31 s/w engine issue - help requested

I haven't heard of adding a quart of MMO to the oil, but even that shouldn't make the exhaust smell bad.
A vacuum leak, or too lean a carb can give the exhaust a bad smell and make your eyes water.
 
Did you check/repair/determine yes or no on the valves before putting new parts on?If there is a valve problem,and you put on a new carb,the problem will still be there.It will be like covering a hole in the floor with a rug.
 
Tbirdtbird in his previous post suggested adding a quart of MMO to the crankcase after draining out a quart. Then to run the car to heat to oil for the MMO to clean any deposits that may reside on the valves. Perhaps it is a sticking valve and the MMO would clean it, thus preventing me from having to remove the valve cover and adjust lifters.

I was just doing what was suggested by others on the thread. Trying to do the least evasive item first (MMO in oil before pulling valve cover).

I will adjust the carb since that might lead to the smell. If MMO is a bad thing in the oil please let me know and I will drain and change oil. Again, I was just taking advice of more senior members on here and trying least evasive items first.

Thanks
 
OK, I'd forgot about the stuck valve, so the quart of MMO in the oil would be good to try.
I used a can of Sea Foam in the oil on an Olds I bought with sticking hydraulic lifters, and it did it's magic in just 5 miles. The engine was quiet as could be, and I resold the car. The bad thing is I sold it to a relative, so never got the last half of the payment.
 
The MMO in the oil will help dissolve any crud that has built up in the crankcase and valve chamber while sitting for so many years. It won't hurt anything, but don't leave it in there for a long time. Drain the oil and the crud it breaks loose after driving it a few times.

The MMO in the gas is what gives the exhaust the funky odor. Don't worry about it. Unlike the MMO in the oil, which contacts everything that is splashed by oil and cleans it, the MMO in the gas contacts things inside the intake/exhaust manifolds and the combustion chamber. It will help lubricate the intake and exhaust valve stems. If you have a sticky valve, this is a good way to free it up.

If one or more of your adjustable lifters have closed, none of the above will help. The lifters are not opening the valve(s) enough and the engine can't breath. One indication of this would be noisy lifters when the engine is hot. (A few noisy lifters on a cold engine is not a problem.)

In addition to the vacuum gauge test, doing a compression test on an engine that is at normal operating temperature can help you spot problems with rings and valves. Low compression will not give much power.

Pulling the valve cover and check the clearance of all the valves is not a big deal. Many people are intimidated by this procedure, but should not be. It is easy to do.
 
Tom - I checked again for a vacuum leak. It appears that one of the bolts that holds the carb onto the intake manifold had worked its way loose a bit. That probably let the carb rock a bit on the intake manifold. I had to take the carb off and chase the threads to ensure they were clean. The bolt was tight but I don't think it went all the way down into the carb. After chasing the threads, the seal is nice and tight now. Thanks for the insight!

Jim TX/GA - I drove the car a few times today with it reaching operating temperatures. It sounds to me that I have a bit of noise from the lifters so it appears to be a lifter issue and not gunk on the valve. I will drain the oil/MMO later this week to flush the gunk out. I will have to get some help from one of my club members to look at adjusting the lifters and also evaluating the valve springs (as was noted by a previous post). I have not done this before so hopefully that will help the motor run smoother. Thanks for the help!
 
tbirdtbird said:
can you post a link to the vacuum vid?
I did not see it first time around



Virtually every single Model A that comes into our shop is retarded, despite the owner telling us he has it timed properly. When we get done, the car has way more pep and the owner can't believe how well the car runs

Tbird:
Can you give us a detailed, step by step description of how you set your timing.
You can have two people set timing, and you'll get three different results.
And if my engine is retarded, well, that explains why it and I get along so well.
Click to expand...
 
I follow the standard procedure. Supposedly everyone does, but the issue of backlash befuddles most everyone thus causing their timing to be wrong.
Any two Model A mechanics will set the timing exactly correct every single time.
 
tbirdtbird - I am befuddled then by the backlash issue. I looked at a few posts about backlash and most are talking about clockwise rotation of the cam - some up to 1/2 inch. How do you address this and what do I need to do to address it on my car to ensure the timing is correct?

Thanks
 
Always adjust the points first to .020" then set the timing. Once the timing is set, you shouldn't have to touch it again for the life of the engine, unless you remove the distributor cam or turn it for some reason.

Slowly hand crank the engine until the timing pin drops into the camshaft gear dimple, then STOP and remove the crank. At this point the rotor should be positioned as in this picture. If your rotor is as pictured, you are done setting the timing.

