Really Dumb 69 427/390 Question About Belts

[Brad H.]

Guys,
i really feel like an idiot asking this question, but I can't find the answer. I have restored a 69 Coupe previously and this is my first BB car. I have a 427/390 vert/ 4spd car with no PS and no AC. It has two belts. One runs around the harmonic damper pulley up around the water pump and then around the alternator. There is another belt that just runs around the water pump and harmonic damper only. I assume it's a redundant water pump belt but my main question is: How do you adjust the tension?
Sorry for the stupid question because I'm sure there's a simple answer right in front of me. There is no idler pulley as it is a non-AC car.
Thanks in advance!
Brad

[Terry M.]

Re: Really Dumb 69 427/390 Question About Belts

There is no adjustment for that "captured" belt. It is not unique to large motors either. Getting the new one on can be a challenge, but other threads have offered several options.

[Joe L.]

Re: Really Dumb 69 427/390 Question About Belts

Guys,
i really feel like an idiot asking this question, but I can't find the answer. I have restored a 69 Coupe previously and this is my first BB car. I have a 427/390 vert/ 4spd car with no PS and no AC. It has two belts. One runs around the harmonic damper pulley up around the water pump and then around the alternator. There is another belt that just runs around the water pump and harmonic damper only. I assume it's a redundant water pump belt but my main question is: How do you adjust the tension?
Sorry for the stupid question because I'm sure there's a simple answer right in front of me. There is no idler pulley as it is a non-AC car.
Thanks in advance!
Brad

Brad------


It's "adjusted" by getting the EXACT length belt.

[Brad H.]

Re: Really Dumb 69 427/390 Question About Belts

Thanks Joe

[Michael M.]

Re: Really Dumb 69 427/390 Question About Belts

Yes, and the exact length belt is GM discontinued, I believe, a few years ago. I can't recall the GM part number, but it should be in the archives. There may be some still sitting on the shelves of dealerships. I bought several for future use, just in case. The search function should lead you to the GM part number and I presume there are cross references to other manufacturers. Good luck.

[Joe L.]

Re: Really Dumb 69 427/390 Question About Belts

Yes, and the exact length belt is GM discontinued, I believe, a few years ago. I can't recall the GM part number, but it should be in the archives. There may be some still sitting on the shelves of dealerships. I bought several for future use, just in case. The search function should lead you to the GM part number and I presume there are cross references to other manufacturers. Good luck.

Michael-----


Quanta supplies a good reproduction that fits fine.

[Wayne W.]

Re: Really Dumb 69 427/390 Question About Belts

Problem is exact length don't mean much these days. Belts are metric instead of standard, and that makes the width slightly different. On a belt that is as critical as that one, you just have to keep trying until you get one that fits like it should. Even originals may not be exact enough to really fit. I don't know if Quanta belts are standard or not.

[Joe L.]

Re: Really Dumb 69 427/390 Question About Belts

Problem is exact length don't mean much these days. Belts are metric instead of standard, and that makes the width slightly different. On a belt that is as critical as that one, you just have to keep trying until you get one that fits like it should. Even originals may not be exact enough to really fit. I don't know if Quanta belts are standard or not.

Wayne------


The Quanta belt I used fit perfectly for the big block application.

[Brad H.]

Re: Really Dumb 69 427/390 Question About Belts

Thanks guys

[Wayne W.]

Re: Really Dumb 69 427/390 Question About Belts

Wayne------


The Quanta belt I used fit perfectly for the big block application.

Thought you would have a NOS one or two in that stash of yours.

[Joe L.]

Re: Really Dumb 69 427/390 Question About Belts

Thought you would have a NOS one or two in that stash of yours.

Wayne-----


I do have some NOS [none for sale]. However, they're old and I didn't want to use them if I could get a new belt that would work properly.