Well if you want the real lowdown how about rearing testimony after testimony from your fellow team chevelle members in thier own words about thier experiences with elec fans having thier motors running 220-230 deg then per my rec removing the elec fans & applying my rec upgrades to gm clutch fan setup and getting 20 deg temp reduction on avg and sometimes 35-40 deg while in most cases retaining the same rad where elec fans had motor running 220deg.
I go by consistant results and thats what my rec setup delivers big time,consistant results time after time with many diff setups and perf lvls of bbc & sbc street perf motors.
This testament below shows his motor was running up to 230deg with elec fans and the 220deg with a flex fan. Then his motor temp was reduced by 40+ deg to 185-190deg tops in 85 deg temps with a 772 clutch fan and HD hayden 2747 fan clutch along with other suggestion i made too .
Thats a solid 35 - 40+ deg reduction in engine temp depending on if compairing to elec or flex fan setup which is a significant temp reduction post following nmy rec setup.
I have been busy these couple of weeks after I did the upgrade, so I havent had a chance to
take her out again on a warm day.
I do plan on bringing her to work on friday, it is suppose to be in the low 80's on friday. So I will test her out then.
Just for anyone following this thread, I am giving you a little run down of what I been doing.
I been battling the hot temps on my Chevelle for a few years now. I had the flex-a-lite electric fans with a Mr. Gasket HP 160 t-stat. On warm days, she will get up in the 210-220 while cruising, on stop and go traffic there would be times she would hit the 230-240 mark in traffic. When this would happen I would just pull over and let her cool a bit. The I dumped the electric fans, and went with a 6 blade flex fan I had laying around, and thru on the stock 70 shroud. Temps got a little better, but would still hit the 210-220 mark on stop and go traffic.
A few weeks ago, I just pretty much had it, I just couldnt get good cool running temps on her that I would honestly not even drive her around in late spring, summer or fall. Only winter and early spring.
Well after posting my problem on here, Scott suggested a few things. Which I tried and so far I can say it has been succesfull.
1st I dumped the 6 blade flex fan, went with the stock 7 blade 772 fan, I also purchased the Hayden 2747 HD clutch, but kept the Mr Gasket 160 t-stat. I also switched from the 70 shroud to a 71 shroud (which the 71 covers the whole radiator, which the 70 does not). Temps got better, took her out on an 80+ temp day and in stop and go traffic. Temps where about 185-190 on 85+ outside temp with stop and go traffic.
I was very pleased with this. though now I changed the Mr. Gasket 160 t-stat and went with a standard autozone 160 t-stat Scott rec, I also drilled 2 extra holes in it.
Now this friday, I will take her out again, on 80+ outside temps and in stop an go traffic. now i will see what she will do with the standard autozone t-stat. Which i think it will do better than the Mr. Gasked HP one. After I installed the standard 160* t-stat i did take her out on a quick spin, and she never hit the 165 mark. but then again, it wasnt hot that day, it was in the mid 70's.
I hope all this info will help any fellow TC member with the similar problem I had.
Once I take her out on a hot day, I will report my findings.
Thanks Scott for all the help, and thanks everyone else that had thier .02 in it
Followup from the original poster for his above post when he tested the autozone duralst 15356 160 stat vs a hi flow mr gasket 160 deg stat.
I did take the Chevelle out on friday to work, and hit stop and go traffic on the way home, though outside temps werent as warm as I expected. Outside temps where high 70's, maybe like around 78-80 outside, BUT the good news was that even on stop and go traffic for a good 45 min stretch, she never hit 185. She was steady for the whole time in traffic at around 180, climbed to 185 when traffic started to pick up, but then she dropped to about 175-180 all the way home.
Thanks again for the great advice. I would definately say the standard autozone 160 t-stat beat out the Mr. Gasket HP 160 t-stat.
FINAL FOLLOWUP UPDATE:
Jul 5th, 11, 10:32 AM mad70ss Tech Team Join Date: Sep 2006 Location: Corona, CA Posts: 685
Re: Help on 70 BB overheating issues....**UPDATE**
Ok, here is an update on my Chevelle....
Took her out this past friday, brought her in to work. After work, on the way home, outside temps were in the 90's. Hit about a good 30-40 min of stop and go traffic. In 90 deg heat she got up as high as 190. Did not go higher than 190. Driving down the freeway with no traffic, she was doing 175-180.
WOW!! What a difference, before with the elec and or flex fan, she would be doing 210 easy and forget about being stuck in traffic.
