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My 1941 180 Sport Brougham (356 c.i. engine with hydraulic lifters) has a very curious problem.

I bought the car halfway through a very long and unfinished restoration with it?s engine already done by a very reputable shop, now closed. I have slowly been working on it and now I have the car almost ready for street use. In fact, just today I took it out for a long drive on a mostly hot day, and then for the first time home, night driving. The car works wonderfully, with no overheating and an incredibly, silky smooth and powerful engine.

The problem is the following: Once running, after a few mintutes, the engine works really wonderfully, silent, smooth, powerful... but after stopping it and allowing it to sit for a day or two, something happens that once that engine starts, it misses and works awfully for a few minutes, till it gradually improves to it's almost perfect performance.

After thinking about it with my mechanic, we believe that what's happening is that the valve lifters, while sitting down for days, somehow allow oil to come back or out of several of the valve lifters, so that when you start the engine, you are really having it work without proper valve functioning, or in other words with perhaps only 4 or 5 cilinders... till, after running for a few minutes, the lifters get gradually filled again and then everything works like a clock. Could this theory be correct? Perhaps a check valve or something in the oil pump / oil line, or defective valve lifters (though it puzzles me that it is several of them).

If not, what do you suggest could be happening here?

I would hate to take the engine appart and I am hoping something can be done via the oil pump... but I will have to do whatever it takes to get it into normal working condition.

Thanks for any help,
Victor

You may be looking in the wrong place for the cold startup problem. Even with no oil pressure, the hydraulic lifters will still operate the valve action sufficiently for the engine to start and run on all 8 cylinders. I think you should take a closer look at carburetion and other matters before considering some hydraulic lifter problem.

If your mechanic's idea was correct, you'd hear a god-awful amount of lifter clatter after startup, which you don't mention.

I think Dave is correct. Look closely at the carburetor. It sounds like some type of fuel problem till the pump catches up with the demand.

True, the engine does not clatter or there is a lot of valve noise when starting, which puzzles me as to the oil pressure problem theory, but about gas, we cleaned carb, installed a new pump kit, added an electric pump and cleaned and coated the gas tank, so I think the problem is not really gas. Besides, why would gas give those symptoms? Starts missing a lot, and you can barely maintain it running, and gradually starts to improve, but it takes at least about 4 minutes to start to work smoothly. Really puzzles me. We will be checking on everything again today, including spark plugs, but I really think there is something else behind the problem. I will post my findings.

Thanks!
Victor

Is the choke adjusted and working properly?

Quote:

1) That's not a proper carb rebuild. It would be OK if you already knew the carb was fine, but you don't. I had mine done for just under $200 and it's amazing. A professional carb rebuild will do wonders, even on an already running "well" car.

2) Do you know *for sure* that the fuel pressure is correct on that pump?

If it's too high, it'll force the carb to take fuel it can't handle and will flood it while starting and make it run rich most of the time. The warmer the car is, the better it can burn that rich fuel off and maybe smooth out.

EDIT: Actually it would load up while warm and while it'd run better warm at first, it would start running terribly after totally warm, especially in stop and go traffic.
END EDIT


Is the pressure too low? Then the car is starving for gas at the point it needs it most, when it's cold and it needs the richness to run well (hence why the choke was invented)

Mechanical pumps work well for most people in most situations. I still like it more than electric pumps by far. If you have one and can run it, hook it up and test with it.

To test your electrical pump, start your car for about 10 seconds, then shut it off. That should fill the carb up. Then disconnect your electric pump and wait about an hour or so. Start the car. Does it run fine and smooth (until the carb runs out of fuel)? If so, pressure is likely too high.


Quote:

Gas gives those symptoms because it's the fuel that runs the motor, depending on what's wrong with fuel delivery, it can cause anything from sputtering to knocking and pinging to running hot or not running to running lean and burning a hole in a piston. Gas is important so it can affect every system in the car.

