Fairlane671

Just purchased a 1970 Ford Fairlane with a 302 with a bds 671. This is what I know about the engine.
Rebuilt last year. The block was magnafluxed and cleaned with new freeze plugs and cam bearing installed, new crankshaft turned down .10 .10, new comp cams hydraulic lifters, bds hydraulic flat tapper cam, Pete Jackson noisy gear drive, stage 2 bds 18 % under driven, bds harmonic balancer, 2 new Holley 650's,big tube headers with junky turbo mufflers, new 3 core aluminuim radiator with 10x10 trans cooler mounted to the front with a 1700cfm push fan and 6 blade mecanicle fan.

The car run at 175-190 depending on how hard I push it. The car spits radiator fluid from the overflow tank when it is turn it off. The temp rises after the car is turned off and the upper and lower radiator hose have very high pressure. I have check the oil and there is no water in it. I also checked the radiator fluid for exhaust gases and the test came up negative. The thermostat is a highflow 180% and installed correct.The water appears to be flowing well through the radiator when I take the cap off.

Is this normal or should I be worried or is everything ok?

TheYellaBrick

Sounds normal to me.

Note; Your overflow is filled too high causing the spill.

The temp going up after turn off is cuz the coolant is not being cooled then and is 'percolating' causing a little more pressure in the system and a higher temp reading. As the engine cools, the pressure goes down. Normal stuff.

Fairlane671

Not sure if this will make a difference but the radiator was recently install along with the new thermostat. I opened the radiator cap with the front end elevated in hopes of burping the air out. The radiator still was holding pressure from a drive earlier in the day. I had to add at least a 1 1/2 gallons of coolent water mixture. After topping it of I went out for a short drive the temp never made it over 180 but the upper and lower hoses were rock solid with pressure again. I must have a bad head gasket.[/u]

fast75vega

dont sound like a head gasket... plus you tested for gases in the coolant and said it was neg. :wink:

what pound rad cap are you using?

Fairlane671

The radiator is made by champion radiators, it was bought from Leadfoot racing. The cap is rated at 19 psi. I was running a 13 psi cap on the old radiator . 19 seams high? At what psi will the hoses split? After the car sits the pressure disipates for the most part in the hoses.

What heads should I run if decide go to aluminium? Can I run GT40's or is that was waste?

fast75vega

i have neven seen anyone run more then a 15 or 16 pound cap.... 19 does seem a lil high to me

TheYellaBrick

We run 21 pounders in circle track. :shock:

fast75vega

yeah... we do too...lol but i was referring to street use :wink:

roadkill2

Physics . . The frickin' class none of us gearheads needed when we were in high school . . .

You put 3 gallons of water in a water heater (your engine) at 50°, then heat it up to about 180° and can't understand why it pukes . . Simply because that 3 gallons takes up more room at 180° than it does at room temperature!

Your car will tell you how much coolant it has to have. If it pukes 16 ounces then it will take 16 ounces to fill it up so it'll puke 16 ounces again. It's trying to tell you something . . . It's frickin' full when it's 16 ounces low at garage temp.

Want to know EXACTLY how much water a system will take? Heat the water to 180° BEFORE you put it in . . .

Just went through this with my Boss . . . (And no telling how many street rodders)

And, here's an old Sprint Car Crew Chief trick on finding a possible head gasket leak. Fill your radiator to the top, shake the car to get any air bubbles out, and add water if necessary. Then bring the first cylinder up on the compression stroke with a long ratchet or breaker bar, count to ten and if there isn't an air bubble, proceed to the next cylinder . .