explorer brackets/underdrive pulleys

[painterdude923]

I am putting 1990 302 in my 97 ranger. have front brackets off 97 explorer. I have brand new set of BBK underdrive pulleys for 5.0. anyone know if I can run those pulleys with my set up? or should I get the pulleys for 97 explorer?

[Grumpy]

you will have to get under drives for the explorer setup as the crank and water pump pulley's will not line up properly .....cuz the explorer setup is like an inch or so closer to the engine then the mustang setup.... hope this helps ....

[faststang90]

i dont have a explorer but it shows the crank is a 3 bolt set up and a mustang is a 4 bolt pulley. not sure if the pic is right but if it is it will not work
http://www.summitracing.com/parts/JET-9 ... refilter=1

[cgrey8]

I'm not familiar with Mustang setups or underdrive pulleys in general. But I do know the Explorer crank pulley is a 1-piece cast unit with the harmonic balancer. The pulley doesn't separate from the balancer. So if you want to underdrive an Explorer engine, you would need to also replace the balancer. And as already mentioned, Explorer front dress is much more compressed putting the pulleys and belt much closer to the engine than previous 5.0L setups do so replacing the pulley/balancer with balancer and pulley setup meant for a Mustnag isn't likely to work as the pulley will locate the belt further out than the rest of the accessory pulleys and idlers.

[MalcolmV8]

Well he doesn't have an explorer motor right? Just the explorer brackets and accessories on there if I read his post correctly which means he has the mustang balancer and lower pulley. If so that's exactly what I did on my red truck and I installed a mustang under drive pulley set just fine. Crank of course is mustang so it swaps right in and accessories where no issue either, all swapped over that I remember.

[cgrey8]

If his timing cover is Mustang, then yeah, shimming the brackets is all it takes. However if this is an Explorer motor with Explorer timing cover, then I'm not sure I'd trust shimming the water pump pulley.

[MalcolmV8]

Agreed. He says a 90 302 with Explorer brackets so I think he'll be fine. His brackets should already be shimmed or his belt wouldn't line up so he should just have to swap pulleys and probably get a new belt.

[cgrey8]

How much shorter of a belt is usually required with an under-drive?

[MalcolmV8]

No real answer. Crank pulley gets smaller but other pulleys get larger. In theory they could cancel each other out but not usually. Every kit has their own sizes depending on whether you're under driving 10%, 15% etc. Plus you could choose to not put the larger pulley on say just the water pump or just the alternator etc. if you're having issues with something been under driven to much.

Personally I wouldn't use under drive pulleys again, at least not on the alternator. Head lights dimming when you're idling and each time you pull off from a traffic light at night your dash brightens along with the head lights and I'm sure the other electronics on the car such as heat O2 sensors etc. just love that fluctuating voltage.

Only exception is my Cobra. The alternator was so over driven by the factory it eventually fails (lots of debate on actual reasons for failure). I run a metco under drive pulley on only the alternator (stock crank pulley) and I still see a solid 14.2 volts at idle. It's so over spun you'd have to put a much larger pulley on it to see a voltage drop.

Speaking of belt sizing, when I put a smaller pulley on the factory blower on the Cobra years ago I also added some idlers to help with belt wrap around the blower pulley and that combo cancelled each other out and it took the stock sized belt. Sometimes you get lucky like that.