some jeep cj cooling options on the affordable side

[Dusty]

People talk about it, people allude to it but no one ever seems to post the specifics. heres what has worked for me in pretty hot central valley CA temps 100+ in the summer

For $269.76 this combo keeps a warmed 401 reasonably cool in the summer.


Engine fan:
For engine fans that fit the stock shroud and suck lots of air.

1. early 1970s - late 1970s Cadillac eldorado and others running 472s and 500's came with an 18" in diameter and 3-1/4" high pitch 7 blade fan
2. also there is the 1981-1986 Cadillac with the 4.1L v8 it is 7 blade an 18 inches in diameter also with similar pitch right at 3" -3-1/8" and moves a lot of air. It is unique in that it as a reverse bend on the top of the blades easy to spot.

I picked up one of each for $5 a piece from pick and pull so $10 total they both seem to pull the same amount of air. pretty incredible difference. I ended up running the old el dorado fan because it was the second one i installed. Its moving a TON of air at idle now. I was going to install an electric fan. now i am not going to bother

Fan Clutch:
For the fan clutch I used a Hayden Severe duty fan clutch #2797 (buick with the diesel in the early 80's on some models like napa i had to notch the holes just a smidge to clear the bolts into the water pump but on a summit model i didn't, it was slotted deeper with universal slots). $48.79 from my local napa

For Shroud:
Stock CJ7 V8 shroud (stock no cost)

For Radiator:
For an aluminium bolt in radiator i so far have only found 1 that is really a bolt in dont change anything else option. Everything else is cross flow and requires a different shroud and radiator hoses which is fine but i didnt want to spend booko bucks and change too much at once.
Go to ebay type in "3 row aluminium jeep radiator" up will pop 20 adds for a down flow design radiator made by champion radiators. it bolts in, it fits and it cools better than the extreme 4 core radiator i got from extreme radiators. I paid $139+ $30 shipping it has 3 rows of 5/8" cores. a little less than the 2 1" cores of many of the cross flow radiators but it seems to be doing the job so far. I would like to some day later find a radiator with a 1" taller core and dual 1" tubes but thats splitting hairs when you look at what this el cheapo aluminium radiator costs compared to other options.

For a thermostat:
Combined with a 180 mr gasket or robert shaw high flow thermostat $14.21

For coolant:
I run 30% dextron synthetic coolant and 70% Distilled water with 1 bottle of water wetter $32.87

Water pump:
Flow cooler water pump $89.95 (i already had one since my old water pump puked i did not include this in total price since most guys i know have em already on their jeeps)



Few details on the jeep. CJ 7 mildly warmed 401, t18 D300 4.5" spring lift, 35's, 8274 winch and winch plate in front, 1" body lift.

I have a 1" body lift which put the stock 7 blade 17" fan right close to the shroud. To clear a bigger fan and to help with geometry when lifting the tranny I moved the MORE motor mounts up and that created ample room clear the 18" fan in stock shroud. Since i was going for a flat belly pan with my clocked dana 300 things needed to be shifted little any ways i re=drilled the more mounts 7/8" up and 3/8" for ward sliding the motor slightly ahead helped with valve cover clearance at the fire wall, moving it up allows you to continue using the stock radiator shroud. I only re drilled one hole, lifted the motor up slid two bolts in (one from each side) and then proceeded to drill out the other 5 holes. you will only be able to use 5 bolts the 6th hole is too close and wont clear a nut. i reused the factory frame cross bar on the lower holes. also much over 7/8" will not give you enough material to bolt to on the bottom 2 or 3 holes. FYI My flat belly pan is actually 5/8" below my frame but that is fine for what i wanted. I would not move it any further forward you will have shroud fan contact issues.


Tests so far:
In my garage with no air flow at 94 outside degrees and inside 95+ degrees with the jeep running for 30+ minutes or longer heating up the garage, front of the jeep facing the rear wall and 2' away from the wall. the jeep at idle does not get past 195-200 degrees idling and being rev'd for an hour at a time dialing in the idling characteristics of the TBI it still did not climb over 200, sustained 2000-2500 rpm in the garage for 10+ minutes it saw 210 then crept back to 200. it used to clear 220-230 no problems idling and at highway speeds used to hoover at 215-220. driving around in 95 degree weather never saw over 205 even on the highway around on city street maintains 195-200




As a side note:
I also changed to a high zinc full synthetic motor oil 20/50 and found i did shed another 5+ degrees in engine temps at highway speeds and it looks like i may have dropped some temps in lower situations also not much but noticeable. I run a 20/50 around here even in my fresh motor summer time we regularly see 90-100+ days on the trail and around town. with 10/30 or 15/40 my idle oil pressure drops down to 12-15 psi at 200 + degrees.

I have nickle timing cover, mid plate, HRC gears valley oil bypass line and small cam bearing holes with 7.5 qt oil pan. engine at 200-220 degrees maintains 20-22 psi at 600 rpm with dino oil, with the synthetic 23-25 psi at 600 at 1200 rpm+ it jumps to 55-60 psi no matter what.