I am very pleased with the new set up (7 Blade fan, clutch, 71 shroud and 160 autozone t-stat)....
thanks again Scott.....Now I can get to enjoy her on the summer __________________ _____________________________________ Ralphy Corona, CA "MAD70SS" 1970 Chevelle SS http://i103.photobucket.com/albums/m...kers064-vi.jpg
1996 Chevy Silverado Z71 1996 Impala SS (SOLD)
In summary this case from the above testimony showed his motor went from running up to 230 deg in traffic with elec fans and up to 220deg in traffic with a flex fan to running 175-180 deg on avg with my rec cooling system/motor tune setup.
Here's another example (pasted below) of going from a dual elec fan seup that was running as hot as 220 in traffic to a gm 772 fan/2747 hayden HD clutch fan/and stock type fan shroud reduced temps by approx 40 deg.
With an AC Condenser on my Chevelle and the trans cooler pressed up against the radiator the (12" dual puller Flexalite) dual electric fans I had just wasn't enough air flow at idle and low speed. Temps crept to 205 and kept rising in traffic to 220 on a 90 degree day.
So replaced the dual electric fan setup with a '71-'72 28" stock type 2 piece fan shroud, installed the gm 772 fan i already had, and a HD Hayden Fan Clutch (2747 ).
Was hoping I didn't have a bad radiator.
It was about 85 degrees yesterday, took the chevelle for a ride and tried to heat her up. Highest the motor saw in 85+ deg temp temp was 179 at cruise & when sitting in traffic it actually went down to the high 160's.
I would call it a 40 degree drop in idling temperature.
I do have a brand new Dual Fan setup in the box, but that is where that will sit.
ANOTHER EXAMPLE OF STOCK COOLING SYSTEM OUTPERFORMING AN AFTERMARKET AL RAD & ELEC FAN SEUP.
Feb 3rd, 12, 1:06 AM jm209modesto josh Join Date: Feb 2012 Location: modesto ca Posts: 3
THIS GUY WENT FROM A GM CLUTCH FAN COOLING SYSTEM THAT WAS COOLING JUST FINE TO AN AL RAD WITH ELEC FAN ,SEE THE RESULT IN HIS OWN WORDS PASTED BELOW.
Hi,i have a 67 chevelle 468ci engine i recently upgraded from a stock radiator,mech fan,mech w-pump to an aluminum also electric fan and now my car now runs hot. it doesnt get hot right away after driving for about 30-45 minutes it starts creeping up. it never got hot when i had mechanical water pump mechanical fan and a stock radiator..
HERE'S ANOTHER TEAM CHEVELLE SUCCESS STORY
Took the car out today for a cruise. It seemed to be running a bit warm. It was about 86 degrees today, but the motor was running about 220. In the winter months it get up to about 210 and stays there. I noticed this last summer, and at times it would creep over 220 when at a stop light. I am running stock 4 core radiator with 50/50 antifreeze, and a 180 thermostat. Is there a better coolant mixture that may help with this? Living in Colorado the summers get a bit warm.
ORIGINAL POSTERS RESPONCE POST FOLLOWING MY INSTRUCTIONS:
Today, 12:03 AM MikeSS Lifetime Premium Member Join Date: Jan 2005 Location: Aurora, CO Posts: 229
Re: Car running a bit warm
I just finished up the mods to the car to correct the heat issues. I had initially been running about 210 degrees just driving around town.Sitting at a light, or in stop and go traffic, the temp would rise to 220ish. This was all with an incorrect 4 core rad and a 180 thermostat.
Scott Wheaton made a few recommendations, and I put them into place.
Here is what I did.
-Replaced the fan clutch, with a Hayden HD 2747. That mod alone dropped the temp to just under the 210 mark. -Replaced the radiator with a stock style 4 core (manual trans) -Installed a 160 degree thermostat -Replaced the old coolant with a 30% coolant, and a 70% distilled water mixture
Drove the car and the temp while cruising is about 176 deg. At a stop light, sitting for about 4 min, it crept up to about 185 deg. Overall this reduced the operating temp about 20-25 deg total.
Thanks for all the help Scott. __________________ MikeSS 70 SS TC Member #5479
Here's a couple examples!
I have a 71 Chevelle with a 496 built pretty tough and having trouble keeping cool. Went from 4 core radiator with single electric fan to a 2 core 1 inch tube aluminum radiator with dual 14 inch fans and when running on the highway on hot day running around 215 to 218.I had a 50/50 mix of water and antifreeze, but water out of a hose with a 180 thermostat. I have 4:11 in rear end and running about 2500 rpms at 55 to 60 mph. If I run faster than 2500 I will creep up to 220 and thats when I pull over to cool off.
