10 vs 11 tooth pinion

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Oldav8tor
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10 vs 11 tooth pinion

Post by Oldav8tor » Tue Nov 12, 2019 8:25 pm

From those of you who have tried both, I'm curious as to what differences I can expect if I swap out my 11 tooth pinon gear for a 10 tooth. In addition to performance, what did it do to your gas mileage?
1917 Touring
1946 Aeronca Champ
1952 Willys M38a1 Jeep
1953 Ford Jubilee Tractor

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Henry K. Lee
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Re: 10 vs 11 tooth pinion

Post by Henry K. Lee » Tue Nov 12, 2019 8:41 pm

Tim,

Much better "Get out of the Hole" and shifting to high but limited high speed. Normally drops you down to around 38-41 MPH.

Hope this Helps,

Hank


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Re: 10 vs 11 tooth pinion

Post by Scott_Conger » Tue Nov 12, 2019 9:56 pm

This pinion was typically used on heavier closed cars in the mountains. I think it would take a very healthy engine to get to 40MPH for any length of time, myself. A tired engine and a 4:1 rear end, more like 30MPH wound out. Would be great with a Warford and overdrive.
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kelly mt
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Re: 10 vs 11 tooth pinion

Post by kelly mt » Wed Nov 13, 2019 12:27 am

I'm running the set up Scott mentions. 10 tooth with a KC Warford and a built motor in a 27 Tudor. It is a great set up here in the mountains of Montana and Idaho. I never have to use low pedal unless I creeping over rocks on a logging road.

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Oldav8tor
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Re: 10 vs 11 tooth pinion

Post by Oldav8tor » Fri Nov 15, 2019 11:52 am

I see mine isn't the only thread asking this question <viewtopic.php?f=2&t=8325>. I know that a Ruxtell or Warford is the way many have chosen to go, but that isn't in the budget for me. I have purchased disc brakes and floating hubs to install, all in the goal of making my car safer for touring. Although I live in fairly flat country, I have hopes to tour in other parts of the country which can be quite hilly. This year I did the Covered Bridge tour in Indiana which had some pretty significant hills. I have a touring car and expect that the rear seats will often be occupied. I do not care to drive my car at higher speeds, being most comfortable when I can keep it under 35.

Being a newbie with limited tour experience I may be operating under some false assumptions, but it seems the trade-off in top end might be worth the extra power on hills and smoother transition between low and high gears. I do have a Z head so my engine has a little more power than stock.
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1946 Aeronca Champ
1952 Willys M38a1 Jeep
1953 Ford Jubilee Tractor

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walber
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Re: 10 vs 11 tooth pinion

Post by walber » Fri Nov 15, 2019 1:10 pm

If you are happy with moderate speeds (typically 35 or lower) and like a full car, the 10 tooth pinion should be a good fit. Possibly a little hit on MPG but not a big one as the motor will be under less strain for the same performance level. Moderate speeds are great when the roads and traffic permit. I've loved touring with a stock T at moderate speeds in more rural areas where it fit in nicely.

On a different note, I really like the 10 tooth in my speedster but it's an apple and oranges comparison as I have a Chicago aux transmission with overdrive and a Fronty overhead. Direct lets me climb twisty turny hills with ease and overdrive lets me go faster than I want to (or should) on the straighter roads.


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Re: 10 vs 11 tooth pinion

Post by Scott_Conger » Fri Nov 15, 2019 2:16 pm

Tim

I ran one of the South Dakota Black Hills National tours in a 1919 depot hack with an engine with "0" miles. Not an ideal break-in but I did a lot of oil changes and maintenance on the car each day. That said, the car had stock rear end, was a very heavy car, and passed a lot of broken cars (all of which passed me and most of which encouraged me to "hurry up"). Funny thing, the hack was hot at the top of long hills but cooled right off within a mile on the down hill. The speedy experts all panic'd at their motometer, stopped at the apex, and watched their cars geyser the water into a bloom of steam. We just waved as we went by. Point is, this very heavy car drove this TOUGH tour with standard gears and survived for 15 years on STEEP E. TN hills before receiving its Ruckstell. To date the car has lasted well and runs fine despite a tough break-in.

Touring CAN be done with a standard rear end, but if you don't mind the modest loss of top end speed, the 4:1 would be fine.
Scott Conger

Full Flow Float Valves - deliver fuel like Henry intended!

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