Souping up a Model A

50Trucking

50Trucking

Member
I want to improve the performance of my model A coupe but I am on a budget. I have purchased a used Webber carb and manifold and a electronic distributor with centrifugal advance and a lightened flywheel.

What can I economically do to the engine to improve the performance such as porting the intake and exhaust, headers, smithy muffler etc?

If anyone has any parts and or information please contact me a t goodallh@bellsouth.net or answer the post.
 
What performance are you trying to improve? Higher top speed? Faster takeoff from start? Better shifts?
 
When you're looking for more performance, remember the three C's: Carb, Cam, and Compression. Since the Model A engine has a large displacement relative to the number of cylinders, the more air you can get in and squish, the better. These three C's will help you achieve that. A modern distributor will not help as much.

Carb - If you already have a downdraft carb then that's one of the three (given you have a compatible intake manifold)

Cam - Suppliers sell touring cams or will grind one to a touring spec

Compression - This all depends on what condition your engine is in. Low mileage insert bearing engines can handle a 6.5 head while babbitt engines should be treated more gently (no more than 5.5:1).

If your engine had some mileage on it, your performance additions and driving style will influence how long it lasts, so consider longevity and cost when you make your decisions.
 
50Trucking -
Before you spend any more money on speed parts, buy Jim Brierley's performance enhancement book and read it cover to cover. It will not only advise what to do to reach your goals, it will save you money spent on things that only marginally increase performance or are a waste of money. In terms of squeaking every bit of hidden horsepower out of Model A and B engines, Jim's been there, done that for decades. Follow his advice and you'll blow the doors off other local souped up Model A's!
Marshall
 
hard parts aside... cams, heads, etc, i personally like the accuracy of an electronic ignition. imo, a must on any performance upgrade engine package. the mechanical parts will help fill the cylinder, but the hotter ignition will get more out of what is compressed in the cylinder. if it was mine, and i never really ever heard of hi-po on a budget... (:D) I would want a 12-v system. then i could run a better coil and some sort of spark dwell enhancer such as MSD makes. they used to offer 6-A's for 6 and 4 cyls. and lower resistance hi-po plug wires such as Magnacore makes can be used. 8mm.


when we had the Speed Shoppe... behind the counter was a sign:


"Speed Costs Money, How Fa$t Do You Want To Go!?"
 
Timing is important. limit your advance range to 14-18degrees and set to 24-30 degrees max running at 2,000 RPM. watch out for pinging.
timing static with the pin is only to get it running.
 
What is the existing level of performance?
Will it comfortably drive over 60 now?
Perhaps just fixing it to run properly would be enough.
To go fast safely the brakes and suspension should operate at least at the level of a car restored to original tolerance and specifications
 
Just remember the one obvious element, that is often overlooked. You still need to be able to stop.
Adding all this power and speed, make sure your brakes can handle it.
 
Beware!
 

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Bob Bidonde said:
Beware!
Click to expand...

Yup. Kind of limited on compression if you stick with the original babbitt bearing. The tendency is to "whip" the center main out.

Snyder's et al do sell a "high compression head" (6.0) which supposedly can be bolted to the babbitt engine. I say "can" but you may not want to. Instead limit your compression to the "police head" 5.22 number (or a variant, Snyders 5.5) and let the higher compressions go with insert bearings - or a Model B crank insert. (i.e. confronting the "clearance issues" of a Model B crank in a Model A block.)

Vince Falter at Fordgarage.com discusses the various heads available at the time of his writing - not too much on the downside. https://www.fordgarage.com/pages/ABcylinderheadcomparison.htm

As described by Vince, it is surprising to me the high compression (7.0) that was used on the "Wood-Gas" engines of German origin. But these engines may have labored under a "near vacuum" condition pulling as they did through "generation & processing" of the wood-gas.

Wood gas by virtue of it's "non calorific nature" (low BTU) probably also required the higher compression to make a practical engine output.

Joe K
 
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butch chase said:
Timing is important. limit your advance range to 14-18degrees and set to 24-30 degrees max running at 2,000 RPM. watch out for pinging.
timing static with the pin is only to get it running.
Click to expand...

The above is very good advice, but in an earlier post someone said that babbitt should not be used with compression above 5.5:1, this is not true. I run B engines with bigger than A bearings, and have run 153 MPH at Bonneville, with 10:1 compression, on 100% babbitt and 167 on the same engine but with inserted rods and the same babbitted mains. full oil pressure of course. Babbitt was used at the Indy 500 for many years.
 
Let me pass on my earlier comment Jim. Not to bring discredit upon anything you've said. You've obviously "done it." You've also "paid the price" to get there.

BUT - that Allstate replacement engine (painted red) in the truck (avatar) when I got it had SERIOUS miles on it - the odometer read 143K - and this replacement probably the second engine. (i.e. 70k per engine - a typical life for the non-air cleaned non oil filtered stock Model A engine - Air cooled vw bugs were similar.)

The center main you could literally see the "wiping" as the babbitt had been turned to a mush and been pushed around by the non-circular motion of the journal.

But as I say it was an engine with "hydrodynamic" not pressure lubrication, and probably line contact (i.e. no bearing half circle for support/egg shaped journal AND bearing.)

It is an engine that with the wear should not have been running the 4.25 stock compression. Not that there was a lot of choice.

Whipping of the center main DOES exist - it can be compensated for by proper fit, pressurized bearings, modern oils, and - as mentioned - timing.

My online mentor Vince Falter opines that the Model A standard manual timing adjustment is about double what the later centrifugal Model B distributor had as capability - Ford must have had a reason for "narrowing the band."

So - not to discredit ANYONE - or any opinion. "Your mileage may vary" applies directly.

And thank you. You were "polite" in your refute. Nice to see when it happens.

And my father comes to mind: "Courtesy is the lubricant that oils the machinery of human interaction."

Joe K
 
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The 14 degrees of advance in a Model B distributor is ideal for most model A and B flat beads. they start easily and have good acceleration. Ford knew what they were doing in 1932
 
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