401 overheating advice needed

401ton

I have a TBI 401 in my CJ-7. Motor has been in it for 8 years. Last setup that worked was a Be Cool aluminum radiator, stock flex fan that had been trimmed to fit, a mediochre shroud I made and a cheap 16" electric pusher. Now I am using (2) 16" fans, pusher and puller because I modified engine, frame and body placement and there is no longer room for the mechanical fan. I have been wheelin on 80-90 degree days under load at 220-230 degrees. I used to keep it under 210 with the old setup. Should I: A. Buy a better 16" electric puller fan and replace the cheapo? $150-250 ? B. Cut holes in the hood and install louvered vents? $50 ? C. Buy a 4 core copper radiator and replace the aluminum unit? $300 ? Maybe cheaper cause I could sell the aluminum rad. D. Buy a 4 cylinder and complain about power? Ha! Ha! No Way!

youdidwhat

A & C but mostly C

401ton

Why would a copper cool better? What does you or anyone else without a engine driven fan have for a cooling setup?

zero cool

First thing to do is to determine if your radiator is getting clogged up. If it is, a good flush and fill could solve your entire problem. That being said, I'm putting a TBI 401 (bored 0.030 over) into my Cherokee. I have a 4 core copper radiator, Flow Kooler water pump, stock fan and fan clutch as well as a stock shroud. I should be just fine running that setup. Oh, and one more thing to do is to datalog the O2 sensor while it's running. If you're running too lean, you'll run too hot. If you're running too lean, check fuel pressure and clean the injectors. Then look at tweaking your fuel tables if you are still running lean.

donwag

I have had good luck with a Flowkooker water pump. Make sure everything else is working up to spec and try a Flowkooler pump and a high flow thermostat, about $90.

youdidwhat

401ton wrote
Why would a copper cool better?

What does you or anyone else without a engine driven fan have for a cooling setup?

IMHO copper disapates heat faster.. plus it is a four core, as opposed to the three core you are running. ( the alu. is a three core correct??)

easyer trail repairs.. copper can be fixed with sodder and a torch..alu. is not so easy to fix.

with that siad I agree with z-cool you should do a flush and fill.. I just assumed you already did.

and a higher flow water pump could help in a big hurry.
alot of the big V8s run the bigger water pumps because of the high heat and low speeds of wheeling.

a synthetic oil blend could lower your friction level and reduce heat as well..

is the four core copper the only answer... No... but it was the best option you mentioned..

does your rig have a tranny cooler or ac cooler in front of the Rad???

alot of rigs arount here get mud built up between the layers of coolers and rads. andf that can cause terrible overheating troubles... so that is also something to consider..

as for set ups.. my fav for the non mech style is twin mini blowers up front and one quality puller behind.

the twin minis, can be set at the corrners or sides (depending on the size of the blowers to push the air right at the intake and exit of the rad. and the big puller will bring the flow thru the middle.. but that is just my $.02 and some may think that is too complex of a set up...

but I always did hunt rabbits with shotguns anyway.. (over kill much :shock: )

hope this helps...

401ton

I have always had a Flow Cooler pump.

I run a manual transmission too so no extra problems there.

I also have my full hydro power steering cooled by its own fan and it is back by the firewall.

Radiator isn't dirty or plugged inside either.

I did order some stainless louvered vents for it to help as I only need about 10-15 degrees to get the temp. more to my liking.

Sooooo, back to the next best place for my money:

Better puller fan or copper 4 core radiator?

I know the better puller will help, but I thought the high dollar aluminum radiators were supposed to fix cooling problems?

I have had this 2 core aluminum Be Cool radiator for 8 years cooling Jeep with mechanical fan and extra 16" pusher. Only changes in comeplete system were removal of engine driven fan changed to puller electric. Also, now I don't run inner fenders.

Here's what I know about aluminum vs. copper radiators: Copper disapates heat better, but aluminum is supposed to cool beter because they can't make copper as thin as aluminum for a dependable radiator application. That and stock cars used aliminum radiators to keep them cool. I have heard that aluminum may need more air flow than a standard copper radiator though.

Any more opinions?

