Will high pressure rad cap make it run hotter??

-
W

Watts0001

Member
Joined
May 13, 2013
Messages
16
Reaction score
0
Location
Uk
Guys i need some help please....ive tried everything

408 stroker, eddy ali heads, h-beam rods, ross pistons, 11:1 comp, high stall, demon carb, MSD at 18 degrees initial, approx 14.0 AFR

I'm running a CSR electric pump, 28" ally rad, 2 x 12" electric fans, 3/4" restrictor in the stat housing.

it keeps boiling over and pushing water out of the over flow then of course keeps getting hotter as it has less water, 200+ degrees and i have to switch it off.

I fitted a 25-28lbs rad cap in an attempt to keep the water in it......it still gets super hot, this is ticking over in the garage and hotter even quicker on the street.

i've got all the air pockets out, flushed the system (its all basically new) fresh water and antifreeze......and it seems a little better as i did have air in the system

i fitted cooler spark plugs 8's NGK racing, think this has also helped a little

Is it now the cap making/allowing it to get hot 200/220 degrees???
or
are those CSR pumps only good for racing, short duration, 1/4 mile and turn it off???

any suggestions welcome
 
Nope, it will just raise the boiling point of the coolant. 3 degrees for each pound of pressure.
 
Bad Sport said:
Yes.
Click to expand...
NO, the cap will not make the engine run hotter. It will prevent boiling at a higher temp as has already been mentioned. That electric pump doesn't seem like a good idea on a street car, and you have a electric fan? that's where your problem most likely is
 
I would try buying a infrared thermometer and hit the top hose then the bottom hose......just to see how good that aluminum radiator is doing its job, and how hot that top hose really is.

Also, when you say "boiling over", is it dribbling out coolant from the radiator's overflow hose or is it actually starting to really puke it out all over the floor, like it's boiling somewhere in the system? If I had to suspect anything, I'd suspect the electric water pump or a Made-in-China radiator.
 
NO, the cap will not make the engine run hotter. It will prevent boiling at a higher temp as has already been mentioned. That electric pump doesn't seem like a good idea on a street car, and you have a electric fan? that's where your problem most likely is
Click to expand...


Hmm.... I've always been told the opposite. Well except for now of course. Interesting.
 
To some extent, a cap will have little or no extent on the actual operating temperature. In some cases it might affect flow so this would be one of those cases.

In other words if the system is working OK, has a large enough rad and pump, and is capable of cooling below the boiling point (which depends on altitude!!!) the cap will have little affect

An example might be my old 86 Dodge 600 (now long gone). It first developed a minor head gasket problem, due to the loss of a heater hose, and I discovered that by running it with no pressure, it would "just" use a little antifreeze every couple of weeks. So I destroyed the pressure gasket. But it did NOT overheat.

If you cannot cool it with a 10--15 psi cap, there's something else wrong besides "not enough" cap.
 
I noticed you have a restrictor instead of a thermostat. I would put a thermostat back in. The restrictor can't regulate temperature just reduce flow. If the coolant is going through the radiator too fast it isn't cooling off, preventing the radiator from doing it's job. tmm
 
I would put a high flow thermostat in and lose the restrictor if the water doesn't stay in the radiator long enough you can never get the heat out of the engine also adding something like water wetter to the cooling system it keeps the air bubbles out of the coolant. you can't cool air you need coolant that is solid (if that makes sense) Also you may want to add a crossover tube to the back of the intake manifold to help move the coolant from one side of the engine to the other that gives the engine another bypass. Good Luck
 
Does your lower radiator hose have a spring coil inside it? Sometimes they will collapse under higher revs when the water pump tries sucking up the coolant, and thereby starves the pump from coolant.
 
The problem is those electric fans, and water pump. If you were to install a mechanical fan, with a proper shroud, it would likely fix the whole issue.
 
68gtxman said:
Does your lower radiator hose have a spring coil inside it? Sometimes they will collapse under higher revs when the water pump tries sucking up the coolant, and thereby starves the pump from coolant.
Click to expand...
He has a electric pump, reving the engine makes no difference to water flow in his case
 
replicar ' suggests your electric fans.
i would agree if they move less than 3000 cfm
 
I have been fighting the same problem. I have tried everything Mentioned and more. Different Carbs . Different size restrictrors for the T-stat. I moved the cap to the intake. A bleeder in the pump. New Be-cool twin fans to go with the Big Be-cool Rad. I put a bleeder in the pump

Here is my next move. I bought a new ,Same style Rad., " Just incase the air flow is the cause.

But what I thought of was the cavity between the pump and the adapting plate where the old pump use to sit. I was wondering if the coolant is using it for a by-pass and not circulating properly. I bought the timing cover pictured below to correct the problem. This will all get changed when the pro-charger is added.

I parked the car after three years of fighting this issue and gave the car to my son. The motor definitely should have the rod bolts and lifters change. So he is going to drop the Compression while he is in there .

