Two piece crank shaft pulley
 

Just read an article in the "Restorer" by Fred Binkley which recommends a two-piece crank shaft pulley, instead of a stock one-piece, because they may be removed without having to lift the motor so high. No mention in the piece of any down side to using a two-piece pulley -- or even what they are made of out, i.e., steel or cast iron. Seems like a steel one-piece would be less likely to fail, but if the two-piece unit is reliable, perhaps it's good advice to use one. I am about to install my Schwalms-built motor and don't expect any problems, but you never know. Any thoughts or recommendations?

Re: Two piece crank shaft pulley
 

I use only one piece however, the good quality 2 piece if installed correctly and kept TIGHT will perform well.


I think most of the problems with the 2 piece design is poor quality of manufacture and not keeping them TIGHT.


It is true that a 2 piece is a lot easier to change in the car, but after tens of thousands of miles in a Model A, I have not had to change a crank pulley while the engine is in the car.


My experience and opinion,


Chris W.

Re: Two piece crank shaft pulley
 

I have always preferred the two piece crankshaft pulley because it is more user friendly . I have only had to replace a one piece pulley with the engine in the car once and it was a real pain !!!

Re: Two piece crank shaft pulley
 

Use a 1-piece. Any time you have a joint of any kind, i.e. fuel line connection, wiring connection, etc. or 2-piece pulley, there is a possibility of failure. I've been driving A's since 1958 and have never had a problem with a crank pulley. I mostly have used a steel pulley but have used a cast iron pulley with no problems.

Re: Two piece crank shaft pulley
 

That was a good article in the restorer - very informative. First thing I did was run out and check if I had a 1 or 2 piece. Was glad mine is a 2 piece. Even though it's a part that rarely fails, at least if it does it won't mean a major headache by the side of the road.

Re: Two piece crank shaft pulley
 

I do not see how a crank pulley could fail. I am with Jim on this. If it did fail ,the joint would probably be involved.

John

Re: Two piece crank shaft pulley
 

The one piece pulley that failed for me was caused by problems with the front motor mount yoke . I ended up disconnecting and removing the headlamp bar and headlamps . I also removed the radiator . I almost needed to remove the engine to get the needed clearance to remove the broken pulley . When the two piece pulley is used , if the pulley is the same style, only the outer part will need to be removed and replaced and no other parts will have to be removed .

Re: Two piece crank shaft pulley
 

The thin wall of the cast iron V is fragile, and I've seen them broken several times by careless handling.
The last engine I bought had a 2 piece cast aluminum pulley, which I planed to keep on the engine and use. I bumped it and broke the V, so I replaced it with a good original cast iron one piece. I feel good with either one or two piece, as long as they are installed correctly and kept tight. The V belt doesn't need to be any tighter than just enough so the fan and generator don't slip.

Re: Two piece crank shaft pulley
 

Cast iron crankshaft pulleys fail from harmonic imbalance..one piece or two,its a hand grenade waiting to blow. Steel stops this.

Re: Two piece crank shaft pulley
 

Cast iron pulleys fail from using pry bars to install or remove the engine. I use lots and have several originals that are perfect except for the seal area being worn. I don't see any reason why a cast pulley would just fail from running. Operator error. The only reason to use a two piece pulley is to not break it from improper removal/install techniques.

Re: Two piece crank shaft pulley
 

Re: Two piece crank shaft pulley
 

All 2 piece pulleys are NOT made by the same manufacturer.


Yes, if I had a pulley fail while on a tour, I would change it on the side of the road if it was a 2 piece and I had a spare with me.


A few years ago, one of the participants of a tour in Utah changed a head gasket on the side of the road.


Changing a 2 piece pulley would be simpler than a head gasket but you better have a GOOD wrench for the crank ratchet bolt.


My opinion,


Chris W.

Re: Two piece crank shaft pulley
 

Re: Two piece crank shaft pulley
 

There were (are?) at least two variations of the two piece pulley. One involves a "dog clutch" arrangement where the sheave and hub pieces are held in engagement by the tension of the ratchet nut.

The other version mates the two pieces on a male/female thread, which is then held by the ratchet nut - which in my mind might complicate removal in the event of breakage of the v-sheave. Threads, as all threads are when exposed to the weather, are wont to "rust together." Which might complicate your removal if the sheave breaks off at all arms (or even if it doesn't.) This would bring removal into the realm of a pipe wrench - or removal of the hub portion anyway. Which sort of puts this two piece variant back into the level of difficulty of the one-piece.

I have used both one piece and two piece dogclutch, might prefer the dog clutch type for the "on the road" experience should it occur, but have never had either version fail.


Joe K

Re: Two piece crank shaft pulley
 

The Riley 3" steel pulley kills two birds with one stone,being steel it wont fail from vibration and its smaller diameter slows the water pump down,stopping water overflow at high rpm.

Re: Two piece crank shaft pulley
 

I recently bought a harmonic balancer from Engine Restorations in New Zealand that is machined steel. I have not had a chance to install yet. Nice looking unit.

I doubt you will ever have to replace it on the side of the road. Good thing too, it is quite a bit thicker (and heavier) than a Model A pulley.

Re: Two piece crank shaft pulley
 

Re: Two piece crank shaft pulley
 

So, Paul ... did you learn what you wanted to know, or are you more confused? :-)

Re: Two piece crank shaft pulley
 

Hi Jim -


This was an interesting thread. Thanks to all.


I am going with the notion that: "if it ain't broke, don't fix it" or - maybe: "if Henry put it in there, don't change it!"


While steel would be better, the motor I am about to install in my Tudor was just built by Schwalms and, therefore, I expect it will run for many years without a problem with the stock cast iron pulley.



Best. Bj

Re: Two piece crank shaft pulley
 

I tore down 1 engine that had a die cast, pot metal, 2 piece dog coupling pulley. The rope seal ate into the inner sleeve about 3/16". Total junk.