Starting the Engine - Day 3

It was difficult to focus at work today as my mind continued to wander to the Mustang.  I started thinking about other possible causes for the issue and kept sticking on a vacuum leak.  As the day progressed, I started wondering about the lifter preload and if my new oil breather was causing the problem.

I called Comp Cams and they said lifter preload can really be between .5 turns and 1 turn.  As long as the lifters are not making much noise at start-up, you are going to be fine. This was the answer I hoped to hear.

I printed out my carburetor instructions and noticed the PCV valve connection is at the front of the carburetor.  Mine is connected at the back to a port labeled 'brake booster' in the instructions.  I connected it at this location as that is where it was on the old carburetor and the molded OEM style tube connected there near perfectly. 

I started questioning if this would be the cause an searched the internet a little.  Seems the PCV can be an unmetered source of air.  Since the carburetor is only metering some of the air when adding fuel, it causes the engine to run lean.  I wondered if the PCV valve port was metered and the brake booster port was not.  If this was the case, it would explain why the motor is running lean now and all the trouble I had previously tuning the carburetor.

I called Holley and they said it did not matter.  However, at lunch, I purchased a new PCV valve and some tubing and connected the PCV valve to the proper port.  I then blocked off the port at the back of the carburetor. 

I picked up a total of three fans from friends of mine.  Two are on stands and can be pointed at the headers.  The last is a box fan I can point at the radiator.  With everything in place, I primed the system, installed the distributor, and started the car with the help of Kyle and my wife.

I sat in the driver seat and monitored the gauges and varied the RPM.  They checked for leaks and kept an eye on the headers.  We ran the car for about 8 minutes before the temperature went to 210 and I turned it off to cool.  The radiator was starting to steam from the top as well.  I've heard new engines run hot for the first several hours but I don't want to over do it.

We let the engine cool and were super excited to have fixed the header issue.  However, now we have a cooling issue.  We let it cool and ran it again about 30 minutes later for 6 minutes before it reached 210 again and the radiator started to steam.

I took a few pictures of the spark plugs during this process. The first two pictures are without the idle mixture turned up.  The curved tip is very white and ashy.  After turning it up, it turned to move of a dull grey color.  I'm sure my fuel mixture is not perfect but it is better and running a little rich is better than running lean.