would seem to me you are running way too much centrifugal and then adding more with the vacuum advance. These sound more like Chevy small block numbers and if what I am seeing/interpreting is correct, they are way too high for a 472/500 and would most certainly cause overheating.
Pretty sure that may be distributor degrees, not crankshaft degrees, check it out.
Quote from: 35-709 on July 20, 2022, 07:40:52 PM "The timing could be slightly retarded still but 34 total without vacuum advance seems fine."
Maybe I am misinterpreting this, but the maximum centrifugal advance (without vacuum advance) for '73 472 engine should be 11-13 degrees. Your 500 (depending on the year) might be a little different, the later 500s were less.
Maximum vacuum advance should be 12.75 degrees for a total of vacuum and centrifugal advance (under some conditions) of about 25 degrees.
It would seem to me you are running way too much centrifugal and then adding more with the vacuum advance. These sound more like Chevy small block numbers and if what I am seeing/interpreting is correct, they are way too high for a 472/500 and would most certainly cause overheating.
I have a pretty aggressive cam in it so it likes the timing. It isnt pinging so I don't think it is too much and the exhaust has always been crushed so I have no clue if it is the culprit.
So, what type of fuel are you running?
When I was drag racing, I was running my bored out L88, that was out to 440 Cu. in. on Alcohol, and the advance timing was set at 40 Degrees at 3,000 RPM with my "aggressive" race cam. But, the thing wouldn't idle below 1,200 RPM, and a Red Line of 7,500 RPM.
This was on a non-vacuum advance distributor.
Try that on todays' petrol, and the thing would have been pinging its' heads off, ultimately to total destruction.
When timing a street engine, it is always about timing at the Crank Shaft.
Bruce. >:D
If the engine is built for performance it's going to require high octane fuel .
if it's not pinging on pump gas, then it likely is too far retarded which increases engine running temperature.
I would suspect a restricted exhaust would create incomplete combustion and power loss but not over heating?
I had a 77 that plugged its cat and it just got slower and slower until it just died not to restart. But overheating was not an issue I remember.
When I say aggressive cam, I mean about as aggressive as I'm willing to run on the street. It's a cad company can with .561 lift at valve, 274 duration, and 110 lobe separation. So in the racing world a small can but for street, a little bigger. I run 91 non ethanol and I can through more timing at it if it didn't get hot, it loves a little more timing when it stays cool during the winter but during the summer I have to back it off cause it's getting hot, and then starts pinging. But 34 total mechanical and 8 vacuum still seems like it isnt to far retarded. Also what's the best was to listen to pinging, I can just tell it's happening when it start bogging a hair but I have never actually heard the ping noise people talk about.
William,
As we "un-pack" this more relevant facts seem to be popping up. First of all that 274 degree duration must be at .001 lift and even that sounds like a Cad Co 300T cam. I ran that cam in a most street-able car, but without a VERY free flowing exhaust and stock heads it too wanted to run a bit warm (210 degrees).
Excellent cam to base a high performance engine on and I will assume you have something like a 2000 RPM stall converter behind the motor.
A heavy duty water pump (Flow Kooler) is a must,as is making sure your exhaust is not restricted.
Getting to timing, the 34 (engine degrees) total mechanical is okay, but the vacuum, which has a lot to do with cruise operations should be something on the order of 28 degrees at 16" vacuum, starting at 0-4 degrees at 5". That would be a #VC 1833 (AS-1) vacuum advance unit. If everything else is correct you should be getting something like 15" of vacuum at idle seed which with that cam and a good converter would be around 800 RPM.
I don't know where you are but if you can you might try some 93 octane gas.
With my mild motor using that cam the stock fan and radiator (with stock shroud) was more than adequate.
Let us know how this works out.
Greg Surfas
Quote from: wschimberg on July 21, 2022, 09:37:39 AM........Also what's the best was to listen to pinging, I can just tell it's happening when it start bogging a hair but I have never actually heard the ping noise people talk about.
When you hear the "Pinging" noise, you will definitely know what it is. And you will back off the gas pedal to stop it happening, believe me. It even sounds abnormal. Like someone inside the engine with a hammer, happily belting away, really fast.
What it is is pre-ignition coming from the engine wanting to destroy itself by blowing holes in the tops of the pistons, hammering the big end and main bearings, and generally shocking the internal parts of the engine as the flame in the combustion chamber is firing as the piston is still on the way up to Top Dead Centre.
Bruce. >:D
So
Quote from: The Tassie Devil(le) on July 21, 2022, 08:04:46 PMWhen you hear the "Pinging" noise, you will definitely know what it is. And you will back off the gas pedal to stop it happening, believe me. It even sounds abnormal. Like someone inside the engine with a hammer, happily belting away, really fast.
