Cruise’n with Grampa Articles re Shortening Pitman Arm
"In my opinion"
This is a review and enhancement of my previous comments on the above procedure.
I firmly believe the procedure to be one of the most dangerous, irresponsible and reckless modifications that can be done to your car. Province of Ontario "Safety Standards" state that any modifications, cutting, welding, evidence of heating, bending to the pitman arm results in disqualification!
In various automotive competition organizations such as NASCAR etc., any evidence of tampering / modifying the pitman arm in any way results in expulsion of the car, crew chief and crew members from the garage/pit area only to be re-admitted at a subsequent event after appropriate scrutiny.
I have heard comments that pitman arms have been cut, "V" ground and welded; the weld ground down; a procedure that can reduce the strength of the weld by up to 70%, and painted to completely camouflage the procedure. In my personal opinion totally irresponsible!!
Over the years this procedure has been performed I would say many hundreds of times. I have personally only seen the result of one that failed (fell apart); a nice coupe at low speed that rolled into a right side ditch shaking up the passengers and damaging the right front fender. It could have been much worse!
If it is your quest to reduce the effort to steer your car there is now a forged steel shorter pitman arm available. A major Model A parts supplier took on the project and it is now available from most major Model A parts suppliers. When installing a "short" pitman arm it should be realized that the procedure will reduce your turning radius.
Beyond the foregoing to ease the effort to steer your car, various procedures can be completed. These have been discussed on other occasions and include installing roller bearings in the steering box sector shaft housing and installing a "roller"(*) thrust bearing at the base of the steering column. A premium lube in the steering box is also of assistance. I will comment on this a bit further in my next article.
(*) A "roller" thrust bearing consists of a cage to retain sideways mounted rollers and a steel shim on either side.
SPARK PLUG INDEXING
WHAT IS IT? WHY DO IT?
It is a procedure to position your spark plugs after you have ensured the polarity of the coil is wired correct.
It will improve engine smoothness at idle, will improve pulling power and it will improve gas mileage slightly by 1% -2%. Is it worth it? Completing the procedure will only cost you some time which will certainly appeal to most Model A owners.
How to do it?
When spark plugs are installed their ground strap should be facing "back" to the right side of the car and the open side facing the left side of the car, within a range of say 10:00 o'clock to 2:00 o'clock. (Remember the old Timex time). This will direct the flame front towards the piston, as opposed towards the "closed" side of the (inside) head. The open side of the plug should face the piston, not the valves.
Here at least two suggestions to help with the procedure.
Mark the side of the plug with a felt pen/Sharpie etc. (NOT A LEAD PENCIL THE LEAD RESIDUE CAN BE AN UNWANTED CONDUCTOR OF ELECTRICAL CURRENT) where the open side of the ground strap is located. Or you may prefer to use a piece of rubber hose and slip it on the plug from its top and put a mark on the hose to indicate the position of the ground strap.
Now comes the fun part; thread the plug in to determine where the open side locates once tightened to spec. Depending on the cut of the threads on both the spark plugs and the head it is to be understood that this is a "crap shoot" where the plug will position itself. Remember the objective is to have the open side of the plug face the piston. So by moving plugs from one of the cylinders to the next cylinder and using a few of your spares, you should be able to achieve success.
Note: The popular Motorcraft TT10 spark plugs are available at all Ford dealerships usually next day delivery. Prices are competitive and no annoying shipping costs. If you buy them by the box (10) you have more options to choose from in your indexing project. If you have more than one car, all heads are threaded differently and plugs will tighten in different positions; double the fun.
All said, I am not suggesting you should do this or you must do that but in the field of race cars every trick in the book is utilized. How do you think Steve and Colin run in excessive of 50 mph most of the time? Besides, if nothing else you will find this tip interesting to explore.
John made a presentation on a number of subtle clutch plate clearance problems people have run into. Typically they show up as a light ticking noise when the clutch is not engaged, but goes away when engaged. These problems occur under 2 conditions, both of which are caused by incorrect assembly or substituted fasteners.
1-Not exactly a clutch thing but closely related. If the original bolts used to fasten the flywheel to the crank shaft flange are substituted and are just slightly too long, the threads can protrude out the back of the flange, hitting on the rear bearing housing. With the flywheel and the bolts installed it is virtually impossible to see their back side. So it is a measurement project. Add together the thickness of the flywheel at the mounting flange and the thickness of the crankshaft flange; compare the total measurement to the thread section of the flywheel bolts. The bolts should only protrude through the crankshaft flange by one or two threads MAXIMUM.
