First few miles and it's overheating

[AA-ron]

Hello,
So I just put the first few miles on my roadster and she's overheating. To date, I've run it back and forth in my driveway, let it idle for lengthy times and it never creeped over 180 F. After only a few minutes of drive it headed north of 220 and rising before I headed back home. I've tried to bleed the system by letting it cool a bit, removing the radiator cap and running the engine up to temp. I used a funnel that made a good seat and the coolant surged up and down releasing bubbles, but would also retract well below the fill level. I'd rev the engine and the coolant would surge to the top of the funnel and bubble, then quickly retract. I've done this several times now with always the same result.
My set is a pretty common 302 ford racing crate motor and the fill spot is at the highest point.
I'm at a loss at this point.
Any words of advise would be greatly appreciated.
Thanks

[MB750]

I'm guessing Forte put the engine together? If so, that greatly reduces the chances the head gaskets are on backwards.

Water pump spinning the correct direction?

My engine took about 3.5 gallons of 50/50. How much did you put in?

Also, during your idling sessions, did the fan ever come on?

[Papa]

Is your fan operating?

[GoDadGo]

Is your fan operating?

I'd hard wire the fan to run all the time since your muffler system is up front just below the radiator.
It might be a good test to see if you can at least control the heat.
Anyway, I think your muffler is creating the issue.
Just a stupid suggestion.

Good Luck!

[cv2065]

If it's not overheating for long periods at idle, then it's not your cooling system. You could be running too lean at higher speeds. Check your timing and fuel pressure. You could also pull a spark plug and check the color. White will confirm a lean condition. Also check your water pump, as it could be moving water at idle but cavitating at above idle rpm and not moving fluid through the system. Partially stuck thermostats can cause that as well.

[Ted G]

yea, I would guess this is a rad fan not turning on. Should turn on at 185. Where is your thermostat? Is it connected to ground? Can you hear the relay click?

[mrglaeser]

+1 on CV2065's advice. Any time I've had overheating on any of my cars it's normally timing or fuel mixture related as well. I have had to upgrade my radiator/fan before on classic mustangs but that is normally a slow creep on the temp. As in a degree or two every few minutes until it gets uncomfortable. Though checking the basics is never a bad idea (thermostat opens, water pump moves water, and in the correct direction, etc).

[MB750]

I'd hard wire the fan to run all the time since your muffler system is up front just below the radiator.
It might be a good test to see if you can at least control the heat.
Anyway, I think your muffler is creating the issue.
Just a stupid suggestion.

Good Luck!

OH.... That's this guy, I had no idea. I've watched his build videos. Neat idea, but you're right about the heat.

Mufflers get substantially hotter under load than at idle.

[egchewy79]

I agree w/ godad. wire up your fan to run at all times and see if you can control the heat under load. with the muffler directly under the bottom of the radiator, it possibly heats up the coolant in spite of the heat shield put in place.

[AA-ron]

Problem solved!!!
I reversed the polarity on the fan when I plugged it in after painting the body.
Now running at a cool 185 degrees. Gave her a hard rip just now with ambient temp of 80 degrees and it never went above 185!
Success!!!!!!

[AA-ron]

Problem solved!!!
I reversed the polarity on the fan when I plugged it in after painting the body.
Now running at a cool 185 degrees. Gave her a hard rip just now with ambient temp of 80 degrees and it never went above 185!
Success!!!!!!

And yes, I do feel a big stupid. The fam was originally correct— just too eager to assemble things after paint. :)

[CaptB]

Don't sweat it, there's a lot of things all of us would do differently if we had to do it all over again!

[JohnK]

Glad you got it figured out! For me, the cost of "duh" mistakes usually starts at $100 so any time you can find and fix a problem for free it's a moral victory. :p

[GoDadGo]

Problem solved!!!
I reversed the polarity on the fan when I plugged it in after painting the body.
Now running at a cool 185 degrees. Gave her a hard rip just now with ambient temp of 80 degrees and it never went above 185!
Success!!!!!!

Great Job & Bravo!

[cv2065]

Nice! Glad you got it figured out and it was simple. Now go have fun!

[Blitzboy54]

You kidding me. That's not even the dumbest thing I've done this morning. :)

[Mike.Bray]

One time I connected the battery backwards. The horn sucked and the radio listened.

[MB750]

One time I connected the battery backwards. The horn sucked and the radio listened.

:D:D:D That's a good one.