MTFCA Forum

For the last few years I've noticed that when I climb a hill at 25+ mph the engine tends to run rougher the further I go, and I lose climbing power. I can start a hill at 35 mph and by the time I reach the top it drops down to about 20 mph. Today I was out for a morning drive, and being still half asleep, forget I was running in Ruckstell low. Well, the car effortlessly climbed at full throttle and I was running at a steady speed of just over 25 mph. On my way back home, when I was back in Ruckstell high, it returned to it prior poor hill climbing performance. I am really curious if anyone knows what I should be looking at to improve my hill climbing performance. I have Ron Patterson rebuilt coils, a TW timer which i cleaned at the beginning of the summer, cleaned and gapped plugs, there's plenty of gas in the tank, the gas tank has no residue, I do not have a fuel filter, I retard my spark for hill climbs, and am I think I'm adjusting my fuel/air mix so that I'm not too rich or lean. Other than hills, it runs real smooth. Thanks in advance for any ideas.

Do you notice any difference climbing the same hill with the gas tank full or at 1/4 tank or less? Does the engine smooth out if you back off the throttle? Some float valves will not feed enough fuel for long pulls up hill at full throttle. That allows the fuel level in the carburetor bowl to decline, which can cause diminished power and rough running.

My tank was about 3/4 full for both hill climbs, the only difference was that in Ruckstell low it pulled fine, but in Ruckstell high (which is how I usually run) it has issues. I have not tried to back off on the throttle, but will try that. But that does not explain why it runs much better at full throttle in Ruckstell low??

Do you use full throttle in both gears? Losing power on hills often indicates a fuel delivery problem, but if it runs better in the lower gear at full throttle, it may indicate an ignition problem. Does it start easily and run well at other times? Does it idle well when warmed up? Does it run smoothly when you accellerate at full throttle in high gear from 20 MPH or so up to 35 MPH or so on level ground?

I was running full throttle in both gears. It does idle smooth when warm. It does accelerate smoothly at full throttle on level ground. I'm stumped why it ran so well in Ruckstell low

Going up the hill you can keep full throttle , but you have to retard the spark at least half to retain engine power at lesser vehicle speed to crest the hill. You have to remember that's a 20 horsepower engine, and even though throttle may be fully open the engine will only go as fast as it can, according to the weight of the car, weight of passengers and /or cargo..... Ruckstell gearing will help to climb hills at a higher engine speed.,, even though it will be at a slower vehicle speed.

I can't explain it either. Have you tried adjusting the carburetor a little richer when the problem occurs? Be sure the gas cap vent is not obstructed.

I haven't read all the posts completely, so I'll just jump in and ask, how long has it been since the engine has been rebuilt? Maybe it's just plain old tired!

I'm stumped why it ran so well in Ruckstell low.

The lower gear sacrifices some ground speed to put less strain on a weak engine. You could climb an even steeper hill in Ford low, but you would have to creep along to do it. The real question is why the engine is weak.

Moxie26 wrote: ↑

Sun Aug 28, 2022 9:46 pm

Going up the hill you can keep full throttle , but you have to retard the spark at least half to retain engine power at lesser vehicle speed to crest the hill. You have to remember that's a 20 horsepower engine, and even though throttle may be fully open the engine will only go as fast as it can, according to the weight of the car, weight of passengers and /or cargo..... Ruckstell gearing will help to climb hills at a higher engine speed.,, even though it will be at a slower vehicle speed.

Retard the spark & find that point of maximum performance. If you have not been doing this the difference will shock you..

Here are a few things I don't know: Do you know what percent grade your hill is? My cars will pull a 6% grade at about 25 mph in Ford high. if I approach the hill I get a run before starting up. It maintains the speed all the way unless I stop on the hill. If I have to start out in low I need to stay in low all the way to the top. If I have Ruckstell, I can use Ruckstell with Ford high and it goes right up.
Is this a hill you previously could climb just fine or is this a new problem? Have you done any work such as ignition or carburetor exchanges or manifold work? I found that a high volume intake manifold gives a lot of speed at top end on flat ground, but does not go very well on hills. it's kind of like trying to blow out a candle with the mouth wide open as opposed to blowing with the mouth puckered. That is at low speeds the engine does not suck in the fuel as it would with the standard manifold. If you have a timing problem which can come if you changed the timer, because some timers require a re-set of the timing from the old timer which was removed. Also are all coils functioning and good spark plugs? Sometimes spark plugs will fire with low compression such as idle or moving along at a constant speed on level ground, but with full throttle, you also have maximum compression, and the spark might not be jumping in the plug. Clean plugs with a slightly closer gap will usually fix that.
Anyway, suspect anything which you have changed since it ran better, and if that is not where the problem lays, maybe your screen in the sediment bowl needs to be cleaned. In fact if the car has been parked, sometime the fuel in the line will jell up and you might need to run a wire down the fuel line to clean it out.
Norm

Find someone in your area to adjust your coils for equal and consistent firing Time using an ECCT. You will likely notice a marked improvement in engine performance if your timer, coil box and plugs are in good working order.

