Mitchell and 3.54 gears

[Fatboy Tim]

Anyone running this combination?


I've ordered one (for a 32) and hoping will keep the engine to around 2200rpm at 70, it doesn't like running at 3000rpm for 7 hours on the motor(free)way.


Thanks in advance for any replies.

[Ken Arms]

I would think you will be practically at an idle at 70! does the 32 have enough clearance to the floor for the Mitchell? I wanted one for my 34 but from my measurements it would hit on a good pot hole. Ken

[whizzernick]

mine do hit . just go to 3.54 gear in rear end

[Karl Wolf]

I'm running 3.54's in a 1930 Roadster. I think that a Mitchell would be a nice addition.
I would go for the lower ratio overdrive. (Said with no experience).

Karl

[TJ]

3.54s with a Mitchell would make that flathead fall flat on it's face. Do either the 3.54s or the Mitchell , but not both.

[40cpe]

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Tim, what ratio Mitchell did you order? The 26% ratio should cut 3000 rpm to 2220. The 36% would be pretty steep for a flathead. I've seen comments that their ratios aren't what they advertise, please keep us posted on your results.

[bluardun]

Have you considered going to a 3:23 ring and pinion? Taller rear tires?

[mrtexas]

Originally Posted by 40cpe

Tim, what ratio Mitchell did you order? The 26% ratio should cut 3000 rpm to 2220. The 36% would be pretty steep for a flathead. I've seen comments that their ratios aren't what they advertise, please keep us posted on your results.

I run a 36% with a 4:11 on a 37 21 stud flathead. However no hills in Houston,TX area.

[Fatboy Tim]

Thanks for the comments, based in Scotland its a long drive to most shows so 7 hours at 3000rpm isnt good - a lot of oil! Even with 3.25 gears would stil be too high, neighbour next door has a 35 with 4.11 and Columbia and 284 flathead like mine and his is nice at 2200rpm / 70mph. I reckon the torque will keep it moving too. Clearance should be ok. The unit should be shipped November time so will put photos up.

[tubman]

As I read your last post, you are running a 284" engine. Big difference from a stock 32 with 65 HP. You're probably good to go with that engine.

[JWL]

I have a very heavy(3675 lbs. with me on board) 40 two door with 276 engine and a/c. I have the Mitchell they call 36%(but it is NOT) and 3.78 gears. I sure wish I had 3.54 gears AND the Mitchell.

[Old Redneck]

A buddy of mine put 3:23 in his 40 Ford sedan and what a dream to drive. We live in hilly country and no problem pulling the hills. He has a stock engine. I WOULD NOT BE AFRAID OF 3:23 gears in a 32.

[Ed Pitts]

That's the combination that I have in my A V/8. Works great. Ed

[Fatboy Tim]

Well that all sounds like a plan, hopefully it won't get dropped of the ship in the Atlantic.......Will post photos when doing the work.

[john in illinois]

Assuming 29” tires and overdrive of 26% it would be 2109rpm at 70 with 3.54.

Here is one of the easier speed,rpm calculators. Enter 3 values and solve for 4th.

http://www.advanced-ev.com/Calculato...Size/?speed=70

John

[Fatboy Tim]

Thanks John, appreciated.

[SUHRsc]

I have a stripped down Model-A roadster with a hopped up model-B engine... it has 3.54 rear gears and a home made overdrive in the torque tube... the problem with mine is that it also has Lincoln transmission gears so its not as snappy feeling off the line.... I also have 7.00x16 rear tires... I can pretty much idle at 65 or so down the road.

[blucar]

My 36 has a well built 59AB engine, the differential is a 46-48 Columbia with 3.78 gearing, 600x16 tires. I tried 26 tooth Lincoln gears in the trans in my '36 for a very short while, big mistake. The car was totally gutless. I went back to a 28 tooth gear set and decided to leave the gearing alone..

[Automotive Stud]

I have 3:78's and the 36% mitchell in my '47 with a max 1 cam and two carbs. I think if you are after highway you'll be happy with the 3:54.

[40cpe]

Hello Mr. Stud. Can you give us a RPM comparison, in and out of overdrive, at a given road speed?