Idler Pulley

[Dsertdog]

As I took a closer look at my '66 Polara yesterday, I discovered that the engine fan/water pump belt uses an idler pulley. Whaaaaaaaaat?
Where does one one purchase this? I've been online for the last hour and haven't seen what I'm looking for. I see lot's of 67 and up brackets and pulley assemblies, but not this.
Maybe I've missed something, but could someone point me in the right direction please?

 

[Polara_500]

Either the pulley or the pulley w/bracket.
manciniracing.com

 

[Big_John]

You don't say which engine you have.

There's an alternative for a big block.

 

[Dsertdog]

383

 

[Big_John]

383

Here you go...

If you use this pulley, you can eliminate the idler by using the rearmost groove and looping the belt around the power steering pump pulley.

BPE Water Pump Pulley - Bouchillon Performance Engineering Call them to make sure of fitment etc.

I've done this on my '70 300.

 

[FURYGT]

1966 Polara 500 Ragtop

Original post

 

[Ross Wooldridge]

Used in 65-66 AC equipped big block cars.

 

[Ross Wooldridge]

Here's the pulley. Mounts with a bolt and lock washer.

https://www.ebay.com/itm/For-1966-1...6497895hash=item442a3e3c67:g:ansAAOSwj91cLm4b

While this says it's for 67 and up, it looks identical to what's on my 66s - but I could be wrong.

1967-72 MOPAR A B E C BODY 383 440 FAN BELT IDLER PULLEY BRACKET WITH A/C AIR | eBay

Try Desert Valley dvap.com and ask for one from a 65 or 66 big block AC car

 

[Ross Wooldridge]

Nigel at National Moparts will have too.

1-888-652-7464

 

[Big_John]

While this says it's for 67 and up, it looks identical to what's on my 66s.

Did some of the '66 cars come with a 1/2" wide belt?

 

[Ross Wooldridge]

Not sure...

 

[Big_John]

Not sure...

I know I've seen them on earlier cars, but not sure where it stopped or if that applied to A/C cars.

 

[Dsertdog]

Here you go...

If you use this pulley, you can eliminate the idler by using the rearmost groove and looping the belt around the power steering pump pulley.

BPE Water Pump Pulley - Bouchillon Performance Engineering Call them to make sure of fitment etc.

I've done this on my '70 300.

This would be a vast improvement over the original design. My mechanic might have one these pulleys. Thanks!

 

[413]

I have 1962, 1967 and 1970 AC big blocks. They all use this idler pulley. The bracket changes design on the 67 and 70 but the 62 bracket has the same bolt locations and could interchange.

 

[CBODY67]

Did some of the '66 cars come with a 1/2" wide belt?

I seem to remember that our '66 Newport had a wider ps belt, but not sure if it was 1/2" or not. Once we learned how to adjust it, with the flex-mount ps pump, that belt "lasted forever". Have to check the FSM for belt specs.

Usually a .380" belt and .440" belt width can use the same pulley Vee width. Just that the .440 belt doesn't go as deep as the .380 belt will. IF the car was spec'd for .380" belts' length, then add 1 Inch to that belt length if you want to use a .440" wide belt in its place. From experience.

Using the ps pump pulley to tension the water pump belt seems good, but ONLY on solid mount ps pump brackets (later OEM Saginaw pumps or converted earlier pump brackets with the larger ps pumps).

I always looked at the water pump-only belt as a "fail safe" situation. If the a/c belts flop and kick themselves off (hopefully leaving the upper radiator hose intact), or the ps pump belt goes away, still can drive the car with the engine not overheating. There's still some dead spots in cell phone coverage.

Just some thoughts,
CBODY67

 

[413]

It was a good idea on the new cars. But now after 50+years it’s the idler pulley that fails.

The 1967 and older PS belts are wider than the WP A/C and alt belts.

Was 67 C-body was last year for the goofy wobbly PS bracket?

 

[Big_John]

I always looked at the water pump-only belt as a "fail safe" situation. If the a/c belts flop and kick themselves off (hopefully leaving the upper radiator hose intact), or the ps pump belt goes away, still can drive the car with the engine not overheating. There's still some dead spots in cell phone coverage.

Easier to change/find a new belt than get hung up somewhere if the idler pulley craps out. In my experience, the idler pulley always does fail somewhere along the line and the new ones are probably not as good as the old ones. I carry spare belts and a couple wrenches. Usually the old ones I took off LOL.

The nice thing about hooking it to the P/S pump is you will know immediately that you've lost a belt.

 

[LocuMob]

Great, something else to contemplate on my Monaco. Are the replacement idler pulleys junk? I haven't ever looked as my A/C cars never had the A/C working, or the parts were already gone.

 

[LocuMob]

Great, something else to contemplate on my Monaco. Are the replacement idler pulleys junk? I haven't ever looked as my A/C cars never had the A/C working, or the parts were already gone.

Or maybe not, doesn't look like the P/S pump is there.

 

[jct]

Easier to change/find a new belt than get hung up somewhere if the idler pulley craps out. In my experience, the idler pulley always does fail somewhere along the line and the new ones are probably not as good as the old ones. I carry spare belts and a couple wrenches. Usually the old ones I took off LOL.

The nice thing about hooking it to the P/S pump is you will know immediately that you've lost a belt.

My idler pulley bracket always came loose with the annoying loose belt squeal after about 10+/- miles. Idk why it did that, it just did.

Dual pulley on the water pump ftw