Cooling issues
- Thread starter Tad
- Start date
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Plymouth 65
I'll be in the shop
Fan shroud will definitely help, add a high flow water pump and you should be good! 65'
You should also check the General shape of the cooling system. Pump and the shroud have been mentioned. Check the belt condition and tension as well as the coolant level. Check also that the radiator fins are straight and not blocked with insects and other crap.
If the previous owners did not change coolant or flush the system occasionally then the passages in the radiator and engine can be restricted and will not transfer heat effectively . You can get a general idea of the passage condition by removing the rad cap looking down into the radiator the water level is low enough. You may have to drain some coolant out. Are the tube openings clean and clear? If you see deposits restricting or blocking the passages you can try using a flush additive and follow the directions. Then remove the thermostat and reverse flush the system until it runs clear. Check the tubes inside the rad to see if they are less blocked.
If the previous owners did not change coolant or flush the system occasionally then the passages in the radiator and engine can be restricted and will not transfer heat effectively . You can get a general idea of the passage condition by removing the rad cap looking down into the radiator the water level is low enough. You may have to drain some coolant out. Are the tube openings clean and clear? If you see deposits restricting or blocking the passages you can try using a flush additive and follow the directions. Then remove the thermostat and reverse flush the system until it runs clear. Check the tubes inside the rad to see if they are less blocked.
Define runs hot!
Did it ever run "normal" temp?
What has changed between running normal and running hot?
The engine looks newly painted, was it recently altered?
What temp is the thermostat, and when was it last changed?
The shroud might help when at idle but not at speed.
First I would run a hose connecting the heater hose outlet and inlet together rather than blocking them off. Cheap easy and might make a difference?
Did it ever run "normal" temp?
What has changed between running normal and running hot?
The engine looks newly painted, was it recently altered?
What temp is the thermostat, and when was it last changed?
The shroud might help when at idle but not at speed.
First I would run a hose connecting the heater hose outlet and inlet together rather than blocking them off. Cheap easy and might make a difference?
Thank you for your feedback. I was actually thinking I should’ve given a little more information. The engine was just put back together. Brand new water pump, brand new oil pump, new belts, new thermostat, and all new hoses. The radiator is the one I used in the car prior. It ran fine with my 273. Hot is getting up to around 190-200 deg. Also has all new fluids.
190 200 is totally normal.
What temp thermostat, 195?
What temp thermostat, 195?
I’ll have to look back and see what temperature the thermostat was. When I use my infrared temperature gun it was reading right around 200. When I shut the car off that jumped up to like 235-240.
My temperature gauge is the stock one in the car. Usually the needle is running pretty far over to the right hand side like if it was a fuel gauge it would be about a quarter tank of gas left.
Might think about having the radiator cleaned. When I swapped engines about 7 years ago I took the two radiators I had in and let the shop choose.
He liked the A/C radiator better. Said he was concerned about rodding it out so he cleaned it in a hot tank.
No problems since.
He liked the A/C radiator better. Said he was concerned about rodding it out so he cleaned it in a hot tank.
No problems since.
That's a pretty big water pump pulley. How does it compare to the diameter of the crankshaft pulley? It should be a good bit smaller.
Wyrmrider
Well-Known Member
shroud will help
thermostatic fan will save some hp and be quieter 7-9 plades
plug the holes in the core suport except the one for your cold air to carb
valance/ spoiler helps
50/50 helps with some water wetter
what water pump? solid or plated impeller or just bent metal fins
what rrr said but I think 340's had a larger pull due to higher revs
is this an AC car?
thermostatic fan will save some hp and be quieter 7-9 plades
plug the holes in the core suport except the one for your cold air to carb
valance/ spoiler helps
50/50 helps with some water wetter
what water pump? solid or plated impeller or just bent metal fins
what rrr said but I think 340's had a larger pull due to higher revs
is this an AC car?
I forgot about Water Wetter. I used that too.
I'll need to get some more since my recent engine swap.
I'll need to get some more since my recent engine swap.
Non AC
Bent metal fins if I remember correct.
That sounds like the low side of normal. My 273 dart runs there in the 20 deg winter and about center to just left of center in the hottest part of the summer.
I don't think you have anything to worry about.
I bet you also changed the sender with the engine refresh. That alone could account for a change in the reading.
Where did you measure with the thermal temp gun?
200 running and 235 immediately after shut down does not suppose me.
I really think you have a non issue.
If you want for posterity have the rad cleaned.
