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Sbc V-belt Help Needed

82K views 92 replies 13 participants last post by  ralphvlad 
#1 ·
I need help with my v-belts on sbc400ci. I know most of you will say convert to a serpentine system, but this is in an '89 chevy p/u and i kinda like the engine to have the old school look. Ok here's the problem, i have two v-belts on this engine. One is attached to the power steering/waterpump/crank..the other is attached from alt/waterpump/and crank. I have a horrible sqeal! I've taken the alt belt off and the sqeal stopped si thought maybe the alt bearings were bad.. replaced alt...Still sqealing! Took the power steering belt off stopped squealing..changed p/s pump and sqeal returned and i can't seem to pin point where it's comimg from.. THis is also my second set of belts with the same sqeal please help.. Thanks in advance!!!
 
#27 ·
The pulleys were never change by me. Its the exact same set up as when i pulled it from a large motor home..As far as the guy that gave me the engine he said he has never had any mechanical problems since he bought the motor home new in '73 lol! So maybe they were changed by the motor home manufactor not sure but I'll look into it and change them as needed! Thanks for the help guys!!
 
#28 ·
I'm having a tough time trying to follow parts of this thread, and how you have your belts routed. Any chance you could post some pics?

The other thing to be mindful of when working with v-belts and pullies on an SBC is that there are two completely different setups out there.

One is designed for a short water pump ("SWP") and the other is for a long water pump ("LWP")

Most engines newer than 1969 were "LWP"
The easiest method of identification is which side of the block the alternator sits.


Motorchrome.com


If you have a long water pump Small Block Chevy your alternator will be mounted on the passenger side of the engine
 
#29 ·
Sorry 66gmc my camera took a dump on me the other day so cant post pics..it would make it alot easier I know !! OK so took another look at it.. Yes i have the long water pump..ALT. is on pass side, powersteering is bottom drivers side... Crank has three pulleys both are equal sizes,water pump has a larger pulley on the outside and a smaller one on the inside(closest to the block). Power steering has two pulleys of equal size. And the alt. for now only has one pulley...
As far as the belts are right now... one belt is from crank to water pump to powersteering pump (this belt is on this inside) second belt is from crank to water pump to the ALT. And tommorrow I will add a second belt from crank to powersteering pump. As suggested above. Sorry for any confusion.. :sweat:
And this is a '72 400ci 4bm
 
#36 · (Edited)
V8&4spd said:
The pulley is the problem. It will be a night and day difference when you put the right pulleys on there. This is the crank pulley that works with the correct water pump pulley.
Thanks v8! So the water pump pulley i have is wrong? I need the one that has the same size pulleys on it? And my crank pulley has three equal sized pulleys so this is wrong also? So has someone just changed all of the pulleys?? Thank for your help again!
 
#40 ·
pontiacjosh said:
its the same setup i have on my monte 1 belt goes from water pump to power steering and 1 belt goes to crank water pump and altenator
Ok so now I'm confussed...no matter where or how you run the belts they do/are crossing paths at one point or another.. so if one is running at one speed and the other at a different speed they will in turn "fight" each other at some point right?
 
#45 ·
Belts And Pulleys

The original belts and pulleys were working just fine on the engine when you took it out. This deal about the having to be same size pulleys is just crazy. There is a purpose on a factory application for the reduced size pulleys. . I'm sure you can find a picture on the net of your exact engine and I will bet you it won't have all the matching pulleys. Somebody has been shopping at speedy Bill's and Jegs to much. Large and small pulleys work just like gear size reduction and speed of what it turns. :cool: This is about as crazy as the comment about one belt turning one way and the other one turning the oppisite way. Lets see a picture of how you come up with that one. :confused:
 
#47 ·
CHEVYRODS said:
The original belts and pulleys were working just fine on the engine when you took it out. This deal about the having to be same size pulleys is just crazy. There is a purpose on a factory application for the reduced size pulleys. . I'm sure you can find a picture on the net of your exact engine and I will bet you it won't have all the matching pulleys. Somebody has been shopping at speedy Bill's and Jegs to much. Large and small pulleys work just like gear size reduction and speed of what it turns. :cool: This is about as crazy as the comment about one belt turning one way and the other one turning the oppisite way. Lets see a picture of how you come up with that one. :confused:
If you are only running a alternator and PS pump both the pulleys have to be the same size. The crank pulley drives both of them first. If you use the smaller pulley in back the water pump pulley wants to run at 2 different speeds. It's a fact there is a night and day difference when you have the right size pulley on the water pump.
 

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#48 ·
Sorry CHEVYRODS i must have skipped over your post some how.. And yes this excatly how i pulled the engine from the motor home! And as far as the engine having a/c or anything else this it did not either.. only alt and powersteering. I did how ever remove the belts when i was pulling the engine and i believe i installed them the way i took them off?? I dont understand factory pulleys being wrong either but I'm not much on v-belt applications either..So if i have to buy other pulleys I will to solve the problem but I dont understand the purpose ? I do understand gears and ratios though and see the point in the reduction of the pulleys sizes also.. But i do appreciate everyones help with this!!
 
#49 ·
Put your camera in movie mode and make a video of it running both the alternator and PS pump with the water pump pulley you have now. Then make a video of it running with the water pump pulleys that are the same size. You already know there is a problem with the way it is now. When the right pulley is put on you will be amazed at the difference.
 
#51 ·
Who knows why some thing were made the way they were. The picture of the water pump pulley I posted came off a V6. It bolts right onto a V8. If you look at the pictures of the chrome water pump pulleys they sell, they are both the same size. The V6 water pump pulley throws everything out of wack when it's put on a V8. It causes vibration and belt squeeling.
 
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