Belt size for smog delete w/BBK pulleys

BlackVert

15 Year Member
Oct 3, 2003
5,589
9
98
Bethesda, MD
What would the belt size be for smog delete if you have the BBK underdrive pulleys?

My search found lots of threads about smog delete and they talk about different belts (895K6 and 887K6:ASP), but I did not see anything definitive in regards to the BBK pulleys.

Thanks!
 
belt.jpg
 
I had the bbk pulleys back when I did the smog elimination, and cant remember the # off hand.. What I did to come up with the # was take a string and wrap it around, mark it where the two ends meet, and measure that.. and then subtract and inch from the measurment for the tensioner to tighten on the belt.


SO say, it measures out 865(k6=6 rib) Just an example, that means the belt is 86.5" long.. and of course one inch larer would be a 875 (aka 87.5") I believe they go in half inch increments also.
 
The smog pulley is definitely NOT free spinning, that's why they make a delete kit, or people bypass it with a short belt. It is more or less an air pump that pushes air into your catalytic convertors, and also into the backs of your heads. The A/C is a power robber also, more so when it is on and the clutch assembly is engaged, but either way it still takes power to run it. I'm not sure what kind of difference it would make in the 1/4, but I'm sure getting rid of it frees up some horsepower.
 
BlackVert said:
i assume it is OK for the water pump to spin the other direction?
The water pump isn't spinning the other direction, it is still spinning counter-clockwise. As long as the belt goes over or under depending on which way is right, the pulley turns the right direction. Look at the picture again and you will see what I am talking about. But, if it was going the opposite direction, then that would probably be a problem.
 
94MustangGT5.0 said:
The smog pulley is definitely NOT free spinning, that's why they make a delete kit, or people bypass it with a short belt. It is more or less an air pump that pushes air into your catalytic convertors, and also into the backs of your heads. The A/C is a power robber also, more so when it is on and the clutch assembly is engaged, but either way it still takes power to run it. I'm not sure what kind of difference it would make in the 1/4, but I'm sure getting rid of it frees up some horsepower.

ok cool thanks what would be the right length for bypassing the smop pump and A/C pump? and diagram!
 
i just measured mine with a string and it came to 91". i'm not sure why, but that is a little longer than i expected. i included the tensioner in the measurement. should i measure again, this time ignoring the tensioner? that would probably bring it down to 89-90" ...
 
i got a 90.5" belt ... too long.

then i tried a 89.5" ... it fits, but i don't like how far the tensioner is for a new belt, i think i'll get an 88.5" and an 89.0" and return the one i don't keep. they are only $25.

i was surprised that it took like 5 minutes to swap belts, it is really easy once the engine has cooled off.

btw, the tensioner takes a 15mm socket.