Cooling system questions on new Engine

[Jeepedo129]

Just finished installing my new stroker in my jeep about a week ago and it seems to be running hot. I did the break in on the cam and during the break in she sat at about 215-220. This was understandable due to the high rpms with low airflow. However, Ive taken the jeep out and around and it runs at 220 with the A/C on and 215 off. When idling in a parking lot It went above 220 (stupid dummy gauge just pegs 260 once it hits 220). I checked the fan, its coming on full speed, and the mech fan feels good. I installed a 180* thermostat and a new water pump when I installed the motor. Radiator is the stock single core, it was fairly new before the engine rebuild, I did flush it really well before hand. Also, I still have all the shrouds on the fans.

Questions

Should I ditch the 180* thermostat and put back in the 195?

My current thermostat didn't have a bubble hole or anything, I don't know why, but I'm thinking maybe I have some air in the head.

Should I be looking into a 2 row radiator? is it worth the $$?

Electric fan upgrade? ditch the mech fan and go electric? Which ones?

Just dropped almost 3K on this stroker, so funds aren't in excess if you know what I mean. Because of that, I want to kind of brainstorm before I go shotgun some parts at it.

Living in Vegas, I want to make sure this thing doesn't overheat.


Specs are
4.6l
KB421 pistons
4.0 rod
258crank
.020 deck
9.0:1 CR
comp 68-231-4
.051 HG
stock fans
stock water pump
180* thermostat
stock radiator single core.

 

[Tim_MN]

A single row radiator is inadequate, and if the age or condition of the mechanical fan clutch is unknown, it should be replaced. Consider installing the ZJ fan clutch that has been discussed previously. Consider installing hood vents also.

Few, if any, electric fan modification CFM's exceed the stock cooling system CFM's. You just need a solidly performing stock cooling system with all newer parts.


Suggested reading >>> http://www.naxja.org/forum/showthread.php?t=1115626



.

 

[cruiser54]

52028186 stat from the dealer.

 

[RCP Phx]

A Hesco water pump is a good investment!
BTW, there's no need for a bleeder hole in the t-stat. The bypass in the head and t-stat housing take care of that with constant flow thru the heater core.

 

[RCP Phx]

In your other thread you show a 68-232-4 cam?

 

[Jeep Driver]

Another 4.0 running hot?.........hmmmmmmmm

Imagine that.

 

[lazyxj]

Best radiator, IMO, from both a cooling and durability standpoint, is Mopar's own HD Cherokee radiator. Pricy but it's worth it.
PN 52080104AC
1-1/2" thick, dual core.
I have been running them, in three XJs, for many years, without issues.

A 195 degree thermostat is what the engine was designed for, a 180 thermostat will not run any cooler, once the engine is warmed up.

The 2001, my coolest running XJ, has a Hesco water pump and ported thermostat housing.
I run stock fan clutches and replace them every few years, as their efficiency drops.
A ZJ clutch works well but is very noisy, stays partially engaged all the time and will negatively impact your gas mileage.

 

[Jeepedo129]

A Hesco water pump is a good investment!
BTW, there's no need for a bleeder hole in the t-stat. The bypass in the head and t-stat housing take care of that with constant flow thru the heater core.

Thats good, I was wondering about this.

In your other thread you show a 68-232-4 cam?

You're right, I mistyped i have a 68-232-4.

Best radiator, IMO, from both a cooling and durability standpoint, is Mopar's own HD Cherokee radiator. Pricy but it's worth it.
PN 52080104AC
1-1/2" thick, dual core.
I have been running them, in three XJs, for many years, without issues.

A 195 degree thermostat is what the engine was designed for, a 180 thermostat will not run any cooler, once the engine is warmed up.

The 2001, my coolest running XJ, has a Hesco water pump and ported thermostat housing.
I run stock fan clutches and replace them every few years, as their efficiency drops.
A ZJ clutch works well but is very noisy, stays partially engaged all the time and will negatively impact your gas mileage.

Good to know. I'm tearing into the jeep today, and Ill get a new clutch, 195 thermostat. And ill see about ordering a new radiator.

Is the hesco water pump a high flow pump?