2- If the original wire lock bolts are substituted for regular bolts, the heads may be too high or if lock washers are used, the combined thickness may be too high resulting in them hitting the dampening springs on the clutch plate. This can have a disastrous effect if left long enough as the springs will eventually deform enough to get caught by the bolt head and destroy the clutch plate and/or cause serious damage to the pressure plate.
Always be sure to gauge the clearances between the face of the flywheel and the fastener heads as well as from the clutch plate face to the associated springs to be sure they are not too high. A normal clearance, even with proper fasteners and assembly, is only in the order of 1/8 in. To measure, may I suggest you cut a disc approximately 4" in diameter and 1/8" thick (cut from panelling ,aluminum, masonite or something similar) with a hole in the center of about 1/2" to 3/4". Before you assemble and bolt the clutch components to the flywheel, do a trial fit in the following manner. Put the little disc you fabricated against the flywheel bolts and the clutch disc against the flywheel hold it against the flywheel snugly, you should be able to put a finger through the centre hole in the clutch disc and move the little trial disc a bit. If the trial disc is tight, cannot be moved, the clearance is probably too tight. To correct the issue use flywheel bolts with shorter heads or have a little bit trimmed off the heads of the flywheel bolts, best done in a lathe, grinding can overheat the bolts and release their temper (turn corners or all blue).
Keep the shiny side up! John"Grampa"Cruise.
Subject: Evans Coolant
Several meetings ago a member ask a question about "Evans", at the time my mind was churning, organizing my next subject, and my answer was short and perfunctory. I would like to answer more properly and more in depth, with also some observations about our Model A cooling system.
Evans Coolant, is a chemical solution, glycol based, with surfactants and adhesion components. It is meant to be used undiluted, in a clean uncontaminated system. To be installed in a new/fresh engine and radiator. When installed in a system with previous water, or water/antifreeze solution, they direct that the system be completely drained, and "purged" with their specific product. One major benefit of their product is its boiling point of 375 degrees Fahrenheit !!
In our Model A cooling systems, simmering/steaming while driving is often experienced. With straight water we know what is happening. With a water/antifreeze solution, only the water portion is steaming, leaving the solution to become more concentrated. With LESS cooling efficiency, actually as a water/antifreeze solution becomes more concentrated than 50/50 it becomes LESS efficient. In modern cooling systems, the water pump pushes the coolant through the engine with about four pounds pressure, our Model A pump pushes the coolant into the radiator with a similar approximate four pound of pressure. If the radiator is not high quality and in EXCELLANT condition, the coolant will not drop through fast enough to avoid slightly pressurizing the top tank. The result is droplets on the windshield and dribbling from the overflow pipe. When the coolant level drops somewhat this more or less stops. We hear it said that the system finds its level???
What actually happens is that with less total fluid in the system, the water pump is partially starved, with less fluid to pump into the radiator, the droplets and dribbles slow down. Unfortunately the cooling system efficiency is reduced and the engine runs warmer/hotter. One or two meetings ago we discussed the excessive flow question, particularly with a good properly installed water pump. The issue has become more prevalent with higher driving speeds, various options were discussed, and I might add one or two. Steve Latimer spoke of reducing the size of water pump impeller vanes, or removing two. A smaller crankshaft pulley could be installed, which would reduce the water pump speed, but would inadvertently also reduce the generator/alternator speed ( undesirable ). Myself I installed a one inch larger water pump pulley, which reduced the water pump speed about 25%. Also very easy a thermostat could be installed in the upper radiator hose, parts suppliers sell them in a stainless steel tube/barrel, they assist in warm-up and provide some restriction in fluid flow.
To return to the Evans subject, if fluid is being pushed out your overflow, a catch canister could capture the fluid to be re-installed.
Various Differential Ratios Compared to RPM's and Road Speeds
Over the years various ratios have been identified in Model A's, we will list them here in numerical order with some casual comments.
* 3.27 Originally available in the 1930's as an aftermarket option, probably with the improvement of roads.
Now available from several Model a suppliers for retro-fitting.
* 3.54 Possibly originally supplied in some early 1928 models. (not confirmed)
Has been available for several years from most Model A suppliers.
* 3.78 Generally believed to be original equipment in almost all passenger Model A's
Reproductions available from most model A suppliers.
* 4.11 Rarely seen in original Model A cars.
Quite popular in Model A pickups and commercial cars, particularly in vehicles originally supplied in hilly mountainous areas.
For many years owners have retro fitted their vehicles with the 3.54 gear sets, resulting in a modest reduction of engine RPM's at the same road speed OR a slightly higher road speed at the same RPM's.
