Jeepthing

Rad core size is roughly 17" wide x 18" tall, not exact measurements but enough to tell you that it is TINY! There is no real way to go bigger and retain A/C as the hard lines coming out are in the way. The grill is even smaller in width as well...

It is dual pass as inlet and outlet are on the same side.

Scott68B

iTrader: (1)

Sounds like you're making progress. It's nice to know a radiator that small might work. I'm going to try to cool my LS4 in an MGB with a radiator that's about 19" wide X about 21" tall. I might have a small advantage because the car sits low to the ground and I'm using a front air dam that will help reduce the pressure under the car and help to keep air moving out of the engine bay. I'm betting your issue is not getting enough air through the radiator at speed. Good luck......I'm following your progress closely.

Scott

mk2000

Patro46- The flow return from the heater is what opens the thermostat. You could still pull the metal stubs off the housing and use pipe plugs, but you will need to machine an internal passage to keep flow to the stat.
-mk

mk2000

Jeepthing-
I apologize if posted already, and I missed it... do you have pictures of your actual set-up? Grille and accessories front view, and underhood : radiator & plumbing & cap location.

Few things come to mind:
Blocker plate (for the 2 pass) correctly installed in the radiator tank? This might require a borescope.
50%/50% Gycol/Water?
At 5000' I wouldn't run any less than 22psi cap.
Is the pressure cap sealing / holding pressure?
Headgasket/ coolant to combustion leak - has that been ruled out? If checked then what method?


-mk

Jeepthing

MK2000 thanks for the post, could you please explain what a blocker plate is in reference to the radiator? I have not heard that term before.

Stu Cool

iTrader: (13)

I have been following this thread with a lot of interest as I have been working on a similar issue for a while, I am making progress. My most recent mod was to add an air dam under the radiator. I went to my local self service wrecking yard and found this plastic air dam/deflector from a Saturn.(they charged me $1 for it!) I installed it and was very pleased with the results which I feel are significant. Test drove on a 95 degree day, on level ground it stayed right at 195 with AC on. Previously it would sneak up close to 210 doing that. I drove up into the foot hills where there is a long, about 5 miles, steep climb. Temp did go up to about 210-215 but held there even with my AC on. I also did not turn on my extra pusher fan which I have done in the past. Previously on that hill I have always turned off the AC and turned on the extra fan and still saw it go up to 225 or more. This demonstrates how effective an air dam can be. I have some other things I plan to do, move the trans cooler and move my AC condenser close to the radiator, it is almost an inch away now, and I expect those changes will get me where I want to be. I just have to be even more careful with driveways. My radiator is a Griffin down flow with 2 x 1.25 in rows, made to fit my Studebaker with a shroud and a strong puller fan controlled by the computer.

I think the the blocker plate he is referring to is the divider halfway down the intake side radiator tank that forces the coolant to go across and then come back the other direction to exit.

Avarookie

iTrader: (8)

STU,
That is pretty much what I was suggesting. But as I said, if he has room, to mount it further back to direct the air into the engine bay tp help with air flow as well. Great picture of yours installed, not bad for a buck and a few screws.

Stu Cool

iTrader: (13)

Actually, you don't want them further back. The idea of the air dam is to create a low pressure area behind the radiator so air is drawn through it. Most of the 80s and later Camaros have them too, as do a lot of Mustangs. I wanted one that was more vertical, but this one seems to work. Can't beat the price.

Pat

Jeepthing

As far as I can tell there is no blocker plate or baffle in the radiator to direct coolant through the radiator. I have never heard the term "blocker plate" so I was confused, thanks for the clarification.

A little update, went on a trip this weekend and it looks like other changes are needed. Never overheated but actually got hot on the trail, saw 240. This was during a 20-30 minute period of very high load attempting a very difficult obstacle off road. Jeep wasn't moving so it was stationary and saw 3K RPM for a while. On the drive back up the steep inclines in the mountains it got up to 220 or so (185 under no load downhill), better than before and this was under more load than driving around town on the highway.

I noticed the hood and engine compartment was VERY hot, to the point that raising the hood was difficult because it was so hot. This further reinforces to me that I really need to get more hot air out from under the hood. While the hood vents helped the solid inner fenders and skidplate under the engine and transmission is not allowing air to escape.

