Just curious what other guys have done. I pulled the 350 out of a 69 cutlass and replaced it with a 455. I have been using the same radiator without the shroud, but my temps have been getting hotter especially due to the weather pushing a 100 degrees. I am thinking that it is time to upgrade to a larger core radiator but they are a bit pricy. I can add the shroud back on but will that give me much? I am looking for a cheep solution.

 

How much hotter?
At highway speeds?

If it came with a shroud, use it.

Norm

 

Put the shroud back on and see how much it helps. You may be surprised.

 

Norm's questions are the right ones to consider. If the car overheats at idle and slow speeds, the shroud should help. If it overheats on the freeway, the shroud will do nothing and may actually hurt things if it blocks airflow.

 

i think it would be save to say it gets hot at all levels. Even on the interstate i went down and back a 3 mile streatch of freeway. Not babying it but getting on it. and by the time i got it back home she was pretty warm. I do need to get a machanical gauge on it as well. Am i right thinking that the radiator made for a 350 is not big enough? I downed the percentage of coolant to water as well as pulled the thermostat thinking that will help. additional note that i have bypassed the Heatercore. It leaked.

 

Pulling the thermostat is possibly the worst thing you could do, particularly under the circumstance of the radiator possibly being too small for the engine. The thermostat gives the radiator time to cool the coolant/water mixture, take it out and in short order the coolant temperature will be exceeding the boiling point. Do you have a gauge on this car? If so what is its actually reading. "Pretty Warm" is not on any gauge or thermometer I've ever seen.

Also does this car have an automatic tranny? If so don't forget the radiator is "trying" to keep the fluid at correct temperature as well. Running hot is just about guaranteed to take out the front pump seals and pump in any automatic transmission.

 

http://highperformanceolds.com/phpbb...f104594ef9d4e5

You should read up on a subject before you give advice in areas that you do not understand.

Norm

 

And you are an idiot! I guess every damn automotive engineer over the last 80 or so years has been totally wrong. GM has been wrong, Ford has been wrong, Chrysler has been wrong, Mercedes-Benz has been wrong. Yeah, right!

The continually Mixed up World of Norm!

And since you claim to live in San Diego, why don't you remove the thermostat from any liquid cooled engine in any car you have and jump out on I-8 towards Yuma, Arizona. Tell us just how far you get before your cooling system is totally out of coolant. Then you can call California's DOT and tell them they can pickup all those 55 gallon barrels of water they have every mile along I-40 and I-8 as those roads cross the Mojave and Imperial Valley.

 

Cool it guys or this will be another closed thread, once again cheating the guy who started the thread out of the information he is seeking

 

X 2

Joe,

Would you be so kind as to elaborate on, Sorry I'm a little slow.


"the shroud will do nothing and may actually hurt things if it blocks airflow. "

 

first, you have to find out what the temp really is.
second, if it is overheating then you should put in the T stat and shroud
third, i do have experience with both the above. (with and without T stat) both can be true, there several factors that determine weather it will run cooler or hotter without a T stat. some of those are condition of the radiator, size of the radiator, air flow, condition of antifreeze, more times than not it will run cooler without a T stat. if the radiator is a little on the small side but in good condition you are just about guaranteed to be overheating without a T stat. that being said if it is to small it may just barely get by with the T stat. there are several other factors and cenarios but is just better to run with it in place.

 

Start with the least expensive and hope to find the problem soon! First make sure the simple things like the radiator you have isn't plugged up, that the thermostat isn't stuck and the clutch fan is working correctly. If you run the heater on high will it cool it down noticeably? If that all checked out OK I'd try a 160 thermostat first, then add the shroud, and last go for the 4 core radiator. My 2 cents, John

 

x2 Derek...try the cheap fixes,and if no luck,get a 4-core.I pulled mine from my 69 442...had 20+ patches...got a brand new 4 core for $3oo.Cndn....no overheat worries in my future!

 

I believe it worthy of note here that neither a fan shroud or fan clutch play any part in an engine overheating at speeds greater than 35-40 miles per hour. Both are intended to improve air flow across the radiator in basically city and/or stop and start driving. The shroud improves the fans ability to pull air across the radiator at low speeds when the clutch has engaged the fan. On the other hand the clutch is there to disengage the fan and reduce drag on the engine once air flow from forward movement of the vehicle should be adequate for the radiator to function as a cooler.

In the most simple terms neither the fan or shroud has a darn thing to do with engine cooling when forward motion is at or above the 35-40 miles per hour range even with ambient temperatures over 100 degrees.

If an engine is overheating at speeds above 35-40 miles per hour the issue is either from a clogged or inadequate capacity radiator; water pump failing; bad radiator hoses either collapsing at operating temperature or beginning to delaminate inside from age; thermostat wrong temperature rating or not functioning properly; engine intake manifold and/or head gaskets improperly installed and restricting coolant flow; and lastly engine ignition timing incorrect from improper distributor adjustment, worn cam, or worn gears and chain.

 

Not a good substitute for proper diagnosis.

First, find out what temperatures he actually has. http://www.harborfreight.com/cpi/cta...emnumber=93983

If it was already 200° how would a 160° stat make it run cooler?

Norm

 

Since 1958, heaters have been part of the cooling system.

Lack of a heater and shroud can cause it to run warmer than normal.