I would like to see what you find I never had a chance to fill the void in the timing cover with epoxy. You might want to consider it. I also thought of the Rad. not flowing air which seemed low. That is why I bought the new rad.
 

Attachments

  • timing cover.jpg
    46 KB · Views: 305
  • timing cover b.jpg
    52 KB · Views: 305
  • spoiler pics 664.jpg
    96.2 KB · Views: 273
  • spoiler pics 663.jpg
    85.3 KB · Views: 277
Fans that don't move any air and water pumps that don't move any coolant will make your car run hot.

I know this sounds crazy but it's true.

Funny thing..... People on here make the same mistakes over and over and over.

We must have a couple hundred threads on this very issue.
 
The higher PSI cap raises the boiling point. So yes, the engine has the capacity to run hotter. Since the boiling is raised, that means that the coolant will not boil until a higher temperature. To notice a real difference though, you would need to go to like a 20 PSI cap, which is totally not necessary. If you are fighting an overheating problem, the cap is not your answer unless the one you have is bad.
 
wow a lot to take in there

just a few answers to the above, the pump draws water from the bottom of the rad and pumps in in the top......correct??/not??

the bottom hose is perfect, doesn't collapse

fans pull air from the outside and draw it trough the rad into the engine bay

i also read, DO NOT use a thermostat as the electric water pumps do away with the bypass and a stat doesn't flow until up to temp, so therefore you need a restrictor to allow some water through.
i looked on Stuart Performance, they do a stat with holes that acts as the bypass until upto temp.......so out came the drill and .......this is where a may have messed up......6 x 1/8 holes later the stat now has the equivalent of a 3/4" hole.

i know i'm bonkers!!......'oldmanmopar' will probably agree to how desperate you get..bare with me...

so it flows some water, warms up .......then the stat opens and lets more?? water through.......now flowing to fast and not staying in the rad long enough as 'toolmanmike' suggests???......what do you think????

i really want to keep this CSR pump on the car, it looks great, i've also read of people using these on daily drivers
 
Don't forget that the stat could be bad

six 1/8 holes, for the record, is not the same as one 3/4" hole, but the holes are NOT the problem

I'm not versed in electric pumps, but THERE IS SOME experimentation with reversed flow cooling. So make sure that the pump is running the correct direction FOR THAT PUMP. You are right that factory flow should be into the block from the pump, flow out the block at the stat and into the top of the rad.

Just about all modern "brush" electric motors are permanent magnet, meaning that reversed polarity will reverse the motor. PLEASE double check this.
 
toolmanmike said:
I noticed you have a restrictor instead of a thermostat. I would put a thermostat back in. The restrictor can't regulate temperature just reduce flow. If the coolant is going through the radiator too fast it isn't cooling off, preventing the radiator from doing it's job. tmm
Click to expand...

this^^:blob:
 
One thing I forgot to mention is this is two totally different motors doing the same thing. The only thing used over was the pump and the Rad. They had different carbs. Dist. Cams. even the valve covers were different.

One other thing I noticed is. I would pull over and let the Pump and fan run with the engine off. It would cool as if they were not even running. The battery would go dead before it would cool. I un-threaded the upper hose one day and hit the pump switch the coolant shot over to the neighbors. So it is pumping water.

When the stock block was in the car I had a B&M electric fan on the original rad.. If you would get out of the car with a hat on and the hood open it would blow your hat off. These fans barely blow your your hair around. One reason I believe the rad is not flowing air. It looks as if the tubes expanded. But I am not sure. I never put the new rad. in yet. The trans cooler lines need to be re-plumbed for a cooler in the new radiator.
 
I always throw this out there when guys do everything to the cooling system and nothing works. Fatten up the carb. Lean engines run hot and it could be real hot! What the heck its the cheapest thing to try and we are all cheapos. Why don't we do that first?
 
Any fatter I would have had to run methanol. Its down to the water pump or the Rad. I tried everything else. Including cam timing on two different cams. and Dist. 35 total in a 25 and locked. MSD 6al .factory electronic orange and chrome, MSD digital 6, Crane box, also procomp , direct conection race , and billet MSD dist. carbs and various jetting. 750 proform, 750 holley, 850 holley, 1000 blp, and 1050 quik-fuel. Pump gas , 110, 112, 116, and aviation fuel. Nitro and methanol mixed. Three years of fighting this, any richer I could use a catch can on the exhaust. You know its rich when you have fuel on the rear of the car. Right now the jetting is perfect as well as the bleeds. air fuel ratio guage installed always in the 12 -14 range. If I would go any colder plug. they would be ice cubes. I know what he is going through.

Like I said I tried another motor. and it is not a vacuum leak. smoke tested with a camera in the dist hole.

I honestly believe its water flow or air flow. why wouldn't it cool down with the motor off. and the pump and fan running. You should be able to see the temp come down in minutes. Mine does not.
 
You must log in or register to reply here.
-

Back
Top