What it is is pre-ignition coming from the engine wanting to destroy itself by blowing holes in the tops of the pistons, hammering the big end and main bearings, and generally shocking the internal parts of the engine as the flame in the combustion chamber is firing as the piston is still on the way up to Top Dead Centre.
Bruce. >:D
I guess the question I am asking is the small noise that sounds like a click that I hear when I step on it isnt it? The engine could also not make enough cylinder pressure to hurt itself but I'm not sure.
Quote from: "Cadillac Kid" Greg Surfas 15364 on July 21, 2022, 12:30:38 PMWilliam,
As we "un-pack" this more relevant facts seem to be popping up. First of all that 274 degree duration must be at .001 lift and even that sounds like a Cad Co 300T cam. I ran that cam in a most street-able car, but without a VERY free flowing exhaust and stock heads it too wanted to run a bit warm (210 degrees).
Excellent cam to base a high performance engine on and I will assume you have something like a 2000 RPM stall converter behind the motor.
A heavy duty water pump (Flow Kooler) is a must,as is making sure your exhaust is not restricted.
Getting to timing, the 34 (engine degrees) total mechanical is okay, but the vacuum, which has a lot to do with cruise operations should be something on the order of 28 degrees at 16" vacuum, starting at 0-4 degrees at 5". That would be a #VC 1833 (AS-1) vacuum advance unit. If everything else is correct you should be getting something like 15" of vacuum at idle seed which with that cam and a good converter would be around 800 RPM.
I don't know where you are but if you can you might try some 93 octane gas.
With my mild motor using that cam the stock fan and radiator (with stock shroud) was more than adequate.
Let us know how this works out.
Greg Surfas
That is literally the cam that is in it. But when I say streetable, this car is practically my daily right now as my real daily bit the dust. With the vacuum advance, I have the adjustable can on it and it starts running rough when turn it up and hold it at 3 grand. That's obviously too much timing right? Also to note, with the proper thermostat in now, it stays at 180 unless I'm climbing a hill or its hotter then 90 out. It has a stock stall in it right now but I'm planning on switching it out when I get my other car running and I can start toying with it again. I also cant find any 93 anywhere around me but I could get 108 low lead from the local airport but that would cost me an arm and a leg. But once it isnt 90 out I think the correct thermostat fixed it enough that I wont have issue, until I step on it or decide to get the ac working.
With a set back timing lite you can accurately determine all your timing settings at any rpm.
Quote from: wschimberg on July 22, 2022, 12:06:20 PMSo I guess the question I am asking is the small noise that sounds like a click that I hear when I step on it isnt it? The engine could also not make enough cylinder pressure to hurt itself but I'm not sure.
Don't know what a click is, but if it is one single click, then it isn't Pinging.
Not a small noise either, as it really draws your attention when it starts, and makes you want to back off the gas pedal to stop it.
The only real click that I can think of is the noise when universal joints are wearing out, but that click is only when moving off, after going in the opposite direction. This noise is the needle rollers destroying themselves.
Bruce. >:D
Lot of advice here, obviously we are all handicapped by distance, this "pinging" seems to be undetermined as preignition.
With that cam I would hope you have some sort of "performance" rocker arms. If so, they can be noisy, and if not what you are hearing might very well be the stock RAs rattling around. You did not say anything about the valve springs, valves sizes or rocker arms. It sure is helpful if any and all information regarding modifications is contained in your post so all the pertinent facts can be considered. Otherwise we are all shooing in the dark.
Greg Surfas
With today being the 1st day in Colorado back below the nineties. I took it for a drive and the overheating issue seemed to stop most of the time it ran exactly at 180 and even warmed up to 190 at some point but never got hotter than that. I think most of the issue is just the Heat and the fact that I had the wrong thermostat without the block off it seems to be solved them out. I'm think the click may the the start or an exhaust leak or the new rockets I got. It isnt loud enough to concern me though. Thank you for all your help, it really helps me out, I have the mechanical knowledge and know how, just fall flat on my face in the experience realm.
I think that you are actually running the engine too cool, as they were designed to run at around 220 F. With the radiator pressure cap at 15 Lbs, this raises the boiling point of water to around 242 F.
For peak performance, any engine is designed to have all the parts reach the hottest they can get, before boiling, with a bit to spare.
When machining is done, all measurements are calculated to allow for expansion at operating temperature. Running an engine too cool, does not allow the parts to attain their designed sizes.
I have found that one gets the best performance when the thing is actually boiling, but that is not adviseable in a street engine.
BUT, too much heat, and things can go wrong, like seizing, when clearances become too tight, or too loose, and lubrication suffers.
Bruce. >:D