indigovette

Just about at my wits end with my car.6-71 blown small block New water pump, hoses, duel spal's, no stat, all seals around rad are good, can't get it to run cool. With both fans on after 20km of hwy driving I'm up to 220 I know it shouldn't be this hot, got the timing backed out 26 deg. total advance not just the gauge either installed a mechanical also. Please help !!!

NitrousSam

Lots of things to look for.

First, you need a t-stat or at least an aluminum restrictor ring because it is probably moving the water to fast and not keeping it in the radiator long enough to get the air to cool it down thus the water just circulates and is heating up.

Second, turn up your ignition timing to 30-32 degrees total advance and add a boost retard system that will pull out ignition timing based on engine boost.

Third, is it possible that you have the engine a little lean? Do you have a camshaft with tons of duration? Do you have idle pulsing or is the idle smooth?

These are just some quick ideas.

Happy Hot Rodding and enjoy some cool time ahead!

NitrousSam

How much compression are your running?

What size of header and are they coated?

How much boost or overdrive?

Is your engine a 400 SBC and if so did you add the steam holes in the heads?

big632

220 is not that bad,make sure to fatten it up til you see a little black smoke than back it off, 32 degrees is good timing start,18-22 initial,colder plug,make sure no vacuum leak.

norvalwilhelm

I run a 8-71 blown big block and I have worked out the cooling system.
I do NOT run a thermostat or a restrictor. After many tests I found it runs cooler without anything. Head temperature also equalizes faster without a thermostat.
I run my waterpump 30% overdrive or faster then the motor. My waterpump pulley is small.
I run 43 degrees of advance.
I run the engine lean, 15-1 at cruise and with power valves referenced off the intake, not the penum under the carb and it drops to 13-1 under load. I run an oxygen sensor.
I have a 3 inch aluminum rad.
I run 2 16 inch electric fans, each with a seperate switch.
Most of the time I run without any fan and the motor stabilizes around 185-190. In town I run 1 fan but as soon as the traffic clears out I turn it off.
2 fans in stop and go.
About 5 minutes from home I turn both on and the motor cools into the 170 range. I like to cool the motor before shutting down to prevent the heating spike on shut down.
I run 8-1 compression, 12 pounds of boost for 14.5 -1 compression under load and I do run a MSD boost retart computer to pull timing out under load.
MY motor would never see 200 with fans on.

Schmucker

Still have the chin spoiler?

norvalwilhelm

Forgot. I found this is important. It helps direct air up through the rad. I also found the motor runs cooler with the lights down or off.

norvalwilhelm

Mike I am just of opposite. I like lots of timing and I can adjust it from inside the car. I kept playing with it until I got what I felt was the best running condition and then checked it with a timing light. It was 43 degrees. The boost/retart computer pulls 2 degrees per pound of boost.

I also like them lean, my plugs are white after a cruise and my oxygen sensor is 15-1 or leaner but drops to 13-1 under load. I run standard heat range plugs. I have been running this exact combination 4 years without a problem. If you are seeing black smoke out the back you are washing the cylinder walls. I get an honest 15 mpg and never load up.

Again I like the motor a little cooler to prevent detonation and I find the blower likes to be cooler to keep the mixture on the cool side.
Even after hours of running I can pull the motor temperature below 180 with both fans on.
I do run wrapped headers which really helps under hood temperatures

indigovette

Still have chin spoiler, running a little on the rich side, 1 7/8 headders uncoated 2.5" exhaust 12% under drive 9.0-1 comp. stock L-82 block .030 over,

big632

There must be some mystery to your combo, no one here can run that much timing,run that cool and run 15.1 air fuel ratios without major heat. Let alone that much boost without 112 or better fuel.I have been running blower motors for years that put out huge power and it is just about impossible to stay below 200-220 water temp even with the new spal extremes and be cool radiators, I am adding a second rad to mine to see if it helps. I know mine is an extreme case but even mild ones are hard to keep cool.

Simmo

43 degress minus 2 degrees per pound boost, so when the throttle is down so is the timing. Indeed with 12 lbs boost in in theory he would only have 19 degrees total assuming full mechanical advance was in.

What Norvel has worked out is that retarded timing at cruise developes lots of heat in the motor. High volume waterpumps eg Edelbrock Victor driven faster than normal also help.