I guess my plan is still the same, I believe two major changes will help significantly. The trans cooler is huge and gets hot on the highway thus drawing hot air into the radiator. I will also be adding mesh to the inner fenders to help heat escape. Have even thought about adding some fans to the hood or fenders to get more air out...

I appreciate all the info everyone has posted, as much as I would like to add an air dam its just not possible on a vehicle like this. I do agree 100% that I need to create a low pressure zone under the hood, I think this is my issue. The best way to do this is to gut the inner fenders at this point.

V8Rumble

iTrader: (9)

Hey, I apologize if this has already been asked (I don't have time at the moment to read through the entire thread again), but would it be at all possible for you to raise the rear edge of the hood, even 1/4" or so?? I'm thinking that if you could shim it just a little bit, then repeat the tests that cause the high-temp problems, that would probably be a pretty quick way to verify your hypothesis...

Good luck!

Avarookie

iTrader: (8)

I guess my plan is still the same, I believe two major changes will help significantly. The trans cooler is huge and gets hot on the highway thus drawing hot air into the radiator. I will also be adding mesh to the inner fenders to help heat escape. Have even thought about adding some fans to the hood or fenders to get more air out...

LOL, I was thinking of this for a temporary fix, but didn't know if you would go with it.

Other thoughts:
1) Is it possible to add vent holes without losing structural integrity of the skid plate and such?


2) I was thinking of adding two (or more depending on size) louvers to the rear area of the hood? Sorry, no picture and I'm no good at photoshop. They would be like two decent sized ram air scoops, just not very long.

I really would like to see what your actual vehicle looks like to get a better idea of what were are trying to help you with. I searched your TJ, but don't know what it actually looks like for your particular set up.

From what I can gather, highway temps are ok? But, at slow speeds under medium to high rpm/torque is where your current problem exists. Is this correct so far? While researching I found this, I "think" it is similar?


Lastly, for now, check in with this guy, he dropped a LS 5.3 in his TJ. http://www.jeepforum.com/forum/f9/5-...od-tj-1531228/. When I had my 2003 JGCL WJ, I was a member of the JEEP Forum, I found a lot of information there as well.

Avarookie

iTrader: (8)

BE sure to check out page nine, for pictures and video of cooling system.

mk2000

"As far as I can tell there is no blocker plate or baffle in the radiator to direct coolant through the radiator. I have never heard the term "blocker plate" so I was confused, thanks for the clarification."

If there is no blocker there.. then return the radiator. The engine outlet coolant must enter the top hose fitting on the radiator then forced across the top "pass" to the opposite tank, return across the bottom "pass" to the outlet hose and back to the thermostat housing.
Still no pictures?
Still no head gasket or combustion to coolant check?
Cap ? Holding pressure when hot?
50/50 Glycol?

Jeepthing

Spoke with Novak, there is a blocker plate in the radiator. They clean the weld as it is added before the tanks are welded on. I confirmed with a piece of TIG rod down the inlet.

Yes I am using 50/50 Dexcool and water, cap seems to be holding pressure. Sorry no pics yet, I will get an underhood soon and post it up.

I have not been able to do a combustion to coolant check yet, its on my list.

Thanks again to all for the info and advice.

chafik

Ok ... I see several TJ owners have trouble with the Novak rad/shroud/fan combo ... same as me!

Getting hotter on the highway than expected.

After having fixed a slight coolant leak the cooling system is now correctly pressurised and still same effects.

Oh ... and I have a full aluminium block LS1 car engine (f-body setup from a Holden) with LS2 style WP which is now about 2 years old.

And to add to the confusion : I did not always have a large transmission cooler and ps cooler combo in front of the A/C condenser ... and it was like this from the beginning!
Highway with rpms over 2200 and I get temp creep. I can wheel all day long in the dunes with changing rpms and high load situations and the cooling recovers easily ... even with A/C on.
And I know my fan is wired as fan 1 controlled by the pcm ... and I did play with different on/off temps via HPtuner and with different speed shut off limits.
Same effects with only slight variations ... (not sure if the speed shut off limit for the fan actually affects fan 1 which originally is the low speed fan anyway which gets activated when I switch on A/C as well!?)

