Cooling system, wits end

[diesel_lv]

1967 Coronet, 383 stroked to 496. 26" 2x1-1/4 aluminum core. Flowkooler water pump, robert shaw 160 n 185 thermostat. Serpentine pulley setup w reverse rotation water pump. W 2 electric fans 12" n 11", aluminum shroud w 10 additional 2" holes in it for highway airflow, it idles at 192° in 112° outside air temp w a/c running. But on the highway at 60+ it gets to 220 on flat n level. Changed to Derale 18" non flex reverse rotation direct mount fan w factory shroud. Idles at 228 w a/c on in 114° temps. Haven't gotten it on the road yet to see if it will be cooler at highway speeds. Any rpm above 1400 n trailing edge of fan blade nicks a/c compression rivets. I have a 1" spacer. The fan is perfectly 1/2 in 1/2 out. If I move it 1/4" forward, it will hit radiator lower tank. Definitely not happy w idle temps compared to electric. And the fan touching the a/c compressor is definitely no-go. Any suggestions? Lightly bend traing edge of fan at area where it hits a/c compressor? Before someone asks timing, a/f ratio etc. Everything is dialed in. "Only" issue is temp at idle w mechanical fan and touching a/c compressor. Thank you

 

[F4R/T]

Personally I’d remove the reverse rotation pump assembly, start over. Also sometimes too much flow is just as bad as low flow, what was the condition of block and heads, over bore? I’d also try a different radiator, it’s sounds like you have saturation at low and no speed, the reason I said the radiator is how well does the air/ water flow thru it? Just for sanity and I know you said it’s dialed but air fuel and time if are spot on. Look at the basics, if nothing else remove and put it on a run stand ... this thing isn’t crazy tight is it? Isolate things one at time, see if you can locate parts that are known good from a friend ... you are probably staring right at it and just not catching it... we’ve all done it so just relax and be patient... AC adds about 20degrees while running to the cooling system. Also I would not bend a fan, it can cause balance issues or fatigue and with it spinning like crazy that could be ugly..best of luck keep us posted. Post some pics so we can help visualize what you have especially the ac.

 

[70chall440]

Ok, so you seem to have a number of issues from the sounds of it.

Fan hitting the AC comp - you need to space the fan out. Bending it isn't really a great idea. If it is close, just get a piece of sheet metal and make a spacer.

Pretty clear that the fan/shroud/radiator combo is not working. Have you tried a factory 7 blade fan? Flex fans have always been controversial and for some work well but many others don't work well at all. Factory fans always see to work pretty well.

I am assuming (perhaps incorrectly) that you went to the mechanical fan in an attempt to cool it more? Sounds like you were in the ball park with the electric fans.

Have you tried some water wetter? Might give that a try and see if it helps.

 

[diesel_lv]

Personally I’d remove the reverse rotation pump assembly, start over. Also sometimes too much flow is just as bad as low flow, what was the condition of block and heads, over bore? I’d also try a different radiator, it’s sounds like you have saturation at low and no speed, the reason I said the radiator is how well does the air/ water flow thru it? Just for sanity and I know you said it’s dialed but air fuel and time if are spot on. Look at the basics, if nothing else remove and put it on a run stand ... this thing isn’t crazy tight is it? Isolate things one at time, see if you can locate parts that are known good from a friend ... you are probably staring right at it and just not catching it... we’ve all done it so just relax and be patient... AC adds about 20degrees while running to the cooling system. Also I would not bend a fan, it can cause balance issues or fatigue and with it spinning like crazy that could be ugly..best of luck keep us posted. Post some pics so we can help visualize what you have especially the ac.

AFR 13.4:1 at idle. Fuel injection. Timing at 32° at 850 rpm w manifold vacuum. "I will not get into 'theories' of vacuum advance. Again, with dual electric fans at idle w a/c on using flowkooler water pump and both a 185 n 160 thermostat, the engine can idle for over 30 minutes waiting for an accident in 112° temps and stay at 196ish. And at slow speeds it stays below 200°. I'd rather not throw away 1,500+ in accessories n brackets and find all new brackets n accessories for standard rotation.

 

[69 GTX]

Do you have a picture of the shroud used with the mechanical fan?

 

[F4R/T]

How many passes on the radiator? Also is the water pump running the correct direction for the set up you have? Sounds like you are saturated quickly with heat and won’t loose any of it. Also how does the coolant flow look thru the neck when warmed up? To fast isn’t good..

 

[Tony Tee]

Is the pump housing and pump. both designed for reverse direction?

 

[F4R/T]

Silly question here, you said a reverse rotation pump but stock fan ? Sounds contradicting, fan and pump spin the same way.

 

[moparedtn]

Is it just me or is 32BTDC a shitake of timing at only 850 PRM?

