CJim7
('84 CJ7) A few years ago when I swapped in my 401, I left the stock 6cyl radiator in to handle cooling. I never ran into a cooling issue that I could see, It ran a bit warm at times but never overheated.
Im rebuilding the block at the moment so I have everything ripped apart. If I need to upgrade my radiator, now would be a good time.
For those that went from a 6cyl to a v8, what did you do for a radiator? Stay with the 6cyl rad? Custom radiator? Radiator from an earlier V8 equiped CJ? :-|
tufcj
I'm running an aluminum crossflow in my CJ from Be Cool, pretty expensive.
I'm running a 4 core from Extreme Radiator in my AMX (about 425HP 390) with no problems, and a LOT cheaper.
[url]http://www.extremeradiator.com/store/ProductDetail.aspx?sku=583-4[/url]
Bob
tufcj
warhammercustoms
Ive used a stock radiator for a 304 on my modified 360 CJ
Ive had zero overheating problems as long as I use the stock fan shroud with it.
Ibby
When I got my CJ it had a 304 with a 6 cylinder rad. I had heat issues when crawling, so I put in a stock dimension 4 core rad and a high flow pump. Zero overheats, but the heater no longer gets hot either.
Mudrat
I stuck a stock 3 row in for the CJ's 360 swap (probably similar to Warhammer) - haven't had a problem yet. If your going with a lot of mods and will be making more heat, a 4-row or the 'Be Kool' (like Bob) would be a good option.
I'm pushing 400+ HP in mine and unless it gets stuffed with mud (and I don't clean it right away), I've been ok.
- 'Rat
CJim7
So are the stock 6cyl radiators 2-core? :-|
tufcj
Most were 2 core, some were 3. If the CJ had a factory towing package, cooling package, or A/C, it got a 3 core.
The 2 core on mine was plenty for the 304, but couldn't keep the 360 cool when rock crawling. I went for overkill with the aluminum rad. It stays at a steady 180 on all but the hottest days, I've never seen it over 200.
Bob
tufcj
CJim7
Thanks for all the info guys. I think Im going to look for a stock radiator for a 304 equiped CJ or even one of those 3 core jobs for the 6cyl...im pretty sure the one i have is a 2 core.
ironman_gq
4wd.com has the 3core ones for a pretty decent price. Im running one in my cj with a 304 and have no problems keeping it cool
80cjinnc
I had no problems when i swapped out the 304 for the 360 with the stock radiator but now i have a 401 and can not cool it on the street. I am running a alum cross flow but in the summer here in NC on the street it gets hot pretty fast..
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 :lo1l:
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 :lo1l:
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. :-|
