An article by Lowell Frank
DRAFT -- DRAFT -- DRAFT

March, 1997 Dear Grant,

It has been a long time since not only talking with you, but writing, too. I thought I might bring you up to date on my tinkering with the Ford Model "A," "B," and "C" engines. As you know, my main goal is to show or prove the "A" and "B" engines can be a dependable power plant for the Pietenpol.

First of all, the "A" engine with babbitt bearings and Pietenpol modifications can be a dependable engine if;

• the babbitt is sound, oil pump is not worn and has a close fit between gears, end plates and bearings,
• the oil tube assembly is pressed into the 5/16 hole in the valve and lifters oil galley area and
• oil tubes are directed into each of the three main bearings with a press fit to reduce excess oil leaks in the valve lifter area and maintain oil pressure.

A restriction is necessary in the oil line at the prop-end bearing or one will have oil leakage behind the prop. Don't run a positive crankcase pressure; this invites oil leaks. Two bored holes 3/4" diameter are required through the bottom web between cylinders one and two -- and between three and four to allow oil to drain into the crank case and allow oil to drain into the crank area and allow vapor oil to lubricate valves, guides, and springs. Condensation is also dissipated easier. The "A" block oil dams require a drain hole in their bases to allow oil to drain to the pan area and flush impurities out. A hole is also required at the lower end of this chamber to flow oil into the timing gear chamber area.

The "B" block has a 5/16" hole at the end of the oil galley that must be plugged. Oil pressure is available at around ten to twenty psi by close fits and controlled oil distribution. The attention to oil lubrication allows one to run an "A" with babbitt at a higher compression ratio and higher RPM's. I've run two years (100-plus hours) with 2450 max. RPM and 2125 cruise RPM with a 7:1 compression ratio head. After complete disassembly of the engine, there was no sign of babbitt damage or wear throughout the entire engine.

Cam end thrust must be held close to keep valve timing proper for good horsepower. A "B" cam grind is required for added horsepower. I've tried numerous carbs. The carbs. used on Continental engines are good but require carb heat for safe operations. The Funk carb and manifolds used with a 6.25:1 head will produce sixty-two horsepower at 2125 RPM. This is very noticeable on a Piet. I've tried a side-draft carb. with numerous jets and rods combinations. The airflow over the carb inlet, attitude of the airplane and carb. fuel pressure all had adverse results and at this time I'll need more data and trials to get this type of carb to work on an "A."

Fuel injection worked extremely well with a mechanical fuel pump and adjustable pressure. This bolt -on experiment produces seventy horsepower with port injection and a three-inch air tube to the intake manifold giving better breathing to the intake ports. Overall, the single venturi carbs. so-far tested, injection is the most expensive -- more than $2000.00.

I tried a 8:1 compression head and with regular fuel ran for two hours flying and take-offs. I removed the head from the babbitted "A" and found number two piston had a small 3/4" long crack starting at the center radiating toward the pin side of the piston top. This indicated that the older pistons may not be strong enough to take the added compression. A higher octane may have prevented this cracking, but stronger pistons are available and should be used.

The latest carb. that I've tested is a new Weber 32-36 progressive two barrel downdraft mounted on a manifold that allows a separate and independent air tube to each intake port. The idle speed is smooth at 550 RPM and RPM's up to 2000, is handled well with the primary venturi, but as the secondary opens the engine fails to respond. I've redrilled the main jets of the secondary numerous times until the engine turned a flawless 2600 RPM static. This combination worked extremely well from take-off to 5000 ft. at 450 ft. per minute. The problem comes when you back off the throtttle down to one quarter open and with the conditions the carb ices up quickly. One need to manipulate the throttle movement to get the Piet back on the ground without engine stoppage. I took the front head water vent pipe over to the carb primary inlet and made three loops with aluminum tubing and then up to the radiator return pipe. This solved the ice problem. Since the Weber is a downdraft carb. and sets rather high on the engine, the wing fuel tank is a must, or a fuel pump would be required to get the fuel pressure. I've also notice that the Ford Pinto engine used a Holley/Weber progressive carb. This carb. is a good candidate. I'm using Pinto jets in my Weber carb.