Update:
Air flow wise under the hood i decided to cut in and add a few louvers. temp wise it hasn't changed much but it cant be hurting you can really feel the air coming out now.

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[a440plus6]

GREAT post....thanks!!!!!!!

[LanceM]

Many thanks

[cj5doc]

Hey Dusty.... Why not use the electric fan and shroud combo..... You should move more air at idle or crawling speed, and you won't have to do all the engine mount relocations.

[Old Rugged Crosser]

Hey Dusty: You better get that bug out of your computer.

Thanks for that detailed post on cooling. Much appreciated.

[Dusty]

Hey Dusty.... Why not use the electric fan and shroud combo..... You should move more air at idle or crawling speed, and you won't have to do all the engine mount relocation.

I could and actually have the electric fan in my garage and thought long and hard about it, i dabbled with it some and have all the fixings to do it and planned to do it until this setup worked so well. I ahd to move the motor up regardless because i wanted a flat belly pan and without the motor lif the engine would have been at a slight off angle to the t-case

also last year two of us lost our alternators on the same trip on fordyce, my jeep right at the first creek crossing and one other rig in our group a bronco with an electric fan smoked his too at winch hill 1. It was an eye opener since we were running in a group of 3 with the third rig a Toyota. all three rigs run dual batteries but that bronco was burning through batteries and even with my EFI i went all day Saturday without a charging system out at committee and down to Cisco on my two batteries. barely .... i died when i made the turn onto pavement but made it to pavement none the less. the bronco burned through batteries alot faster an and required a couple 3 swap outs from the toyota which was a major undertaking, we suspect the low voltage at in the system took its toll on the fan motor because at committee the electric motor crapped out. flexilite warrantied the motor but that made for another very long weekend on fordyce "carnage run".

it was a good opportunity for me to really eye ball my setup and made me realize i wanted to keep with a mechanical setup either partial or full so that in dyer situations i could stretch my battery system to the limits over having to rely on swapping batteries to keep me going. the electric fan is a good option for some but i thought it would be interesting to really find some mechanical fan combo that would work and could be done reasonably in a CJ with a 401. figured if i could make the system work efficiently with a mechanical fan then if later i add an electric it should just be a bonus

[cj5doc]

Thanks for the post Dusty..... I gues I will need to add an alternator to my spare parts list. I know that most the guys I travel with carry and extra, but I think you just finalized my decision.

BTW.... I would like to see a photo of your flat belly pan and your drive- line angle. Did you say you had to cut some of the tub to get your setup to work?

Sean

[Dusty]

i did notch the floor pan a little on the passenger side. it wasnt necessary but i did it to help with access to the D300 shifter levers if something ever goes south when on the trail. the t-case is about 1/$" from the body. if i had had the tranny and t-case out i would have cut out the body re-inforcement that is right above my t-case that would have given me nearly an inch to 3/4" more to work with down there when moving things up but as it was i was fine. driveline angle made me nervous but the 1310 cv seems to be just fine after this last run through rubicon if it was going to compress and rub it isnt going to be in this rig.

pictures to follow maybe tomorrow once i get the garage cleaned up.

the alternator used to go with me but weight has become an issue with all the parts i carry. starting to try and put jeep on a diet. if two batteries can get me out then alternator will stay home if i am on Dusy trail spare alternator is definitely going.

[Dusty]

heres the flat belly pan picts looks like a bolt backed out on this last trip i'll have to keep an eye on those threads maybe chase em and re tighten. i could have gone a touch higher but the t-18 belly was low already (i ground that down some) and still ended up 1/4" lower than the t-case at the lowest point of the t18. used simpson foundation 2" bearing plates to weld to the frame. pre drilled square and $.49 a piece (i did grind on them a touch too but the 5/8" bit would have cost me more and then cutting the flat bar) and then used CJ 7/5 front 2" rear spring bushings the big ones that come int he front springs. reason was the size the availability and the fact that the bolt could also be removed and used on the jeep in a pinch just used square tube and a piece of angle to setup the cross member. couldnt bolt the tube straight to the adapter the front yoke would have been a bear to change a driveline on.

used 5/8x2" flat bar for spacing down things and to bolt to. used 1/4" plate with big notched out holes so the bolt heads would be recessed. welded the 1/4" plate to the 5/8x2 plate in the jeep with all bolted up. no movement. brought it down and then welded it on the inside a little at a time no issues with Warp (previouslly watched someone overheat 1/4 plate and for a skid plate and spend the next 3 years complaining about his belly pan being a bear to bolt up. mine is a 1 person jobber

really tightened up the frame too.


forgot to turn this but its driverside frame







dana 44 tipped up a hair 1310 CV and 1310 ujoing combo 4.5" RE lift T18/AA to dana 300



note the extra piece of 1/4 welded slightly lower on the front of the skid. thats where the drain plug of the t18 is and where i ground on the t-18 but still needed to give myself a little more room. skid plate could have been bigger but i was a little concerned about trapping too much heat between my floor and the skid



spare driveline is on the floor