Norm

 

Technically, radiators only have 1 core, and multiple sets of rows.
But other than that, this is sound advice.

 

If the lower rad hose is soft and flexible then it is possible that it might be colapsing under the WP suction...if so you should add that coiled wire insert PN 401273 in the lower hose that was original equipment...

 

Wow, how about citing any shop service manual for any make of automobile that includes the heater as being described as a part of the engine cooling system....... GO!

Then please explain how there was any major difference in automotive passenger compartment heater systems in any make of automobile after 1958 verses those prior to 1958........ GO!

More of the Norm imagination factor?

 

mcutlass1969
From your post it sounds like finances are tight right now, that's why I suggested you consider the cheaper items first. A couple more thoughts I'd like to share with you. I've gotten in the habit of running a 160 degree thermostat in the summer and changing it to a 195 for the winter. In my part of the country it gets over 100 maybe two weeks total, and in the 90's for several more weeks. The winter time is down in the 20's with a few colds snaps in the teens or single digits. My 1970 was overheating with the stop and go of town driving in the summer. I eventually went to the 4 row radiator and that fixed the problem. If you have to do that you'll also need something for the top plate and bottom radiator brackets. The factory pieces are going for crazy money, but if your handy you can cut and weld your existing brackets to be wider or I have some from a full size car you could weld in place.

I'm sure you've noticed we all have an opinion on this, and the way we express those opinions varies widely Please look beyond the communication style and look for ideas that may help you. You could also use the search option to find other threads on overheating. Keep us posted on how this goes for you. John

 

The whole purpose of the shroud is to improve the efficiency of the fan. At highway speeds you don't need the fan and the shroud can actually block the airflow that's generated by the motion of the car. Some cars actually have rubber "flapper doors" in the fan shroud. At low speeds the fan creates a minor vacuum between the shroud and the radiator rear face, which also serves to hold these rubber flappers closed. At highway speeds the positive pressure due to the motion of the car overcomes the fan-generated pressure and causes these flappers to open, increasing airflow.

 

I'm not sure what your point was, but the heater core is just another heat exchanger. It does pull heat out of the coolant, particularly if the heater fan is operating. That's why A/C cars have a heater valve to shut off the flow of hot coolant to the heater when the A/C is on MAX. An old trick for a car that was marginally overheating is to turn on the heater.

 

How about citing any shop service manual that includes the removal of a thermostat as a cause of overheating.

I am not aware that there was.

More of your "alligator mouth"?

Norm

 

"Water flowing so fast that it cannot give up its heat" is not one of them.

Norm

 

If so, it can be verified by momentarily raising the engine speed to about 2500, while observing the lower hose. It would be more likely to collapse if the thermostat was removed.

Norm

 

Excellent point...
I have one of these IR thermometers and it works great for the price.
So cheap and easy to use, every car guy should have one!

 

Starting in '58, government regulations required windshield defrosters (read heaters) in all new cars, sold in the US.

Prior to that, heaters were "optional at extra cost" and, as such, could not have been a factor in the design of cooling systems. From '58 on, they were included in the design parameters of cooling systems.

Sorry if this came from my memory, instead of a "manual".

Norm

 

Not sound advice.

Poor substitute for a proper diagnosis.

Is there a doctor who would say: "try the cheap fixes,and if no luck,do a heart transplant"?

Norm

 

The point is quite simple. No part of the passenger compartment heat is ever described as being an integral part of the engine cooling system ever. Granted it was discovered that it was possible to bring down the coolant temperature, usually due to coolant loss, by turning the heater to max temp. Basically opening the heater control valve, though not too pleasant an idea in the middle of the summer. Heater control valves have always been used where cabin heat utilizes coolant, even before any car had air conditioning.

In simple terms to present the idea that cabin heaters are an integral and necessary part of engine cooling is totally incorrect, though on some normally aspirated vehicles coolant was/is teed from the heater circuit ahead of the heater control valve through the intake manifold and/or carburetor choke control. The latter being a basic concept also found on many multi-port fuel injected vehicles.

 

Did this thread have something to do with a guy asking questions about his car running hot??

Maybe Joe should put a new section up on this board for personal debating sessions and "useless diversions from the original question".

Concentrate. If the original poster wants to watch arguments all he has to do is turn on the TV and watch one of those political talk shows. I think he came here because he had a specific problem. Sorry about the rant but that's what came to mind.

 

A 1958 Federal mandate, had it existed, requiring a defroster system for automobiles is a far cry from cabin heating being considered a part of engine cooling. The only "design parameter" change to the overall cooling system involved was to add to the radiator coolant capacity specs the capacity of the heater core and associated hoses. Had absolutely nothing to do with engine cooling, which worked/works just fine without cabin heating.

There was no Federal defroster mandate in 1958 and heaters and defrosters were considered an optional cost item on many vehicles into the 1960s. Even the darn 1952 CJ3 jeep had forced air defrosters, such as they were.

 

Ok guys get back to helping the original poster take care of his problem please you can start a new thread to discuss the history of cooling systems and the impact heaters have on them. Lots of your have done 350 to 455 engine swaps did the stock radiator work or didn't it, if not what was the solution

 

I haven't yet found a requirement from 1958, but this goes back to at least 1964:

49 CFR Part 571, Standard No. 103: