MTFCA Forum

I am having trouble with low end power on my 1911 Touring. It has the original.engine and it was completely rebuilt and a new 250 Stipe cam wss installed. The engine has about 1500 to 2000 miles on it.

Since it was rebuit, the engine has lacked low end power, but it is strong on the top end. I am using a good NH carburetor. Compressoon is around 55 to 60 psi in each cylinder. My experience with the Stipe 250 cam in other Model Ts is that it provides good power through the whole power range, but this car lacks low end power. The valve clearances had been .12 to .15, but I have readjusted them to .10. I have not run the car since this adjustment was made.

Any thoughts? Thanks.

Jim Woolf

What kind of ignition/timer set up are you using?

It has 4 rebuilt later Kingston coils and an Anderson timer.

Opening up the valve clearance a little will act to "tame" the cam somewhat. I don't know how much is acceptable. Is it possible that the timing gears are not meshed correctly? I believe you can advance or retard the cam timing to help with low end torque.
Model T's need the complete magneto assembly in place to have good low end power.

Did you have the car before the engine was rebuilt? If so, did you drive it and did it have more low end power? Did you do any other alterations than the cam shaft? I won a high volume intake manifold as a prize at one of our tours. I put it on my stock engine with a NH carburetor. It was very sluggish at the low end but had a lot of pep when it ran faster.
Most likely the car would have needed other modifications to increase the low end. Since we live in a mountainous area, when we tour the slowest cars need to shift down and hold up the entire tour. I put on the standard manifold and it runs fine.

If this problem was existing before you rebuilt the engine, you could have a higher gear rear axle. This will give more speed at the top end but slower at low speeds. Need to shift down at speeds a standard rear gearing will take in high. Going up the hill to Alpine I can go in high if I go about 30 mph. But if I slow down I have to use Ruckstell. The other cars pull the hill fine at 25 mph. So when on a tour, I need to shift more often unless I am the first car.
Other things causing the problem might be bands dragging. That will eventually lead to cracked drums.
Norm
Norm

Is the Anderson timer new to the car? It is not unusual to have to make adjustments to the timer rod to get the correct advance/retard at the lever end.

Allan from down under.

Good comments posted here about needing a magneto for low end power and checking the advance/retard on the timer. Sounds like your engine is in good order; I would go back to the basics and pull the carb and clean it up and re-check the float level or put another one on and see what that does. In some cases in my cars when there is an idle or low speed problem there has been a vacum leak of some type that goes away at speed so maybe a redo on your manifolds. And maybe a good look at all of your ignition connections and components.

Try running the new New Day timer. I switched from an Anderson to the New Day and couldn't believe the difference in power. It is difficult to get every cylinder firing at the correct time with the Anderson, believe me I tried. I got close, but not as good as with the New Day.

I have better results using the high volume intake manifold with an NH straight through carburetor.

My experience with stipe cams, other than the super is they have too much low end running out of power @ higher RPM's/speeds.
Might be worth degreeing valve opening & closings & comparing to spec. Sounds like your cam is too far advanced.
Mistimed cam gear? defective timing marks?
Seems I have seen mis-marked crank gears on this forum.
When I build a motor, I degree & evaluate all timing events.
Once I found a defective cam grind by checking that would have meant another tear down.

advance the timer more towards the fan and see if that changes, who ever is making the anderson timers now, the timer rod is always into the fan belt to get them to run correctly.

John, your experience going back to a New Day timer may just be that the Anderson timer was never set up with the correct length to give you optimum advance. Most times i have had to shorten the connecting rod at the timer to get this set.

Allan from down under.

Jim, you never mentioned whether you had the problem with the engine before it was rebuilt. Others with more knowledge may disagree but my understanding is that the aluminum high-volume intake results in sluggish performance at lower speeds like Norm said. Low revving engines seem to perform better with long, narrow intakes which is why the high volume intakes disappeared in later model years. The configuration of the rear end can make a big difference. I replaced the standard 11 tooth pinion with a 10 tooth and experienced a noticeable low speed improvement without sacrificing fuel economy or top end (she'll do 45 easy if I want to go that fast, which I don't). I recently joined a tour out of Luray, VA and handled the hills just fine without a ruckstell.

Jim..... According to your posting, you did change the the valve clearances..... Why don't you get the tool that helps you to set your valves according to piston position .... then set your valves accordingly. You will find that the engine will be a little bit more perky. The aluminum intake manifold was installed when your car was built, wouldn't hurt to to look into purchasing and using.

The car is a new restoration. The engine was in bad shape so I never ran it before it was rebuilt. The rearend was also rebuilt with a standard ring and pinion.

I rechecked the timer and it is set to where the engine fires just past TDC.

I assumed the valve timing was correct because it has a new Stipe 250 cam. I did not check the timing with a degree wheel. That will probably be my next step.

Setting the valves by piston travel was to get better valve timing for a worn cam shaft, your new one will be fine with feeler gage setting. 10 inlet,12 exhaust.

Carrie and Jim... Do what you want but setting valves by piston position will equal out and give better engine performance no matter if it's a new cam or old cam. Good luck on what you choose.