Radiator help

[killahxft_jeep]

I just went with a stock 3 core from napa.. $200 have'nt had an issue with my 360 in the CJ-5..

[highlandercj-7]

I have run a 3 row for years. With the stock 360 and a 160'f stat, it would never get over 180'f even wheeling on 95'f days in the summer. When I went to the built 360 I get up to 190-195'f wheeling in the summer. When it needs a new rad I'm going to the 4 row.

[shawnsc25]

im running a 401 in my yj and went with the RadLock 3 core Radiator from novak convertions I love it no heat problems hottest it ever got was 190 on a very hot day in traffic im also running a flexalite electric fan keeps it nice and cool

[Ted Wendel]

i have a 401 in my scrambler, and afco cross flow aluminum radiator and the biggest electric fan that summit had which it thick is an 18 inch and it has a gutted thermostat to keep some restriction on. it also has a flow kooler high flow water pump. an still cant keep the damn thing cool trail riding. it also pushes coolant out but i think its just getting too hot. its not running like it has a blown head gasket or anything. any suggestions?

[shawnsc25]

hmmm you are not the only one to ask me this question one other guy had the same problems I told him to fix everything starting with the thermastat you may have a problem with the water pump test the power lead to it and see if it is getting enuff power another thing flush the whole system you might have a water port plugged my opinion start with the cheap and work your way up


can u give me a little info on your rig is it a cj yj fj are you running block hugger headers and are they tie coated or wrapped this could pose a heat problem

[Ted Wendel]

its a cj-8 scrambler. i have checked the voltage to the fan and its got over 12 volts when the engine is running. aside from the relay that controls it its hooked directly to the battery. the water port isn't impossible but i wouldn't think so the motor has less than a 1000 miles on it since its been rebuilt. it has in frame headers they are not coated it has t tf727 in it and the drivers side header had to be pie cut and bent and re welded to clear the trans and i just havnt pulled them back off to have them coated. the drivers side one is partially wrapped to keep the shifter cable from melting. when i get the extra money i was going to completely wrap both headers and the pipes all the way back to the mufflers. funny thing is the first trail ride it went to with a 401 and a tf 999 it had a mech fan and a stock brass radiator and i barely had any trouble out of it. it only got to 210 once according to the cheap mechanical guage. it pegged the auto meter guage 2 260 the first time with alum radiator and a smaller elec fan

[LugNuts]

Not that this is a fix all for heat issues, but if anyone is in the process of a complete re-build good practice is to clean the water passages in the block. Even if you get your block hot tanked it doesn’t mean that all the crap is out of the inside of your block.
You will be amazed at the amount of casting sand you may find. The best time to do this is right after it’s been tanked. On the stand with some kind of face protection on, tilt the engine so whatever ever comes out will fall straight down, you can use an air nozzle with a piece of bake line attached to the end and shove it into the casting or frost plug holes. The first time I did this was the 2nd rebuild on my 401. I’ll bet I got about 2 to 2-1/2 cups of sand and some other crap out of it and yes it ran a little cooler on a stock Cj V-8 radiator. I am in process of the 3rd rebuild; I did the same thing, after the tank on the stand. Being more aware of what comes out; I was more diligent and got about another ¼ cup. I was very surprised to see this. I remember helping my cousin do a redneck rebuild, (different heads and oil filter and pump) on the stand on an old Ford and we decided to use my pressure washer on that and we got a lot of junk out of that, not sure of the amount because we did it outside and we did not capture any of it, we only put the nozzle on the water ports on the deck of the block but it did take a while to get clean water coming out. So I took my block out side and nailed it with the pressure washer while it was on the stand, stuck a bucket under it in attempt to see what I could catch and still got more, very surprising. The water I managed to catch was black so I let it settle for a couple weeks and it amounted to a thin layer about .03 on the bottom of the bucket, this is just from what I captured.
I guess my point is that if you’re going through the process of doing a rebuild, take the extra step and clean the inside of the engine also. No pockets of sand sitting in the corners preventing your machine from cooling properly. I don’t know if this is true with newer blocks but certainly would do it on older ones where the casting practices where not extremely tight.

You can make it look as pretty as you want, if pretty is all you got, I may leave you suck in the mud.

[msalaba]

Removing the thermostat or "gutting it" is a big no-no. It is an engine heat regulator and engineers did not put it there for no reason. Running an engine outside it's specified heat range can cause damage. A factory engine's tolerances are designed around a 195 deg. coolant temp. The thermostat brings your engine temp up more quickly on cold starts. This is nore critical on performance builds. Tolarances are usually tighter and an engine should be up to operating temp before putting the coals to it.

For most, the water temp sendor is mounted in the intake manifold. Air usually gets trapped in the thermostat housing during system service. Some recommend drilling a small 3/32" hole in the thermostat to allow trapped air to escape. Most of the time a guage that is "pegged" there is air trapped around the temp sender so the guage is reading a steam pocket.

When filling the coolant system, it is recommended to have the rad cap be the highest point in the coolant system. This also helps the air work out.

I run a mild 360 with a 2 core 304 rad, shroud and stock fan. The warmest I get is 205 deg. Usually stay around 195 deg.

As said above, proper cooling system maintenance will ensure adequate cooling. Generally you only need the fancy and expensive aftermarket parts when you greatly exceed the performance perameters of the original design. For most of us, the engineers earned their paycheck and OEM will function adequately.

[shawnsc25]

X2 on cleaning the water passages this should be apart of any motor re build

[retrorod]

I have been looking at radiators my self and have found that you can buy a howe radiator for around $200 if you don't mind making your own mounts. I figure that it is the same money for a stock one why not go aftermarket and aluminum. It is also half the cost of the direct fit aluminum ones.