289 Running Hot

[prayers1 153]

I did not overheat, but did notice the mech. gauge reading 210-220.

 

This past week, the car died in the middle of traffic. It was more like fuel starvation. It would start and die. When I pulled over there was bubbles flowing through the glass fuel filter. After about 15 min I was able to get it to run but had to set the idle higher to 1500 rpms, so that it wouldn't die. I got home within 10 minutes.

 

I believe I have a faulty mech fuel pump. I haven't started the car yet, but I did change the fuel pump to a Holley 80 gph, replace the rubber fuel line with aluminum and an in line metal fuel filter.

 

The motor is a rebuilt 1967 289 bored 60. Comp Cam 31-226-3, 512 lift, 1965 Heads w/ 190 valves installed, Holley 570 Street Avenger Carb and a Weiand Street Warrior Intake.Stock water pump, Stock 20" Radiator & Shroud, Flex fan, 180 Thermostat.

 

The above set up was all done prior to going to body shop about 2 years ago, the car ran around 195. I have only driven the car approx. 30 min. From sitting too long I believe things dried out and that the fuel pump diaphram may have dried out and that the thermostat maybe sticking.

 

I'm thinking to change to a 192* thermostat.

 

 

What to you think.

Edited October 4, 2013 by prayers1

[MustangChuck 16]

I think running lean will cause it overheat.

 

Now that you have the fuel pump replaced, give it a go and see what happens. I also wouldn't change the thermostat. A 180* is good.

 

Chuck

[prayers1 153]

Here's the second part to this problem-

 

I installed an aluminum 3/8's fuel line from pump to carb, inbetween I have an aluminum 6an filter. The line is bent away from anything HOT.

 

I took apart the Holley 80gph fuel pump off and found a tiny slit in the diaphram. I called Holley to get a rebuid kit, there's none available. The Tech confirmed that my problem was air getting into the line via the slit, so I bought a new Holley Mech 80gph pump. Another reason I bought a new pump was that the old pump was not new when installed.

 

I also replaced the 195 thermostat w/ a 180. The car was running between 210/220 the day this happened. With the new thermostat it's still around 210. I verified that I'm getting a good flow through the radiator.

 

I installed the above and started the car, I can't seem to get it to idle below 1000 rpm's and it seems a little rough. I have a 4 speed. I can crack the throttle and it will rev up. Fuel pressure is 6-7. Carb floats check OK. I did notice a few times dribbles of fuel coming out of the squirters w/o touching the throttle. I went for a test drive, it fills like it has no power.

 

Possiblity- This is a recent rebuilt motor. I did all the breakin precautions.

The day this happened, I got on it for the first time and Rev'ed around 5000 rpms in 1st, 2nd & 3rd. I drove steady for about 1 mile, stopped at a red light, drove to the next red light, then drove 4 miles, stopped and got out of the car for about 10 minutes. I pulled on to the highway and it stalled within a 1/2 mile. This is when the trouble began. I have a new gas tank, new fuel line & a new carb.

 

Could something been pulled from the old pump into the carb, too hot, Power Valve.

I don't know!

 

What do you suggest

[69mi 10]

How about checking the timing. And I don't think 210 is hot, a 195 thermo is what's suppose to be in it.

Edited October 6, 2013 by 69mi

[miketyler 15]

I would have said carb float or fuel pressure on the dribble or idle problem but sounds like you are already on that. I am not much of an engine tune guy but what about vacuum leaks? They can cause higher idle and high temps. Some old schoolers will tune with a vacuum gauge. May not be a bad idea to check for leaks to see what you are pulling at idle. I would think ~15-17inches of mercury?

[prayers1 153]

I though of that and have tried squirting Starter fluid to quickly find a leak. I will have to try the Vacuum gauge later. I usally do the non-engine work on weekends, the exhaust is too loud even though I have flowmaster 40 through the tailpipes. You know how the neighbors can get?

[miketyler 15]

Yup, gotta keep the peace. Do you have power brakes? If so, don't overlook the brake booster.

[danno 128]

How would you test for a leak in the brake booster? Disconnect it and take it for a drive? Shut off the motor and pump the brake pedal? 2 normal power assisted pumps after then engine is off should be what you get?

 

This is kind of a general question not pertaining to your problem, but why do engines run faster with a vacuum leak? I would think the opposite. A vacuum leak means a lower fuel to air ratio, which should lower the engine speed.

 

I kind of have a related problem, I turn both the idle adjust screws all the way in, and I can only get the idle down to maybe 900. Maybe I have too many leaks? Maybe you do also?

[Hoover 12]

Did you put in a new radiator after the rebuild? How about a radiator flush, and inspecting the heater core?

These are contributing factors to high temps.

Aluminum tubing also transfers heat easier than steel, and can cause heat soak.

[prayers1 153]

I was amazed of what I found. After replacing the rubber fuel line with an aluminum line, metal filter and new fuel pump the car still ran bad. I later discovered that my Holley 570 Street Avenger has 2 Bronze stone filters at the neck of each opening. I figured it wouldn’t hurt to give it a look and to my amazement, I found what looked like clay or mud. You can see in the picture below.

I guess that after installing the new carb, later I replace the fuel tank and line from tank to pump. I assume that prior to this, the other tank must have had some sludge in it and was sucked up before replacing it. I cannot think of any other way how that mud got in and I guess that is how the fuel pump went bad.

So I did this-

Cleaned the 2 bronze filters w/ carb cleaner and used high-pressure air to blow it out.

Verified that the float level is OK

Opened throttle 1/2 way at a slow - medium speed had 2 strong stream of gas, but it is not continuous, after the steady stream it stops.

The LEVER on the accelerator pump- Moves freely, is not stuck.

I sprayed brake cleaner using long nozzle in holes in top of the carb then in fuel mix screw holes.

I used a Vacuum gauge to adjust the mixture screws and found one turned only 3/4s out and the 2nd a ½ out and this was preset by Holley. I turned each in and backed out 1 1/2. I turned the Idle screw out enough so that the car would not die, then I adjusted each mixture screw until I had the best Vacuum reading of 12. I then did the initial timing and found it at 6*, I adjusted to 12* at 900 rpms.

I took the car out for a ride and drove 5 miles and stopped for about 10 min, then drove back 5. The car has a slight hesitation off the start, like a no power feeling, but once it revs up it climbs fast, I shifted at 4K a couple of times and I had more to rev. I didn’t change the 180 Thermostat, it was 69* at the time and the engine stayed at 195* When I came back I checked vacuum and found it a 7, I readjusted it back to 12, the timing was still at 12*

Is my cam too big, Comp Cam 31-226-3, lift 512, duration 280, lobe center line 106 and lobe Sep 110. 289 bored 60 over, valves 190/160, 4 spd, 3:50 rear.

I’m thinking of changing the carb cam from the #2 to #1 position.

Should I take the bowls off for further cleaning or just drive it for a couple tank fulls.

I think the HEAT was related to running too lean and timing being retarded.

I did not flush the Radiator but verified that coolant flows pretty fast, I have replaced the heat core 2 years ago.

How can I improve the off idle hesitation

[Hoover 12]

Running an engine with .060 overbore will run hotter. My engine was rebuilt by a person who builds sprint car engines for a living. He miked my engine that had a 030 overbore, and said that he will try to go 040. If that wouldn't have worked, he would have found another block to bore out. He cited 060 would have "too much" for a thin walled block.