401ton

Also. I did change oil last night to full synthetic. I used to run synthetic blend.

youdidwhat

try your new puller fan idea prior to the new rad and see what you think. you are aimed in the correct direction. :lo1l:

rollen dean montoya

puller fan 1st. if no difference then go with the new radiator. but if you are too lean then you will still run hot.check the air fuel mix

401ton

Well I ordered some stainless steel louvered vents (cheap) and a 3000 cfm puller fan ($100 Summit) a couple days ago. Yesterday it was 85 degrees here. I was driving across town and it was over 210 getting my destination. It was probably 75 or so on the way back and temp gauge dropped to 195. I'll let you guys know how it turns out after I install the vents and then the fan.

Dusty

update

401ton

Finally took it out for a good test on Saturday. It was 97 degrees here! Most of the time I could get around at 220 degrees. Fist time I made a few bigger throttle passes it got right up to 240 again. :angry4:

I figure I did help it out, because it was hotter than the previous 90 degree day.

Air coming out of louvers wasn't all that hot.

Monday did a little checking on a Spal 3,000 cfm fan to replace other 1,625 pusher. Another $200 plus shipping and no garrantees.
I read a Spal FAQ that although you can change the direction of a fan by swapping wires, Spal says it works better to just have it designed that way from the start. I swapped the current Zirgo to make it a puller. Hmmm?

Looked at Flex a Lite fan built for CJ's. They are dual 11" fans, but don't look like they would fit the Be Cool radiator.

Spoke with Extreme Radiators yesterday. He said although he thought his 4 core copper brass was a better choice, (which I curently agree for repair purposes, price and surface area) that both the Be Cool rad that I have and his should cool it to 190-200. He said my problem was air flow.
His downflow models for CJ's have approximately 380 square inches of surface area. I figured my Be Cool aluminum has about 324 square inches or about 17% less. The Be Cool has a little less because of the side tanks. Then I got to thinking about the corners my 16" fan schroud don't cover. I think I may losing up to another 100 square inches of surface area for the fans to blow and pull though! Hell, no wonder it doesn't cool.

Current plan now is to make a very good fan shroud to mount the puller on. This will probably only cost $10-20 and may fix the problem. If that doesn't work, I'm going to a junk yard for the Taurus, Lincoln and similiar high output factory fan and make the Zirgo back into a pusher.

Here's pictures of my stainless steel louvered marine vents:

Dusty

you've got a similar setup to me for front suspension. how does yours handle on the road. believe my axles are narrower than yours... did you use a sway bar? is yours a little soft in situations on the road like braking and accel? nice rig. it isnt possible for you to trim the rad support and move the rad even further forward is it? i moved my engine up a hair and forward (using the m.o.r.e. motor mounts and redrilling one hole in the mount and using the forward 4 holes in the frame out of the 6 there. i had to trim out the rad support to move my rad forward to clear my clutch and fan. still no shroud. that will be next. running a 195 thermostat right now for FI purposes but may have to drop down on a built 401

401ton

Dusty wrote
you've got a similar setup to me for front suspension. how does yours handle on the road. believe my axles are narrower than yours... did you use a sway bar? is yours a little soft in situations on the road like braking and accel?

nice rig.

it isnt possible for you to trim the rad support and move the rad even further forward is it? i moved my engine up a hair and forward (using the m.o.r.e. motor mounts and redrilling one hole in the mount and using the forward 4 holes in the frame out of the 6 there. i had to trim out the rad support to move my rad forward to clear my clutch and fan. still no shroud. that will be next.

running a 195 thermostat right now for FI purposes but may have to drop down on a built 401[/quote)

Front suspension is an upper wishbone/lower links (true 3 link) with no sway bar or track bar. It handles very good. It leans a little on corners, but not too much because I have the springs attached top and bottom. During braking it doesn't dive too much, probably because I have anti dive built in to the suspension geometry. Acceleration it is also good.
My front axle was cut to be 63" wide WMS to WMS. I do have 3" backspacing is all though. I'm at 82 1/2" outside of front tires and 83 1/2" outside of rears.

Thanks

Moving the radiator forward for fan room isn't the problem. After I postioned the engine lower in the frame to keep center of gravity down and just barely have room for the Atlas even with trimming the floor, the fan would just stick way too low below the radiator and too close to wishbone.

I have had a 180 degree thermostat for 9 years even with the Howell TBI. My 401 is warm anyway so figured I would try to help the cooling.