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Old 11-03-2020, 11:16 AM   #21
katy
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Default Re: Why do I have to keep pulling the choke out ?

Quote:
Here is the Correct name of the small brass compression fitting that
fits on a fuel line to seal the line from leaking at the fitting. It's name is "ferrule"
I once worked in a place where they called them olives, when I said ferrule they didn't understand me.
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Old 11-03-2020, 10:05 PM   #22
40-A Twins
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Default Re: Why do I have to keep pulling the choke out ?

I removed the intake manifold and checked flange flatness using the cast iron wing of the tablesaw and a feeler gauge.
Flanges were warped by approx. .006. I lapped the flanges with a sheet of 150 sandpaper by holding each flange down firmly against the tablesaw surface and moving in a circular pattern. Both flanges now have .003 gap at the lower edge.
I opened up the valve cover to check tappet clearances and found these to be the old solid type.
I measured each of these 2 or 3 times each to be sure - motor does not turn over smoothly when using the hand crank and is difficult to see when each tappet reaches the top of its stroke.
clearance measurement are as follows:
#1 .018
#8 .015
#2 .010
#7 .014
#3 .012
#6 .013
#4 .015
#5 .018

In my spare parts collection are nearly 3 full sets of solid tappets of varying lengths. I might be able to swap out tappets and get nominal .015 clearance at every tappet location.
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Old 11-04-2020, 08:55 AM   #23
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Default Re: Why do I have to keep pulling the choke out ?

I would do a compression check first you might have burned valves and then a leak down test.
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Old 11-04-2020, 10:22 AM   #24
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Default Re: Why do I have to keep pulling the choke out ?

"In my spare parts collection are nearly 3 full sets of solid tappets of varying lengths. I might be able to swap out tappets and get nominal .015 clearance at every tappet location."
Why would you go through the work to replace a few lifters, at that point you should just replace with adjustable type. It would require tearing down the engine to the level of a short block to get the cam and lifters out. With solid lifters it is the valve stem that is ground to adjust the gap. Did you take the plugs out when you checked the gap? But before you do all the work I would do as rocket1 said, check compression and leak down.
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Old 11-04-2020, 06:44 PM   #25
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Default Re: Why do I have to keep pulling the choke out ?

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Originally Posted by 40-A Twins View Post
Hi new member here, Model A owner since 1979.
I have run out of ideas to get the motor in my '29 to run right.
Motor starts right up and runs ok for about 10 seconds, then begins to slow and starts sputtering. Pull and release choke and this cycle repeats for 3 to 5 minutes - which requires me to sit leaning over with my hand on the choke. After this long warm up phase it continues to run at idle without choking but always a little rough.
I assumed this to be either an intermittent fuel blockage or vacuum leak issue, so have done the following:
Added filter screen to fuel shutoff valve.
cleaned out fuel line.
Adjusted carb float level to 5/8".
Cleaned carb passages.
cleaned jets.
New throttle shaft - old shaft had wear.
New manifold gasket.
New intake gasket.

What else could this be ?
I have tried swapping the Zenith carb out for a Tillotson, but it still runs poorly.
Any ideas ?

Kevin
Thinking back to the early 1950's, my dad was still driving a 29 Model A as a daily driver. He started having problems with a similar situation you describe. He found the problem was rust in the gas tank that would gather by the fuel outlet, and the scales were so big they would block gas flow! He eventually emptied the tank and then remove the fuel petcock and did something to put a short hunk of copper tubing in the inlet of the petcock so that the fuel was not drawn from the bottom of the tank. This easy to check as you can disconnect the fuel line from the carb get a can and let the gas flow and see if it stays steady.
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Old 11-04-2020, 10:24 PM   #26
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Default Re: Why do I have to keep pulling the choke out ?

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Shutoff valve fuel tank screen installed recently; carb inlet screen is clean.

Fuel line protrudes 1/4" past the ferrule at carb inlet fitting.

Compression test results:
#1 55
#2 55
#3 60
#4 60
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Old 11-05-2020, 04:29 AM   #27
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Default Re: Why do I have to keep pulling the choke out ?

I think most fuel issues have been covered in the responses, and we're all assuming fuel , but intriguingly 40-A Twins you wrote in your OP " I have tried swapping the Zenith carb out for a Tillotson, but it still runs poorly.". so some more simple stuff...
Is this a new fault - did the car run OK before?
Are you sure the jets are correctly sized? and GAV seat seat not blocked?
Trim the fuel line down to just 1/8 inch beyond the ferrule each end.
What do the s/ plugs look like ?
Any chance of substituting with a known good-running carb? (was the tilly you tried known to be good on another car?)
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Old 11-05-2020, 10:45 AM   #28
Ernie Vitucci
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Default Re: Why do I have to keep pulling the choke out ?

Good Morning...If you are pulling the choke out all the time, then you are changing the fuel mixture...making it more rich. When I have had this problem, over the years, I have found that there was an air leak some place...even a cracked intake manifold a couple of times and those cracks are not always easy to find...Ernie in Arizona
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Old 11-05-2020, 11:11 AM   #29
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Default Re: Why do I have to keep pulling the choke out ?

I have never gotten this car to run well since it was assembled.
I have 2 Tillotsons as spares, and motor runs just as poorly using either.

Checked jets a couple months ago and I recall that main was oversize by .003.
Zenith has been blown out, wire poked thru all holes multiple times now.

Fuel tank has been dipped and has no gunk or rust flaking.

