Ok, I just put high compression heads on my car, well high for me anyway. They are about 10.2:1 or so. I also put a victor series water pump on as well with a 3 row copper rad. Well now if I fill the rad to just above the first fins it spews out the over flow tube. Also it got maybe 210ish or a little below and the cap popped up and let out steam... I know I don't want to stay at 210 but it was just in traffic for a little while. Is there something I'm missing or do I just need an aluminum rad?
Radiator problems
- Thread starter steel1212
- Start date
krash kendall
Active Member
How many pounds is your cap? It also may still have air in the system. I just had the top my 3-row copper rad rebuilt and installed it last Thursday and it took several refills with the car running with the cap off to purge all the air.
This is normal.
The coolant expands when it gets warm and vents steam/coolant out of the cap. That's one of the reasons the cap is there.
If you do not have an overflow tank, it vents the coolant onto the road.
Get an overflow tank or just don't fill your rad to the top.
210 isn't bad for hot weather in traffic, but if it gets much more than that, it's time to start looking for other options.
The coolant expands when it gets warm and vents steam/coolant out of the cap. That's one of the reasons the cap is there.
If you do not have an overflow tank, it vents the coolant onto the road.
Get an overflow tank or just don't fill your rad to the top.
210 isn't bad for hot weather in traffic, but if it gets much more than that, it's time to start looking for other options.
I was thinking of an overflow tank. What is the diffrence between the recirculating and just catch cans. I know one brings the fluid back but how?
Also a buddy of mine said that when we put the new heads on that it might not be sealing right and bleeding compression off into the water passage?
Also a buddy of mine said that when we put the new heads on that it might not be sealing right and bleeding compression off into the water passage?
iskwezm
10 Year Member
As the syatem cools it creates a vaccume and sucks the coolant back in.steel1212 said:
Get a exhaust gas dye(not proper name), it goes in the coolant and tell you if theres a head gasket problem.
steel1212 said:
Yes, a leaky headgasket will also blow coolant out of the radiator. But it is also normal for the coolant to expand and blow out of the cap when the radiator is hot and full to the top. The trick is to watch it.. if it doesn't blow out anymore coolant when it's down a couple of inches, then your probably fine. If it keeps blowing out coolant when your rad is 1/2full, then you have problems. A compression test is always good for finding head gasket problems.
As for the overflow tanks. The "catch can" style has the hose go to the top of the overflow tank/can and just fills the can.
The reciculating ones have a hose that connects to the bottom. It brings the coolant back because when the radiator/coolant cools down, it creates suction and "sucks" the coolant back out of the overflow tank into the radiator. Make sence?
Perfect, thanks. I'm going to do a compression test probably tomorrow to check the heads, if thats ok I'm going to get a cheap recirculating one. Any suggestions on a good cheap one. I was looking at the one from Jegs and it looks like a good deal and matches my march pulleys and pump 
http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=498788&prmenbr=361
http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=498788&prmenbr=361
steel1212 said:Perfect, thanks. I'm going to do a compression test probably tomorrow to check the heads, if thats ok I'm going to get a cheap recirculating one. Any suggestions on a good cheap one. I was looking at the one from Jegs and it looks like a good deal and matches my march pulleys and pump
http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=498788&prmenbr=361
Something like that one will work great.
iskwezm
10 Year Member
krash kendall
Active Member
I just put a brand new 13lb. cap my rad after having it rebuilt and it doesn't overflow at all even in this 30*C weather. I previously had a 16lb. cap, but it is apparent now that the rad wasn't cooling properly.
krash kendall
Active Member
The cap has to seal on the sides as well as the bottom. It will work for both systems so long as there is an overflow spout on the neck. I don't know if you can even get a cap that doesn't seal on the sides these days. To make a rad recover the coolant from a catch can you just have to push the overflow hose to the bottom of the can then you rarely have to top up.
Here are two more things to try. Sounds to me like you have air trapped in the top of the engine. Relying on the upper rad hose to let this out completely rarely works. Remove your thermostat and drill a small (1/8) hole thru the mounting flange, in an area where it would be exposed to coolant. Install the thermostat making sure this hole is at the 12:00 o'clock position, straight up. When you add coolant this hole will let most if not all the air out of the top of the engine. I also recommend that you loosen the temp sensor as you add coolant. Loosen it up a couple of turns, as the system is filling air will escape around the threads. When you start to see coolant, tighten the sensor back properly.
These two things stopped the problem you describe for me on my car, good luck, Jeff
These two things stopped the problem you describe for me on my car, good luck, Jeff
Ok, had air in the system and thats why it would send a lot of coolant out the overflow BUT its still getting to hot and the cap is blowing. I'm pretty sure with the high compression heads and the more hp they are making I'm going to need a new rad. It does fine as long as your movine around 180-190 but once sitting still it starts to climb.
I'm useing a flex a lite fan 1300 series 16" fan. I don't have a shroud. I was wondering about getting a pusher fan and putting it on the front of the rad and useing it with a toggle switch? That way I could toggle it on when getting hot and when cooling off at the drag strip. Do you think the addition of that would be enough or do I need an aluminum rad? I can afford one or the other but I would rather not drop 500 on the rad right now.
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