Typically, if it idles and maintains a temp in the range of the thermostat temp your cooling is spot on. Then when driving at a steady state at say 50 to 70mph the temp might be slightly higher but should not steadily increase, still spot on.
If you climb a hill like going over the Rockies and the temp will rise but if it doesn't get out of the "normal" range you're still spot on.
A thermostatic mechanical fan is only a fuel saving device it does not add to cooling.
As my dad always said. "The parts you don't add don't cause you no trouble"
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383Scampman
Well-Known Member
O.k. , start with a clean cooling system . Next , install a high flow water pump (A/C) . Then a highflow thermostat@ 160-180* . OEM 18" fan and shroud . Make sure your pulleys are the same diameter . Use 50/50 coolant with w ater wetter . At 190-200* you are almost there . another 5-10* cooler and your golden . La engines were designed to run cooler .
nm9stheham
Well-Known Member
BTW, temp jumping up when the engine is stopped is normal... the cooling of the rad stops dead, but the heat in the heads in particular keeps heating the coolant more and more for quite a few minutes after stopping.
Shroud and rad cleaning are step 1. IMHO.
Shroud and rad cleaning are step 1. IMHO.
383Scampman
Well-Known Member
As an addendum ,it's normal for the temp to go up after running for a while and then shut down .
Wyrmrider
Well-Known Member
from fbbo
They did another episode on fans and how much power is lost with various fans and a rad with shroud in front. Very revealing. Clutch fan best at keeping as much power as possible. 7 blade solid steel fan the worst. Clutch fan cost 14hp and 7 blade lost about 30hp. So it's amazing how much parasitic loss there really is on an engine for a street application where you require things like power steering, alternator, crank driven fan, etc.
sorry about your new stmped fin water pump
we weld a round thin steel plate to the fins to inrease flow and avoid cavitation
if you really run up against a wll get one like that
run whatever thermostat your motor calls for
a low temp t stat does not cool an better than a high temp one
they flow the same
cold stat may not rid condensation as well and get's worse mileage
may get a little better WOT
They did another episode on fans and how much power is lost with various fans and a rad with shroud in front. Very revealing. Clutch fan best at keeping as much power as possible. 7 blade solid steel fan the worst. Clutch fan cost 14hp and 7 blade lost about 30hp. So it's amazing how much parasitic loss there really is on an engine for a street application where you require things like power steering, alternator, crank driven fan, etc.
sorry about your new stmped fin water pump
we weld a round thin steel plate to the fins to inrease flow and avoid cavitation
if you really run up against a wll get one like that
run whatever thermostat your motor calls for
a low temp t stat does not cool an better than a high temp one
they flow the same
cold stat may not rid condensation as well and get's worse mileage
may get a little better WOT
It’s not. It’s off my 383. I have the original 340 fan but was told it might be dangerous as it looks like a flex fan style
I'll never understand why people spend so much money on a new engine then gamble their investment with same 50 yr old radiator. The 340 is larger and tighter than the worn 273 you pulled. It generates more heat.Good luck with it.
lead69
hopeless car junkie
I have a hard time believing the various fan tests are accurate. Everyone I have seen they test on the dyno, this does not simulate the ram effects of incoming air channeling through the fan. I have seen many examples of guys comparing big 7 blade flex fans to clutch fan/electric fan at the strip and not seeing a discernible difference in et. One that stands out is a big block corvette that runs 9s.
yellow rose
Overnight Sensation
Yep. I've taken the fan off and beat the hell of it more than once, across several brands and it NEVER made a difference.
Keeping the coolant temperature under control is infinitely more critical than what fan you have.
Just got my dart back from getting the top replaced.
On the drove home it never any warmer than what is shown below
I pulled into the driveway and instantly popped the hood and checked the temp at the temp sender with an infrared temp checker.
Lastly I let it idle in the driveway for 20 plus minutes. The temp guage was slightly higher then while driving
I continued to let it idle and kept watching the temp guage and the temp fluctuated between 190 and 204.
This is a stock 273 2bbl, stock radiator, cast iron replacement WP , stock 7 blade fan, stock no shroud.
Outside air temp was about 60.
On the drove home it never any warmer than what is shown below
I pulled into the driveway and instantly popped the hood and checked the temp at the temp sender with an infrared temp checker.
Lastly I let it idle in the driveway for 20 plus minutes. The temp guage was slightly higher then while driving
I continued to let it idle and kept watching the temp guage and the temp fluctuated between 190 and 204.
This is a stock 273 2bbl, stock radiator, cast iron replacement WP , stock 7 blade fan, stock no shroud.
Outside air temp was about 60.
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