30 weight oil

[capt den]

i know oil is a long running topic, but i have one more question. i run conventional 10/w40 in my 265 . compression numbers are 90 to 95. should i go back to 30w non detergent? i am looking for the engine to run cooler and was told this might help. also, in a recent book i am reading it says there are hot rod shops that can make me a shroud to fit my car.it says a proper shroud will create a venturi effect and pull more air through. also, a flex fan is more efficient than the original. not sure if messing with the engineers design will help. not alot of room in this car for a shroud, but i know some of the plymouths had them. the fan is very close to the rad., but a flex should fit.  anybody have any experince with any of this?     capt den

[knuckleharley]

11 minutes ago, capt den said:

i know oil is a long running topic, but i have one more question. i run conventional 10/w40 in my 265 . compression numbers are 90 to 95. should i go back to 30w non detergent? i am looking for the engine to run cooler and was told this might help. also, in a recent book i am reading it says there are hot rod shops that can make me a shroud to fit my car.it says a proper shroud will create a venturi effect and pull more air through. also, a flex fan is more efficient than the original. not sure if messing with the engineers design will help. not alot of room in this car for a shroud, but i know some of the plymouths had them. the fan is very close to the rad., but a flex should fit.  anybody have any experince with any of this?     capt den

If you are already running high-detergent oil in your system and the oil galleries and oil filter are not clogging up,keep running it. It is better oil by far. 

 

If you buy an antique car and don't know much/anything about the maintenence history,don't take a chance on running high detergent oil until you have owned it a while and know it has no problems. It is probably safe them to drop the pan and take off the side plates,to clean them out. Don't forget to clean out the oil cannster and blow out the lines if you have an optional oil filter.

 

The danger of modern oil in old cars comes with the chance of the detergent oil breaking loose decades of sludge and clogging your oil lines,causing your engine to fail,and maybe even throw a rod.

 

If you have been using it for a while and none of this has happened,there is no reason to switch back to non-detergent,and a couple of good reasons to keep using it.

[Sniper]

Lets address the premise of this evolution.

 

Why do you want it to run cooler?

 

That asked, thicker oil takes more HP to run the oil pump, but it's not significant.  Here's a link to geek out on the math, lol.  https://www.engineeringtoolbox.com/hydraulic-pumps-horsepower-d_1464.html

 

I prefer to run the thinnest oil I can that gets me the minimum oil pressure I want. 

 

If you want a shroud there are a number of universal, you cut, shrouds out there that you might think about.  Such as

 

https://www.speedwaymotors.com/Walker-WS70-Radiator-Fan-Shroud-Style-F-19-1-4-x-20-1-8-Inch,22622.html

 

Scroll down to the CHARTS section for a listing of available sizes.

[keithb7]

My understanding is a venturi speeds up air flow. I’m not sure it moves more volumes of air.  Maybe. I’m no scientist. 
 

These engines don’t make a crazy high amount of heat. They have adequate cooling systems designed to keep them cool.  When extra fans or shrouds are wanting to be added, something else is up. 
 

Often 60 or so years of scale and rust is what’s up. Deep in the block. Maybe a totally failed water distribution tube? Or a rad that is internally plugged with the same crap that’s settled in the bottom passages of the block.  Or maybe the outside of the rad is full of sticky, dirty crud. Road grime. Oil. Dust. Bugs. Mud.  Added up, they accumulate and do hamper air flow across the rad. Then the rad cannot cool the engine down. 
 

Oil gets as hot as the heat source around it. No matter if its detergent oil or not. I’d wager the oil will get as hot as the engine makes it. SAE30 won’t help anything run cooler. The heat source has to be addressed.  That heat source is likely an inefficient cooling system in need of service and repairs. 
 

Many others have indeed put band-aids on a hot running cooling system. It may end up a being lesson in futility. Best to get it all sorted first. Then see what you’ve got to work with before modifying things. 
 

 

 

[Doug&Deb]

How hot is your engine running? My Coronet runs between 190-200 all day with no overheating problem. If you’re experiencing overheating or coolant loss you need to pinpoint the cause.

