68 RR 383 Still Getting Hot

[dburnett6263]

This topic has been out there a long time and my problem is similar to many others, how hot is too hot? Many different thoughts on this and I realize different conditions can have an effect. I personally am a 200 max guy. Over the last few years have been through various 22" radiator, shroud, and fan (electric & mechanical) combo's with basically the same results, too hot, 205 down the road, 220+ at idle. Can't even think about running the AC. This is a typical August day in Southwest Ohio, upper 80's with close to 70deg. dewpoint. I've checked this with my hand held temp gun, pretty close. Engine is original 383, .040 over, head and valve train work, comp cam (.230/.236 @ .050), AR stainless headers. 6AL box, MSD billet dizzy (no vac. adv.), Holley Terminator Stealth EFI, Tremec TKO 5 spd. Timing 14deg. @ 950 idle, AFR 13.7.
During the pandemic went through some upgrades and mods which included the Tremec, Terminator, Dakota Digital, cleaned up the engine compartment. Along with this I went with a Cold Case MOP754K 26in. 2 rows of 1.250in. tubes, 16 fin/in. and dual 12in. fan kit claiming 3200CFM. Reviews on this unit are mixed from greatest thing since sliced bread to great radiator but ditch the fans. Can no longer find it as a kit on the cold case website, maybe that's a clue. Anyway, thinking on ditching the fans and going back to what Mother Mopar intended, that being factory shroud, 7 blade fan w/thermal clutch. I have 4in. of space so should be plenty of room. Before I move forward with anything I'm open to input, comments, advice. BTW have a couple of nice 22in aluminum's come get them! 3 pics. Thanks Dale.

 

[diesel_lv]

For reference, 496 stroker in '67 Coronet w a/c. 2 - 1.25" row, 26" aluminum radiator, flowkooler water pump, 180° t-stat, mechanical fan w factory shroud, 50/50 antifreeze w 2 bottles of water wetter, 16lb cap, 13.7 AFR also. 120°+ outside temps, 80 on interstate w a/c on at about 186° and around 196° stop n go. Hits about 222° idling for 10 minutes w a/c in 120°+ after a long drive and then very slowly comes down slightly.

A 180° t-stat starts to open at 180° and is fully open at 195°. For '67, 383 w auto n a/c, stock was 26" radiator and 180° t-stat. Slow, in town cruising, 195ish is absolutely normal. Stopped and idling, definitely above 200° is normal. For some reason, people see a 180° t-stat n think that meant the factory/engineers meant for the engine to run at 180°, they did "Not".

 

[Ranger16]

Anyway, thinking on ditching the fans and going back to what Mother Mopar intended, that being factory shroud, 7 blade fan w/thermal clutch.

That works for me sans the thermal clutch (mine is direct drive). With a 180° stat I rarely ever run over 190°

 

[diesel_lv]

The issue for some w the 2 - 12" electric fans w shroud not cooling effectively on highway is the open area. 2 - 12" fans have only 226 Sq inches of space and a "flat" shroud that creates too much turbulence at highway speeds. Mine would get over 220° w electric fans n shroud at 80mph in my above setup. A factory shroud opening is about 20" and has an open area of about 314 sq inches. This allows much more air through and is also curved inside allowing air to flow smoother.

 

[pnora]

What do you have over the top of the radiator? Cold Case still lists them. I have that on my 528 Hemi with a/c. Runs nice and cool.



https://www.coldcaseradiators.com/product/66-74-be-body-17x26-auto-aluminum-performance-radiator

 

[#41]

I have never gotten an aftermarket electric fan set up to work as well as a good belt-driven, stock fan with a good shroud.

 

[dburnett6263]

The issue for some w the 2 - 12" electric fans w shroud not cooling effectively on highway is the open area. 2 - 12" fans have only 226 Sq inches of space and a "flat" shroud that creates too much turbulence at highway speeds. Mine would get over 220° w electric fans n shroud at 80mph in my above setup. A factory shroud opening is about 20" and has an open area of about 314 sq inches. This allows much more air through and is also curved inside allowing air to flow smoother.

