340 Pulley Misalignment

[Black_Sheep]

Working on my brother in law’s 340, the single groove alternator pulley does not line up with the crank and water pump pulleys. It had a home brewed bolt and spacer arrangement that was pretty nasty looking so I ordered a reproduction pre-70 bolt and spacer kit. If I lay a straight edge across the water pump pulley the alternator pulley is 3/4” farther back. The crank and water pump pulleys line up perfectly. The alternator brackets are correct for 1969.

I suspect the pulleys are ‘70+ but I’m a big block guy so I don’t know for sure. What do you small block gurus think? Do we need to find pulleys with less offset? Would a double groove pulley on the alternator be an easier option? The water pump pulley is 2 1/4” deep.

 

[Black_Sheep]

Before

 

[R413]

Try it like this and it might work a bit better.

 

[RemCharger]

^^^^

 

[Dodge33]

Without seeing the w/pump pulley and lower crank pulley, it's hard to tell. Since your using a factory cast iron waterpump, you need 69 and earlier pullies for a cast iron pump.

 

[RemCharger]

 

[Black_Sheep]

Try it like this and it might work a bit better.

View attachment 1674695

Mounting the bracket like that would move it even farther back…

 

[RemCharger]

Get the right waterpump pulley and go from there

 

[Black_Sheep]

Without seeing the w/pump pulley and lower crank pulley, it's hard to tell. Since your using a factory cast iron waterpump, you need 69 and earlier pullies for a cast iron pump.

When he got the car it had a ‘70+ timing cover and a ‘69 harmonic balancer. We had to use a piston stop and re-mark the balancer so the timing could be checked. The motor was a conglomeration of mis matched parts.

 

[66 Sat]

Mine is like this, Poly engine but should be similar.
My waterpump pulley is 2 3/4" deep though.

 

[Dodge33]

Mine is like this, Poly engine but should be similar.
My waterpump pulley is 2 3/4" deep though.
View attachment 1674734otView attachment 1674736

66 Sats car has the correct pulley setup, even tho his motor is a poly motor. LA 69 and older motors with the cast iron waterpump uses this style pullies. The waterpump pulley is called the hat style, or that's what I call it. Crank pulley needs to be off a 69 and earlier forged crank engine. Question: While I was viewing your engine, the pics you posted, I was wondering if the 340 motor had a forged crank or a cast crank? The harmonic balancer looked in the one pic, like it was a thick balancer which is for a cast iron crank, but could not see it well enough.

 

[Black_Sheep]

66 Sats car has the correct pulley setup, even tho his motor is a poly motor. LA 69 and older motors with the cast iron waterpump uses this style pullies. The waterpump pulley is called the hat style, or that's what I call it. Crank pulley needs to be off a 69 and earlier forged crank engine. Question: While I was viewing your engine, the pics you posted, I was wondering if the 340 motor had a forged crank or a cast crank? The harmonic balancer looked in the one pic, like it was a thick balancer which is for a cast iron crank, but could not see it well enough.

Forged stroker and aftermarket balancer, I didn't build the motor...

 

[R413]

Your water pump pulley is so short we can see the snout of the pump. With an aftermarket balancer they had to get a WP pulley to meet up with it. So using stock configuration is out the window.

Trying a double alt pulley may be easiest. Beyond that you may have to cut spacers to get the alternator in the correct place.

 

[Black_Sheep]

For the benefit of others who may find themselves in a similar situation, we got the misalignment squared away this evening. Since the crank and water pump pulleys were perfectly aligned, it made sense to try and get the alternator pulley on the same plane. After measuring things up and doing some calculations we sourced steel spacers and longer bolts from the local hardware store. It moved the alternator forward so the alignment came out perfect, and it doesn’t look too cobbled together.

 

[Krooser]

These photos will be valuable to me in a short time when I get the front end done on my 318...thanks.