Ever seen or tried this?

[Jokester]

When I bought my 33 Chevy the previous owner had drilled and tapped threads into the intake manifold that led into the water jackets at cylinders 7 and 8.  He ran hose from those holes to a spacer under the thermostat housing.  He said it helped in cooling the rear cylinders.  I had never seen that done before.  Last night at a cruise in I saw a similar mod on a big block Chevelle, except that on it the hose ran from front to rear water jackets; like from cylinder 1 to 7 and 2 to 8.

Does this really help?  Does it cool the engine more, or does it just even out the temp at different locations in the block?

Thanks for your input.

.bjb

[enjenjo]

I have seen it done on sprint car motors, no experience myself. I'll ask my brother, he was a crew chief on a sprint for over 20 years.

[40]

I have also seen this done on circle-track cars years ago but have no personal experience.Seems it would definitely help distribute the heat more evenly but unsure about the additional cooling.

[chimp koose]

the more even cooling helps to reduce detonation in hot cylinders allowing for a more agressive tune on the motor.

[Jokester]

Thanks for the replies.  

How about this.  I was considering using the holes at cylinders 7 and 8 to plumb to an auxiliary radiator (more like a heater core) that would mount somewhere remote for additional cooling.  I have a small one that I could mount under a fender out of sight.  But the holes are only 1/4" pipe thread, so I won't get a lot of flow through it.

I'm not concerned about "aggressive tuning", as it's a relatively stock 327 driver.  My issue is high temps at highway speed when the A/C is on.  By "high temps" I mean it's just pushing the red area of my gauge.  It's never tossed out any water or gotten seriously hot, I'm just not comfortable having to constantly watch the gauge.  If I could take out 10 degrees, I'd be happy.

thanks again.

.bjb

[Beck]

Here is a trick I learned from 4 cyl Cummins diesel guys;
Some of those motors use a water to air cooler for the intake air. The turbocharger heats the air as it is compressed so cooling is used to cool the intake air. The problem with the stock setup is motor coolant is used for the water in the heat exchanger. Cooling with 180 deg water isn't very efficient. To get the water temp down in the heat exchanger they create another complete coolant system. The TRICK here is the use of school bus heaters. The rear mounted heaters in school busses have their own blowers. A small water pump is needed. If the water is passes through the school bus heater (radiator) the water is cooled. With their built in fan you don't have to buy another small electric fan. I don't know how much coolant you would see in use with an existing system, but it's a thought.

[wayne petty]

I'm not concerned about "aggressive tuning", as it's a relatively stock 327 driver.  My issue is high temps at highway speed when the A/C is on.  By "high temps" I mean it's just pushing the red area of my gauge.  It's never tossed out any water or gotten seriously hot, I'm just not comfortable having to constantly watch the gauge.  If I could take out 10 degrees, I'd be happy.

.bjb

coolant flow in a motor...   from the water pump.. into the block...  up the back and forward through the heads..  to the thermostat housing. through the bypass hose and back into the pump and the block, heads again and again..  this happens till the thermostat opens slightly..  this lets the cooler water in the radiator to get exchanged for warmer water  in the block...  the cool water closes the thermostat.. and circulates inside the block and heads picking up heat...  the stopped coolant in the radiator now can loose the heat from the airflow over the tubes..


without a thermostat...   the coolant rushes around faster and faster through the radiator and engine... the speed of the coolant through the radiator prevents the airflow across the tubes from properly cooling it ...

with a  thermostat thats too cool for the system..  .  the temperature differential is not enough to loose enough heat to properly cycle the thermostat...

so it gets into a runaway heating when running down the road...

it may allow the thermostat to cycle at lower speeds.. but at some speeds . or on hot days..  the thermostat will go wide open and let the coolant circulate faster and moving the temps into the HOT area...


some water pumps have been found to have universal direction impeller blades..    straight out form the center...  these do not pump water as well as directional blades..


having a bypass from the intake manifold coolant crossover.. to the inlet of the water pump allows coolant to properly circulate behind the thermostat.. and past the thermostat ... until it builds enough heat to open the thermostat...

making sure that any ram air through the grill is actually going through the radiator and not around it...

bring the engine rpms up and see if a shop rag will stick to the front of the radiator..   this will sometimes show that there is enough air flow from the cooling fan to properly cool the system...

investing in a hand held temp gun...

http://www.harborfreight.com/catalogsearch/result/?category=&q=Infrared+Thermometer

can really pay off and be useful around the shop...


most newer cars run a 192F thermostat..  the last digit of the part number is usually a 9....

this and 50% to 70% coolant mix with a 13 PSI or 16 PSI radiator cap will let you run safely to about 250F on long uphills..

normal operating range with these is going to be around 195 to 225..
this is just fine for most engines....

[58 Yeoman]

Some of the larger conversion vans also had/have rear seat heaters, though I don't know if it would be large enough to supply the kind of cooling that you are needing.

[river1]

I'm not concerned about "aggressive tuning", as it's a relatively stock 327 driver.  My issue is high temps at highway speed when the A/C is on.  By "high temps" I mean it's just pushing the red area of my gauge.  It's never tossed out any water or gotten seriously hot, I'm just not comfortable having to constantly watch the gauge.  If I could take out 10 degrees, I'd be happy.

thanks again.

.bjb

is your gauge accurate? you might be running at the motors happy spot but the gauge's inaccuracy is telling you that you're hotter.

later jim

[model a vette]

"I was considering using the holes at cylinders 7 and 8 to plumb to an auxiliary radiator "

The pressure difference between these two holes would be minimal. You would have to plumb both of them to dump into the pump intake to get flow.