The 3.27 gear set has become available now for about twenty years, and has found their way into several members’ cars. Some skepticism has been expressed versus engine power, seemingly now unfounded. With a good running fresh engine one might find pleasant results.
21" Firestone Tire 440 / 450 19" Firestone Tire 4.75 / 5.00
Manufactured Quoted Height 30.79" Manufactured Quoted Height 29.80"
Revolutions per Minute vs Differential Ratio Revolutions per Minute vs Differential Ratio
Differential 3.27 3.54 3.78 4.11 3.27 3.54 3.78 4.11
55 MPH 1,963 2,125 2,269 2,469 55 MPH 2,028 2,195 2,344 2,549
45 MPH 1,606 1,738 1,856 2,018 45 MPH 1,659 1,796 1,918 2,085
35 MPH 1,249 1,352 1,444 1,570 35 MPH 1,290 1,397 1,492 1,621
As you will see the chart was based on the use of Firestone tires, they are currently the highest/tallest tires available in those sizes. Alternate brands are generally somewhat smaller in diameter; the more economy tires are correspondingly smaller. Therefore to maintain the same road speeds modestly higher RPM's would be required, conversely at the same RPM's a modestly lower road speed would be the result.
If you have a specific situation, tire size, gear set, RPM, road speed, I would be glad to try to use your data to extrapolate (big word, like marmalade) to find the result.
In another article, I may try to offer an assist to understand overdrive ratios, percentages, etc. which are due to some interpretation, and understanding.
To open, a short review of some internal electrical components. In starters, generators (alternators) and coils the
multitude of copper windings appear to be "bare". This is not accurate, they are actually coated with "back-in-the-day" varnish, the coatings may now be some more modern material. As the years pass and these units are
continually heated and cooled the coatings of the copper wire age and deteriorate. As the bare windings touch
each other the efficiency/strength is reduced. Not drastically when one or two windings touch but as more and more
touch the unit (starter, generator, or coil) will eventually fail.
In the Model A coil, some now 60, 70, or 80 years old, it is possible that they no longer have their original strength.
The interior windings, and circuitry are all subject to aging. A test with an ohm meter, taking a "reading" between
the two small terminals should be 1.5 ohms. A reading either higher or lower is undesirable!
Current new coils of "original" appearance are available from most Model A suppliers.
Locally new coils are available from NAPA, a suitable number for stock Model A 6 volt system is an IC!2. This coil
has a "vintage" look , small terminals are screw-on not modern clip type. The package includes a new boot for the
high tension wire and double nuts and both split and star lock washers. The coil itself is stenciled " # 904 12V use
with external resistor ". DO NOT be deterred, the ohm rating of this coil is 1.5 ohms. ( for 12 volt use the resistor is
necessary). Also VERY important, installation instructions note. COIL POLARITY MUST BE CORRECT. If the
negative battery post is grounded , the coil terminal marked (-) must be connected to the distributor.
If the positive post is grounded, the terminal marked (+) must be connected to the distributor.
This information might apply to most coils.
A good coil, good condenser, properly adjusted points, good properly gapped spark plugs, and all good connections
in the ignition system ALL contribute an engine that stars easily, runs well, has good pulling power, and good gas
Oil Filter Suggestions
For anyone that has their vehicle equipped with an oil filter, particularly the type that mounts to either the valve cover, or the timing gear cover, changing the filter can be a bit of a messy operation, due the horizontal mounting of the filter. If you are interested, I can offer a couple of suggestions to help.
Over the years Ford Motor Co has used various 90 degree filter mounts; some were used several years ago and may be still found. They may have been used on commercial vehicles, particularly 6 cylinder pick-up trucks and vans. Part numbers for some of those units were 83TM6884AA and C5TE-6684-A; be sure to get the mounting bolt if you can find a used one.
Ford Motor Co. now sells a new 90 degree unit through all dealerships, it is a Ford Motorsport item # M-6880-A50 and it does include the mounting bolt.
To continue if the full size filter that fits the valve or timing cover , Fram PH8A, Ford FL1A or the equivalent is being used there are shorter options if space is an issue.
Known as a “Short” filter the Fram PH43.
“Extra Short” Fram PH3512 or Wix 51335.
Note; Fram or Wix part numbers can be cross referenced with other manufacturers Hastings, Purolator, etc.
There is also a billet aluminum filter assembly, with a stainless steel cleanable and re-usable filter.
This article is offered as “food for thought”, ideas, suggestions ONLY no "should do's".