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Author Topic:   Urgent, Also Way Too Hot!
George Gilliland
Dirt Forum Racer

Total posts: 92
posted April 19, 2004 07:54 PM  
Just went to a limited this year, was regular modified previous year. Running on 1/2 pump gas, 1/2 cam II, 360 CID, 9:1 compression, stock heads, stock intake, stock Holley two barrel, open 1" adapter. Run good aluminum water pump, aluminum radiator, shroud, no thermistate(had 160 in it got hot removed). Started 74 jets, too hot went to 80, does not help, running fan slightly faster than engine(was running 1;1 and got hot). Thought that maybe leak in head gasket. Compression check is good. Ripped engine apart head gaskets were good. Oil pressure good, oil clean,engine 250*, day was about 80*. Started with 33* timing went to 30* (timing locked, vaccuum advance locked, mechanical advance locked. With a stock car years ago with similar arrangement, but more compression and a larger radiator,mechanical advance, we ran between 190-200. This present car slowly builds up heat and after about four racing laps is 250* does not come down on yellows, is not loosing but a cup of coolant(60* antifreeze). I have done all I know to do and then called it names, that did not help either. This is not good at all, any help will be appreciated. Can not believe this with methanol I had to block the radiator to warm the engine before the race and it would race at 190 and come down to 160 on long yellows.

Dirt Forum Champ
Total posts: 874
posted April 19, 2004 08:14 PM  
well george dont know what tot ell ya... i run with ya up there i only made one lap in my heat then had ignition and starter problems...
what power valve are you running?? also did ya build the engine tight??
i get up to about 180 and it sits there no shroud at all... 25 percent reduction pullys though... i'm also on 70 jets... what plugs are your running??

Dirt Forum Racer

Total posts: 92
posted April 19, 2004 08:16 PM  
When I ran b-mod, I had to drill holes with a hole saw in the front nose, I also ran water lines from a spacer under the termostat housing to the back water jacket through the intake, I ran a 17" aluminum bladed fan as well as the shroud, it is important how the fan fits in the shroud also, the fan needs to be half into the shroud as well as fairly tight around. I also ran the pulleys 1:1, I also ran a water restrictor, i think it was the biggest one Moroso had in their water restrictor kit, Also it is very important to keep the radiator clean, to do this, I put mine in a baby pool with soapy water and swished it around, let it soak then rinsed it with a garden hose every couple races.

[This message has been edited by speedy79 (edited April 20, 2004).]

George Gilliland
Dirt Forum Racer

Total posts: 92
posted April 19, 2004 08:42 PM  
The power valve is the one that came in it 35 which seems a little low usually we ran 65 in the four barrel. The plugs are Accel 274 gaped at .040. Cylinders 8 & 5 are warmer than the rest, but all are very rich. The plugs(all) show timing specks. I wonder if the locked timing is a mistake, I always used mechanical advance before. The engine is not extremely tight,immediately after the engine was cooled with water down to 180, I checked the oil temperature and it was 235, which is general right on target for me.

Dirt Freak

Total posts: 229
posted April 19, 2004 09:19 PM  
have you checked to see when it's running if you have good coolant flow through the radiator...maybe the tubes are collapsed or plugged?..also without a restrictor in the t-stat and slightly more than 1-1 pulleys you maybe pushing the water through the radiator to fast..maybe borrow a timing light to double check against yours..

Dirt Maniac

Total posts: 182
posted April 19, 2004 09:40 PM  
ok i'm going to admit to this hoping it might help. we had this similar problem many years ago, same thing, would go up to 250 and just stay there no matter whay we did. yes we even checked head gaskets too. we found the problem about 3 or 4 weeks later. in the rush to make first night the two cappillary tubes for the water and oil temp gauges got mixed up going through the fire wall so the water temp was actually stuck in the oil pan. you could dump tons of water on it and it just wouldn't cool down. hope everybody has had a good chuckle!!! we remember this every time we put a gauge panel in a car. we even laugh about it now.