Still ... I have the strong feeling it is some air flow problem ... air is not forced with enough pressure THROUGH the rad. Either there is some weird restriction somewhere and/or the air is flowing around the rad.
(and thats why the flaps in the modified shrouds do not open enough? mine is still unmodified)

Soooo ... my next experiments will concentrate on improving the dam effects:
- A stock TJ has some kind of rubber flap covering a gap at the lower end of the stock radiator to the grille!
- A stock TJ has some kind of foam rubber insulator between upper condenser edge and radiator.
- A stock TJ does NOT have a gen right louver at the most forefront edge of the hood excess (mine ended up to be exactly above the radiator and not behind like intended to generate low pressure area behind and above fan )

In my case there is too much room for air being directed around ... these are my next suspects.

cheers

Jeepthing

chafik thanks for the post, very good to hear your experiences. I also believe airflow is the culprit and will continue to work on addressing that.

I will be relocating the trans cooler as drawing hot air into the radiator is not the best situation. I don't think this alone is the answer but I do expect temps to go down a bit.

So in terms of getting more air through the radiator, and creating the low pressure zone in the engine compartment, what are your plans? I plan on doing the following...

1. Seal hood to grill with stock JK seal of same type
2. Add large vents (mesh) to the inner fenders to allow hot air to escape
3. Reseal condenser to radiator as there is a gap at the top currently

I still have the stock rubber at the bottom of the grill as well as the stock rubber inside the grill. I may look into sealing this area off better but as of now its pretty much stock.

Punisher8738

iTrader: (1)

Besides going to a lincoln fan and new radiator I plan on building an air dam for mine similar to trucks out there. I have a skid tow radiator skid plate that I'll just bolt the air dam too to create the low pressure area.

I'll also be going to a larger poison spyder hood louver and leaving the two rectangular gen right style ones on the back.

We shall see. I honestly think it's due to the depth or lack of depth in the novak shroud.

chafik

I have some A/C pipe insulation tube (rubber foam) lying around which I will cut and use to insulate upper gaps (condenser to rad) and eventually hood to radiator (after closing the front gen right louver or "redirecting its suction").
For the lower part I will mock up something with card board and zip ties before thinking about more durable solutions.
As for the inner fenders: I have 1.25 body lift ... and if I remove the gap cover flaps it should be enough.

As for the transmission cooler: I have not noticed much difference in engine cooling before and after dropping that in! And temp creep on the highway happens regardless if day or night time or "winter" or summer here. With here I mean Abu Dhabi/UAE! And day time in the summer is quite(!) hot and humid.

I prefer to have that transmission cooler there no matter what! I cannot get enough transmission cooling doing some serious dune bashing here ... and I have actually TWO, one below the tub with fan (was not enough in the sand!) and one came later in front of the rad! Since then the tranny stays cool! If I see some peak after some steep "hill" climbs I simply switch on the A/C and the fan permanently pulls air and cools the transmission oil down quickly

Jeepthing

To clarify I have swapped to the Grand Cherokee fan so the Novak shroud is currently off. The new fan is 19" diameter with about 5/8" gap between the fan and the stock shroud. I do not believe the shroud is restricting air flow at high speeds now and can't be sure it was with the Novak.

Your idea about an air dam off a radiator skid is a good idea, let us know how that works out. I know based on my set-up that is still a long shot fitment wise but the results could be priceless!

I am glad to see so many willing to help with this issue. Obviously I am not the only one with this problem and appreciate others with similar issues posting to get more useful info in this thread!

chafik

Different fan AND rad would be my plan if the "cheaper" things do not work out. With this rad I cannot use a different (deeper) shroud/fan combo ... I have merely a finger width between fan motor and WP pulley right now
(well, yeah I have that fatter SPAL fan meanwhile)

(Actually one experienced workshop guy was telling me that the Spal fan cage itself has too much restriction (relatively) ... too much "fence" which could be lightened up some ... heheh)

Oh ... and one more thing ... the Novak rad fin area is less wide than could be ... due to that "smart" clamping mechanism around those wide side tanks. I might go custom rad if things do not work out!!!