NitrousSam

I have a couple of questions for you: What kind of horsepower do you think you are making? Do you have a relatively stock camshaft or do you have blower specific camshaft ground on a 114 LS? Do you have a relatively stock torque converter and a highway cruising gear? At 55 mph what RPM are you turning? It sounds like when you are cruising your car at 60 mph your car would be cruising at 43 degrees of total timing because you truly would not be building boost unless you throttled it. I find 43 degrees of total timing on a big block high with a blower but you did say your plugs are white. The only thing I can figure out is that you are turning such a low RPM when you are cruising the car that it is not generating much in the way of heat which is why your car is running so cool. The way you have your cooling system set up it must be moving the water so fast through the radiator that it would almost bypass any cooling effect in the radiator (obviously this is not the case because yours is running cool). I totally understand your boost retard system because I have one on my 509 which has a 14/71 on it.

norvalwilhelm

Nothing mysterious at all.
For timing. First I built the distributor with NO built in advance, only fixed timming here. I then run a MSD timing computer that puts 20 degrees in electronically by 3000 rpm.
Next I have another MSD timming master that allows me to set timming up to 15 degrees from inside the car.
To set timming I first set the interior dial to zero, remember it has 15 degrees. I then bring the revs to 3500 or total timing and set the fixed distributor timing at 30 degrees.
I then take the car a cruise with it and play with the 0-15 timming *** just turning it , fine tuning the engine until it feels like it is running freely, no surging, no resistance, just a nice free running motor. This is only seat of the pants but the car seems to run the best at this setting. I later looked at the dial and it was 13 degrees, I then put a timming light back on the motor, bring the revs to 3500, remember 3000 was full advance and read the fulled degreed damper and it read 43 degrees. This is what the motor said it liked best, the seat of the pants anyway and this is where it seems to run the smoothest. Lots of cars running vacuum advance are in this area, actually most are well above 40.

norvalwilhelm

I am posting in stages because I could type out a reply and loose it.
For cooling I run a special 1 1/2 twin tube 3 inch grifin aluminum rad, a high volumn TRW aluminum pump running 30% overdriven. I make my own pulleys and calulated a small pulley with a smaller diameter then the crank pulley. 30 % less so the waterpump is driven faster then the motor.
I tested and run no thermostat, no restrictor. It runs cooler this way. I run 2 16 inch tornodo fans, each swith/relay controled and only run a fan or two if necessary but most cruising is without any fan. I like the motor around 185-190 max and with the fans this is no problem, I NEVER see 200 unless the motor is shut off in the shop then it spikes.
After over 1 hour on the road Wednesday night about 4 or 5 miles from home I turned both fans on and brought the temperature down into the 170's so when I parked it the spike heat temperature would not be high.
I can run anytime, in any heat and stay well under 200. I never see 220 unless it is heat soak from parking after a hard run and that is only if I don't run both fans for a few miles before shutting down.
Heat is never a problem. I do run the lower small spoiler and I find with the lights on and up of coarse it runs slightly hotter.
Leanness. I run the motor LEAN. I have an oxygen sensor and I run it at 15-1 and sometime above. I hand built the carbs, I buy new carbs and the first day before they ever see the car I tear them apart, fill in some holes, drill and jet others and reference the power valves off the intake, not from under the carb.
I run NO springs on the power valves and when the vacuum goes from vacuum to boost the power valves are blown open and mixture goes to 13-1.
MY plugs are white, I run normal heat range NGK 276. They last forever and like all new cars I beleive in lean mixtures for long life of the motor and flooding a motor is a quick way to shorten ring life. Also a lean motor puts out more power then a rich one. The old qualify motors for Daytona and the speedways run leaner and hotter then the race motor.
I get honestly 15 plus miles to the gallon.

norvalwilhelm

So I have covered my fuel mixture, my timing and how I keep the motor cool.
Boost is the last question. I run the blower 15% overdrive. Why because I want quick response at low rpm, off the lights, just normal cruising I want the boost right there.
With little throttle I get 9-10 pounds off the light without pushing it.
Sure if I buzzed it up to 7000 I would be overreving the blower but remember this is a street driven car only and my rpm is most in the 1200-3000 range. It has incredible torque in this area where all/most street driving takes place, sure I buzz 5000 occasionally but it is not necessary. Blower motors generate torque.
That led me to dumping the 411 gearing and going back to 308. The motor is quicker with 308's because in 3rd gear it hooks. With 411's I needed 4th before you could push it without totally breaking loose.
Trust me I totally scared myself when I pushed a little too hard in 3rd and put the car right around in busy traffic. 308's are enough that you can not push it in 2nd at all without lighting the tires up.
Anyway with more pushing the boost is around 12 psi.
I start with a blueprinted 8-1 and looking at a boost chart it shows 14.5 to 1 at this 12 pounds of boost. I run Sunoce 94 octane gas but do run a boost timing computer set to pull 2 degrees per pound of boost or 24 degrees out of the timing at full boost.
Regardless of what anyone says it works, works great in fact and I have been running this combination 4 year.
It never never loads up, never overheats and always seems to run great.
I have gone 10.28 with another motor and this is by far the best I have ever had.

