Crank Hub Question

D

drinkin_buddy

Member
I've noticed that there are 2 different crank hubs used on the sv engines.... I have 2 different sv's with 2 different hubs. One, has the belt pulleys molded on, the other has them bolted on.

My question is this. Can these units be interchanged? My new engine has the molded hub, but I want to re use my other hub that has the bolt on pulleys.

Will there be balance issues if I swap these things out???
 
Possibly (probably?)

assembled IH engines were externally balanced at the factory.

"material" was added to the crank hub (and flywheel) as part of the process.

Could be another "issue"...

I do not know the different variations of IH crank hubs...

By "molded", do you mean that the hub is two metal pieces held together with a rubber compound?

And, the other hub is a single solid piece - with the pulleys bolted to it?

The "two piece" is usualy considered a "harmonic balancer" -- designed to "negate" the "natural" rotational vibrations (frequencies) of a rotating mass such as an engine.

Depending on the engine (non-IH), some engines used a solid crank hub; others used a "harmonic balancer"...

I do not know what IH did - I know some (all?) were "harmonic balancers" because I have read of people getting theirs (IH) repaired when the rubber deterioates and the two pieces slip (or worse case - come completely apart)
 
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The engine from my 71 has the "harmonic balancer" of sorts and my other engine has the crank hub, 2 pieces with attached pulleys.

I guess I will put my unit from my 71 on it and just not worry about it. If it is not right, it will let me know.....
 
Keep the crank hub with the crank hub engine.

Keep the harmonic balancer with the harmonic balancer engine.

That is the only way to keep this stuff straight unless you are going to have the entire running assembly balanced again.

There is a difference in the way the engines were originally treated during their balancing phase on the assembly line, so we gotta keep 'em that way unless they are balanced at a later point.
 
The thing is, I cant...... With the crank hub, my accessories dont freakin' line up.

Talked with the machine shop today and if I bring them my crank, rods and pistons, flywheel and harmonic balancer, they will correct this issue for a fee.

Holy crap this is turning expensive quick! By the time I am done, I could have probably had my original engine worked over and rebuilt.

Leave it to me to do things the stupid way.....
 
drinkin_buddy said:
the thing is, I cant...... With the crank hub, my accessories dont freakin' line up.

Talked with the machine shop today and if I bring them my crank, rods and pistons, flywheel and harmonic balancer, they will correct this issue for a fee.

Holy crap this is turning expensive quick! By the time I am done, I could have probably had my original engine worked over and rebuilt.

Leave it to me to do things the stupid way.....
Click to expand...

What the machine shop is talking is...a full "balancing" of the engine assembly. Definitely the way to go if the money is there, no two ways about it.
 
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