• The Roadster Factory Recovery Fund - Friends, as you may have heard, The Roadster Factory, a respected British Car Parts business in PA, suffered a total loss in a fire on Christmas Day. Read about it, discuss or ask questions >> HERE. The Triumph Register of America is sponsoring a fund raiser to help TRF get back on their feet. If you can help, vist >> their GoFundMe page.
  • Hey there Guest!
    If you enjoy BCF and find our forum a useful resource, if you appreciate not having ads pop up all over the place and you want to ensure we can stay online - Please consider supporting with an "optional" low-cost annual subscription.
    **Upgrade Now**
    (PS: Subscribers don't see this UGLY banner)
Tips
Tips

Narrow Belt Conversion

T

TRDejaVu

Guest
Guest
Offline
I am making the change on the TR4, although I am staying with the Generator for now. Anyone know which NAPA belt number will work?
 

Moseso

Jedi Knight
Country flag
Offline
Not sure -- I went with the Denso alternator, and that changed things. Which brings me to my point: They come in 1/2" increments. The folks at my local Napa were happy enough to sell me several of them to try the fit. I returned all the ones that didn't, and kept the one that did. Assuming you're not too far from the Napa store, it's a workable way to get just the right belt.
 

Geo Hahn

Yoda
Country flag
Offline
Not clear to me whether you want the NAPA wide belt for the generator (possibly 25-24379) or the narrow belt you will need when you install the alternator (it depends).
 
OP
T

TRDejaVu

Guest
Guest
Offline
Geo Hahn said:
Not clear to me whether you want the NAPA wide belt for the generator (possibly 25-24379) or the narrow belt you will need when you install the alternator (it depends).
I have obtained narrow pulleys for the crank, water pump and the generator.
 

martx-5

Yoda
Country flag
Offline
When I got the narrow belt conversion, it came with the narrow belt. Since I was installing an alternator, the belt they gave me turned out to be too short. The belt they sent was a Quinton Hazell QBA<span style="font-weight: bold">975</span>. The belt NAPA gave me was a 7385, which is 9.5/10mm x <span style="font-weight: bold">995</span>mm (25/64"x39-1/8"). You most likely need the NAPA size closest to 975mm. Probably one or two sizes smaller then the 7385.

Hope this helps.
 
OP
T

TRDejaVu

Guest
Guest
Offline
Thanks Art.

The outside diameters of the pulleys are 5 1/2" (crank), 4" (water pump) & 2 3/4" (generator). I presume that the crank and water pump ODs do not change, but I don't know if the alternator pulley is a different size. How do those sizes compare to yours?
 

martx-5

Yoda
Country flag
Offline
Pretty hard for me to measure the crank and w/p pullies, but if they aren't the sizes you mentioned, they are very close as best I can get in there to measure. The generator pulley I did not use, as I have an alternator on there. It measures exactly what your's does.

As far as the alternator goes, the QBA975 belt would've fit, except for the fact that the alternator is fatter then the generator and hit the block before I could get the belt on. I couldn't push it toward the engine as far as the generator will go. That's why I had to go for a longer belt. The alternator also has a 17mm shaft, and the generator has a 15mm shaft. That's why I didn't use the pulley that came with the kit. Besides, the alternator came with a pulley already attached.
 
OP
T

TRDejaVu

Guest
Guest
Offline
My local NAPA say they have either a 970 or 985 equivalent so I will try them. Thanks again and I will post info on which one that fits.
 
Similar threads
Thread starter Title Forum Replies Date
M TR4/4A Narrow belt conversion with thermo fan. Triumph 0
Lukens TR2/3/3A Narrow belt conversion. I can't understand why... Triumph 25
GTP1960 TR2/3/3A Moss alternator & narrow belt conversion questions Triumph 22
T TR4/4A What narrow belt on alternator conversion TR4a? Triumph 7
J General TR Narrow Belt crank pulley Triumph 0
croz TR2/3/3A Harmonic Balancer - narrow belt pulley Triumph 12
Popeye TR4/4A Crankshaft pulley recommendations: One piece alloy, two-piece steel, wide, narrow...? Triumph 12
S TR2/3/3A narrow wheel tr3 Triumph 13
Bruce Bowker Narrow tires Racing 5
Z Early BN1 Narrow Brake Drum Identification Austin Healey 6
D TR2/3/3A layout for lap type seat belt Triumph 5
waltesefalcon Miata Water Pump and Timing Belt Other Cars 3
tr6nitjulius General TR Fan Belt Replacement '72 TR6 Triumph 1
K TR2/3/3A Overtightening the alternator belt? Triumph 14
D T-Series Shorrock supercharger drive belt MG 7
WHT Late BJ8 Seat Belt Mounting Points Austin Healey 8
M 1972 Midget Seat Belt Replacement Spridgets 4
Lin Fan belt for 1275 with alternator Spridgets 4
nichola TR6 Seat belt reinforcing plate question Triumph 15
NutmegCT Belt preservative? Restoration & Tools 6
2 TR2/3/3A V-belt obstruction Triumph 0
Michael Oritt Seat belt anchors--introduction Austin Healey 2
T BJ8 Fan Belt Change Austin Healey 7
longbridgehealey Bonnet belt Austin Healey 16
B TR6 TR6 Fan Belt Triumph 4
F TR6 Seat Belt Module? Triumph 4
tahoe healey past post about sholder belt foam Austin Healey 2
M TR2/3/3A Water Pump Belt After Alternator Conversion Triumph 6
B Wanted Kangol Seat Belt Receiver Jaguar Classifieds 5
B Wanted Kangol Seat Belt Receiver Triumph Classifieds 0
steveg BJ8 Alternator - small belt in large pulley Austin Healey 4
I General TR Seat belt dissassembly help Triumph 0
I TR6 Seat belt restoration Triumph 1
C TR6 Seat belt warning bypass for new harness. Triumph 6
KVH TR4/4A Belt Size for TR4A Triumph 4
G TR2/3/3A Fan belt Triumph 6
2billydavies TR2/3/3A dead battery, generator, belt Triumph 13
2billydavies TR2/3/3A belt size for TR3a? Triumph 13
C "Belt Type" squeal BN1 - Throw out bearing? uh oh... Austin Healey 14
B TR6 Seat Belt Brackets - Any Better Ideas? Triumph 1
J TR2/3/3A Changing fan belt. Triumph 9
C MK1 3000 fan belt Austin Healey 1
Lukens TR2/3/3A Cog v-belt causing noise. Triumph 8
Lin Pulley and belt configuration for air conditioning Austin Healey 2
T TR2/3/3A Question on spacer in Moss thin belt/damper conversion kit 837-508 Triumph 3
J TR2/3/3A Local fan belt supplier. Triumph 7
M TR2/3/3A 3/8" belt and pulley conversion kit Triumph 10
M TR2/3/3A Another seat belt question Triumph 8
Jeepster Seat belt fixing Austin Healey 4
B Gen/waterpump belt Austin Healey 13

Similar threads

Top