Dirt Full Roller

Total posts: 35
posted April 20, 2004 08:34 AM  
I hope not to affend you, but is your radiator cap the highest point in you cooling system? And when you fill you radiator do you do it with the motor running as not to vapor lock the system? Also try a new cap.

Dirt Maniac

Total posts: 145
posted April 20, 2004 08:45 AM  
try filling the rad from the top hose first forces out the air bubbles. 2nd drill the holes in the nose and put a screen backing in.

Ego Racing
Dirt Forum Champ
Total posts: 724
posted April 20, 2004 12:31 PM  
With over 1:1 and a restrictor you may have over pressured the tubes and swelled them to the point to where there is no airflow through them. Get in the dark and use a flashlight to see if the tubes are touching.
A 9:1 motor will run hotter than a higher compression motor due to the burn pattern in the cylinders.
You say a good pump, If it is an import I would think of replacing it. You need something to slow the water flow through the radiator so the heat can transfer to the tubes and be cooled. What cap pressure are you running? Get a 22lb cap and try it. Over that and you can damage the radiator.
With the engine running and the cap off run it up to temp and see if water is flowing through the rad. I have seen some water pumps cavitate and stop moving water. Check your hoses, at over 1:1 you could be sucking them shut. We have run 2 inch aluminum tube and just enough rubber to make the connections. See the "TO HOT" post for some more ideas. As I may have forgotten some things.

Dirt Maniac

Total posts: 195
posted April 20, 2004 10:27 PM  
You might try setting your timing to 36 degrees, it will actually run a little cooler. Ran distributor locked and unlocked and cannot tell a difference in temp. Do you have a good tight fan shroud? You will need duct work on the front of the radiator to "push" the air into the rad from the bottom of the nose piece. Don't cut holes in a solid nose piece unlees you are going to run tubular ducts. The front holes actually dissapaite air from the rad. 80's for jets on a stock unaltered 4412 sound rich which can cause a heat problem. I would start with about 76's and go from there. Drain all of the coolant out of the motor and only put water back in. Ethel glycol will hold heat longer than just water. With just water and a water pump lube you will notice that it will cool down much quicker. if it still runs hot then you have other issues like a rad or hose problems.

Dirt Maniac

Total posts: 195
posted April 20, 2004 10:29 PM  
Also if your plugs show detonation then you will have reduce the amount of pump gas in your mixture. You might try a cooler plug, sorry not familiar with the accel line of plugs. Good luck!

George Gilliland
Dirt Forum Racer

Total posts: 92
posted April 21, 2004 09:17 PM  
Thanks to everyone, I think that it is working good now! I changed the fan from 15" to 17", and moved it back 1/2" to center in the shroud. Took the aluminum mud guard off that used to block the bottom 1/3 of the radiator. I made an aluminum piece that goes where a thermostate normally goes, I put a divider in it that seperated the right and left sides of the manifold water passage, and ran each side through a 5/8" diameter hole. Changed the Jets to 77, I did not have 76. Put in a 65 power valve. Put in an advance kit, timing is 18* at 2,000 and 32* at 6,000. Took out some of the antifreeze and reduced it to 50%. I ran it pretty hard in the garage and the temperature topped off at 160* and stayed there, (under similar circumstanes it went to 200* before). I think that there are a number of variables and the lion's share have to be right or it will not work. There is a funny part . . . If I would have gotten a slightly bigger fan, I could have saved a lot of weight, in that I would no longer need a transmission!

Thanks very much to ALL, George.

Dirt Forum Champ
Total posts: 5390
posted April 21, 2004 10:58 PM  
i'd lose the anti freeze and go with distilled water that will help some also i'd put some more timing in it we run 36 in my econo these lower compression motors like timing i've even heard of guys going as high as 43 in hobby there in wc seams a little hi to me but it works for him. if all goes well i should be there this weekend so see ya then

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