Overheating Problems!!???!!

[enduro racer]

I run a factory stock in 100 lap enduro races. Metric monte with a 355 SBC. I'm having big problems cooling the engine properly!! We only race every 3 weeks and just had a race this past weekend. The air temp was in the low 70s and my car was running at 230F! I had the same problem last year and really want it fixed.

I screwed up a little while building my engine (rookie). I put factory rebuild pistons in and didn't deck the block so the pistons are 0.020" down in the hole more than they should be. Could this be my problem? I don't have the time or money to build a new engine so please don't recommend I tear down my engine. I'm going to try to get a spare and then replace it over this winter. It has lower compression 72cc heads on it and flat top hyper pistons. I have some double humps bur I hear this will make my problem worse.

I run a rochester Q-jet that was brand new last year. The car starts and idles great but I didn't really tune the carb much at all. how do I do this? Will this help my overheating? It bogs for a quick second when the secondaries kick in but that seems to be a separate issue. Can this be solved with tuning the carb or does it sound like an accelerator pump issue?

My cooling system consists of a GM 3 row radiator (must use factory radiator) 6 blade 17" fan, 3-4" from rad, stock monte shroud. I can probably squeeze a 18" or maybe even a 19" fan in there. Should I try that? What fan should I buy?

Also, I have a crappy stock lower radiator hose without a wire in it. I have a proform high flow water pump with a 180F t-stat with 2 holes in it. Anything I should do differently there?

Any help will be greatly appreciated!!

[Egoracing]

Replace the bottom hose with a performance hose and get rid of the T-stat unless it is a high flow fail safe T stat. Check the radiator, you should be able to see thru it with a light on the other side. If you can not the radiator tubes have been expanded and you are not getting any air flow.

[enduro racer]

I will double check the pulleys but they really seem to be the same diameter.

Where can I get a 19" GM fan? Where can I get a molded hose or one that will not close? I tried the universal fit ones and neither worked. I found one for the upper but not the lower. The car is a 84 monte.

I forgot to mention I have distilled water with water wetter in it in the radiator and I can see right through the fins on the rad.

The shroud definitely is not the best for the fan I have on it. Are there any others they sell that would work great without me making my own? I don't really have much to work with as far as tools and supplies to make my own. Not to mention a lack of time. I'd rather buy one if the price was reasonable.

Where should the fan be positioned as far as distance from the rad and distance from the end of the shroud? I heard half in half out of shroud and as close to the radiator as possible. Is this right? My shroud would not be very deep if that were the case and I would think I'd be cooling the center of the radiator and neglecting the ends.

[dluna11w]

Cheapest place I have found the 19" GM Four blade is:
rockauto.com

ACDELCO Part # 1580752 {#00405442, 405442}
Category: Radiator Fan Blade

$40.99

[enduro racer]

Excellent, thanx. So the GM 19" 4 blade is better than an AFCO or other aftermarket fan? That's hard to believe.

[dluna11w]

It is a diesel fan. Much more pitch on the blades than the afco and other knock-offs. In staging, I can feel this fan blowing on my face

[rubbinsracin]

the fan should sit so half of the pitch of the fan blade is within the shroud. a good shroud is worth its weight in gold and then some. id spend a few bucks and pick up a good one or have someone that really knows how to build one put one together for you. if you want to go the easy route here is about the best option we have found if you just want to order one: http://www.summitracing.com/parts/HRE-34307/?rtype=10

also make sure you have a good radiator cap on it too the higher pressure the water is under the higher the boiling point. pick up a new high pressure cap one and get rid of that t-stat. youre running 100 laps, keep that sucker cool.

also, do you have any type of opening in front of the radiator or do you depend on getting all your air from under the car?

[Egoracing]

I would not go to high a pressure cap on a stock radiator.

[enduro racer]

Well I like the 19" fan but with that shroud I can only run an 18". I'll definitely pick up one of those fans. I definitely cannot feel the air on my face when lining up.

I just replaced the cap before the last race. What pressure cap should I be running? I don't want to burst any hoses.

I heard getting rid of the T-stat completely will make the cooling problem worse??!! It makes the water go too fast through the radiator or causes the pump to cavitate. True or false? I have no allegence to running a T-stat but I don't want to make the problem worse. I tried ditching it one race and the problem was no better. Maybe I'm collapsing the hose? Where can I get a non-collapsable hose that will fit? All i get on speedway motors is this:

http://www.jrmotorsports.com/searchD.cfm

Found this on summit. Might work??

http://www.summitracing.com/parts/MRG-11010B/?rtype=10

or a molded one? but this looks just like a stock one that will collapse.

http://www.summitracing.com/parts/GTR-60620/

I have a big opening in the front. I still have the stock bumper cover and the molded plastic piece around the grill and headlights but the grill is removed and the there is "screen door" screen and one layer of chicken wire covering it to protect the radiator (I had one get destroyed by not having enough screen there). here's a pic of the front of a monte like mine. Like I said, I have everythign except the grill and headlights and there is a screen over the middle. i even added an airdam before the last race to hopefully get more air up from the bottom.

http://www.google.com/imgres?imgurl=http://cache.gawkerassets.com/assets/images/12/2010/03/500x_84monte-front-500px.jpg&imgrefurl=http://jalopnik.com/5486155/1984-chevrolet-monte-carlo-cl&usg=__GFt6el7SKqlg0H64KUcW2kSIvyQ=&h=334&w=500&sz=55&hl=en&start=70&zoom=1&tbnid=cYA9R2lfpIWAHM:&tbnh=164&tbnw=219&ei=2cLbTcyrHsfe0QHxuqnADw&prev=/search%3Fq%3D1984%2Bmonte%2Bcarlo%2Bfront%26um%3D1%26hl%3Den%26client%3Dfirefox-a%26sa%3DN%26rls%3Dorg.mozilla:en-US:official%26channel%3Dnp%26biw%3D1272%26bih%3D873%26tbm%3Disch0%2C1881&um=1&itbs=1&iact=hc&vpx=371&vpy=486&dur=2606&hovh=183&hovw=275&tx=128&ty=99&sqi=2&page=4&ndsp=20&ved=1t:429,r:1,s:70&biw=1272&bih=873

[rubbinsracin]

when i first started racing hobby stocks back 10 years ago, we ran a 13lb cap all the time with our stock radiator. if your radiator cant handle that kind of pressure, you should change the radiator with an OEM replacement. heck in a pinch we even bought a cap from the modified next to us that had a 28-32lb cap and had no problem running it for last month or so of racing for the year.

just go to your local napa or any national chain parts store and they should have some hoses that have the wire in them.

also, does it state that you have to run an OEM radiator for that car? or can it be any OEM radiator? if it can be any radiator, i would find the biggest baddest OEM radiator out there and put it in. probably something out of like a caprice cop car if i had to guess.

[Egoracing]

A common misconception is that if coolant flows too quickly through the system, that it will not have time to cool properly. However the cooling system is a closed loop, so if you are keeping the coolant in the radiator longer to allow it to cool, you are also allowing it to stay in the engine longer, which increases coolant temperatures. Coolant in the engine will actually boil away from critical heat areas within the cooling system if not forced through the cooling system at a sufficiently high velocity. This situation is a common cause of so-called "hot spots", which can lead to failures.
This is STRAIGHT from the company that has more water pumps on more Cup, Nationwide, Truck, Arca, IMSA and other classes than any other mfg. Here is his website: www.stewartcomponents.com
Read the Tech and questions areas. In the tech you can click on the "tech tips" 1-5 for more info.

[Egoracing]

Go to Stewart's site.
"We strongly recommend NEVER using a restrictor: they decrease coolant flow and ultimately inhibit cooling."
Pressure is a product of the pump and water temperature, creating false pressure with a restrictor only inhibits flow, No on would run a 3/4 inch radiator hose but they will put a 3/4 inch restrictor in the line when in reality the 3/4 inch hose will flow more water smoother than a 2 inch hose with a restrictor due to the turbulence in the flow caused by the restriction.

Oil temps are affected by MANY things that have NOTHING to do with the coolant. Crank and rod friction increase oil temps but will not raise water temps until it is melted into one lump.

[enduro racer]

Ok, so, I should:

Replace my lower radiator hose with one that has a wire in it
Where can I get one? I tried the universal fit ones from Napa, they were either too long or too short.

Remove my thermostat.

Get a GM 19" fan and position it half in half out of the shroud.
Why would 1/2 in 1/2 out of the shroud be best?

Get a new fan shroud that will accommodate the 19" fan

Replace my cap with a higher pressure one
My current setup does not push water thru the cap. Anyone know the max pressure for a stock rad?

Replace my coolant with straight distilled water with a corrosion inhibitor.



I'll give this a shot. Anyone have any other ideas?

[rubbinsracin]

go to your local NAPA or any national chain auto parts store....thats where we get ours.

- take out the t-stat. it inhibits to much flow
- run the biggest radiator possible
- put at the very least a 13-15lb cap on possibly even up to a 20-22lb. when we went to a 13lb cap over the stock 8lb cap we dropped about 10*
- possibly build a cheap air dam along the sides and top in front of the radiator to keep from losing air that just "goes around" the radiator. we gained 10* on our LM with this
- build or buy a good shroud. probably worth 20* easy
- also might want to try to richen up the carb a little bit. pull a plug and make sure you arent running to lean.

[usafracer]

What's your timing set at?