What you say here makes a lot of sense. I have plenty of radiator, just need to get more air through it. one electric fan setup I had with the 22" (2-1in. tubes) had 2, (claimed 11" fans more like 10+in.) drew near 50 amps and sounded like jet engines, but did do slightly better than what I have now. After your experiences, sounds like I'm not in a danger zone yet and so far it hasn't puked any fluid. I am running 50/50 coolant w/2 bottles of water wetter, 165 deg. T-stat, stock water pump. I considered the fan clutch thinking it might be an easier install but would do direct drive if it's more effective. What ever I end up doing will be a winter project. I'll keep this going feel free to chime in anytime. Thanks. Dale

 

[dburnett6263]

What do you have over the top of the radiator? Cold Case still lists them. I have that on my 528 Hemi with a/c. Runs nice and cool.



https://www.coldcaseradiators.com/product/66-74-be-body-17x26-auto-aluminum-performance-radiator

That's a custom valance / cowling I had made to compliment the engine compartment clean up. I did take it off and drove around for a couple days, no noticeable difference. I really scratch my head when I read your statement and talk to folks cooling more iron than I am with similar or even lesser systems that have no issues at all. I just haven't found my sweet spot yet. Yes, ColdCase does list them but pic is rad only, no fans, I didn't search any further than that. Thanks for your input. Dale

 

[dburnett6263]

I have never gotten an aftermarket electric fan set up to work as well as a good belt-driven, stock fan with a good shroud.

I'm becoming more of a believer in this every day. Electric fans have there place and many folks with more to cool and even lesser setups than mine say they have no problems. I just haven't found the right combo yet. Always open to input and advice. Thanks. Dale

 

[dburnett6263]

That works for me sans the thermal clutch (mine is direct drive). With a 180° stat I rarely ever run over 190°

Was considering the thermal clutch because thought it might be an easier install but could do direct drive. Thanks. Dale

 

[747mopar]

I have never gotten an aftermarket electric fan set up to work as well as a good belt-driven, stock fan with a good shroud.

What electric fans have you tried.. CFM's, shrouded, unshrouded, single, dual, pusher, puller? It's physically impossible for a belt driven fan to outperform an electric fan if it's sized properly IMHO. A mechanical fan is limited by motor rpm's so it produces the least cfm at idle where it's needed most (no natural airflow) whereas a 3,000 cfm electric fan delivers it regardless.

I run a set of shrouded dual puller Spals rated for just under 3,000 cfm. Before installing them I had a clutch fan and shroud, worked fine unless I got stuck in traffic then temps would start climbing. Since adding the electric fans it never rises now.

 

[pnora]

That's a custom valance / cowling I had made to compliment the engine compartment clean up. I did take it off and drove around for a couple days, no noticeable difference. I really scratch my head when I read your statement and talk to folks cooling more iron than I am with similar or even lesser systems that have no issues at all. I just haven't found my sweet spot yet. Yes, ColdCase does list them but pic is rad only, no fans, I didn't search any further than that. Thanks for your input. Dale

Just click on the box below products and it opens the fan option for ordering as a kit.

 

[pnora]

What water pump housing are you running. There were many discussions about those being restrictive. Have you verified that your temperature readings are correct?

 

[Ron H]

Among the half-dozen things I did to obtain lower temps was reduced the ratio of coolant to around 35% since my car never sees winter and is stored in a heated garage. Researching engine oils (have solid lifters) came across how heavier weight oils can retain heat - 'racing' oils of the 20/50 visc were not so much advised for street driving. I had noticed how the oil pressure was always high and barely would move even after running the car 50 miles. Dropped to 10/30 since I don't race it anyway and the OP came down. Ok, not sure this did theee trick among all the things I did - but have reduced engine temps. Exploring electric fans - sure seems to be a love/hate issue...read enough to avoid this unless I got no results with the other things I did or getting a radiator.

 

[dburnett6263]

What electric fans have you tried.. CFM's, shrouded, unshrouded, single, dual, pusher, puller? It's physically impossible for a belt driven fan to outperform an electric fan if it's sized properly IMHO. A mechanical fan is limited by motor rpm's so it produces the least cfm at idle where it's needed most (no natural airflow) whereas a 3,000 cfm electric fan delivers it regardless.

I run a set of shrouded dual puller Spals rated for just under 3,000 cfm. Before installing them I had a clutch fan and shroud, worked fine unless I got stuck in traffic then temps would start climbing. Since adding the electric fans it never rises now.

