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Need cooling help on blown big block

11K views 6 replies 5 participants last post by  bln 
#1 ·
I need some cooling help on my application. I have a 496 BBC in my 67 Chevelle. It has a 8-71 Dyers blower and is running about 5.5 lbs of boost. The car runs 9.66 in the 1/4 mile at 4050 lbs with driver. With the original build, I was not able to fit a fan as a puller behind the radiator due to clearance issues with the blower belt (long water pump housing set up). I ran a pusher and no thermostat and the temp would climb up to 220 - 230 degrees which I think is too hot for this street cruiser. Recently, I modified the radiator support and set the Be Cool radiator (rated to 700 hp) back a few inches and was able to install 2 12-inch puller fans to give me a 2400 flow. I put in a 160 degree thermostat and the car now still climbs up to 210-215 degrees. I have antifreeze and water mix with purple ice in the system. I have the big Meizere water pump as well. The fans take up just about the entire surface of the radiator so I did not need to have a shroud.

Is there anything else that I can do to get this beast to run cooler on the street? I do not ave room for a larger radiator. Is 210 all right? Am I experiencing a heat soaked condition with the blower? Would an under blower cooler help? Should I remove the new thermostat or use a restrictor plate in its place? Any thoughts would be appreciated.
 
#2 ·
210° isn't all that bad, but most everyone I know would like to see it lower - unless your sensor is in the head, then it's probably fine - sensors in the head seem to run 20° hotter than in the manifold.

Get a high flow thermostat and waterpump. Stewart waterpumps as an example.

Make sure none of your hoses are collapsing.

Look at airflow that might be going around the radiator instead of through it, and correct. I understand even small air dams (hidden) under radiator help force air through it. Also, look at ways to get the air OUT from under the hood, like fender openings, etc.

Check your timing and air/fuel ratio, if off it could be part of the problem.

Check with Don at Alumitech for some custom options that would cool better. I'm sure he could set you up as needed.

last resort: www.evanscooling.com - won't cool any better, a little more difficult to set up at first (don't mix with water), but it won't boil over or have hot spots even at higher temps.
 
#3 ·
when you are using pusher fans, you need some pretty good ones(like spal)
what happens is the fans are trying to blow the air thru the radiator, and if their not strong enough, it just doesnt happens-i had a 67 el camino with a b/b with a 1/8" overbore, 671, and it would run hot-i used to spal pushers and it needed them both at times, but it cooled-how does it run when cruising, cooler than idle? sometimes you have to use water restricters, experiment with stuff-if other stuff is contributing to heating, the radiator cant compensate, no matter how good(expensive)-every time i put a new car together, i always wonder how the cooling is going to be-hell, i know guys that have tried every trick in the book and couldnt get it to cool, then i have seen crappy little radiators with a stock shroud and mech. fan cooling 600" motors-you never know
 
#4 ·
My next move is to remove the thermostat and try a restrictor. I will start with the medium opening and go from there.

Any other thoughts?
 
#6 ·
Ok I guess I will chim in here .

Mark (Xtreme70SS396)
makes some good points here

the fact that your using a Meizere water pump electric ... you need to be at 55 gal a min ... you may be only 35 gal ... these are ok for strip use .. where you can run your cooling fans and water pump to cool between runs
but for street use not the best ....keep in mind hi flow is most important along with hi cfm draw trough the radiator .
there are several things that can work against you trying to keep cool
when you run boost .. you must compensate with air fuel mixture .. not to get to lean ... richen things up this will help to run cooler .. who cares if the guy in your rear view mirror is caughing his head off....lol
timing must not be too retarded .. this will cause over heat conditions ..
sensor location .. should be in the manifold .. not the head .. but i never trust gages .. a i/r gun shot at the t/stat housing will give you a truer reading of what is really going on .
Ok back to the rad fan combo
Be-cool cross flow converson ... you have already moved the rad foward to make room for puller fans ... problem is your pulling air trough the size of the fan disks aprox 800 sq inchs each and a lower cfm then needed ... here is my suggestion .. if you can move the rad foward enough to drop in the spal twin 11 inch with complete shroud this will give you 400 sq inchs of air trough the core and 2800 cfm
Do a search here for ALUMITECH and see what other guys with this fan set up are running at ... check this link pdf file for the print of the fan
http://www.spalusa.com/fans/automated/tech_sheets/2052.pdf

Don Alumitech Reproductions
 
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