SWHEATON posted many threads about how to cool these BB down. I wasn't on board because aluminum rad and dual fans come on that should do it without problems right NOT!
Well many posted how well it worked doing what SWHEATON suggested.
I decided to drink the Koolaid. It worked better than I expected. Here is what I did:
I kept the aluminum radiator and changed the mix to the 70/30 distilled water and straight antifreeze. Changed the thermostat to the autozone 160 and drilled the 2 holes. I ran the car this way with no change. Decided to go all the way. Pulled the electric fans and shroud and replaced with a 772 7 blade fan with the hayden 2747 clutch and orginal shroud.
Here is what happened: went for a drive in 90 to 95 degree weather and to my suprise I ran about 190 to 195 average on the highway at 2500 rpms. Took it up to 3000 rpms and stayed about the same. Ran up to 4000 to 4500 for couple of min ran about 185. I did creep up to about 197 for brief time but never went over 200. Got into town and ran about 185. Plan to go on a drive on a hotter day above 95 deg to see what happened but so far
SWHEATON I am a believer now Thanks for helping with cooling my BB down. JP
Another followup in extreem temp on this same motor/car! _
Well here is my update on a hot 98 day and 2nd trip after changing everything Scott suggested.
Today I went to a car show and it got up to 98 degrees today. On my way to the car show I ran average of 185 on highway doing 3000 rpms and when I got off the highway and pulled up to register I was 178. On my way home at the hottest part of the day I averaged 190.
This car used to run as high as 220 deg at 3k rpm cruise speed in similar temps but now avg
185 deg (35 deg cooler!) in same cond!
I have to give credit again to Scott because I have been fighting this cooling problem for over a year and was afraid to drive my car too far of fear of overheating and when I did drive I had to take back roads to keep my rpms down so that I wouldn't overheat. This sucked because you spend so much on these cars and its a bummer to have problems like this that you have to question to go somewhere with overheating in that back of your mind.
Thanks to Scott ready to drive and go anywhere!
Of all the things I have lost, my mind is the thing I miss the most!
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#2 Jul 10th, 12, 10:29 AM 1971ss454Elco Tech Team Marc Join Date: Nov 2008 Location: california Posts: 969
Re: Overheating! SWHEATON Thanks for the help!
Scott helped me as well on our 71 SS 454 which used to run 225-230 degrees.
We now run 175-180 degrees on 100 degree day weather here in cali right now WITH A/C on no less.
Stock appearing LS5 with A/C, TH400 and 4:11 rear.
Alumitech replacement rad, stock shroud, HD clutch w/stock type fan.
Timing correct, carb tuned, foam tape used to seal shroad to radiator and radiator to support. All new hoses from pacecarJeff.
ANOTHER TESTIMONIAL !
My '70 started running hot (210 and climbing) with a big block conversion...usually on hotter days, for sure in traffic. I went with Scott's (SWHEATON) advise: '71 Fan shroud - full radiator coverage A-Zone 160 thermostat HD fan clutch Summit HI-Flo Pump. Now, In 95 degree heat it tops out at 190 degrees MAX!...cruises at 170-175 all day.
ANOTHER ELEC FAN RUNNING HOT SETUP TO A TWEAKED MY WAY GM CLUTCH FAN SEUP SUCCESS STORY!
Bellow is the testimonial from a t/c memeber:
I like threads that have some type of closure to them, so here is the update.
After pulling the thermostat, I was driving around in 90+ weather and thought I had my temp issue fixed, then on a drive of stop and go in in 90+ degrees outside, it started to get hot.
So, I followed Scotts suggestions and purchased the 2747 Hayden fan clutch, and it bolted right on my short shaft water pump no problem. I added a radiator spacer in my car to put the radiator where it would be with a big block, essentially moving it a bit farther away from the fan, so it would be situated in the shroud perfectly. Since I wasn't going for stock, I found and installed a shroud from a 68 impala, which covers the entire core of my radiator. I also found a 7 blade thermal clutch fan at a junk yard that would fir in the shroud... I believe it is an 18" fan. I threw it all together, put the 160 degree thermostat back in and just got back from an hour long spirited drive in 93 degree weather.
Temps didn't even hit 190. They moved from about 183-186. As stated earlier, my temp sensor is in my intake manifold as the correct 461 heads from 65 don't have provisions for the sensor, but with nothing else changed, I just decreased my overall temp from my dual electric fan setup that would climb to 225+ in traffic, to maxing at 186 in the same conditions.
Thank you so much Scott for the help with this, and I hope this can help someone down the road.