EricMLexington wrote: ↑

Sun Aug 28, 2022 8:57 pm

For the last few years I've noticed that when I climb a hill at 25+ mph the engine tends to run rougher the further I go, and I lose climbing power. I can start a hill at 35 mph and by the time I reach the top it drops down to about 20 mph. Today I was out for a morning drive, and being still half asleep, forget I was running in Ruckstell low. Well, the car effortlessly climbed at full throttle and I was running at a steady speed of just over 25 mph. On my way back home, when I was back in Ruckstell high, it returned to it prior poor hill climbing performance. I am really curious if anyone knows what I should be looking at to improve my hill climbing performance. I have Ron Patterson rebuilt coils, a TW timer which i cleaned at the beginning of the summer, cleaned and gapped plugs, there's plenty of gas in the tank, the gas tank has no residue, I do not have a fuel filter, I retard my spark for hill climbs, and am I think I'm adjusting my fuel/air mix so that I'm not too rich or lean. Other than hills, it runs real smooth. Thanks in advance for any ideas.

When you say it was the same hill, was the grade and length of travel up the hill the same heading away from home and returning on the way back home? That's 2 different grades

As Scott Conger has pointed out, if you have a modern float needle valve, it will probably have a smaller hole that Henry's original. About 0.093" instead of 0.125".
That's only 55% of the area so you don't get enough fuel after a short time on a long hill.

If you want to try drilling it out, find a ball bearing that just fits in place of the needle, and hammer it gently onto the over-bored hole end to form a good seat. Then the old needle should seal on the larger diameter.

You said that you usually run in Ruckstell high? Ruckstell gear is a mid-range lower gear than Ford. I live in a some what hilly area of Virginia. The only time I use Ruckstell high gearing is to cruise through local parks I never use Ruckstell low (bulldog gear) bobt

Ignition problems can show up under high engine load due to higher cylinder compression pressures at or near full throttle. Actual compression presssure is probably highest at the engine's peak torque speed with the throttle wide open. That would be around 900 to 1100 RPM, which would be around 25 to 32 MPH in high gear. Putting your car in a lower gear would allow the engine speed to increase to near or above the peak horsepower speed, which is around 1800 RPM. Compression presssure would very likely be lower at the higher engine speed, even at wide open throttle, due to lower volumetric efficiency at higher engine speeds, which might mask an ignition problem. I'd check the condition and adjustment of the spark plugs first, and if the problem persists, go on to check the timer wiring, timer, coil points and adjustment, and the condition of the coil box and contacts. I would not rule out a fuel system issue, including a restrictive float needle and seat assembly.

EricMLexington wrote: ↑

Sun Aug 28, 2022 9:15 pm

My tank was about 3/4 full for both hill climbs, the only difference was that in Ruckstell low it pulled fine, but in Ruckstell high (which is how I usually run) it has issues. I have not tried to back off on the throttle, but will try that. But that does not explain why it runs much better at full throttle in Ruckstell low??

Well, maybe the hill is just too much for the T to pull in high gear. With the Ruckstell downshift you're letting the engine get back to its maximum torque. (That's what Ruckstells are for.)

Besides, running at full throttle hides weaknesses that sometimes only show up at low engine speeds and high loads, when every cylinder is stressed to its max and where issues become evident.

Also, I don't know what ring & pinion ratio you've got, but I think if I ran my T in Ruckstell low at 25 mph, the engine would jump out of the car.

Check the compression on each cylinder, both dry and with oil.
Art Mirtes

I am a little confused by what you call Ruckstell High or Ruckstell Low. When the stick is forward, you are in standard Ford gear, either high or low depending on the position of the pedal. With the lever back toward you it is in Rucksell. Ruckstell high would be with the lever back and the pedal back. Ruckstell low would be with the lever back and the pedal to the floor. Usually hills are climbed with Ruckstell lever toward the seat and the pedal out. And when you start out from a stop on a hill you can have the lever toward the seat with the pedal to the floor. This would give you a Low Low gear or what was called compound low.
Norm

You've all given me a great place to start my work through. To clarify one point, based on Norman's latest post, the car runs rough in standard Ford High and runs well in Ruckstell High. I can now understand why my original terminology may have caused some confusion. I appreciate all your responses and will report back once I get this diagnosed.

