Hot Rods How much power can a banjo rear take?

So, my kid is putting a 1924 t together with a 264 nailhead and an open driveshaft banjo. My question is will the rear end hold up to dropping the clutch and banging gears in a 160 hp nailhead with 8 inch wide tires on the rear.

 

It might last a while. Short life but a merry one. Learn to take off easy and develop some momentum before you give it the works and it should last a lot longer. It will take far more stress on a steady pull than on a sudden shock.

 

I’m thinking repairing a broken axle or two will teach him how to launch successfully.

 

Banjo rears and axles break easily. Best to install a stronger rear.
Plus, when the axle comes loose the tire destroys your wheel and fender sheet metal.
Read about it here.
how much torque can a banjo rear take - Search (bing.com)

 

Ive had banjos survive considerable abuse but one thing they do not like is a sudden shock from a start. I had a 40 rear live a whole season of drag racing, at 3 different tracks and then on sand. Always water burnouts, always scraped tracks with no fresh prep. I also destroyed a banjo with a 40 rear with a 4.44 gear at the track Ist time out, first burnout.
I’d say the most accurate answer is they’re good until they arent.

you must torque the axle nuts, must have tight keys and my opinion it’s better to shim the gaskets on the tight side.
I now run a 9” in my drag car.

 

90hp.

 

If you don't break an axle, there's always shearingthe axle keys to increase your fun!

 

I think the keys are the weak link . Old Craftsman Screwdriver cut off used for the key , helps a bunch .

 

If you're shearing keys the hub is loose on the axle. When the tapered hub and axle are in good shape, the hub is lapped to the axle and the nut properly torqued, you won't be shearing the key.

You may break an axle, but the key will still be in good shape...

Tell him "No Dumping the Clutch" and it will be fine.

 

When I was young and didn't know any better, I used mild steel keys half as long as stock so I had a predictable point of failure That came about after I changed my first broken banjo axle ( I had been lulled into a false sense of comfort by changing broken axles on the '51Ford I bad before).

It worked out for me as it's a lot easier to change a key than an axle. No problem getting the hub and drum off either. You did learn to take it easy rather quickly.

 

Jim, warbird1 is correct, the taper on the axle and hub must be lapped to insure that the contact is constant. Just like the tail stock on your lathe. But your son will soon learn to be an expert on banjo axle R&R. I run a '40 axle with a Columbia in my '32 Roadster and spent hours lapping the axles and hubs. A good friends in New Mexico is very happy with the pull out conversion for banjos. But then you're dealing with the pinion and ring failure. I'd never use a banjo in any dump the clutch situation. Ron

 

As a kid(16 years old in 1964) I had a nice 40 Ford convertible with a banjo rear end and 8:20 x 15 rear tires with a stock flathead. Every time I executed a “quicker than normal “ takeoff I broke an axle key(usually sheared them in half with half in the axle and the top half in the drum). I bought axle key material in various lengths and kept the pre cut keys in the fabric top,so when I sheared one (the drum had been off so many times that a puller was not required) I simply replace them regularly until one day I broke an axle. Got rid of the weak early Ford trans and weak banjo rear ends and ran a Muncie 4 spd and nine inch ford rear and problem was solved. I know that early banjo rear ends survived with fuel Chryslers but how long they lasted is in doubt. They were weak when new 90 years ago and are even weaker as they age and suffer abuse from the hot rodding community. Flatheads Forever!!!!

 

To put this in perspective, in the early fifties when they were nearly new it was common to break axles with a 125HP flathead - if you revved up and dumped the clutch. Another 75 years of age and metal fatigue has not done them any favors.

On the other hand some Bonneville racers put 500HP through a carefully prepared one on a steady pull.

Early drag racers and street racers used a rolling start for this reason.

That is why I say if you take off easy and develop some momentum before you give it the works you should be ok, at least, as good as you can expect for something that old.

 

The 8" wide tires and the torque of the Nailhead says no (or at least not long). Even the Hot Rod Works slide in axle kit will only hold around 200 hp (per them).

 

Similar car to what you're describing, about 100 horsepower (if we're being honest) and 6.50-16" bias ply tires, dumped the clutch at a flathead drag race and snapped it off pretty clean. It's a '40 rear.

Granted, I am NOT an experienced racer, I'm actually pretty terrible, so that's part of it. But 8" wide tires and another 60 horsepower, I think he's really going to have to be careful with it to avoid breaking stuff like I did.

 

If questioning whether the banjo rear will hold up, why would you even consider dropping the clutch and banging gears?