[capt den]

my engine runs to the top of the normal range on the guage when operating in stop/go traffic and over 90 outside.i have never actually overheated but i have always stopped before i think it may get there. i have done all the usuals, new distribution tube, rebuilt water pump. removeed core plugs and flushed, re-cored radiator, new hoses, new heater core,160 thermostat, passages in head clear, and i run mostly straight water this time of year. if i let it idle in this hot weather it goes right up to the hot zone. maybe keith is right about crud deep in the block preventing good flow. not sure about a flex fan. i have one, just not sure it will help at idle or low speeds in traffic. i would like to drop the pan but for some reason i think it will be too difficult a job. if i have to drop steering parts i am scared of that.at any rate, i am not having issues with the 10/40 oil, so i will stay with that. next time i am out in the bad conditions i will bring my thermomneter and get a reading. i thought 200 was too high, but doug and deb say it is ok for their car.   thanks for all the replies.   capt den 

[Booger]

Seems to me youve done all the right things, and then some. Im not comfortable with that 200 number. But some like it hot. Be glad you dont live in Vegas.

maybe time to ignore what was once the norm. (Take a look around)

[desoto1939]

Capt den:  i think you are ok, so you say when its 90 degrees outside and in stop and go traffic the engine temp around 200. remember these engine want to have air movement going past the engine block. So yes when driving in 90 degree heat and at a stop light for a regular amount of time or even an extended amount the temp will go up.

The next questions that are you get moving again and assuming you are not stopping for another light is the temp going down say to around 180. If this is happening then the air movement is cooling the engine block and you should be ok.

 

Rich Hartung

 

Desoto1939@aol.com 

[capt den]

yes, it does cool down a bit. not enough to my liking, but it has never boiled over. just if i stop, the heat build-up is alot. sometimes i have to wait 45 minutes to re-start.  i have a flex fan but not sure if it would be any help. just so annoying to install. i am a believer in original systems.   capt den

[Plymouthy Adams]

you mentioned a lot of things done to improve and or satisfy the cooling requirement of the stock arrangement.  Couple items not mentioned in your list, proper fan belt tension, lower radiator hose maybe fitted with an anti collapse spring and lastly to ensure your temp sender and gauge are actually reporting the correct temp.   Pretty sure you have the belt adjusted proper but if you have not verified the lower hose condition under speed at temp...pump will suck this closed with some of the modern thinner rubber on today's market without the spring installed.  Verification of temp at block and radiator would be good to take to ensure your gauge is reporting correctly.  Could be nothing more than bad readings....

[kencombs]

oil choice will probably have zero impact on operating temp. Airflow water flow are generally the issues.  Inadequate airflow us the major cause of idle overheating..  Water flow or lack thereof caused most overheating at speed.

 

Be sure the outside of the core is clean.  It is possible for years of dust and dirt to coat the outside of the fins and prevent air from carrying the heat away.

 

A loose fan belt can cause the fan to turn too slowly.

 

IME flex fans never work well.  Either the are too stiff to flex at speed or they are not pitched enough to move air at idle.

 

If you have a 4 blade fan, replacing it with a later 5 blade will help with low speed cooling but use more power to run at highway speeds.

Everything is a compromise.

I like electric fans as they use no power unless needed.

[desoto1939]

1 hour ago, capt den said:

yes, it does cool down a bit. not enough to my liking, but it has never boiled over. just if i stop, the heat build-up is alot. sometimes i have to wait 45 minutes to re-start.  i have a flex fan but not sure if it would be any help. just so annoying to install. i am a believer in original systems.   capt den

So you state that you have to wait approx 45 minutes to restart after stopping.  Are you having a vapor lock condition after stopping and that is why you have to wait.  Doyou have an electric pump on the fuel line to help get the gas pumped throught th elines after a stop.  Most of use experience the same affect with the newer gas.  Might want to wrap the fuel line with a covering or use the old wooden clothes pin trick of putting thme onthe fuel line.  Also might want to put a heat shield under the base of the carb this might help.  Also next time pull the choke or throttle button out some prior to starting the car if it is hot.

 

 

Rich Hartung

desoto1939@aol.com

[busycoupe]

Believe it or not, the point gap and timing can cause it to run hot.  It wouldn't hurt to check the point gap with a dwell meter.