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Discussion Starter #1
My stock BBC ran a little hot in my car and after a rebuild it has the same temp readings - around 215 - 220. Temp is stable in this range.

I have a 180 tstat and a Summit brand radiator - 24x18 core - 27.5 x 19 overall dimensions. It has a full shroud (sealed tight) w/ dual Summit 10" fans.

The shroud and fans came together - rated to pull 2210 cfm - http://store.summitracing.com/partdetail.asp?autofilter=1&part=SUM-381010&N=700+400304+4294924500+4294839058+4294838842+115&autoview=sku

The radiator seemed comparable to most of similar designs - the core measures 24" wide x 18 " tall. http://store.summitracing.com/partdetail.asp?autofilter=1&part=SUM-380428&N=700+400304+4294924500+4294839040+115&autoview=sku

Do you think the problem lies with not high enough cfm fans or too small radiator or both??? Trying to decide what will be the best upgrade to lower temps?
 

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BB Temp...

215-220 is too hot for a street driven car....if you get stuck in traffic...:eek: Where is your temp. gauge sender attached..?? cylinder head or intake..?? it will read higher in the head due to the exhaust heat. Get an infared temp. gun and double check your gauge. Make sure t/stat is opening....check for air bubbles in system...sometimes after a rebuild you have to burp the air out. I assume the water pump is new or rebuilt....start with all the basics...check timing, etc...

wilma
 

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Get yourself a Radiator Thermometer and when it is at the temp you think is to hot carefully take the pressure off the cap and check the temp in the Radiator Ive seen many a high dollar temp gauge not give the correct reading then you will know for sure what that actually 220 truly is and sleep better
i would dam near bet money its lots less at the radiator.
seen lots of pissed off people when they paid well over $100 for a guage back in the day to find out it read 30-40 degrees hotter than the radiator and that was with the sending unit mounted correctly on top of the intake by the thermostat housing.
just food for thought.
 

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Discussion Starter #4
My sending unit it attached on the intake, drivers side, next to the t-stat housing. This should be measuring the temp of the water right before it enters the radiator. I would think popping the radiator cap and checking the temp should be about the same???

I will double check it in the radiator to see if these temps match. I think I will let it warm up with the cap off vs. popping it and scalding myself :D

I run my timing at 28 deg - locked out, just richened the carb a hair to see if that helped - no diff.

The pump is new, I run a 180 t-stat that is working - would running the timing locked out build extra heat? I assume to much advance builds the heat???
 

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My sending unit it attached on the intake, drivers side, next to the t-stat housing. This should be measuring the temp of the water right before it enters the radiator. I would think popping the radiator cap and checking the temp should be about the same???

I will double check it in the radiator to see if these temps match. I think I will let it warm up with the cap off vs. popping it and scalding myself :D

I run my timing at 28 deg - locked out, just richened the carb a hair to see if that helped - no diff.

The pump is new, I run a 180 t-stat that is working - would running the timing locked out build extra heat? I assume to much advance builds the heat???
The only issue I see with checking the temp in the radiator is the coolant will have already passed though the radiator. This means it should be cooler then the coolant in the motor. You may want to use a temp gun and check it at the thermostat housing. Also, not enough timing can cause your motor to run warmer. When you "light the fire" it takes time for the fuel to burn. If you dont light it soon enough, that wasted energy gets expelled out of the exhaust ports and heats up the cylinder heads a bit more and increasing coolant temps at the heads. On my car, it runs 5-10 degrees cooler with 8 degrees more initial advance then it was and having a timing curve that has my advance all in around 2500-2700rpm.

I dont know your motors specs, but I think you could run with more advance then 28 degrees. I know they are completely different animals, but if you add up mechanical and vacuum advance(16 degrees) at an idle on my small block its around 34 degrees at an idle, 52 degrees at a cruise. My total timing is at 36 degrees at 2500-2700rpm.

But yeah, if it was running the same temps before, it is probably the gauge.
 

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With my BB 427 I have a 180* stat and it will run 190* crusing and 210* in alot of stop and go traffic. I have the same radiator as you but in a Griffin and a Taurus 2 speed fan.

Throw another 10* at it and see how it runs. Mine was running the same temps in 80* weather, then I went to 17* initial and 38* total all in by 2500 RPM's. That dropped the temp 10-15*.

My sender is in the head, I will be moving it to the intake soon and test with a gauge at the radiator.

Once in 110* temps it got to 234* on the freeway, but it help that and didn't go any higher. And GM doesn't consider "overheating" until 259*, although I would never want to go there.
 

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Hmmm, sounds like you have a handle on all the mechanicals. Even though its a new T-stat I would double check that and maybe even swap it out with a new one. If its open all the time then you will get real hot like that but not over heat cause the rest of the cooling system is trying to keep up. Ive seen a couple over heating problems with a "stuck open" T-stat. JR
 

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Temp Issues...

You need to know for sure how much centrifugal advance is in the distributor.....we set up most of our cars with 12-14 degrees at idle ( vac. adv disconnected )....22 degrees in the dist...36 total.....all in by 2800-3000 rpm. You definately want to have the vacuum advance hooked up....it will idle better, run cooler, and use less fuel. Check your plugs and see how the engine is burning the fuel....try and borrow a temp heat gun and double check temps in different areas like: t/stat, diff. spots in the rad., heads, block, etc...we run 4 core oem style radiators in most of the street cars...with 6 or 7 blade non-clutch fans...no over-heating issues. I also run a restrictor, rather than a regular t/stat...seems to work for me.

wilma
 

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Discussion Starter #10
Thanks for the suggestions - good to know others run 210 on a "normal" basis and I am in a safe range.