EricMLexington wrote: ↑

Mon Aug 29, 2022 9:58 pm

You've all given me a great place to start my work through. To clarify one point, based on Norman's latest post, the car runs rough in standard Ford High and runs well in Ruckstell High. I can now understand why my original terminology may have caused some confusion. I appreciate all your responses and will report back once I get this diagnosed.

"Standard Ford High" and "Ruckstell High" are the same thing. Did you mean to say Ruckstell low? Meaning the T transmission is in high and the Ruckstell is in low range?

Jerry - you wrote "Standard Ford High" and "Ruckstell High" are the same thing. Did you mean to say Ruckstell low? Meaning the T transmission is in high and the Ruckstell is in low range?

Yes - I originally refered to the T trans in High and Ruckstell in Low as Ruckstell Low, but what Norman had posted had also made sense. But I'm curious to know how you'd refer to the T trans being in Low and the Ruckstell being in Low?

Thanks

EricMLexington wrote: ↑

Tue Aug 30, 2022 7:18 pm

Jerry - you wrote "Standard Ford High" and "Ruckstell High" are the same thing. Did you mean to say Ruckstell low? Meaning the T transmission is in high and the Ruckstell is in low range?

Yes - I originally refered to the T trans in High and Ruckstell in Low as Ruckstell Low, but what Norman had posted had also made sense. But I'm curious to know how you'd refer to the T trans being in Low and the Ruckstell being in Low?

Thanks

If you're speaking of the Ruckstell, it's still Ruckstell low, because the Ruckstell is still in the low range. In other words, "Ruckstell low" if it's in low range... regardless of what the T trans is doing.

A Ruckstell is simple.
A Model T with a Ruckstell has 4 gears. In this order, starting with the lowest gear first:
Ruckstell LOW- gives a super low gear.
Ford LOW - Ford std low gear.
Ruckstell HIGH- for hill climbing mainly- It's a gear between the 2 std Ford Gears.
Ford High- Ford's std high gear.

I know how these things work and even I am becoming confused...

Eric

The Ruckstell axle provides the option to select a planetary-induced underdrive. That's all. The Ruckstell is either set to normal direct drive, or to it's planetary underdrive.

In direct drive, it is a normal everyday axle. Period. When switched to underdrive, it drops whichever FORD gear you're in (FORD high or low) to a lower gear ratio...ergo, there is no "Ruckstell High" or "Ruckstell low", but rather, direct or underdrive/low-range.

I have no idea why your car will not pull hills like it used to, and I won't try to guess, but if it pulls hills when you shift your Ruckstell to low range, it is because you have selected a lower axle gear ratio and the limited horsepower available to you is working through a more advantageous gear ratio for the load it's undertaking.

I hope this helps, or perhaps I'm just late to the party. In any case, good luck and enjoy learning about your car.

Actually, the reason for having a Ruckstell is for hill climbing. It is not good to lug the engine. Very hard on the crankshaft and bearings. I would recommend that you use Ruckstell for all hill climbing. If the car ever ran smoothly going up those same hills, it would indicate either engine wear, causing uneven compression between cylinders, or you need to tune up the plugs, timer and coils. Maybe, the carburetor also needs some work. Usually, the carburetor will smooth out if you try adjusting the fuel mixture.
Norm

Thank you Scott, that was a good explanation. I'm not familiar with the Ruckstell so was getting confused.

YES! Scott is right. Remember Ruckstell is NOT an overdrive. Ruckstell has nothing to do with your transmission. It's basically a quick change rear end. You're either IN Ruckstell or you're NOT in Ruckstell. bobt

If you approach a steep hill at 35 MPH, it is not necessary to retard the spark until, and if, your speed drops off to 20 to 25 MPH. It should not be necessary to downshift the Ruxtell 2 speed axle unless the car's speed falls off to around 20 MPH and you still have an uphill run ahead. The engine should not run rough under load at any speed. If your engine runs rough under load at some speeds, there is most likely a problem with the ignition or the carburetor, assuming it runs smooth at other times. If it does not run smooth at other times, it may have issues beyond the ignition and carburetor. A worn engine will lose some power due to poor piston ring sealing, but if general wear is the only issue, it should still be able to run smoothly. It should not be necessary to adjust the carburetor to climb a hill, unless you are in the habit of running the adjustment very lean on level ground. In that case, a slightly richer mixture might give a little more power at full throttle.