Also, you're totally discounting that most carbs have a separate idle circuit, a choke circuit and controls, and float levels that ALL affect how a car runs in the first few minutes vs after it's warm. On a motorcycle, if you read me those symptoms, i'd say your idle circuit is plugged or mis adjusted and your choke isn't working or air is getting passed it. It sounds like a CLASSIC carb problem.


Quote:

It's not ignition related. Spark plugs don't spark more warm vs cold. If the car fires while you're rolling it over and when you stop operating the starter, does not instantly get better, then it's not ignition. When the starting is running and draining voltage from the system, that's the weakest your ignition system will be, and yours is ok at that point.

Like you said, there is something else behind the problem though. The carb. (or related...manifold, vacuum lines, etc.) Just like the above gentlemen said.




If i thought i had a lifter/cam/motor problem and some wise gentlemen told me it's likely a carb and i knew that, worst case, a professional would charge me $200 or i could do my best to fix it for less, i'd have $200 out SO FAST the paper would catch fire on its way from my hand to his. The carb being an issue is good news, not bad.

Of course I would love to know it is the carb as it would be a much simpler repair than what I fear. Carb is most probably not professionally rebuilt. It looks perfect, with all it's parts impecable, and we just took it appart to clean and assembled again. I will make sure it is really clean with all of its possible internal lines free.

Choke is working fine.

Thanks for the help. I will keep you posted,

victor

If it's really clean, i'd try to get a pressure gauge on that line (or try filling the carb and disconnecting the fuel pump) and seeing if it helps. There's very little mechanically that would cause that issue and not make some kind of noise, lots of smoke, something. I'm still hoping for fuel related. Makes sense, cheap to fix, easy to get to.

Perhaps a head gasket leak? Coolant on the spark plug when started, but as soon as it heats up, the coolant evaporates.
What do the spark plugs look like?

We rechecked on almost everything we could think of, including carburator, points, distributor, fuel pump, etc., just to make sure everything was ok. Here it is, our findings, the good and the bad:

Good:

- Spark plugs look great, with a dry orange color, apparently giving good combustion

- From the very little that can be seen of the combustion chambers, everything looks bright clean, no carbon deposits.

- Carb is clean and looks great. We took it appart again and everything seems to be fine, including choke.

- One running, there is no noticeable smoke, nor gray nor black.

- Fuel pump delivers 6 lbs constant pressure. We forgot to note the mechanical pump pressure but it is working reasonably well when cool, but misses when hot, even though it has a fresh Max Merrit kit. This last thing is a small problem, but nothing compared to the next finding.


The Bad:

My mechanic, still with his failing valve theory, decided to check on compression, and the findings are terrible. Difficult to explain how the engine works so fine when hot, but that's the fact. Compression, measured without plugs, with the carburator wide open, and on 3 full engine turns, reads as follows:

1. 0... yes cero... ouch... though because of the color of the spark plug my mechanic thinks that at higher revs somehow the cylinder does work.
2. 60
3. 20
4. 40
5. 60
6. 60
7. 55
8. 60

I don't know what compression is to be expected from the cylinders, but I do know that it should be about the same in all of them. So, my mechanic still thinks that we have some valve lifter problems. He will come back next wednesday and he is going to check with air to determine losses and use and old analyzer we have. What he thinks is that some of the valves are not closing completely, so either they were not seated properly when the engine was rebuilt or perhaps there is some kind of problem with the valve lifters in that they are a little high and don't allow some of the valves to completely shut against their seat.

Once the engine is working fine, after about 4 or 5 minutes (once with some temperature, of course) Cylinder no. 1 gives us an almost contstant small miss in the engine in an otherwise very smooth running and silent engine. I know... things sound strange. How can an engine with such lowsy compression readings and expected valve problems be so silent and smooth. I guess the nine mains and Packard high standards have to do with it.

So, next week, and after the inspections he want's to do we might have to start taking the fenders off to take a look at the lifters, and most probably take the head off also... I don't like the idea much, but I guess everything is pointing in this direction.

Any ideas?

Victor