To be sure the free play is all on the leading edge, just try to turn the rotor clockwise, and it shouldn't move. If it moves, that's OK just make sure the rotor can't be turned clockwise after you set the timing. As you loosen the distributor cam screw you will turn the shaft counterclockwise, so lightly snug the screw, and with the distributor wrench turn the cam clockwise and set the cam to a point where the points just close and the rotor is pointing to number 1 cylinder as you tighten the screw. The spark lever must be full up for this step. Now the freeplay should be on the leading side of the rotor, and the points are just ready to open.

Remember, the distributor cam and rotor turn CCW, and that's why you lightly try to turn the rotor clockwise to make sure any freeplay is ahead of the rotor.
 

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So the position of the rotor in the picture is with someone lightly turning the rotor clockwise. Thus there is NO lash (freeplay) in the clockwise direction in this position.
Tom has invisible hands but his hand is there providing a gentle turning until the rotor stops in the exact position you see it.

True, you will be able to turn it in the CCW direction, but this is of NO consequence at all and should be ignored.

It is so simple but ppl make it complicated

And as Tom says, and Purdy and others have said many many times, once you have set the rotor correctly, you will NEVER have to set it again, unless you turn or move or loosen the dizzy cam for some reason but WHY would you do that. Just re-set the points gap back to .020 occasionally as the rubbing block wears.

Ppl on here talk about constantly setting the gap and re-timing, again and again. Yes you have to check and reset the gap as needed, but you do NOT have to keep fiddling with the timing. Mechanics understand this.
 
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Tom and tbirdtbird - thank you for the very detailed explanation of the lash issue. I will have to take a look at this during the daylight hours.

Jim TX/GA - you wanted to know what the compression was with the engine at operating temperature. Here are the readings I took today:

Here are the compression numbers from the cylinders. This is in order from radiator to firewall:

Cold engine compression test:

#1 = 100 lbs/sq in
#2 = 92 lbs/sq in
#3 = 100 lbs/sq in
#4 = 100 lbs/sq in


Previously, before adding MMO to the oil/fuel, all were about 10 lb/sq in less than what they are now reading.


Operating temp compression test:

#1 = 97 lb/sq in
#2 = 92 lb/sq in
#3 = 97 lb/sq in
#4 = 95 lb/sq in


All are closer in numbers when warm. But #3 of the #4 dropped slightly.

With the MMO in the fuel, there is a distinct color to the exhaust. When I was adjusting the carb to address the soot covered spark plugs, I noticed the smoke from the exhaust from time to time in the engine compartment. Come to find out that I have a small exhaust leak where the manifold meets the muffler. I can fix this which in turn should help it run better.

Unless there is something that someone notices about the compression readings, I think I am to the point where I need to remove the valve cover and address the lifters. Does this logic sound correct? Any other issues that I might be missing?

Thanks again everyone for the help/input.
 
MMO in the fuel and oil will give various odors and such and need not be of any concern.

As far as I am concerned your compression readings are just fine....all of them.

And yes it is quite acceptable to add MMO to the oil since some of the oil will splash around on the valve stems inside the valve chamber. Mechanics have been doing this for years.

I am not sure I would open the valve cover at this time. According to the comp readings there is no sticking valve.
How about repeating the vacuum gauge test and posting that.

BTW what you call the primary ignition circuit is actually the secondary circuit (the high voltage side is the secondary. The 12 volt input to the coil and points is the primary circuit.)

Have you tried holding each spark wire/strap back 1/4 inch from the top of the plug to see if you have a spark jumping to each plug?

1. Your original complaint was lack of power.
2. Initially the vacuum test suggested a sticky valve. We need that repeated now that some MMO has gone thru the system
3.The plugs are def. way too rich. You will prolly end up for now with the GAV closed all the way up until you can determine if the jets are messed up.
4. Timing seems to be an issue. It has not yet been addressed that I can determine. If the timing is retarded (late) the engine will def. have a lack of power. This needs to move to the top of the list. Use of a timing light has been suggested as an additional diagnostic and it appears that has not happened yet .

To me, this entire thread can be summed up in these 4 points
 
Brian-
I think everything I'm seeing there looks good. Double-check your timing and then drive it for a while. Don't mess with anything else for a bit. See how it runs. You need to learn how to adjust the GAV inside the car (the choke knob). Once you do, your sooty plugs should be less of a problem.

Really. Quit messing with it. Go drive it. Have fun. It won't hurt a thing. :)
 
Guys,

So I have uploaded a couple of new vacuum gauge videos to YouTube. I added a quart of MMO to my oil and ran it 5-6 times around town/block then drained the oil. I also replaced my leaking rear cork seal on my oil pan. Fixed my distributor wobble and retimed the car (with test light) when I had the oil pan off (ensured #1 at TDC and timing gear had a pit for pin to insert).

