|
Sponsored Links (Register now to hide all advertisements) |
|
|
Thread Tools | Display Modes |
11-03-2020, 11:16 AM | #21 | |
Senior Member
Join Date: Jun 2015
Location: Red Deer, Alberta
Posts: 5,056
|
Re: Why do I have to keep pulling the choke out ?
Quote:
__________________
If you don't hear a rumor by 10 AM, start one!. Got my education out behind the barn! |
|
11-03-2020, 10:05 PM | #22 |
Senior Member
Join Date: Oct 2020
Location: Oregon City, OR
Posts: 122
|
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. |
Sponsored Links (Register now to hide all advertisements) |
|
11-04-2020, 08:55 AM | #23 |
Senior Member
Join Date: Mar 2014
Location: Midland Park,N.J.
Posts: 1,108
|
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.
|
11-04-2020, 10:22 AM | #24 |
Senior Member
Join Date: May 2010
Location: Portland OR
Posts: 6,346
|
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.
__________________
I know the voices aren't real but damn they have some good ideas! |
11-04-2020, 06:44 PM | #25 | |
Senior Member
Join Date: Dec 2016
Location: Sunrise Beach, Mo
Posts: 439
|
Re: Why do I have to keep pulling the choke out ?
Quote:
|
|
11-04-2020, 10:24 PM | #26 |
Senior Member
Join Date: Oct 2020
Location: Oregon City, OR
Posts: 122
|
Re: Why do I have to keep pulling the choke out ?
Sponsored Links (Register now to hide all advertisements)
Fuel line protrudes 1/4" past the ferrule at carb inlet fitting. Compression test results: #1 55 #2 55 #3 60 #4 60 |
11-05-2020, 04:29 AM | #27 |
Senior Member
Join Date: Jul 2010
Location: United Kingdom
Posts: 1,445
|
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?) |
11-05-2020, 10:45 AM | #28 |
Senior Member
Join Date: May 2016
Location: Scottsdale, Arizona
Posts: 617
|
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
|
11-05-2020, 11:11 AM | #29 |
Senior Member
Join Date: Oct 2020
Location: Oregon City, OR
Posts: 122
|
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. |
11-05-2020, 11:37 AM | #30 |
Senior Member
Join Date: Mar 2020
Posts: 150
|
Re: Why do I have to keep pulling the choke out ?
Try a vacuum test yet?
|
11-05-2020, 03:01 PM | #31 |
Senior Member
Join Date: Jun 2014
Location: Land of Lincoln
Posts: 3,136
|
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!
__________________
Don't force it with a little hammer tap, tap, tap get a bigger hammer tap done |
11-06-2020, 02:12 PM | #32 |
Senior Member
Join Date: May 2020
Location: Corning NY
Posts: 245
|
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. |
11-07-2020, 11:36 AM | #33 | |
Senior Member
Join Date: Jun 2015
Location: Red Deer, Alberta
Posts: 5,056
|
Re: Why do I have to keep pulling the choke out ?
Quote:
__________________
If you don't hear a rumor by 10 AM, start one!. Got my education out behind the barn! |
|
11-07-2020, 03:32 PM | #34 |
Senior Member
Join Date: May 2020
Location: Corning NY
Posts: 245
|
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.
|
11-14-2020, 11:40 PM | #35 |
Senior Member
Join Date: Oct 2020
Location: Oregon City, OR
Posts: 122
|
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 ? |
11-15-2020, 09:45 AM | #36 |
Senior Member
Join Date: Aug 2018
Posts: 2,332
|
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. |
11-15-2020, 01:50 PM | #37 |
Senior Member
Join Date: May 2020
Location: Corning NY
Posts: 245
|
Re: Why do I have to keep pulling the choke out ?
The Loctite gasket eliminator breaks free quite easily
|
11-15-2020, 03:51 PM | #38 |
Senior Member
Join Date: May 2010
Location: Portland OR
Posts: 6,346
|
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.
__________________
I know the voices aren't real but damn they have some good ideas! |
11-15-2020, 08:24 PM | #39 |
Senior Member
Join Date: Oct 2020
Location: Oregon City, OR
Posts: 122
|
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.
|
11-16-2020, 11:20 AM | #40 |
Senior Member
Join Date: Jun 2015
Location: Red Deer, Alberta
Posts: 5,056
|
Re: Why do I have to keep pulling the choke out ?
Thanks, that's good to know.
__________________
If you don't hear a rumor by 10 AM, start one!. Got my education out behind the barn! |
|
|
Sponsored Links (Register now to hide all advertisements) |
|