Spark plugs are a little sooty.
I don't have a known "good running" carburetor anymore.
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Old 11-05-2020, 11:37 AM   #30
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Default Re: Why do I have to keep pulling the choke out ?

Try a vacuum test yet?
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Old 11-05-2020, 03:01 PM   #31
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Default Re: Why do I have to keep pulling the choke out ?

Spray carb cleaner around the intake manifold at the engine block connections , found a leak for me!
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Old 11-06-2020, 02:12 PM   #32
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Default Re: Why do I have to keep pulling the choke out ?

Replace the GAV assembly (needle and housing). About $17.00 total from Snyders. Also change the condenser

When you have the carburetor off, check the flatness and cleanliness of the flanges on the carb and manifold. Reassemble the connection between the carb and manifold with the gasket, lightly coated with gasket eliminator (it is like a red jelly type goo made by loctite---just a wipe of this goo on the gasket surfaces is all you need)

Try it...easy to do.

Also you will need a 13/32 socket to remove and reassemble the GAV housing. If you cannot get the old one out, take a 10mm 6 point deep socket and tap it over the hex. You should be able to pop it loose. Make a 13/32 open end wrench by filing an old 3/8 open end to size for a snug fit. Mark 13/32 as you may need it later. I am speaking from experience on the GAV. Just did this within the past 2 weeks and really improves performance of my ZENITH carb.
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Old 11-07-2020, 11:36 AM   #33
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Default Re: Why do I have to keep pulling the choke out ?

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gasket eliminator (it is like a red jelly type goo made by loctite---just a wipe of this goo on the gasket surfaces is all you need)
How is that "gasket eliminator" compound for disassembly?
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Old 11-07-2020, 03:32 PM   #34
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Default Re: Why do I have to keep pulling the choke out ?

It is applied lightly on to gasket surfaces. A "belt and suspenders" if you will. As the name implies, it can eliminate the use of a gasket and will seal two flat surfaces together.
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Old 11-14-2020, 11:40 PM   #35
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Default Re: Why do I have to keep pulling the choke out ?

The engine is now completely disassembled on the garage floor for examination.
Valves / guides are worn.
Camshaft has a round lobe between #2 & #3, so it must be a "B" cam.
Pistons & rings appear to be new.
Main & rod shim stacks are approx. .030, so this motor saw very little use after bearings were rebabbited.
Motor serial number prefix is "LB", and the raised boss is still in as cast condition, so this serial number does not appear to be a re-number.
I plan to replace valves, guides, lifters, & springs. Original style and "Modern valve set up" kits are offered by Bratton's. Is there an advantage to using Modern valves over the original? Also gasket sets are available with "Modern head gasket". Does this seal better than original copper type head gasket ?
Any good tips to reduce oil seepage where the main bearing bolts penetrate the crank case ?
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Old 11-15-2020, 09:45 AM   #36
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Default Re: Why do I have to keep pulling the choke out ?

40-a-twins
If the "modern" gasket is the type with a ring of sealant around the gasket openings, do not use. Quite a few have had issues with short time failure, sometimes within a couple of hundred miles. I do not think the issue has been definitively identified, lots of personal experiences both pro and con. Some say correct installation procedures were not followed while others insist they followed procedure to the letter and the modern gasket quickly failed.

Some say the Head and Block were not prepared proper, flat and with the proper finish. But the graphtite and copper/copper clad seems to be more forgiving since it is extremely rare to hear of a short term failure of these gaskets. Some say to break in the modern gasket for a few thousand miles and a few re-torques using water coolant, then switch to antifreeze if antifreeze is desired.

Graphtite works well, but it can be difficult to remove the material from the block/head after they have been on the motor for a time. Graphtite do not need as many re-torques after installation and over longer periods of time - seem to hold their torque better. Copper is a lot easier to remove, but requires a few torques and usually best re-torqued occasionally (once a year is enough). When re-torquing it is best to drain the coolant down below head level to prevent coolant seepage.

Here are more strings on the subject of head gaskets.
https://www.fordbarn.com/forum/showt...te+head+gasket
https://www.fordbarn.com/forum/showthread.php?t=290073

After reading all this, seems the general consensus is the copper/copper clad gasket is the safest bet, just be sure to follw recommended installation, head and block preparation, torquing and re-torque intervals on it.
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Old 11-15-2020, 01:50 PM   #37
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Default Re: Why do I have to keep pulling the choke out ?

The Loctite gasket eliminator breaks free quite easily
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Old 11-15-2020, 03:51 PM   #38
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Default Re: Why do I have to keep pulling the choke out ?

"LB" is not a Ford number, it would have been *A serial number*. When a bare block replacement was sold it would not have had a number stamped on it. The dealer would have stamped the old number on. Could also be later block that was made for industrial use and would have been stamped with that companies number. Send me a PM, Tom's shop, The Model A Ford Works, is in North Portland and he should have all the parts in stock. He is not open for walk-ins right now, only by appointment.
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Old 11-15-2020, 08:24 PM   #39
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Default Re: Why do I have to keep pulling the choke out ?

This motor must be one of the so called "Diamond" motors manufactured after Model A production ended. The Diamond is located above the side timing cover.
Attached Images
File Type: jpg diamond.jpg (52.1 KB, 7 views)
File Type: jpg j216.jpg (57.9 KB, 9 views)
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Old 11-16-2020, 11:20 AM   #40
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Default Re: Why do I have to keep pulling the choke out ?

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Originally Posted by wwirz View Post
The Loctite gasket eliminator breaks free quite easily
Thanks, that's good to know.
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