norvalwilhelm

I had the heads privately flowed so the figures were honest and I fed all the known things into desk top dyno. On desk top it puts out 940 horse and the torque is close to that also. I never have and never intend to bother dynoing it. I do not race, I am only interested in a high performance cross country good running quick car. I do not drag race anymore nor ever do burnouts. I am just not interested.
The cam.. It is a normal street roller at 244@.050 and .623 lift on 112 lobe centers. It is not my choice but Lingenfelter recommended it to me years ago.
After blower 3 700R's in one summer I ditched them and went to a tremec TKO with .68 overdrive.
With the 308 gearing which worked alot better for me then the 411's and the .68 overdrive I have about 2.2 rear gearing on the open road.
1200 at 50, 1550 at 60, 1900 at 70.
I cruise alot in the 100 plus range and the car is very smooth at 120-130 where I chicken out. The fine in this range is $1200 plus 6 dimerit points and a short term liscense suspension. Plus the insurnace company will drop me. That is the only thing keeping me down.
When I am cruising in the 1500-2500 range I am not even running full timming, the motor is under light cruising load and if pushed the timming/boost controller will pull timing out anyway.
I ask the motor what it wants and by the seat of the pants it tells you if you listen.
I pull plugs regularly to check and they are white and look clean, sharp electrode and clean. In 4 years if I was burning the motor up it would have happened by now. I bet 99% of you guys are running too rich. I don't smell gas or burn my eyes letting the car idle in the shop.

I run no thermostat and no restrictor, just the way my friend and race car builder Roger does on his Cascars. I don't believe the water passes too quick through the rad to cool. I run a aftermarket gage and staying in the 180 where I like it is no problem. Sometimes I let it get to 195 briefly but then turn on a fan and I know that the twin fans can quickly pull it down into the 170 range in a few miles.
If yours system is really good you could let the motor heat to say 200 and then quicly pull it down like I can.
Since I run 2 16 inch fans I run one behinds and low and to the left and one in front, high and to the right. Each on a seperate manual switch. The entire rad is covered and overlapped.
My carbs are hand built by me after buying 2 new 850 double pumpers, 4 corner idle.
The combination works. No real mistery

big632

Well I guess I just make too much power to cool.With 640 cubic inches of real engine with a HI HELIX 14-71 supercharger running 20 over and propelling my car to low 7s at190 plus mph. I know all about timing control have a digital 7 with full crank trigger system with locked out advance set at 32 degrees with retard set to back off down to 24 at full boost which is 18-22lbs. Run only 118 renegade pro fuel.No one runs 43 degrees or wants a white plug and a fatter mix going thru a roots will produce way more power.I have full data aquisition on every run telling me o2 readings and egt,We have tried many timing curves and this one is what this motor likes,The bigger the bore the less timing is wanted.I think your combo is closer to 700hp from my experiance.If you run good gas you dont have to pull out as much timing.As far as cooling I have as state of the art cooling system as you can have but you can only cool down so much motor .Its all relative to how much power you are really making and generating heat.You can damn near ur a gas can down a supercharged BB and not run too rich.They love fuel.
I work on blown motors all kinds and have never gone past 34 degrees of timing.Cooling has always been a challenge with anything making big power.

norvalwilhelm

big632 I certainly am not in your legue, not even close and don't claim to be. Mine is a street car, nothing more. I put a tank a week through the motor and won't spend the money on specialty fuel, just not worth it.
The original question was how to cool a blown small block?
This should not be a problem. I posted what I do to keep my bigblock running cool and hopefully he can try some of the things I did and get the same results.

big632

I agree. Iam trying to make mine as streetable as you can as far as cooling. I have the be-cool rad, dual 16 extreme spal fans and meziere 55gpm electric pump,have tried thermostats restrictors and open,open is best with this engine, I have valves on the back of my heads and now Iam putting another radiator down in the lower valance with fans pulling the air towards the ground.This way all air coming thru the car has to go thru one or both radiators. It also adds over a gallon more coolant to the system which should help.I will know next weekend when it is finished. I will post pics and results. I would like to stay below 200 but it hasnt happened yet 220 seems the norm.I can live with that but would like to be a little cooler.Yes his small block should be much easier to cool if he works on the advice everyone has gave.

Twin_Turbo

Mike, your car is so customized, I'm surprised you're even sticking with stock size radiators and the stock shroud. Why not go with something like a big C&R or Fluidyne dual pass radiator, they can be bought in many sizes, the one I have is more than twice the thickness of the BBC rad.