Cooling modifications - what worked for you?

[cudagirl4406pk]

My temp dropped about 20 degrees with the becool rad and i use the drk gray 50/50 mix prestone antifreeze and i add purple ice.


michele

[73plymouth]

Do you have a big block with a 440 source water pump housing? Lots of talk on Moparts & DodgeCharger.com about the housings being bad, looks like the lower ports are a big restriction compared to the stock iron parts!

[cudagirl4406pk]

I run a 440 motor and i run a high volume milodon water pump part number in summit racing is mil-16260.

michele

[ShelbyDogg]

I just cleaned out my other engine by pulling all of the freeze plugs and flushing with a hose. About a pound of rust, scale and GUNK came out of those holes.

Could you have some hot spots? Was your engine rebuilt?

[miketyler]

Its a SB 340, all stock was rebuilt before I got it. I did have it out at one point to have the crank neck knurled.

While on the stand I did pull all the freeze plugs and cleaned quite a bit of crud out. Seems like I do remember a build up around the front freeze plugs but it was so hard, I dismissed it as very rough internal casting and was hesitant to start chiseling on it.

I think I am going to pull the condensor next before I change radiators.   

[ShelbyDogg]

The A/C being on does add lots of heat to the radiator air. You didn't say what the temps were without the A/C on.  I'm guessing that they were high then too?

[moper]

The "otehr side" of the cooling system is the heat generator. If the engine was properly rebuilt, they should have cleaned out the cooling jackets. There typically is a ton or casting sand left in there from the factory install. It sticks, and doesnt get washed out, and then fills the bottom of the water jackets as the engien is run. The places heat is supposed to get into the cooling system is the cylinders and chamber areas of the heads. Which is why the timing curve and compression ratio are important. Either can drive the amount of heat going into the system up. As can pistons that are too tight, adn rings that are too tight and butt. Do you have an HV oil pump? If so, they are also a HUGE contributor to heat. Because they are trying to compress a liquid in a confined space as soon as you get off idle... That creates heat in the 2nd cooling system the egnien has... the oil. If you have 75psi or higher after 2K rpm, it's too much and that HV pump is bypassing trying to pump too much oil through it. That adds a LOT of heat.

Edit: if it was bored .040 or .060 over, it also could be runing with one or two thinner cylinder walls... which also add heat.

You have all the cooling area you need. I think it's an engine related issue at this point.

[ntstlgl1970]

......Edit: if it was bored .040 or .060 over, it also could be runing with one or two thinner cylinder walls... which also add heat. ....

I have to wonder about that as well. A "stock" bore 340 is a pretty rare thing. I hope that is not the problem...

[miketyler]

The car doesn't seem to run much hotter with the AC on as it does off. Greg even mentioned that when I picked the car up. The AC just doesnt seem to put that much of a load on the engine.

IIRC, its actually bored .030" over. I wasnt thinking "bore" when I said it was stock. I think I did put a high volume oil pump on it but oil pressure seems normal and never swings to the crazy high side. I also put one of those Mopar Performance chain tensioners on there and it did seem pretty tight at the time but I dont see that creating enough friction to make it run hot.

[moper]

What is the oil pressure normally? At idle, at 1500rpm, at 2K, at 2500, at 3K? Where does the gage needle stop moving and what rpm does the engine hit it? If it has a stock gage, borrow a diagnostic gage and get seom readings.

[mrob]

Mike,
If you're running hot at idle, it's usually caused by lack of airflow. I've been fighting the same thing for quite some time with my 71 Challenger R/T and I'm finally getting a handle on it now.
Here's some things that helped me:
1) Use a 7-bladed fixed fan - you'll lose a few HP compared to a clutch fan, but you won't have to guess about how much the clutch is slipping.
2) Space the fan about 1" from the radiator core.
3) Try to find a fan with a high blade pitch.
4) Use the stock A/C crank and water pump pulleys. They overdrive the fan, so it spins faster than crank speed.
If you do these things, you should feel strong airflow (I wish this could be quantified better in terms of air velocity or cfm) in front of the radiator core. How does the airflow in front of the core feel right now?

[dodge freak 2]

You can use both a mechanical fan with a an electric fan in front of the rad to help draw fresh air in.

I needed to use an underdrive crank pulley to stop a high rpm belt throwing problem. It worked but then while stop idling my water temps kept going up. Well I'm cheap first but like nice stuff if I go for it. Those Edelbock Victor water pumps were like almost $200 and was thinking of getting one but I removed the T-stat first--it was a high flow 160. Problem solved. Temp still warm up quick but stay around 170 to 190 in 80 degree weather. Come Fall I will need a new T stat for sure--or a screen in front of the rad like those semi truckers use.

[miketyler]

1) Use a 7-bladed fixed fan - you'll lose a few HP compared to a clutch fan, but you won't have to guess about how much the clutch is slipping.
2) Space the fan about 1" from the radiator core.
3) Try to find a fan with a high blade pitch.
4) Use the stock A/C crank and water pump pulleys. They overdrive the fan, so it spins faster than crank speed.

I have a 7-blade fixed fan on there now, spacing is about 2" from the core. I had plans to build some U-channels and move the radiator closer to the engine to slip a 16" SPAL pusher there. I think there is a sweet spot and I wasnt sure that closer to core is better. My fan is OEM 2.0p and the only higher pitch fan is a clutch style and is 2.5p. The custom pulleys I have now overdrive the WP 1:1.2 RPMS. Every five rotations of the crank the water pump picks up one additional rotation.

You can use both a mechanical fan with a an electric fan in front of the rad to help draw fresh air in.

Yup thats on the list and am hoping it doesnt create air obstruction and aggravate the coolability I have now.(is "coolability" a word?)   

 

[dodge freak 2]

No it really helps having a fan in front of the rad. My car needs to have it on most times when its hot outside...hot being 80 degrees up here in Michigan. Maybe when its off it blocks the flow a bit but not when its on. Plus you can leave it on even for a few mins after shutting the motor off to help cool off the rad.

[quagmire]

I agree with moper on there being another issue other than the cooling system.  You have a shrouded, fixed fan now and a 26" radiator that can cool a big block.  You've changed thermostats and water pumps, and nothing has changed.  Your pulleys are spinning them enough.  There is no reason a stock 360 should be running that hot with that set up.  Most performance builds run cool with that combo!

These cars came factory with A/C at times, so I doubt the condenser is the issue either.  You could always remove it and see what happens, but I doubt it will do much if anything.  Assuming all of the hood and cowl seals are intact, I'd take a hard look at the tune and engine itself.  Something isn't right.