Belt Length for 5.0 without air pump?

The thermactor air pump on my '88 5.0 (with dealer installed A/C but otherwise stock) siezed, and I am am thinking of just getting a shorter belt and running without it. Has anyone done so and/or happen to know what length belt I should use? Thanks


Wayne
 
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waynekohn8 said:
The thermactor air pump on my '88 5.0 (with dealer installed A/C but otherwise stock) siezed, and I am am thinking of just getting a shorter belt and running without it. Has anyone done so and/or happen to know what length belt I should use? Thanks


Wayne
aww man that just happened to me, was not fun driving on the freeway at 12am....
 
i got a question about measuring, it will help the origianl poster too.....ive always told people to measure but never needed too.. i have fms ac delete and no smog...i borrowed a friends old belt (has same setup) but it was about an inch or 2 too big)...now, if i measure with the rope do i measure all around the pullies and make the rope tight? cause i was thinking if i do that and then the tensioner comes down wont it be too tight? maybe im just thinking wrong.

and do i just go to the store and tell them my size and it doesnt matter for what kinda car...cause ilast time i did this they were like uhh for what car...i was liek mustang but its just a length, not factory size. thanks for any help
 
Black331Stang said:
if i measure with the rope do i measure all around the pullies and make the rope tight? cause i was thinking if i do that and then the tensioner comes down wont it be too tight? maybe im just thinking wrong.

and do i just go to the store and tell them my size and it doesnt matter for what kinda car...cause ilast time i did this they were like uhh for what car...i was liek mustang but its just a length, not factory size. thanks for any help

If you can, have someone with a big screwdriver pry the tensioner up into the belt stretch indicator somewhere and hold it there until you can run a string around all the pullies and figure out how much belt you need.

Parts store flunkies are another matter all together. Maybe try to find a store that has a selection of belts you can look through.
 
BeltRouting.jpg
 
waynekohn8 said:
The thermactor air pump on my '88 5.0 (with dealer installed A/C but otherwise stock) siezed, and I am am thinking of just getting a shorter belt and running without it. Has anyone done so and/or happen to know what length belt I should use? Thanks


Wayne


If you still have cats on the car you need the air pump. If cats are gone disregard.
 
I have never understood why some people say you need the air pump for the cats. The air tube doesn't connect to the stock h-pipe till after the first two cats anyway. I ran mine wthout an air pump with my stock h-pipe for over a year before switching to my off road pipe. It never hurt anything.
 
The air pump is there to provide excess oxygen to the exhaust stream. It's required so that chemical reactions can continue to occur after combustion reducing controlled emissions (HC, CO and NOx). The excess O2 that's pumped in reacts with the harmful emissions turning them into more H2O, CO2 and harmles oxides of nitrogen; the catalysts speed up these reactions. The air pump doesn't just pump air to the cats (or downstream/upstream of them). It also pumps air into the exhaust ports via the crossover tube in the back of the heads. The computer triggers the thermactor valves which decide whether air gets bypassed, pumped to the heads, or into the exhaust pipes.

If you have A/C and P/S, the belt length should be around the 84.5" shown in the diagram above. But all of them are a bit different. I bought 3 - within a 1/2" on either side of the 84.5", and took back the two that didn't work. Mine took an 84". Each tensioner is a bit different, the spring gets tired and it sits in slightly different locations on each car. So just tell the parts place what you're doing and they should be happy to take back the two you don't use.
 
with all stock pullies I needed an 85.5". I couldn't even get the 84.5 on. best bet is to find an auto parts store that will let you try to put it on in the parking lot before you buy it. I've done it at a couple local autozones and they gave me no trouble. just walk in and tell them you need a 6 rib 80whatever inch serpentine belt and they should be able to find it. if not, tell them to go find it, the lengths are in the part numbers anyway. or yell at the manager cause the employees don't know what they're doing. either way have fun.

its odd, seems like everybodys smog pumps sieze up...I don't get it..they must just suck. I replaced one, and then it seized up a month later.
 
make sure you guys compensate for stretch. I always go an inch shorter so that when i first install the belt it's towards the TIGHT end of it's range. As i drive it, it will stretch and go to the middle of the range
 
napa has a big book of different belts, just tell them the numbers of ribs and length. for some reason when i did my belts it wouldnt come out right if i pulled the string to tight, the belt wouldnt fit over the lip of the pulleys i spent a few hours at napa trying to find the right belt for mine because i have a meziere electric water pump with idler pulley and i did a ac\ smog elimination kit. after finding the right belt i put it on in the napa parking lot, was thrilled i found it, then went to start my car and the selenoid went----sucked to be me