I prefer to run my timing locked out - no vac or mechanical advance. I will try advancing the timing a bit to see if that helps matters.

If not I might go a bigger radiator 31x19 overall vs. the 27 x 19 - the 4 extra inches in width adds up to 76" of extra cooling area.

Also I could stand to go with higher output fans.

Would running the fans directly mounted to the radiator without the shroud help????

I ask because when moving along I would think the shroud becomes restrictive at some point.
I might be better of without the shroud and just direct mounting the fans????? (opposite of what I would naturally think but ya never know). Anyone try this before?
 

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Your intial timming is going to have a lot to do with the temp. My car runs hot if my initial is below 14. Your fans should have enough cfm's.
 

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If you slowly take the rad cap off when hot the hottest you will see the coolant is 212. Thats what water boils at under no pressure. So that defeats the purpose of taking the temp.
 

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I've heard the Taurus fan moves 4700 cfm on the high side, does anyone know if this is accurate ?
I know it moves 4200+cfm.I'm not sure about 4700cfm though.I do know that it moves the living crap out of air.Plus you can get them at a junk yard cheap.
 

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My stock BBC ran a little hot in my car and after a rebuild it has the same temp readings - around 215 - 220. Temp is stable in this range.

I have a 180 tstat and a Summit brand radiator - 24x18 core - 27.5 x 19 overall dimensions. It has a full shroud (sealed tight) w/ dual Summit 10" fans.

The shroud and fans came together - rated to pull 2210 cfm - http://store.summitracing.com/partdetail.asp?autofilter=1&part=SUM-381010&N=700+400304+4294924500+4294839058+4294838842+115&autoview=sku

The radiator seemed comparable to most of similar designs - the core measures 24" wide x 18 " tall. http://store.summitracing.com/partdetail.asp?autofilter=1&part=SUM-380428&N=700+400304+4294924500+4294839040+115&autoview=sku

Do you think the problem lies with not high enough cfm fans or too small radiator or both??? Trying to decide what will be the best upgrade to lower temps?
Those fans dont cut it, I have one sitting here, Send the fan and the shroud back. That shroud dont look very efficient at all, the fan wont have enough power to flow what it says it does on the radiator and pull air through. Ive tried everything on my apps. From radical SBC , procharged BBC, and now turbo LSX.... this fan alone takes the win.
http://store.summitracing.com/partdetail.asp?autofilter=1&part=FLX-155&N=700+115&autoview=sku
It actually has power to pull air through the radiator. Works awesome.





215-220 is too hot for a street driven car....if you get stuck in traffic...:eek:
wilma

Thats what my 99 vette runs at all the time. Factory that way.
 

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If ya going to do a fan do the Taurus... the OEM style fans are designed for 100,000. mile operation and usally have much greater cfm than any after market fan... other wise use a very good mechanical fan....

this new electric fan stuff was for MPG not for HP.... and the small electrics ( fans and pumps) were designed for DRAG racing to cool off the radiator/engine between rounds...

The Taurus, Tbird, and Lincoln MK8 fans are the way to go.. but you will need a min of 140 AMP alternator to run the latter.
 

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I use pretty much the same radiator without a fan shroud.

difference is that you probably make more power, or your fans are not enough.

I use a $45 18" flexalite fan, 7 blade, and it moves A LOT of air. and absolutely quiet to boot.

try it out. its only 45 bucks.

it stays right at 190, sometimes going to 200, but I dont have a shroud yet.


also, I have one of those $20 caps that goes on the radiator that actually has a temp gauge in it. just a double protection in case the other one is off and also so you can see the temp if the car is idling and you are working at around the engine. they both generally read about the same temp.
 

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If you slowly take the rad cap off when hot the hottest you will see the coolant is 212. Thats what water boils at under no pressure. So that defeats the purpose of taking the temp.

In my minds eye, I am checking for gauge accuracy that is making sure 160 is 160 and 180 is 180 and so on. I know there will be a silght differance, but nothing drastic is what I am checking for.
 

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Discussion Starter #18
UPDATE - I ditched the radiator shroud and direct mounted the fans.... HUGE HELP!! Little recommendation - never buy the Summit fan and shroud combo... fans are not that effective and shroud is not good without louvers to vent better at higher airflow rates.

Now runs cool around town and on the highway, but still hotter than my 180 tstat. Also when exiting the highway and entering city driving my temp climbs beyond an okay level - 235 / 240 - no good. This temp increase starts to snowball and without a nice cruise my fans alone will not bring this under control.

NEXT STEP - bought a junkyard GEM.... Ford Taurus fan. This is going on this weekend. Also removing "splitter" behind bumper to let more air flow to the lower half of the radiator. Stay tuned..... if this doesn't work I will be selling my 25x19 alum radiator to buy a 31x19 with a 1/2" thicker core.
 

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My 67 was running 210 most of the time so I installed a custom made BeCool rad about 2" wider than stock and 2" longer than stock and used double 11" Spal hi-perf fans. The car now runs 180 all day long. I had to move the battery into the trunk to make room for the expansion tank.
Lorne
 
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