Gears 3.27 vs 3.54

[Model A Ron]

As I start my full restoration on my 1931 Victoria basket case gearing comes to mind. My rear end is in pieces but it does have 4.11 gearing and that is just not going to work for me.

I have a rebuilt engine and I am planning on adding a high compression head. That said should I go with a 3.54 or could the fresh engine push the 3.27 gears.

[Fred A]

When I bought my '31 roadster It came with 3.27 rear gears and a V8 trans with truck gearing (15/29). The rear ratio was never mentioned during the sale. A big deal was made of the transmission. When it was torn down the rear ratio was quite a surprise as I didn't even know of such rear gearing. The light car performed much like my Town sedan with stock gearing. I hadn't taken it on the highway. I always use a light flywheel for engine consideration which plays against the logic of long gearing. My most recent gearing is quite the opposite and even though the arithmetic looks good, the mindless prejudice among Model A people prevents my opening that to debate. Good Luck: Fred A

[Incognito-A]

Yes it will but you will be going up hills much slower, second gear even. On the flats or declining terrain you will be flying.

You will probably be more than happy with the 3:54 gears.

So, consider what kind of driving you will be doing.

[updraught]

If I remember right .. the 3.27 give %15 taller first and second gears as well over standard 3.78.

[J Franklin]

I think the 3-54 ratio would suit the best.

[BRENT in 10-uh-C]

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Since a rebuilt engine means many things to many people, I would start there. I have seen some ‘rebuilt’ engines that would struggle pulling a 4.11, -much less a 3.54.

The 2nd side of this is that must tell us where the most amount of driving will be done. If around town only, skip the 3.27. I have some Fordors with 3.27 ratios and the owners love them, so it really isn’t that the engine cannot pull them, but more about the intended usage.

[Big hammer]

What shape are the 4.11 gears, if they are good use them and get an over drive!

[jw hash]

I installed a 3.54 in my Victoria over 35 years ago with only a high compression head. we have a lot of hills around this area and it does just fine. I did install a 3.27 in one of my cars and on flat ground it was great, in the hills I was in second gear a lot. unless you are planing on putting in a overdrive I would stick with the 3.54

[nkaminar]

Consider the 4.11 gears and a Mitchell overdrive. "Took my foot off the gas, and man-o-live, I shoved it down into over drive." "Son, you're going to drive me to drink'n if you don't stop driving that hot rod Lincoln."

Sorry for the ear worm. Young people probably won't get it.

[Model A Ron]

Originally Posted by nkaminar

Consider the 4.11 gears and a Mitchell overdrive. "Took my foot off the gas, and man-o-live, I solved it down into over drive." "Son, you're going to drive me to drink'n if you don't stop driving that hot rod Lincoln."

Sorry for the ear worm. Young people probably won't get it.

I get the Hot Rod Lincoln comment lol. The Mitchel OD at 26% and a 3.78 come out to be a final ratio very close to 3.27.

What would the ratio be with 4.11 gears and a 36% Mitchel?

[Ruth]

Originally Posted by nkaminar

Consider the 4.11 gears and a Mitchell overdrive. "Took my foot off the gas, and man-o-live, I solved it down into over drive." "Son, you're going to drive me to drink'n if you don't stop driving that hot rod Lincoln."

Sorry for the ear worm. Young people probably won't get it.

I use my Mitchell overdrive more as a "underdrive". Normally I leave the Mitchell in O/D and shift the Mitchel down if needed on hills. I have the stock 3.78 gears.

[nkaminar]

Ron, 4.11 divided by 1.36 is 3.02, so it would be equivalent to 3.02 to 1 gearing.

4.11 divided by 1.26 is 3.26 to 1. 3.78 divided by 1.26 is 3 to 1.

I don't know what my gearing is but in overdrive I turn 2,500 rpm at 65 mph per the GPS.

Updraught, 3.78 divided by 3.27 is 1.156, so about 15.6% taller. Engine would be turning 1/1.156 or 86.5% as fast at a give mph.

Sorry for the math lesson. Class dismissed.

[GeneBob]

For what it's worth: I have an overdrive with 3.78 gears and I live in a hilly area. This combo is a little too high in 3rd gear to hold more than 55 to 60 on rolling hills. I would like to change to 4.11 gears or switch to smaller diameter tires (6.00X16) to simulate a different rear end ratio.
Assuming you want to keep your stock wheels and tire size, and North Carolina is hilly where you live, I would go with 3.54 to 1 or keep the 4.11's and add overdrive.


Added: I have a HC head, Stipe 340 cam and a fresh engine. I also have a 1935 trans to take advantage of the better shift points.

[Model A Ron]

So if you had 3.78 with a Mitchel 26% you would have 3.00 to 1 final gearing

If you had 4.11 with a Mitchel 36% you would have 3.02 to 1 final gearing

My 29 has a 3.78 with a Mitchel and I just drove it in high without using low. This is not doable unless you want to get up to speed very slow.

3.27 gear with no OD would give 15.5%
3.54 gear with no OD would give 6.7%

Seems to me that a car with a HC head and no OD should be able to pull a 3.27

it also seams that 3.54 is to little a difference to justify the work.

[Synchro909]

When I tour outback, I run a 3.78 rear end with a 26% Mitchell O/D. Granted, the terrain is fairly flat out there but while towing a trailer that weighs in at about the same weight as the car (over a tonne (2,200 pounds)), I have no trouble starting from a stop and I've even done it a couple of times having forgotten to take it out of O/D but it's a struggle.
So, just guestimating, I'd say a 26% O/D with a 3.54 rear end in a solo car would be just fine. The lighter the car, the better of course but even in a Fordor, I think it would be fine. I know of a Model A with 3.27 rear end and O/D. It is a pig to drive.