Vacuum Gauge Readings

[racertb]

So with the car running again, I made an adapter and hooked in my old vacuum gauge into the port on the intake where the wiper line hooks into.  The reading was initially low (around 12-13 hg) and when I advanced the distributor the most I could, the guage was fluctuating between 17-19 hg, but I backed it down to 18hg.  I couldn't advance the distributor anymore due to its position.  The timing must have been really retarded.  Needless to say, I had to adjust the idle screw down on the carburetor because the engine was idling too fast.  I have not checked the vacuum readings yet while adjusting the fuel/air mixture screw on the carb.

The reason for the fluctuating needle on the guage was due to a leaking intake manifold gasket (the small one between the intake and exhaust manifold) that I ended up having to find material and fabricate new gaskets.  I had to make three.  I haven't started the car yet, so not sure if that's fixed, but it looks good!  I will try to post photos.

Not sure if my guage is accurate, but those were the numbers.  I'll try to post a video clip.

[Old Man]

15 inches and above is good for these old engines. It may go even higher when you adjust idle air bleed. In a perfect world the needle should not move at all but they always jiggle some. Not much you can do. If the spark has not got 'holes' in it and the fuel hasn't got 'holes' in it as well, the jiggling will be valves. But to re and re the valve will be expensive and time consuming and the car won't drive one bit different. Especially since we only use them in warm weather. Been there,done that. Your numbers are perfectly usable and indicate good rings and valves. So I wouldn't worry. You never did say why the engine would never start all that time. 

[racertb]

Thanks Old Man...I did explain in another post (The Old Gal is...Running Again) and apparently I was 180 degrees out.  As much time as I was finding TDC, apparently I was on the compression stroke and not the power stroke (if I have that right, both valves were closed on #1).  So I finally just did a 180 on the distributor and she started up, a little "retarded" and then I advanced by ear and took her for a ride.  I just did the vacuum gauge the other day and like I mentioned above, still have to check the carb with the guage on it.  I also replaced/fabricated a new intake gasket.  I have started since, so I'm hoping there are no other leaks.

Two things...1) still trying to figure out how she broke down on me to begin with.  Maybe the timing was way off (retarded) that it finally gave out (with all the backfiring and cutting out).  I hope there was nothing more to it.

2) I don't like the position the distributor is in, since the grease cup is close to the belt.  I want to pull it out and keep the rotor in the same position, but I don't want to screw anything up at this point.

[Old Man]

That's what has me confused. How does an engine move it's timing by 180 degrees while it's driving down the road? You're absolutely sure the timing gears up front are OK? That's about the only place a movement of the timing like this could normally take place. Did you not say you were out for a drive and it suddenly did this? And you barely got it home? This,to us out here reading this,does not make any sense. Engines don't do this. But also the position of the distributor is puzzling. The only other thing is the distributor key on the shaft. Is it in good shape? Is the distributor bottoming in it's hole to keep good contact with the camshaft? Is there anything we're missing in the distributor that can slip. I seem to remember part of the distributor shaft is locked to another by a pin. Has the pin sheared and you're being fooled because it's just assumed another position for now and is going to slip again.       

[racertb]

I've had the distributor out and the pin is fine.  Everything else about it seemed ok.  I had another post about distributor play along with a video clip.  I think the timing being off by 180 degrees was me when I was trying to static time.  I am wondering if the car shut down because the timing was so off, too retarded.

I did check the gear through the rectangular hole but saw no missing or chipped teeth. 

I took the car out the other day before I used the vacuum gauge and although it ran ok, the timing was still too retarded. I also just fixed a vacuum leak (I hope) by fixing an intake gasket.

[racertb]

Here's the gasket that was replaced last weekend...I had to make these and it took three to fill the gap.  Not sure if that's right or wrong, but there were two or three burned out ones that were in there.

[racertb]

Car seems to be running well and the leak that was there at the intake is now fixed.  Although the vacuum guage fluctuates between 17-18Hg, it may be slightly too advanced and I may slightly retard.  The carb is as dialed in as I can get it (mixture screw most of the way in), so I'll adjust the idle slightly upward if I do retard the timing...

Still a slight miss out of the exhaust, but I think I've done all I can do at this point with the vacuum gauge and adjustments that I've made.  Road test coming this 4th of July weekend.

Ted