 

[Tony Tee]

1967 Coronet, 383 stroked to 496. 26" 2x1-1/4 aluminum core. Flowkooler water pump, robert shaw 160 n 185 thermostat. Serpentine pulley setup w reverse rotation water pump. W 2 electric fans 12" n 11", aluminum shroud w 10 additional 2" holes in it for highway airflow, it idles at 192° in 112° outside air temp w a/c running. But on the highway at 60+ it gets to 220 on flat n level. Changed to Derale 18" non flex reverse rotation direct mount fan w factory shroud. Idles at 228 w a/c on in 114° temps. Haven't gotten it on the road yet to see if it will be cooler at highway speeds. Any rpm above 1400 n trailing edge of fan blade nicks a/c compression rivets. I have a 1" spacer. The fan is perfectly 1/2 in 1/2 out. If I move it 1/4" forward, it will hit radiator lower tank. Definitely not happy w idle temps compared to electric. And the fan touching the a/c compressor is definitely no-go. Any suggestions? Lightly bend traing edge of fan at area where it hits a/c compressor? Before someone asks timing, a/f ratio etc. Everything is dialed in. "Only" issue is temp at idle w mechanical fan and touching a/c compressor. Thank you

A cooling system filter screen screen can keep a new radiator from clogging. When crud / debris works loose from an old engine it's tough to get all the nooks and crannies in the cooling jackets perfectly clean. Which might be your problem. I Use screens in all my vehicles and have to clean them out when I see the Temps start to rise.

 

[Frank Mopar]

I would go 2 steps colder on the spark plugs if you haven’t already.

https://www.hotrod.com/articles/10-factors-that-affect-spark-plug-heat-range/

 

[diesel_lv]

Ok, so you seem to have a number of issues from the sounds of it.

Fan hitting the AC comp - you need to space the fan out. Bending it isn't really a great idea. If it is close, just get a piece of sheet metal and make a spacer.

Pretty clear that the fan/shroud/radiator combo is not working. Have you tried a factory 7 blade fan? Flex fans have always been controversial and for some work well but many others don't work well at all. Factory fans always see to work pretty well.

I am assuming (perhaps incorrectly) that you went to the mechanical fan in an attempt to cool it more? Sounds like you were in the ball park with the electric fans.

Have you tried some water wetter? Might give that a try and see if it helps.

As I stated in original post, "reverse rotation" factory 7 blade does not go reverse rotation. Also stated "non flex" direct mount. I do like the idea of a thin piece of sheet metal to space it out just enough.

Silly question here, you said a reverse rotation pump but stock fan ? Sounds contradicting, fan and pump spin the same way.

No place did I say standard rotation fan.

 

[diesel_lv]

A cooling system filter screen screen can keep a new radiator from clogging. When crud / debris works loose from an old engine it's tough to get all the nooks and crannies in the cooling jackets perfectly clean. Which might be your problem. I Use screens in all my vehicles and have to clean them out when I see the Temps start to rise. View attachment 993654

Freshly rebuilt engine. Have flushed it twice "just in cass", no debris and fluid is pretty green.

 

[diesel_lv]

Is the pump housing and pump. both designed for reverse direction?

Only 1 kind of housing. Pump blade design will determine if it can perform standard or reverse. Flowkooler has straight fins w backing plate so it can work in either direction.

 

[theman440]

Seems to me that if the W/P rotates in the opposite direction, it won't work correctly in a stock (standard) housing. Am I missing something?

 

[diesel_lv]

Ok, so you seem to have a number of issues from the sounds of it.

Fan hitting the AC comp - you need to space the fan out. Bending it isn't really a great idea. If it is close, just get a piece of sheet metal and make a spacer.

Pretty clear that the fan/shroud/radiator combo is not working. Have you tried a factory 7 blade fan? Flex fans have always been controversial and for some work well but many others don't work well at all. Factory fans always see to work pretty well.

I am assuming (perhaps incorrectly) that you went to the mechanical fan in an attempt to cool it more? Sounds like you were in the ball park with the electric fans.

Have you tried some water wetter? Might give that a try and see if it helps.

It is reverse rotation, so a stock 7 blade fan will not work. Unless I want to throw away a couple thousand in accessories, mounts, and buy new accessories and source all new stock mounts. The Derale fan is a rigid fan, not flex. But apparently it does not pull enough air at idle.

 

[diesel_lv]

Seems to me that if the W/P rotates in the opposite direction, it won't work correctly in a stock (standard) housing. Am I missing something?

Yes, you are missing something.

 

[diesel_lv]

How many passes on the radiator? Also is the water pump running the correct direction for the set up you have? Sounds like you are saturated quickly with heat and won’t loose any of it. Also how does the coolant flow look thru the neck when warmed up? To fast isn’t good..

I might agree except that w electric fans at idle with a/c on sitting at accident scene for 30 minutes, engine stayed at 204° and a/c vent temps stayed at 40°. With the electric fans my issue was highway temps. Stock radiator has 442 sq in of surface area. Im going to measure n see if possible to squeeze in lager height core to increase to 496 sq/in. 1 sq/in per cubic inch.

 

[dadsbee]

Sounds like you have the solution and really didn't want any input...

 

[theman440]

Yes, you are missing something.

Tell me what it is . . .