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Author Topic:   thermostat or restrictor
Rat Trap
Dirt Maniac

Total posts: 129
posted July 22, 2004 01:40 AM  
What do you guys use running alky? A thermostat or a restrictor? and size? We are slowly getting our temp problem better. We are finding out now that we shouldn't be running with nothing slowing the water flow down. From what i'm reading, we are flowing the coolant through the radiator to fast for it to disapate the heat. We have a 180 high flow stat we can put in, but which is better that or a restrictor?

21racer
Dirt Full Roller

Total posts: 56
posted July 22, 2004 07:52 AM  
i use a 160 deg thermostat with a 3/16 hole drilled in the side to stop air locks never have any overheating problems hard to get engine to temp before starting race

Dman
Dirt Freak

Total posts: 270
posted July 22, 2004 09:40 AM  
If you have an overheating problem with alky there are other problems more serious than a the thermostat or restrictor.We run no restrictor at all with a 22 in. Howe radiator, a steel fan 2 ins.from the radiator and have trouble getting 200 degrees out of our 383 cu.engine.Sure,we have had heating problems in the past but it was not due to flow.We had a bad radiator once. Swollen tubes from a head gasket failure.Radiators are not designed to hold a 13 to one compression ratio.This cut back on the air flow through the rad.Thermostats were to designed not to cool but to aid in fast warm up and keep an engine from running too cold.You can try a 1 in. restrictor but your problem is probably something else.Check for air flow through the radiator.Get the fan bigger and closer to the radiator.How much timing do you run? timing can be critical especially if you run vortec heads.How's your carburetion? It is okay to run a little fat on methanol.Try bumping up your jet sizes and see if you cool off.Check your fuel system.Your fuel filter could be plugged up.Dont use a paper element with alky unless you want to change it every couple of weeks to be safe.Paper filters and methanol will grow things inside and plug up your filter.If you use a stainless element ,blow trough it with your mouth to see if it is clean.It should flow freely.Stainless filters have been known to look clean but get varnished up and won't flow.Soak it in lacquer thinner if this happens.Last in my essay is to check your carb floats.Make sure they are not deformed and will hang freely to the bottom of the float bowls.If they get stuck halfway you will starve for fuel.This is all of the problems we have had (that I can remember)in the past that have caused overheat probs.Other han the obvious stuff like a rad.full of mud.Good Luck!

WesternAuto17
Dirt Forum Champ
Total posts: 569
posted July 22, 2004 10:05 AM  
Try to get your hands on last months issue of Circle Track magazine. It had an article on keeping cool that might be of assistance.

droper23
Dirt Freak

Total posts: 233
posted July 22, 2004 07:35 PM  
I run alky and have no thermostat or restrictor, and when I pull off from the feature, my temp is at 170. I have a 19" griffin radiator, with a plastic fan about 1" from radiator.

Rat Trap
Dirt Maniac

Total posts: 129
posted July 23, 2004 12:49 AM  
What jets should we have? Bigger or smaller? The fan is 1/2" from new griffin rad. Filter is new, stainless steel. Carb is new from speedway, (Alky Plus). Timing set at 34. Motor is 355 with 4 nights on it. Infact everything on the car has only 4 nights on it or less. Motor is strong, doesn't miss or sound bad at any time. We get up to about 230 after around 10 laps, but we know we should be alot lower is why i'm asking. We've pulled plugs and they look fine. I guess well just keep tinkering with it and hopefully find out why? Thanks

2nd2none
Dirt Forum Champ
Total posts: 755
posted July 23, 2004 05:08 AM  
who did your machine work? The wrong cylinder wall finish will result in an engine that always runs hot.

Dman
Dirt Freak

Total posts: 270
posted July 23, 2004 08:06 AM  
Try jetting up (bigger) and see if it helps.
Running a little rich on alky is not a bad thing like gasoline.It wont foul the spark plugs.Jetting can be affected by different engine cominations such as cams,compression,cylinderhead/intake combos,gearing etc. Seldom is the jetting correct out of the box. Good luck!

Rat Trap
Dirt Maniac

Total posts: 129
posted July 24, 2004 01:04 AM  
Means motors did our engine. He was recommended to us. If we don't get rained out for sat. nite we will see how it does. And if we still have the temp problem were going to take the car down to Lucky's Speedshop and have him take a look at it. He's helped us out on the lines, regulater and pump for running the alcohol and told us if we ran into any problems he would help us out on the engine.

2nd2none
Dirt Forum Champ
Total posts: 755
posted July 24, 2004 06:52 AM  
what car # are you again? It aint lookin real good for tonight, but I'd be more than willing to come down and help ya out if you want it. Or you can come down to Mike Jarvis's or Randy Woodside's pits, thats where I'm at.

Rat Trap
Dirt Maniac

Total posts: 129
posted July 24, 2004 10:03 AM  
your right, it's pretty wet. we will see how it goes and might look you up. My car owner thinks he use to race with Randy's dad if his name is Jay. were the red white and blue 29s

WesternAuto17
Dirt Forum Champ
Total posts: 569
posted July 26, 2004 07:37 AM  
I'm no alchohol expert, but 2 things stood out to me. You said your fan is 1/2" from the radiator and you never mentioned a shroud.

I've always heard that you should be 1-1/2" to 2" from the radiator and make sure you have a good fan shroud to make sure the fan is pulling air thru the radiator.

dirtbuster
Dirt Forum Champ
Total posts: 2007
posted July 26, 2004 01:20 PM  
I would look at the carb and jetting. You should have no problems staying cool on alky if jetted right. When we ran on alky we had to have a t stat in the car just to get it warmed up. Otherwise it would never get above 160. Thats with 20% reduction pulleys, cheap aluminum water pump, 6 blade fan with loose belts, and 19x22 single core radiator. On top of that we found out on the dyno we were on the lean side anyway.

What kind of water pump do you have?
4 or 6 blade Fan?, metal or plastic?
Have you cleaned the radiator after ea race?


irace74
Dirt Forum Racer

Total posts: 80
posted July 26, 2004 03:41 PM  
Go to stewart racing water pumps and read their tech info. We have been running no restrictor for 2 years, a stewart pump and 1:1 Pulley system. When it gets really hot and nasty we run 180. Our motors are pretty stout in the over 600 hp class. Follow what stewart says and you won't go wrong. If you are using a stock pump then the water flow and horsepower consumption will be excessive. A little engineering speak, Slowing the water down cannot and will not reduce water temperature. Thermodynamics says that if you raise a pound of water 1 degree that is a btu, more water flow is good, more airflow to remove the heat from the water, this is good too.

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