Lastly, I pulled the carb. I took it completely apart and measured jet lengths and diameters (best I could with calibers). I found that my carb had an extra gasket under the main jet and that the float was not parallel to the casing. I removed the extra gasket, replaced all gaskets and added a shim to the float valve. Now it appears that gas is no longer running out the carb and I am not seeing black smoke out the exhaust. Also, I cleaned the "black fuzz" off my spark plugs.

Now that I have the car ready to run, I did another vacuum test. The first video is the car at idle speed (spark advance 3/4 down on steering column). The second video is with car at operating speed (spark advance 3/4 down on steering column). From the idle video, everything appears correct. However, under load, the needle really jumps. I looked at my Les Andrews book and I can't tell if I still have a valve issue.

When I drove it on a 4 mile loop today, still some power issues up hills but not as severe as it was in the past.

https://www.youtube.com/watch?v=cbvprh4bsUA

https://www.youtube.com/watch?v=N0fKfbJnHbw

Any input?

Thanks,

Brian
 
Tom Endy said:
You seemed to have covered all the electrical issues, timing and point gap. I would concentrate on the carburetor. If you are running an original zenith you need to go through it and install a set of jets that have been flow tested. Once that is done you should position the GAv control to where it is cracked open from a quarter turn to a half turn and see it that solves your problem.

Tom Endy
Click to expand...

But how is he using the spark lever when he is going up the hill?
 
I am running the spark lever at 3/4 down on the steering column. Only time I go farther is when I am at a steady highway speed of 45 with few stop lights. I don't change the lever going up hills. I also have been experimenting with the GAV on hills and straight sections. Still little change. I need to pull the plugs again to see if they have black fuzz again. Should I be doing something different with the spark lever on hills?
 
brianpharmd said:
I am running the spark lever at 3/4 down on the steering column. Only time I go farther is when I am at a steady highway speed of 45 with few stop lights. I don't change the lever going up hills. I also have been experimenting with the GAV on hills and straight sections. Still little change. I need to pull the plugs again to see if they have black fuzz again. Should I be doing something different with the spark lever on hills?
Click to expand...

It sounds like you are on the right track, Brian.

There is no universal correct answer for where to put the spark level under what conditions, except for one thing: it is a good idea to retard it a bit (up to 1/4th the lever travel) when climbing a serious hill in high gear. You don't want the engine to knock.

When climbing a hill in 2nd gear, you want to have the spark advanced because the engine is running at higher RPM. It's really all about RPM. You want more advance at more RPM; usually that means higher speed in high gear.

Ford gave you the ability to adjust the spark up to 40 crank degrees from top to bottom of the spark lever. :eek: That's a lot, but you don't always have to use all of it. He did that because he knew that it is difficult to hit TDC exactly when timing the engine. You might be a little advanced from TDC, you might be a little behind. Don't worry about it. The cam follower also wears as the engine runs, especially on a new set of points, and you compensate with a bit more movement of the spark lever. Don't worry about it.

You figure it out for your car while you are driving and don't stress over it. Get out on the open road at about 35 MPH with engine at normal operating temperature and GAV somewhere between closed and open 1/4th turn -- no more -- depending on what your engine seems to like. (That's an entirely different topic. :)). It sounds like yours is OK with the GAV closed.

Starting with the spark lever about 3/4 of the way down, accelerate gently and note the power and pickup you have. Now go back down to 35, advance the spark a notch or two, and repeat the accelerate test. Keep doing this and if you seem to lose power and pep when you advance the spark, then back off from there back to the prior point and that's your engine's sweet spot for timing. If it turns out to be all he way down, then that's fine.

Run with it like that for all city driving. Leave it like that at stop signs, lights, etc. Only retard it to the top to start the engine. As soon as it starts, put the spark lever at your sweet spot.

At speeds 45 and above, try advancing it a few clicks and see if you lose power; if not, keep it like that for high speed.

There are so many variables and variations of each engine that no one can tell you where the spark lever should be for your engine. :confused: You play with it a bit and do what you feel gives you the best power. Soon you will have a sense for it and adjust it without even thinking about it.

I will add, many overheat cases are caused by not enough advance. Too much advance mainly makes it idle rough, but as soon as you start driving, it smooths out, so that's OK. In general, too much is better than too little. As long as it does not knock going up a hill, under heavy load. (Sounds like someone under the hood, hitting your engine with a small hammer.)

I hope this has helped all of the new Model A owners figure out what to do with that timing lever and how to find the sweet spot for their engine. It's one of the things that differentiates our cars from more modern cars. It's part of what makes driving a Model A special. Embrace it and, most of all, have fun with it. :)
 
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