 

Can an old banjo be converted to splined 9 inch axles, would that help?

 

See my post above (#14).
https://hotrodworks.com/product/1928-1932-ford-axle-conversion-system/

Then you have to worry about the housing or gears.

 

It's usually not how much power the engine makes, but rather how aggressive the clutch engagement is. I invented a simple device called the Hillbilly Clutch Slipper, was a very effective way to reduce the shock sent to the drivetrain when the clutch is dumped. Original purpose was to help Saginaw 4spds live at the track. Turned out adding a little clutch slip also allowed the engine to make more power, as the clutch didn't pull the engine down as far during launch and after the shifts. Lots of successful drag racers using the current refined version of that Hillbilly Slipper that I now call the ClutchTamer. It basically makes non-adjustable clutches adjustable, makes adjustable clutches even more adjustable.

Here's a pic of the basic off-the-shelf hardware store components I bought to make the original Hillbilly version, basic component was a $15 hydraulic screen door closer...


Grant

 

Hi Grant, just looked into this a bit, found http://clutchtamer.com/ but most of their applications are on late model top swing pedals, did you use this idea on older cars, particularly underfloor 40 ford style?
Im putting 9 inch axles in my banjo with a qc center, though that would be ok, but this maybe the little saver I need. Its not a monster motor, 348, but they're meant to be pretty torquey, and a 40 sedan is a pretty heavy car.
Thanks

 

Condition of parts will play a big role. Narrow tires will help longevity

 

How much will it take? Not much, but I like big HP and Torque.

 

@JimSibley,

This might help you.




31 spline Halibrand 2 spider open differential. I bought several of these from Halibrand in Kansas before they closed up.




You have to modify the ring gear like in the last picture but it takes the axles out of the equation. I might have one left. Message me if you're interested.

Bruce

 

Best friend in HS and best man in my wedding had a '40 Ford pickup with a 289, 4spd, and banjo. He got a set of real 12" wide Indy tires he ran on the rear. Combine that with a heavy foot (lost his license for a few months due to too many moving violations!), and the result was spending almost every weekend replacing broken axles.

I put 9" axles in the 2 banjos I put in my Mysterion reproduction. Overkill but made adapting the proper wheels easier.

on the outer end of the axle tube I cut off the snout. Then since I shortened the tubes, I cut the ends off and bored them to accept the seal. Finally I used the aluminum bearing retainer shown in a post above.








On the ring gear end, there are a few modifications required to adapt the 9" axles. First, I used 9" side gears with banjo spider gears in the differential. The tips of the 9" side gear teeth need to be ground down as do the crowns of the banjo spider gear teeth. A purist would do these mods on a lathe but grinder does a fine job.
The other mod is to bore the hole in side housing of the differential and the ring gear to accept the larger diameter of the 9" spider gear bosses.
These mods allow the differential to assemble and accept the splined 9" Ford axles.



I shortened my 9" axles by cutting and welding. I believe this is still stronger than stock banjo axles but if you can't go with welded axles, you can have Moser or someone make you set of custom axles.

 

I don't want to turn this into a sales pitch, so if posting this here isn't cool I can delete.

But in case it's helpful, we make a banjo rear that's good for about 600hp. It uses our tapered steel tubes and bells, which aren't identical to early Ford (they taper to about midway out the axle then go to a straight tube, as you can see in the photo), but they're close. Otherwise they use all new internals (3.78 ratio R&P, wedgelock differential, modern axles) so you can keep the early Ford vibe but they'll hang in there under load.

 

Ok this is an example of the crafty s$&t I came to the hamb in the first place hoping to see lol

 

If you mean cheap, then I am VERY crafty!!!!! I have always preferred going to Pick-A-Part and scrounging a widget I could adapt to my car instead of buying billet. Satisfying to resurrect it and saves $$$$$$$$$$$$$$$$$.

 

Id say taking correct but weak parts and making them stronger using technically era available parts is pretty crafty

 

@ Willys36,
I too have done that with the trumpets. Not too bad on a lathe without the spring perches. I also did it on a mill leaving the perches on. That is a lot of boring but can be done.
Have a customer that wants to do that, but the tubes will be shortened. Only problem there is that my lathe won't swing that much with the perches in place. Oh well, back to the mill!

 

Yep. My saving grace(s) were no perches with Big Daddy's coil spring suspension and, had to shorten both tubes so could cut off the bearing bosses which easily fit in my Chinese 12x36 Acra lathe.