Long story short, is it possible to make dual electric fans cool a SBC or BBC? Probably, but you will spend MUCH more money doing it. MY stuff was middle of the line and my SBC was mild and the $400 shroud/electric fan setup i was running couldn't hold a candle to the cooling of my $3 7 blade GM clutch fan fan with $50 fan clutch, and stock shroud (cost $40). I wouldn't have been a believer, but this concludes my case study.
My/Scott's responce :
WOW,thats a solid 35-40 deg reduction in temps over elec fan setup showing once again the tweaked gm clutch fan setyup i rec blows the avg dual elec fan setup away.
HERES TESTAMONY OF A T/C MEMBER GOING FROM A 6 BLADE NON STOCK CLUTCH FAN TO A 71 & NEWER GM CLUTCH FAN IN A 71 & NEWER FAN SHROUD SETUP HE ALREADY HAD ON HIS 69 CHEVELLE THAT COVERS COMPLETE RAD VS STOCK FOR 69 CHEVELLE SHROUD THAT ONLY COVERS 75-80% OF SHROUD ALONG WITH ALSO DOING MY SUGGESTED MODS
TO GM'S CLUTCH FAN SETUP TO REDUCE TEMPS MORE THEN STOCK GM CLUTCH FAN SETUP CAN DO .
NOTE:THIS CAR STARTED OUT RUNNING UP TO 195 @ CRUISE AND 220-230 WITH AC ON ESP WHEN AT IDLE FOR ANY LENGTH OF TIME IN TRAFFIC.
Well I just wanted to give an update on the fan issue. I finally located a GM 19 inch clutch fan off a 72 chevelle that was a factory ac car. It made a noticable difference in how much better it cools epsecially when at a stop vs the flat 6 blade I was using. It has the curved blades just like the 772 my buddy has on his big block vs the flat 6 blade non GM clutch fan I was using.
My setup that was running too hot was a 3 row aluminum radiator, 71 shroud ,non GM flatter 6 blade cooling fan,std duty fan clutch,180 stat,HD water pump that was running up to 195deg at cruise and 220-230 with AC on especially when sitting in traffic idling .
Then i added a 19 inch GM curved blade clutch fan in place of the flatter 6 blade non gm fan, added a hayden 2747 HD thermostatic fan clutch in place of the std duty fan clutch, added an autozone 160 stat with one relief hole drilled in place of 180 stat.
Anyhow, it went from reading 220-230 deg to now around 200 to 205 when testing it at a dead stop (sitting idling) for over 15 minutes with the ac running. (Thats a 25-30 deg temp drop idling with AC on!)
I would say I'm now doing 180deg when cruising (15 deg temp drop at cruise) and 195 after stop n go driving (30+ deg temp drop in traffic) vs the 195 deg at cruise and 220-230 deg in traffic with AC it used to run before adding the upgrade parts SWheaton suggested.
I definitely have the best setup now for cooling compared to flex fan and dual electric fans I have used in the past.
Thanks to all who helped with advice and tips!
================================================== === __________________ SCOTT 1969 CHEVELLE SS396/4SPD/M20/12BOLT/3:31'S ORIGINAL #'S MATCH/OWNED SINCE 1978. 1977 KAWASAKI KZ1000 (ORIGINAL OWNER) 1976 KAWASAKI KZ900 2006 YAMAHA 1700 ROADSTAR SILVERADO ================================================== =====
May 29th, 13, 8:54 PM
Lifetime Premium Member
Darren Join Date: Mar 2004
Location: Omaha, NE
Low dollar, BIG cooling
Just thought I’d share some of my experiences and pics all in one place with part numbers and a little how to……. I’d also like to thank everyone here that helped me along the way. Before: 3 hole top plate, copper core radiator.. with electric fans taken from an LT1 Camaro. Temps exceeded 220 often. After: 4 hole top plate, Aluminum radiator and the things below…. I couldn’t get it to 190 no matter how hard I flogged it, 102 outside temp. Parts list: • 4 Hole chrome top plate Ebay = 20.00 • 19 inch XT1 -7 blade fan - U pull it = 10.00 • Hayden 2747 HD clutch = 49.99 • Murray 433322 -29 in wide, 18 inch tall Aluminum radiator (specs on their website are jacked up, trust me it drops right in) I paid = 140.00, Listed at 159.00 right now. • Shroud 1971 BB (one piece) from Summit OPG-00T218R = 59.95 • Upper hose Gates 21204 15.00 • Lower hose 21324 lower 12.00
* 160 stat Total 307.00, rounding up. I gained a brand new free flowing aluminum radiator & car that I can’t get to run over 190 with it being 102 outside.