Overdrive / ring gear question

M

MAP

Junior Member
I have a 1931 Slant Town sedan I'm working on. I have a Ryan Overdrive that I want to put on. I was also thinking of putting in a 3:54 RING & PINION While I am rebuilding the rear end. Any thought on this ? I need to replace the original ring gear cause it has a broken tooth. Does anybody have any experience with the 3:54 on a 4dr Town sedan ?
ALso, what is the difference on the rear bumper brackets that bolt to the frame on these slant windshields. Can you use the ones sold for the 4dr Murrays by just changing the rear bracket that bolts to the body ? The ones that were on my car were torched back to the frame .
 
We own with a 30 Town Sedan which has a 3.54 Rear End and a Ryan Overdrive. The engine has a Zenith Carb, Model A Ignition with modern points and a Denver Miller OHV. We can drive the car on Freeway at 65 MPH with ease and it is a joy to drive.

I'm not sure of your engine, but his combination works fine for us.

Sorry, no insight regarding the Bumper Brackets.

Bob
 
Bob, Thanks for the info. Motor isn't built yet. I am building it stock with high compression head, possible burlington crank. Not sure whether v8 style clutch or stock. I had a 31 Two door with stock clutch, seemed to be ok. How is the Ryan overdrive ? Do you think it's better or as good as a Mitchell ? How does it handle the hills with the 3:54 ?
 
Last edited:
We have a Michell Overdrive in the Victoria. It is synchronized and the Ryan is not synchronized. For that reason, I like the Michell better.

Otherwise, I think the performance is similar, it is just the challange of downshifting the Ryan.

Bob
 
I live in Colorado and the travel in the Mountains is hard to maintain speed, etc. The combination works fine in the foot hills along the Front Range (Fort Collins-Denver-Colorado Springs) where the elevation is 5,000-5,500 ft.
 
Seems to me the 3:54 with an OD is overkill on a heavy car. Two guys I know did that on their slants and they keep freezing up pistons...over 10 failures so far between them in 3 years. I suspect it is from the low RPMs that they're over heating and not splashing enough oil up into the cylinders. Lugging is not good for the ctr main either. Contrary to common opinion, a Model A engine is not made to lug..they should be run at moderate RPMs, so they are running easy. I have a 33% OD in a woodie with a 3:78 rear end and its too tall in high gear.
 
The Ryan is a very dependable and rugged "transmission" or more correctly OD. Also the Town Sedan Slant is a very heavy car and lugging a heavy car with too much OD ratio is a bad thing ( see Pats thread above). 3.54 compared to 3.78 is the equivalant of about 7%. Couple that with the 26 to 28 % (I dont remember which) and you have a very tall final ratio.

I am running a F150 with a 28% OD and a standard 3.78 rear end. She cruises comfortably at 65mph and has plenty of east Texas hill climbing ability. High compression 5.5 head. Oversize 1.73 intake. Ported. Zenith carb. B cam. Balanced nad counterbalanced. At 65 the engine turns a comfortable 2250rpm.

Just wait til next week. She will get her downdraft cast iron header and Weber carb and new Snyder 6.1 head. Then we will seee how much Texas mountain she can climb. Ken
 
Sounds like it might be a good Idea to stick with a 3:78 & the OD. I'm in the Northeast and we have some hills. When I would drive my 2 door the fan felt like it would be going thru the rad. going down hill. I was curious as to how the 3:54 would be for the all around drive for the average road. (mix of hills & flats that don't require the OD) Is Ryan still in business ?
 
I personally would not put a high speed gear ratio in a sedan, much less with an OD in it also. Theyre to heavy, and if you looking for a big result you will be dissapointed. If i were you, i would just find another set of standard gears to match up with your overdrive, and it will work perfectly. with my overdrive and standard gears 60-65 all day when i had a bone stock engine.
 
I have two Ryan overdrives. One is a 23% and is installed in a Victoria with a 378 R&P. I believe this to be an excellent combination and have driven it on many long tours, sometimes pulling a Mullens trailer. The other Ryan is a 33% and is installed in a 29 coupe with a 378 R&P. This is not a good combination. When in overdrive there is a tendancy for the engine to lug if there is any kind of an incline. This also causes the engine temperature to climb. If I could find a pair of 23% Ryan gears I would switch them out. The Ryan ratio is stamped on the side of the case.

I would never install a 354 R&P with any kind of an overdrive, it is much too tall. A 411 R&P is better suited with a 33% overdrive.

The Ryan overdrive has a unique syncro mesh and shifts exactly like a Mitchell. The Ryan is no longer in production, but is a very good rugged overdrive.

Tom Endy
 
I have 3.54 rear in a 31 roadster with Volvo OD. 5.2 "B" head, down draft carb, touring cam, V8 Clutch with lightened flywheel. This combination works well, but remember, it's a roadster. If I were to do it again, I'd stick with 3.78 even in a roadster.
 
Tom Endy, Ken Parker and Pat have it right! I run a 23% Ryan with 4.11's in my tudor and it is a bit low for freeway cruising. In my wide bed I have a Columbia, 26%, and 4.11's which I find ideal. When I first put the Columbia in I had 30" tires on the rear, we went from the L.A. area to Las Vegas every year and it did fine but later changed to 28" tires, it then pulled the hills better, ran cooler and got better fuel mileage. 3:1 is close to ideal. A heavy car such as the slant will not do well with too high a final ratio.
 
I just found out that my Ryan Overdrive is a 23%. (new in box). It seems that I will go with the 3:78 RG based on the great feed back. I never had any experience with the 3:54 in a light or heavier 4dr. My concern was to keep the RPM's down on the everyday back/street roads, down hills, etc. and use the Overdrive for the occasional highway drives. I don't want to add excessive lugging to the mix.
 
I have a Mitchell O.D. in my 29 coupe with the stock 3.78 rear and a 5.5 snyder head. I find it to be a perfect combination for the N.E. hills. I also think a 3:54 ratio would be too tall with the O.D.
 
MAP said:
How much difference did the 5.5 head make from running the stock ?
Click to expand...
My 30 roadster is stock with a 3:54 rear and to me it makes a big difference. The coupe marches right up the hills with the 5.5 head and the roadster just doesn't pull as hard which means more downshifting. Even gentle hills can be handled with the overdrive and when it starts to pull hard I just shift it into regular range.The OD having syncros make it easy to shift in and out.
 
So I quess the conclusion is: The 3:54 for the lighter cars. Best combo would be 5.5 head + 3:78 RG with Ryan overdrive ? For best performance on the NE hills.
Would the new 6.1 head too much ?
 
Would the new 6.1 head too much ?

My S/W had an early Snyder (either 5.2 or 5.5 - it was a gift and the giver had no history of it). I had it coupled with a stock Zenith carburetor and stock Model A Exaust Manifold. Ran that combination for about 200 miles and it performed OK. I emphasize OK. She went back in the shop last week for some planned upgrading. New radiator. Snyder 6.1 head. Cast Iron Header. And Weber Carburetor.

I will have her up and running by Saturday and will give report of the improvemnt in performance - estimating there will be some.

P.S. Met with a fellow yesterday who is working on a fuel injection for the A engine. Now that is going to be interesting. Ken
 
You must log in or register to reply here.
Back
Top