K20A Supercharged Accessory Belt

[Karl]

The Brammo-specified part for the accessory belt on a supercharged K20A is NAPA part # NBH25060478.  Concerned about parts availability, I decided to try and find a substitute from a more readily-available brand.  The closest I could find were the Goodyear Gatorback 4060475 and 4060480, denoting each a 6-rib belt with a 47.5" and 48.0" circumference, respectively.  The stock NAPA belt is 47.8" in circumference.  Much to my surprise, the few tenths of an inch made a huge difference in fitment.  The Gatorback 4060480 is too long, and the 4060475 is too short, impossible to fit without somehow pre-stretching it.

EDIT: fitting the 4060475 is entirely possible, though it takes a lot of elbow grease and the clever application of leverage.  A proper tensioner wrench also helps.  Now you can get spare belts from all major parts suppliers!

Moral of the story?  Stockpile the NAPA belts in case they decide to stop making them!

[Terry Kennedy]

[quote="Karl"]
The Brammo-specified part for the accessory belt on a supercharged K20A is NAPA part # NBH25060478.  Concerned about parts availability, I decided to try and find a substitute from a more readily-available brand.  The closest I could find were the Goodyear Gatorback 4060475 and 4060480, denoting each a 6-rib belt with a 47.5" and 48.0" circumference, respectively.  The stock NAPA belt is 47.8" in circumference.  Much to my surprise, the few tenths of an inch made a huge difference in fitment.  The Gatorback 4060480 is too long, and the 4060475 is too short, impossible to fit without somehow pre-stretching it.

Moral of the story?  Stockpile the NAPA belts in case they decide to stop making them!
[/quote]

1) NAPA is scarce in your area? There are zillions of them around here (northeast) with next-day to 3-day parts delivery.

2) Is this the same belt that Ariel UK uses on their supercharged Hondas? Might be an alternative source.

3) I'm surprised that the tensioner couldn't deal with a belt 2/10" longer.

4) A Google search for "6-rib belt 47.8" comes up with this as the first hit. I don't know if it is accurate, but it lists the following as substitutes:

Code: Select all

Crossed From: K060478 GATES 
  4060478 GOODYEAR 
  5060478 DAYCO 
  6PK1212 A & I METRIC BELTS 
  6PK1213 A & I METRIC BELTS 
  6PK1214 A & I METRIC BELTS 
  6PK1215 A & I METRIC BELTS 
  6PK1216 A & I METRIC BELTS 

[Karl]

1. The three NAPA stores near here are located 15 miles north, 15 miles south, and across the bay.  If I drew a 15-mile circle around where I live, I could probably enclose 5 each of AutoZone, Kragen, and Pep Boys.  NAPA's online delivery is mighty quick, however.

2. Not sure, maybe.

3. As was I.  The situation with the tensioner is rather interesting,  When I got the first 47.8" replacement belt, it was a lot harder to put on than the old belt was to take off.  I checked the tensioner indicator, and it was just beyond the "tight" side of the recommended zone - whether that zone has any meaning anymore after the new belt routing, I do not know.  After starting the engine, the tensioner indicator moved to just past the "loose" side of the recommended zone, indicating that some stretching or settling had occurred.  The 48.0" belt just slid into the configuration without pulling the tensioner back.  The 47.5" belt was the last I tried, and even with the tensioner fully retracted I'd need a prybar just to get it on.  I do believe, though, that if one managed to finesse the 47.5" belt on, the tensioner indicator would sit somewhere inside the recommended zone.

4. The 4060478 Goodyear part is a pipe dream, even their own site draws a blank (http://www.goodyearep.com/productsdetail.aspx?id=3128).  The part #'s from Dayco and A&I don't seem to turn up much in a cursory Internet search, either.  The NAPA belt NBH25060478 is the one they specify for the 1985 Mercury Topaz 2.3L, but all other parts outlets come up with a 47.5" belt for the same application.

My motivation for this isn't because of an immediate local scarcity of belts, I'm simply trying to plan for the future when/if NAPA decides to stop making the 47.8".

[Terry Kennedy]

[quote="Karl"]
4. The 4060478 Goodyear part is a pipe dream, even their own site draws a blank (http://www.goodyearep.com/productsdetail.aspx?id=3128).  The part #'s from Dayco and A&I don't seem to turn up much in a cursory Internet search, either.  The NAPA belt NBH25060478 is the one they specify for the 1985 Mercury Topaz 2.3L, but all other parts outlets come up with a 47.5" belt for the same application.

My motivation for this isn't because of an immediate local scarcity of belts, I'm simply trying to plan for the future when/if NAPA decides to stop making the 47.8".
[/quote]

The link I posted in my original reply seems to stock this belt for $5.88. In looking at some of the other part numbers and seeing what they're used on, I come up with a 1992-1993 Geo Storm; 2004-2005 Kia Amanti; 1991-1996 Mercury Tracer; 1984-1987 and 1991-1996 Ford Escort; 1992 Isuzu Stylus and Impulse; 1984-1987 Mercury Lynx and Topaz; 1984-1987 Ford Tempo; 1985 Ford Ranger; 2003-2005 Mitsubishi Eclipse; 2004-2005 Hyundai XG350.

With that list (assuming it is correct) I don't think these belts will become unavailable any time soon.

[Karl]

Interesting indeed.  They allow you to add that product to your cart, but the cart won't display stock info.  I'll give them a call and see what the deal is, but I don't think it's a Goodyear part.

Thanks for finding all those cars!  I ran them through the AutoZone and NAPA sites, and here's what they came back with:

Model: AutoZone (Goodyear)/NAPA (Gates)
1992-1993 Geo Storm GSI: 475/478
2004-2005 Kia Amanti: 470/470
1991-1996 Mercury Tracer 1.9L: 470/470
1984-1987 and 1991-1996 Ford Escort 1.9L: 470/480
1992 Isuzu Stylus and Impulse 1.8L: 475/470
1984 Mercury Lynx and Topaz: 475/478
1984-1987 Ford Tempo 2.3L TBI: 475/478
1985 Ford Ranger 2.3L: 450/<no data>
2003-2005 Mitsubishi Eclipse 3.0L: <no data>/470
2004-2005 Hyundai XG350: <no data>/470

Interestingly enough, both the Goodyear 4060475 (http://www.goodyearep.com/productsdetail.aspx?id=3128) and the Gates K060478 (http://www.cdtruckandequipmentservice.com/Gates.pdf) list the metric 6PK1205 size as equivalent.  Maybe I need to put my back a little more into it to get the Goodyear to fit?

Thanks for your help with this Terry! 

[Karl]

After tackling this again with renewed confidence thanks to Terry Kennedy and some extra-strength elbow grease, I got the Goodyear 475 belt to fit.  As expected, at first startup it stretched to about the same length as the Gates 478 belt, as measured by the tensioner position indicator.  My first post has been revised to reflect the new findings!  I'll update this post if something goes wrong (and I'm packing the Gates belt in the boot as a precaution...).