My engine is now getting high enough RPM's that a prop change will be required. The Sensenich 76 x 42 should be changed to 76 x 50 as I used on the Funk engine Piet. This prop turns 2125 at 62 hp. The dyno test that have been performed with bolt-on updates to the "A" and "B" engines show 72 hp has been achieved, a la Ron Kelley. Now that the carb. has shown its ability, I am proceeding to get the manifolds made up for the turbo version, using a pressure regulator at 5 psi. This combination should allow better breathing which is the main problem the "A" and "B" have. At idle, this engine will operate as the Weber primary did, while at full throttle the should give the airflow and higher horsepower I'm expecting.

One must keep in mind that the higher outputs that have been achieved to date is with strictly bolt-on items. If one wants a complete engine to compete engine to compete with auto and aircraft engines, at added cost, modifications to the block are required. These changes are far less costly than an aircraft engine overhaul and will give a very dependable and powerful powerplant. Shops will do the inserts, valves, and cam job for around $2000.00. If you want dependability with high RPM's, it isn't too bad.

With all the changes I've tried, I fly almost every weekend. With the temperature down to "0" degrees "F." and averaging in the higher 'teens. I try to arrange the new equipment with everything ready to bolt on and assemble; then within a couple of hours I'm in the air after a good ground test.

A prop with more bite has enough thrust to move the Piet on a hard surface at idle. Therefore, a set of brakes will be required. I'm very confident that if the equal effort and money in put into an "A" or "B" engine that is applied to an aircraft engine, the dependability also will be equal. Mags. and their drives, water and oil pumps must be in top-notch condition.

I have a spare "B" block that has a crack that runs from #3 cylinder intake valve to the bore. If this block is re-sleeved and "pinned," it should be a good block.

I'll define crack pinning: A center-punch mark is placed along the crack, preferably at the halfway area, and a hole is drilled into the water jacket. A tapered reamer is used to shape the hole for a long tapered tap. A cast iron plug, coated with "Lock-tite," is turned in quite snug, then cut off at the surface deck and ground flush. The next plug is located to overlap the first plug by about 10%. Continue along the crack with plug pins on both side of the first center plug until the full length of the crack is pinned. A small ball peen hammer puts a finish to the surface. A fine surface grind or sanding renders that total fix. I recommend this process before the block surface has been milled or decked.

I'm now testing a crack fix with a high compression head. So far, at ten hours, it looks good.

As you can see, Grant, I've given a lot of thought and experimentation to the "A", "B" and "C" Ford engines as well as the Continental 65 - 85's, and have worked with the Corvair.

Most of my investigations are to verify others that have tested and modified Fords, but not used in Piets. To this day, it hasn't been proven as to which is better; high manifold pressures and high RPM's, or low RPM's and lugging the engine at full throttle. I've done both. I feel a higher RPM (2400) with babbitt bearings will hold up and give plenty of take-off power. If one is concerned about the babbitt, go inserts. A lot of people do it, which makes the engine less vulnerable to failure.

I always keep in mind what one does on the inside of an engine to get dependability doesn't change the appearance that the critics remark " . . . wasn't the way Bernie did it."

It has been proven the Ford block has a severe breathing problem. Bolt-on corrections are available and can double or triple horsepower.

I'm enclosing Dan Price's bolt-on items, duel intake ports, dual spark plug heads. The horsepower is there; it only costs $$$$.

I'll slip in a couple more successful fuel system pictures I've done. We are talking 70 horsepower, plus a few extra.

Best regards,
Lowell Frank

• 1. "B" block
• 2. Funk head, 7:1 compression ratio
• 3. Wico mag.; side mount per Funk
• 4. Valve cover with oil pressure control adjustment
• 5. Fuel pump mounted opposite mag. drive
• 6. Injection throttle body
• 7. Injection distribution block with primer line.
• 8. Injectors, natural aspirate, above intake opening.
• 9. Funk exhaust pipes with extensions
• 10. High pressure oil pump, 40 - 60 psi.
• 11. Inserts; mains and rods
• 12. Bronze cam bearings
• 13. Reground cam with long dwell, similar to "B"
• 14. Short valve springs
• 15. End thrust cam adjustment
• 16. Aluminum cam gear
• 17. Funk water pump
• 18. Universal intake manifold, can be mounted above or below exhaust manifold; updraft, down draft or side draft.
  Picture #2:
  • 1. Weber carb installation without choke.
  • 2. Air cleaner with pre-heat coil
  • 3. Intake manifold mounted above exhaust manifold
  • 4. Aluminum carb. base block with side outlet to ports
  • 5. Gravity fuel feed
  • 6. Prop thrust housing, Funk

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