 

[Jeepedo129]

A single row radiator is inadequate, and if the age or condition of the mechanical fan clutch is unknown, it should be replaced. Consider installing the ZJ fan clutch that has been discussed previously. Consider installing hood vents also.

Few, if any, electric fan modification CFM's exceed the stock cooling system CFM's. You just need a solidly performing stock cooling system with all newer parts.


Suggested reading >>> http://www.naxja.org/forum/showthread.php?t=1115626



.

Thanks for this, this is good info/

 

[trippled]

A Hesco water pump is a good investment!
BTW, there's no need for a bleeder hole in the t-stat. The bypass in the head and t-stat housing take care of that with constant flow thru the heater core.

The jiggle valve is to help bleed coolant during fill, since air pockets often form in front of and behind the thermostat. It does nothing when the engine is running.

 

[1989AMCXJ]

I am running a mod engine 89 AMC XJ that has the potential to run way too hot, so this is what I did to ensure a cool running engine:
3 row all aluminum radiator (about 260.00 @ radiator express) works awesome.
three Spal 30100435 10" Curved Blade Puller Fans (don't go cheap on this..+
2ea. relays) with custom aluminum fan mount.
flowcooler water pump and hi flow thermostat housing.
195 Mr gasket thermostat. (lasts me longer than oem, and superstat (NAPA)
Lower flex hose with spring.
I also separated the trans fluid from the radiator, which made a huge difference, and now my Trans has its own cooler...so both my trans and motor benefit.

this combo works to perfection for my application.

 

[blakews2217]

Just finished installing my new stroker in my jeep about a week ago and it seems to be running hot. I did the break in on the cam and during the break in she sat at about 215-220. This was understandable due to the high rpms with low airflow. However, Ive taken the jeep out and around and it runs at 220 with the A/C on and 215 off. When idling in a parking lot It went above 220 (stupid dummy gauge just pegs 260 once it hits 220). I checked the fan, its coming on full speed, and the mech fan feels good. I installed a 180* thermostat and a new water pump when I installed the motor. Radiator is the stock single core, it was fairly new before the engine rebuild, I did flush it really well before hand. Also, I still have all the shrouds on the fans.

Questions

Should I ditch the 180* thermostat and put back in the 195?

My current thermostat didn't have a bubble hole or anything, I don't know why, but I'm thinking maybe I have some air in the head.

Should I be looking into a 2 row radiator? is it worth the $$?

Electric fan upgrade? ditch the mech fan and go electric? Which ones?

Just dropped almost 3K on this stroker, so funds aren't in excess if you know what I mean. Because of that, I want to kind of brainstorm before I go shotgun some parts at it.

Living in Vegas, I want to make sure this thing doesn't overheat.


Specs are
4.6l
KB421 pistons
4.0 rod
258crank
.020 deck
9.0:1 CR
comp 68-231-4
.051 HG
stock fans
stock water pump
180* thermostat
stock radiator single core.

One thing I found helped my stroker run cooler is bigger injectors. When it runs lean with the stock injectors it burns hotter because the atomized gas can't pull enough heat out of the air.


Sent from my iPhone using Tapatalk

 

[IslanderOffRoad]

Best radiator, IMO, from both a cooling and durability standpoint, is Mopar's own HD Cherokee radiator. Pricy but it's worth it.
PN 52080104AC
1-1/2" thick, dual core.
I have been running them, in three XJs, for many years, without issues.

A 195 degree thermostat is what the engine was designed for, a 180 thermostat will not run any cooler, once the engine is warmed up.

The 2001, my coolest running XJ, has a Hesco water pump and ported thermostat housing.
I run stock fan clutches and replace them every few years, as their efficiency drops.
A ZJ clutch works well but is very noisy, stays partially engaged all the time and will negatively impact your gas mileage.

Does the mopar hd have plastic tanks?

 

[lazyxj]

Does the mopar hd have plastic tanks?

Yes, they are plastic, so what?

Maybe you are too young to remember the tanks on brass radiators leaking.
Eventually, something on a radiator will start leaking, the most likely candidate are the tank's seams, no matter if it is plastic or brass.

