C3: Engine test fire & cam break-in de-bug.

[Richard K.]

With the fine help of long-time fellow NCRS member, "Dr. Barry" Holmes, we were able to test-fire my 1969 350/350 while in the chassis, and before the body drop.

We were able to get the engine running by feeding fuel into the fuel bowl and cranking it over. We just couldn't keep it running more than 30 seconds or so. Since then, I've determined that fuel is getting from the fuel tank to the fuel pump. I also peeked into the fuel pump pushrod sight hole while cranking the engine, and it appears that the pushrod is not moving, but it is hard to see.

I don't have a fuel pump pressure gauge, so can someone tell me how to test the fuel pump when it's off the engine, and how long the pushrod should be. I believe that I used the original pushrod, but I'm not sure, and the fuel pump is NOS. Lastly, with the fuel pump off the engine, how can I test that the pushrod is pulsing on the camshaft (just put pressure on it with my finger while cranking the engine?). Any suggestions on how to debug this problem will be appreciated.

Thanks
Rich Kossum
NCRS Pgh Tri-State Chapter

[Clem Z.]

Re: C3: Engine test fire & cam break-in de-bug.

the fuel pump rod should move 3/8" and just push the rod up with your finger and have some one crank the engine. check the rod for straightness by rolling it in a very flat surface and if it is not true get a new one

[Richard K.]

Re: C3: Engine test fire & cam break-in de-bug.

Thanks Clem. In addition to having 3/8" of travel driven by the cam lobe, do you know how long the fuel pump pushrod should measure? My thinking is that the push rod is an incorrect length and it's just resting against the fuel pump arm and is not contacting the cam lobe.

[Clem Z.]

Re: C3: Engine test fire & cam break-in de-bug.

sorry as i do not have one around to measure the length but i doubt that is the problem. most large auto parts will have one

[george romano]

Re: C3: Engine test fire & cam break-in de-bug.

If you remove the fuel line from the carb and disconnect the ignition, you can crank the engine and check the fuel pump delivery rate. It should gush out of the fuel line, not just a small dribble. Do not simply remove the coil wire for this test as gas may come into contact with the spark.

George

[Joe R.]

Re: C3: Engine test fire & cam break-in de-bug.

Rich,

Fuel push rods are 5.75".

JR

[Richard K.]

Re: C3: Engine test fire & cam break-in de-bug.

The problem turned out to be the fuel pump pushrod. The one that I removed from the engine was just shy of 5" long. 3/4" too short! The engine builder gave it to me, and I never checked it for length before I installed it. So, I purchased the correct pushrod, installed it, and the engine fired after only a few cranks. I then ran it for about 45 minutes at 2000+ rpm to break-in the cam. It ran smoothly and sounded great with the Allen's off-road exhaust system.

Thanks to you all for the help.