[HotRodMan]

I just installed a brand new Chevy 350 crate engine 260 hp with all new related parts.

I had the radiator cleaned and flow tested and the thermostat is opening. Adjusted the intake and exhaust valves 1/4 turn past zero lash. New Holley 4 bbl carb, Edelbrock performer manifold, points type distributor with electronic conversion. Static timed the engine at 10 degrees BTDC then turned the distributor for best run while engine was running at 1200 rpm. Stock short typed water pump and pulleys, 16 inch electric puller fan behind radiator. Block hugger headers with dual exhaust. No power steering, brakes, or AC. Manual transmission.

I am having trouble with the engine overheating within about 2 minutes of start up, and I can not get the engine to idle. 1200 rpm is as low as it will go.

Any idea what the problem might be?

[derm]

Temp: That's awful quick. Are you getting flow thru the rad? I know it was flow tested, but is it possible the water pump didn't prime? What tells you it's overheating? Checked oil flow at the rockers?

Idle: Checked carb for how 'closed' the butterflies go? Are you reading your advance in realtime? Vacuum leak will sure cause this if you've got a strong fuel flow.

Just a couple of ideas. Can you be more specific with symptoms? Does it die @ 1200 or can you just not get it to back off any further? Is the temp sensor reading hot, or are you getting smoke? Have you used an IR temp sensor to read actual exhaust? Oil pressure good? Etc.

[HotRodMan]

The temperature gauge going to 200 degrees in just 2 minutes after start up is telling me the motor is over heating and then I shut it off. Since it was 85 degrees I have the choke locked all the way open. When the engine starts, you have to give it gas right away enough to get it to 1500 rpm, I will keep it there for about one minute I gradually let off on the gas peddle. When it gets down to about 1200 rpm, the engine sputters and dies right away. You can give it some gas and keep it running but you have to bring it up to 1500 rpm again. There is no smoke, have not used an IR temp sensor to read the exhaust. The oil pressure is much higher than my old engine.

I did notice another symptom that I did not mention in my first post that scares me. Before I started the engine I filled the radiator completely full. When the engine cooled down I checked the fluid level and it not gone down at all. This is unusual. Usually you have to add some water.

I am beginning to think maybe the head gaskets were either installed wrong, or they installed the wrong head gasket at the factory and this is preventing the water from circulating thru the block.

[derm]

Have to agree with your unhappiness with that symptom. I would first chase the lack of apparent flow. Bubble in the system, water pump not primed, bad gasket, clogged port, etc. I'd manually pressurize the system & block the upper hose to see if coolant is forced out the top hose. Although messy, running the engine with a hose off & a full radiator will tell you how well the system is circulating.

As far as the idle issue. Not really concerned, as there is usually quite a big of fine tuning of the carb & timing to get it to lope well, at least every time I do it!

Best of luck! Let us know...

[302 Z28]

Your high idle sounds like a vacuum leak, which can contribute to overheating.

Vince

[Nitrousbutton]

Hotrodman, what kind of vehicle is this in?

[matt167]

Originally Posted by 302/Z28

Your high idle sounds like a vacuum leak, which can contribute to overheating.

Vince

my dad's old '72 350 was sucking air from under the carb ( carb was loose ) and on a long trip, he lost 2 cyls. stuck 1 of the Goodwrench 350/260 crates in, did everything per instructions and it's running fine.

[RPM]

Sounds like a major vac leak. See if there is a plug left out in behind the carb. Either the carb or manifold.

[HotRodMan]

I agree with you guys, it seams like a vacuum leak. I have run a few more tests and I am still baffled. I inspected the bottom of the brand new intake manifold before installing and could not find any problems.

I sprayed liquid wrench all over the carb, the intake manifold, the carb gasket, the intake gasket, the pcv vacuum line, the vacuum line running to the distributor, and I never got a change in engine rpm or any indication that the liquid wrench was being sucked in anywhere.

I took off the plug on top of the water pump which was full of water, sucked out the water with a turkey baster, shined a flashlight in the whole, and I could see the impeller turning and a gurgling sound so the water pump is ok.

I checked TDC of number 1 cylinder and it matched the timing mark on the damper, so I have the right damper.

Even at the 1500 rpm the engine runs like something is wrong with a lot of vibration.
Most cars I have seen will run smooth at the faster rpms even with the vacuum leak.

I have checked all my plug wires to be sure they are in the proper sequence.

Fuel level in carb is correct, idle screws are set at the start up setting of one turn out, choke is wide open. Tried covering the carb gradually, but it ran worse.

I will try the idea of running the motor with one radiator hose off to see how water is circulating tomorrow.

[HotRodMan]

Nitrousbutton, I almost overlooked your question. This engine is in a 1930 model A street rod.

I had a 327 in the car that was there since 1967, the whole thing was worn out and the crate motor was not much higher than completely rebuilding the old block so I went with the crate motor.

Also, I heard someone else mention instructions. I received no instructions, or spec sheet with this motor. There was one sheet enclosed that told me I did not have to re-torque the bolts, and I may have to drill and tap one hole for the exhaust manifold, and that was it. You would think they would at least enclose a tune up and valve adjustment sheet.

[herc88]

Just throwing this in there but you say you have an Edelbrock intake with a Holley carb. Would the intake happen to have a spread bore flange? I had to use an adapter for my truck when I put a holley on my Edelbrock intake.

I am like the others here sounds like a vacuum problem. With that said I helped a friend of mine with his 350 and we had to tune it to 26 deg adv before we got it running right and we could idle it down. All it had was a "vette" cam in it.

[Nitrousbutton]

Hotrodman, I'm with Derm as far as the overheating goes with the air pocket in the system. I have had a couple of motors that i have put together that had air in them that I had a real hard time getting the air out of, 1 took a whole day to get it out. And it did exactly what you describe here. As far as the idle problem,, If you have a different carb laying around I would try that, Have seen more than 1 Holley out of the box that has had problems that i had to send back. Good luck with it man. Perry

[302 Z28]

The intake could be sucking air underneath from the crankccase. Is it the same intake that was on your 327?

Vince

[SBC]

Try using starting fluid in the spray can to check for vacume leaks. I have used everything in the world to check for leaks and this will defantly tell you where the leak is.

[70bird]

My experience with heating up very quickly was timing was way too advanced.

You said the wires are in the correct spots, but do you know the distributor was stabbed correctly?

I have seen distributors stabbed at different angles. When this is done, the wires are not plugged into the factory positions (though the rotation stays the same, of course).

At TDC rotor should be pointing toward cylinder 1 and/or at the contact point for the #1 wire on the cap.

My $.02.