The OEM radiator on my 2001 XJ, lasted 13 years and the 1997 XJ's radiator lasted 15 years. I just changed the original radiator on my 2003 Ford E450-based RV.
Not too bad for plastic tanks.
Back in the day of the OEM all-brass radiators, none them lasted more than 8-10 years, if you were lucky,
Radiator repair shops were common 30 years ago.
Today's OEM radiators are much more reliable than the all brass radiators of yesteryear.

 

[IslanderOffRoad]

Yes, they are plastic, so what?

Maybe you are too young to remember the tanks on brass radiators leaking.
Eventually, something on a radiator will start leaking, the most likely candidate are the tank's seams, no matter if it is plastic or brass.

The OEM radiator on my 2001 XJ, lasted 13 years and the 1997 XJ's radiator lasted 15 years. I just changed the original radiator on my 2003 Ford E450-based RV.
Not too bad for plastic tanks.
Back in the day of the OEM all-brass radiators, none them lasted more than 8-10 years, if you were lucky,
Radiator repair shops were common 30 years ago.
Today's OEM radiators are much more reliable than the all brass radiators of yesteryear.

Most of the advice I've seen around here was to avoid plastic tanks. Just curious

 

[lazyxj]

Most of the advice I've seen around here was to avoid plastic tanks. Just curious

Many here are young enough to have never known any thing but plastic tanks.

I got my driver's license fifty years ago and have repaired or replaced many more brass radiators than plastic/aluminum radiators.
We usually keep our cars 10-12 years, I have never replaced any of the plastic aluminum radiators on our passenger cars since 1990.
The two old XJs and our 14 year old RV are the only plastic/aluminum radiators I have had to changed.

I always follow Factory change intervals and check the coolant's condition every 4 month with test strips, the same procedure I used at work.
A better balanced coolant's chemistry is why radiators last longer today.
Its common on modern cars to change the coolant every five years and have it coming out looking good, instead of the dirty coolant that drained out of older vehicles, even using the shorter change intervals of the time period.
Most OEMs have done their homework in reducing the amount of corrosion and electrolysis present in the cooling system to the point of having 50-100,000 mile, or even longer, change intervals.
It's my guess that people having problems with plastic tanks may be experiencing this with cheap aftermarket radiators or very old radiators. Most OEM stuff is fairly decent quality.
There is a huge range in the cost of replacement radiators, there has to be a strong relationship between the cost quality and the cost.
Like most things in the world, if you shop carefully, you usually get what you pay for.

 

[cwyman6]

Champion 2row all aluminum radiator. They are tig welded not epoxy like all the others. Solved all my problems and i install on all my customers rigs with good feedback.

 

[Jeepedo129]

Just an update, Installed a new fan clutch today. The old one was loose, and you don't realize how stiff the fan is supposed to be until you have a new one in your hand. After I installed it, I took if for a drive around and let it sit and idle in the driveway for a little bit. Temp held below 210 the whole time. I don't want to get my hopes up too high, but I think this may have been a large part of my problem. Thanks for the suggestion Tim_MN and LazyXj.

I'm going to drive it for the next couple days and see where it sits. hopefully this was a good fix.

 

[Jeepedo129]

Also, looked into the Mopar HD radiator. My brother works at a mazda dealer and can usually get cost on a lot of parts from the Jeep dealer. $348.95 was the price the dealer quoted me for it. I'm hoping my brother can get it for cheaper, cause damn, thats a pricey radiator.

 

[Jeepedo129]

So Just wanted to update this thread. Installed the Mopar HD radiator P/N 52080104AC Based on the suggestion from LazyXj.

I've been very impressed with the radiator. It is, in Fact, much thicker than the previous radiator, which was the factory radiator, 52079682AE.



The old one is on top, the new on the bottom. The new one looks like it got kicked around a little bit in the packaging, but only minor.



You can see that the HD 52080104AC has a thicker core. More core= more Cooling

Installed it, no alterations or cutting or anything special. dropped right in and it has dropped my temps dramatically. I drove around with the A/C blasting with the outside temp 92 and it kept the temps below 208 the whole time.


Anyway, Im happy with the purchase so far. 299$ from RockAuto.

Thanks GUYS :thumbup: