a little too hot

[andy16]

the engine im running now got a little too warm last week not sure why. i know there are a million posts about this and stewart has some great info but id still like to hear from some regular guys...
my engine temp got to 240 oil temp 270. didn spew any out but thats too hot for me and i finished the race but was about to pull in. 355 010 block dart 200 flat top 10-2-1 32 deg timing locked sunoco 260 gt gas 17" 6 blade fan 1 1/4" from 19by27 rad single pass bottom pulley is 5" top pulley is 7" i dont know what reduction that is engine speed is 7500rpm distilled water no restriction moroso 29lb cap not leaking napa green stripe rad hoses double clamped. no shroud... never had one before??? plus there hard to make the fan isn centered in the rad i have space on the right side the fan blades dont cover . carb jets are 82 frt 89 rear 6.5 pwrvalve in front only 40 squirters. wich is plenty of fuel compared to other motors i have ran??? is building the shroud really gonna drop my temps 40 degrees?? i doubt it looking for confirmation or suggestions thanks

[Egoracing]

5 inch and 7 inch is turning the pump about 5300 RPM at 7500 RPM which is a little slow but close, I would worry about low speed pumping.
When was the last time you cleaned the radiator? Get a cheap Kiddie pool put the radiator in tubes up and fill with water to cover the core but not the tubes. While filling put a few drops of Ivory dish soap in but not enough to foam up. Let is soak about an hour and go out and gently lift the radiator up and down a few times to flush the core out then let it soak again. If the water gets dirty change it out. Do this until the water stays clean. You would be amazed at what comes out. I have seen this happen with a new radiator as some places put a light oil on the radiator to keep them looking good. This collects dust in the fins and hurts cooling.

[powerslide]

the engine im running now got a little too warm last week not sure why. i know there are a million posts about this and stewart has some great info but id still like to hear from some regular guys...
my engine temp got to 240 oil temp 270. didn spew any out but thats too hot for me and i finished the race but was about to pull in. 355 010 block dart 200 flat top 10-2-1 32 deg timing locked sunoco 260 gt gas 17" 6 blade fan 1 1/4" from 19by27 rad single pass bottom pulley is 5" top pulley is 7" i dont know what reduction that is engine speed is 7500rpm distilled water no restriction moroso 29lb cap not leaking napa green stripe rad hoses double clamped. no shroud... never had one before??? plus there hard to make the fan isn centered in the rad i have space on the right side the fan blades dont cover . carb jets are 82 frt 89 rear 6.5 pwrvalve in front only 40 squirters. wich is plenty of fuel compared to other motors i have ran??? is building the shroud really gonna drop my temps 40 degrees?? i doubt it looking for confirmation or suggestions thanks

You dont have the fan everyone suggests, some claim this will lower it 15-20degrees alone. I will report back next time i run mine, i was 230 coming off the track last time.

http://www.amazon.com/ACDelco-15-80752-Fan-Blade-Assembly/dp/B000IZ26E0#productDetails

[setup479point2]

Put on the 4 blade fan , build a shroud , and put some waterwetter, or similar product in radiator . Make sure its clean , and go racing. Why so much jet ? I would think this motor should need nothing bigger than 76.

[stockcar5]

30% reduction is to much only turning 7500rpm. we turn 7400 and run 15% reduction with the gm 4 blade fan. i run a 15inch fan when its cooler out and switch to the 19 when its hot.

[andy16]

the 19" gm fan wont fit just hits the hard lines on my rack n pinion appleton rack everything in stock location w 1/8 spacer under rack. the radiator is 2 races old. edelbrock waterpump it has a few seasons on it? i started with 76 84 jets w 31 squirters and a 4.5 powervalve, had lean spots at begining of throttle blade movement, went up on jets continiously until the dead spot was gone then had a dead spot in transition went up on powervalve now no dead spots and plugs look good. i did that two or three times because i didn believe it either but thats what it wanted, plugs still arent black or wet pulled after race w engine still hot? getting a shroud made thatl be no problem.

should i go w more fuel?
do i need 15% red pulley instead of 30%?
should i go to a 17" 4 blade thats biggest that will fit without re doing bump steer?
what coolant additive really works?

[twisterf5]

i run a 18inch 4 blade 2.3/4 from rad with good shroud. can you raise engine an inch and then go with the bigger fan. and a 4 blade pulls more air that that heavy 6 you are running.

[merc123]

May not be of any help. We changed to a different chassis this year. Went from a 22" double pass radiator to a 27" single pass and can hardly get the motor over 190*.

We were running 230+ every week. We tried everything except a shroud and the GM fan blade.

Now the only difference is the radiator and now we have about 3" spacing between fan and radiator and still run 190*.

[andy16]

well im putting a 15 inch gm 4 blade on with a budbox shroud, supposed to be the best around they look nice but are a little pricey... thats all im going to change and ill post the results and a review of the bud boxes, so far "bud" has been great with customer service knowledgeable knew what he wanted to do from the get go we got my measurements taken and spent time to get it right... now waiting on finished product. hope it cures it.

[andy16]

Where do you get a 15 inch 4 blade, Ive never heard of one?



http://www.jnjfab.com/gallery/gallerylarge.asp?picid=323

muscle motorsports... they have alot of used nascar parts lmsc parts engine parts etc... used parts broker in mooresvile/concord this one aparantly was cut down and balanced by jgr... or just balanced by jgr has there scribe marks and i can see where they ground a little off two sides just a little. or muscle motorsports goes thru alot of trouble to bs me over a 20 dollar fan, one or the other...

[andy16]

also cv products prt # 1515 i think so maybe jgr just balanced it? anyway a new one from cv not balanced is 38.00 got mine from muscle for 20 and its balanced... score!

[Bubstr]

Cooling system basics. It's all about transferring heat from the combustion chamber to the out side air. Transferring heat from combustion chamber to the water is usually very good. Transferring it to the radiator is a no brainer. This is where your problems start or end. Water flo threw the radiator is usually good no matter how many cores you have, but a fat radiator is harder to push air threw. The big problem is transferring heat from water to air. First it's just not as efficient as from metal to water or just moving the water. Therefore you need a lot of air flow threw the radiator. Think of the things that can reduce air flow threw the radiator. Big fat 4 or more core radiator. Not allowing air to get to the radiator. Not making the air go threw the radiator, by letting it go around.

You actually have two airflow systems pertaining to radiator air flow. Low speed includes the fan and shroud and high speed that involves speed of the air you run into. The second is far more efficient if in fact the air makes it's way threw the radiator. In a lot of cases this is not happening and system one is used to cover the loss of cooling. It's inefficient, It costs horsepower, but it is still used. The air comes in threw that little slot if you have one and under the front spoiler. It goes out under the car and the leading edge of your front wheel openings. The trick is getting it from point A to point B with out going around the radiator. there is a low pressure created in the engine bay area by your body work going threw the air. this is why wedges work so well. If it's sucking from the back side of the radiator and pushing on the front side of the radiator, all you have to do is make sure it can't go around the radiator for the most part. Nice wide open fins help. a little ducting is worth it's weight in cool. Just blocking off the air from going around the radiator. It's there it's free. Use it. You create the most heat when your standing on it and going fast. You also have the most air flow available at that time, you just have to use it. Trying to make up air flow with a fan can be effective to some degree but there is a better option.

[setup479point2]

Waterwetter works , I currently have 2 emods , 1 crate late , and 3 street stocks that I work on , all use waterwetter , none have cooling issues. If you have a lean spot when the blades are just opening it should be something in your accelerator pump , is the cam on the carb worn , or is the pump adjusted right ( at idle ,just shy of touching ). I didn't notice when I first posted that you have a blocked off back metering block , yes rear jets should be 10 higher than front . Still think 76 should be enough in front , but whatever works : ). 4 blade is what the trick is on the fan , bigger is better , 4 is better than 6.

[Bubstr]

Four blade is better than 6, not because it sucks more air threw, but because they don't restrict air flow as much when the air flow exceeds the fan speed. That is pedal down, making heat, when you really need a cool off.

Looking at it in terms of Physics, the fan blade is blocking air flow when ever the airflow exceeds the speed of the fan. More pitch and less area blocked adds up. There still has to be a compromise at lower speed so the fan does it's job then.

Water wetter has sound basis in capillary action. How much it helps is something you must make the call on. Color of your radiator has some effect, but not really sure how much. Black is known to transfer heat more effectively. How much it helps is another, you make the call. Black painted engine blocks are noted to increase the engine bay temps. Them temps got transferred from somewhere. You make the call. Want the heat in the engine or surrounding the engine.

[Bubstr]

One thing some racers overlook is how much of the cooling process is actually done with the oiling system. If you are having your engine built by pros, they generally engineer the oiling system by controlling flow and even in some cases building dams to help cool certain parts like very high valve spring pressures. One of the critical things about your oiling system is don't mix air in the oil. Racing oil has anti foam but cavitation or exposing your pick up to air is a killer. Another thing to think about on oil temps is ventilation and too cool is almost as bad as too hot. If your oil doesn't get above 212 degrees it does not vaporize moisture so your ventilation can remove it, whether that is a vacuum system or just breathers.

I know most of you guys know these things, but there might be a newbe reading and can learn something that can save him a ton of money in breakage.

[powerslide]

You dont have the fan everyone suggests, some claim this will lower it 15-20degrees alone. I will report back next time i run mine, i was 230 coming off the track last time.

http://www.amazon.com/ACDelco-15-80752-Fan-Blade-Assembly/dp/B000IZ26E0#productDetails

442 Fan alone brought the temp down to 180 coming off the track. Might have to put a thermostat in now.

[andy16]

i appreciate all the info... as it stands i left the carb alone it has no dead spots but the plugs sure look clean i wouldn be afraid to go up some more on jet or squirter or pump cam, the accelerator pump is set correctly w the black pump cams on both sides set in position 1. i got a 15" 4 blade gm fan with a bud box shroud and the shroud is perfect i run a md3 nose w lower valance i have no holes cut in it anywhere. went from a 240 degrees w no shroud and a 17" 6 blade to 270 degrees w the shroud and the 15 inch fan. it got worse? the fan is half in half out exactly how it shoul be. ill post pics later this week of it all . running straight distilled water. everything is clean. turned 7800 this weekend we only got to practice race got rained out but was already overheating... may just switch notors and see if it is something w that motor? oberg is clean oil temp is 250-270 engine runs fine?

[setup479point2]

Sounds like a blown head gasket. Engine shouldn't get that hot that fast.

[andy16]

gonna do a pressure test on cooling system and cyl leak down test this week if nothing comes up switching motors. if i switch motors do i stay w the shround n small fan or go back to large fan w no shroud? standing at the carb while engine is running i can notice a big differnce in air blowing on me from the 6 blade to the 4 blade and the 6 blade is moving more air from what i can tell?

[Egoracing]

At idle the 6 blade should move more air but at speed it is more like a wall as is spins and the blades flatten out.

[Mod77L]

This may be a dumb question, but have you tried a different radiator? Sometimes when you overheat, you can "pop" the cores, they change shape and collapse the area between the fins. This blocks air coming thru the radiator. I chased my tail for weeks looking for what was wrong. I should have tried a new radiator first.

[powerslide]

Im betting the 15in 4blade doesnt have the pitch that the 19in 442 fan has. I had a 15in 4 blade and it has about half the pitch of the 442 19in fan. Post some pics/video of the setup you have. Then go to this website and get one of these http://www.amazon.com/ACDelco-15-80752-Fan-Blade-Assembly/dp/B000IZ26E0#productDetails.

[andy16]

i ended up not really finding a problem with the motor but it is new to me this year has a practice and about 4 races on it and it just keeps getting hotter and hotter so i pulled it will send it to get looked at later. i put my regular motor in spaced up the engine about a half inch put my 19 inch allstar fan on took 15 inch fan and shroud off, drained out all the sonoco 260gt gas and went back to vp 110 purple. ive ran this motor with this fan and that fuel all in another car w no overheating problems so i should be fine. once i establish a baseline with this motor combo and all is good and cool im going to switch back to shroud and little fan and see what happens if its still cool then im going to switch back to the sonoco its cheaper and easier for me to get ahold of if its still cool then im sending motor to get freshened/looked at.

the 15inch fan appears to have a 45* pitch if i put angle finder in middle of the blade. i dont know what pitch the 19 fan is but ran it on other cars before and stayed cool. will get some pics up by sat night got alot to do still

[Egoracing]

Are you running the same carb on both motors? 260GT is oxygenated fuel and the jets would need to be larger than when you are running VP110 or the engine will be running lean and causing it to get hot and could melt the engine down.

[9car]

what pitch is that AC delco fan?

[Barbecueboy]

You mentioned that nothing spewing out and engine running fine.......bad temp gauge maybe?

[powerslide]

This one says its 32 degrees. http://www.jegs.com/i/GM-Performance/809/405442/10002/-1