Hey guys -

So with my engine project I'm needing to replace the old cracked belts. As usual this ended up being trickier than expected.

If you have a bone stock FD, it's not too bad to get belts. There is some variation with auto trans cars as I believe their air pumps are different sizes.

Banzai Racing has an EXCELLENT guide on belts and sizes -

https://www.banzai-racing.com/store/...lley_belt.html

The big problem is when you start changing up pullies and removing the water pump. I'd like to eventually have this thread have a list of "this is my setup and this belt size worked" to at minimum make it easy to get in the ballpark on a belt size if not dead on.

My car has the mild under drive aluminum pullies - I think they were Togue Racing off Ebay way back in the day. The pullies Banzai shows on their site are VERY similar to what I have. If they are under drive it is VERY minimal.

So my setup and belt that works:

- Alternator pulley measures in the grooves of the pulley at 48mm
- Water pump pulley measuring outside diameter as best I can 103.8mm
- Main pulley outside diameter (not in the grooves) 102mm
- Pineapple Racing "standard" idler pulley with no air pump

A Bando 5PK1080 belt fit great, maybe just a LITTLE on the end of the tension for the alternator but still good. Also it wasn't too hard to slip on which is good.

The PK belt code is a standard serpentine belt code.
5- number of ribs
P- Metric measurement
K- Automotive use
1080 - Effective length of belt in millimeters

Notes on belt sizes:
https://www.gates.com/content/dam/ga...s/tt001-16.pdf

So the "effective length" is tricky, that's needing special equipment to measure. I bought 3 different belt sizes and they were all "long" compared to the measurement of my original/worn out belt.

5pk1080 - measured at 1085mm
5pk1090 - measured at 1095mm
5pk1095 - measured at 1105mm

Measuring was done with a metric measuring tape going across a long table. I marked a silver Sharpie mark on the inside of the belt and rolled it along the tape measure, keeping it as flat as possible.

Also for reference - water pump/alternator belt is 5 rib, power steering/AC belt is 6 rib. Some people running aftermarket under drive pullies with no air pump had to go to a 4 rib short belt as that was all that was available. This is not recommended IMHO since you have really poor belt contact on the water pump pulley and could be slipping and not driving the water pump.

Some pictures to follow, please post up what combo works for you!

Dale

 

You actually have underdrive main, underdrive water pump, stock alt with normal PR Idler. I don’t like double underdriving the water pump. Not a belt I offer

 

If you have the Metric size, you can convert it to inches with math. 5PK1080 = 1080mm = 42.5. the US belt companies tend to list the same thing in a different order so it would be like K050425 or such like
also "effective length", some companies use the ID and some use the OD, and then since there is usually adjustment, some list a range of belts. if 5PK1080 worked, then 5PK1070 or 5PK1090 would also probably fit

 

I’ve recently had to do mine.. been about 3 or 4 seasons now..
I made sure to make notes since I have unorthodox racing pulleys on my setup so none of the OEM belts fit. Except maybe the one that goes around the a/c.
Here’s mine:Long one: gates micro v k060400

Short one: gates micro v k050280 or if there is a k050285

The belts last a long time on mine since it’s only used as a summer car. I think I’ve only gone thru 3 sets of belts since I’ve owned it. I do check them every season just to be sure..

 

Update on my end -

My main pulley seems to be SLIGHTLY under drive. The stock size 6pk1045 for the power steering/AC was too big.

Banzai's site showed a 6pk1015 for this application for a Pettit power pulley - got a belt of that size, was WAY too small. I think that's a pretty agressive/small main pulley.

Got a 6pk1040 last night - fit perfectly, just the right amount of tension. Hooray!

 

That would have been Belt #7 https://www.banzai-racing.com/store/...lley_belt.html

Make sure you are not getting the part number confused, the 6K1040 is a 40" belt, which is what 6PK1015 a 1015mm belt is

Pettit pulley is tiny, which is why the first belt was too short and it is actually Belt # 6 the PK1000