For starters, to answer your questions, pretty much all the above. Any of the electric's rated less than 3000 CFM were dismal mistakes on my part. Everything prior to my current setup I did with a couple different 22" aluminum radiators. one an ebay special 3 tube, the other a good quality 2-1" tube with duel 11" HDX fans, 3000 CFM, which pulled about 50 amps and sounded like jet engines. This setup kept me out of danger but had to be very careful running the AC. I agree with you regarding electric fans and would love to keep my current 26", rated 3200 CFM, setup as it's a nice clean install. Comments here from diesel_lv make a lot of sense as well.
Thanks Dale

 

[747mopar]

For starters, to answer your questions, pretty much all the above. Any of the electric's rated less than 3000 CFM were dismal mistakes on my part. Everything prior to my current setup I did with a couple different 22" aluminum radiators. one an ebay special 3 tube, the other a good quality 2-1" tube with duel 11" HDX fans, 3000 CFM, which pulled about 50 amps and sounded like jet engines. This setup kept me out of danger but had to be very careful running the AC. I agree with you regarding electric fans and would love to keep my current 26", rated 3200 CFM, setup as it's a nice clean install. Comments here from diesel_lv make a lot of sense as well.
Thanks Dale

I went back and read his post, that's a good point and another reason to buy a quality unit. The unit I bought incorporated vents/passthroughs.. whatever you want to call them to address that issue. They have rubber flaps that work like check valves, at freeway speed they push open and allow additional airflow to pass through but at idle the pulling of the fans holds them shut.

This is with a 2x1" core BeCool radiator, like Ron, I run 10W30.

Honestly if I only drove my car close to home I would probably still have a mechanical fan, no traffic, no long lights.. no need. Sitting at the Canadian border, waiting in line to get out of the Nats, slow traffic at cruises, etc.. I need them.

https://www.summitracing.com/parts/spu-ix-30102052

 

[dburnett6263]

Among the half-dozen things I did to obtain lower temps was reduced the ratio of coolant to around 35% since my car never sees winter and is stored in a heated garage. Researching engine oils (have solid lifters) came across how heavier weight oils can retain heat - 'racing' oils of the 20/50 visc were not so much advised for street driving. I had noticed how the oil pressure was always high and barely would move even after running the car 50 miles. Dropped to 10/30 since I don't race it anyway and the OP came down. Ok, not sure this did theee trick among all the things I did - but have reduced engine temps. Exploring electric fans - sure seems to be a love/hate issue...read enough to avoid this unless I got no results with the other things I did or getting a radiator.

I'm running 50/50 mix with 2 bottles of water wetter. Straight 30w VR1, w/ a bottle of lucas oil stabilizer and a shot of comp cams zinc additive. Thinking on going to Joe Gibb's Driven 10w30 next go round. I only heat my shop when I'm out there so probably leave the 50/50 alone. Only non cooling thing I can think of, which just now came to mind, is I went with stainless steel headers this time around and I know stainless is not a real good conductor of heat. However really no different than the Hookers on it before. Thanks Dale

 

[dburnett6263]

I went back and read his post, that's an good point and another reason to buy a quality unit. The unit I bought incorporated vents/passthroughs.. whatever you want to call them to address that issue. They have rubber flaps that work like check valves, at freeway speed they push open and allow additional airflow to pass through but at idle the pulling of the fans holds them shut.

Honestly if I only drove my car close to home I would probably still have a mechanical fan, no traffic, no long lights.. no need. Sitting at the Canadian border, waiting in line to get out of the Nats, slow traffic at cruises, etc.. I need them.

View attachment 1150596

https://www.summitracing.com/parts/spu-ix-30102052

Thanks, I'll check those out.

 

[diesel_lv]

I went back and read his post, that's an good point and another reason to buy a quality unit. The unit I bought incorporated vents/passthroughs.. whatever you want to call them to address that issue. They have rubber flaps that work like check valves, at freeway speed they push open and allow additional airflow to pass through but at idle the pulling of the fans holds them shut.

Honestly if I only drove my car close to home I would probably still have a mechanical fan, no traffic, no long lights.. no need. Sitting at the Canadian border, waiting in line to get out of the Nats, slow traffic at cruises, etc.. I need them.

View attachment 1150596

https://www.summitracing.com/parts/spu-ix-30102052

I had the rubber flaps over almost every available space that wasn't the fan. It may just be my car, I've read many that work, but not in my heat. The explanation I was given was that the flat shroud causes a high pressure zone, keeping air from coming in at highway speeds even w the flaps. A louvered hood, raise rear of hood etc than help creat a low pressure zone would help suck air through at highway speeds. But for my car weren't an option.

 

[dburnett6263]

What water pump housing are you running. There were many discussions about those being restrictive. Have you verified that your temperature readings are correct?

To the best of my knowledge the pump housing is original to the engine. I have 2 electronic gauges, 1 being the Dakota Digital, the other the Terminator readout. Checking at idle with my laser unit, everybody's pretty close. Thanks. Dale