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Source for Alternator belt?

N

nightflier

Active Member
Patron
I changed my IO540D4A5 narrow deck, to a Zero time Lycoming OVH engine.
Now the alternator belt wont fit. The old belt was a 3VX355, but it's to short.
A 3VX370 is the right length, but even though it's 3/8 wide, I think the grove
is different. Don't even bother asking Vans, they don't have a clue, that's
pretty sad.

Thanks!
[email protected]
 
nightflier said:
I changed my IO540D4A5 narrow deck, to a Zero time Lycoming OVH engine.
Now the alternator belt wont fit. The old belt was a 3VX355, but it's to short.
A 3VX370 is the right length, but even though it's 3/8 wide, I think the grove
is different. Don't even bother asking Vans, they don't have a clue, that's
pretty sad.

Thanks!
[email protected]
Click to expand...
V-belt cross section is defined (by trade specifications) by the first two digits of its description - ergo, a 3V belt of any length is going have the same cross sectional dimensions. The third digit (X) means that the back face of the belt has been "notched" to give better performance around smaller pulleys.

HFS

3VX trade size - 3/8"w x 21/64" deep
 
Same alternator?
Same alternator mount?
Same flywheel?

Not familiar with the terms narrow deck or OVH as they would pertain to spacing differences. Can you take measurements of new vs old to make sure you have the correct mounting bracket for the replacement case?
 
HFS said:
V-belt cross section is defined (by trade specifications) by the first two digits of its description - ergo, a 3V belt of any length is going have the same cross sectional dimensions. The third digit (X) means that the back face of the belt has been "notched" to give better performance around smaller pulleys.

HFS

3VX trade size - 3/8"w x 21/64" deep
Click to expand...
Great info, thanks!
 
recapen said:
Same alternator?
Same alternator mount?
Same flywheel?

Not familiar with the terms narrow deck or OVH as they would pertain to spacing differences. Can you take measurements of new vs old to make sure you have the correct mounting bracket for the replacement case?
Click to expand...
Just discovered the bracket is different! Thanks.
 
recapen said:
Same alternator?
Same alternator mount?
Same flywheel?

Not familiar with the terms narrow deck or OVH as they would pertain to spacing differences. Can you take measurements of new vs old to make sure you have the correct mounting bracket for the replacement case?
Click to expand...
Just discovered the bracket is different!
 
Take your old/too short one to your local NAPA Aircraft Supply and have them measure it and find what they have that is similar. There is no secrete manufacturing method that makes them different aviation from auto. Have them give you several different sizes so you don't have to keep going back for a longer/shorter one. You can take the 'wrong' ones back. A half-inch difference in the length of the belt can make it either fit or not fit. Ask me how I know that........... 😉
 
Last edited:
nightflier said:
I changed my IO540D4A5 narrow deck, to a Zero time Lycoming OVH engine.
Now the alternator belt wont fit. The old belt was a 3VX355, but it's to short.
A 3VX370 is the right length, but even though it's 3/8 wide, I think the grove
is different. Don't even bother asking Vans, they don't have a clue, that's
pretty sad.

Thanks!
[email protected]
Click to expand...
The variations of what can go firewall forward (or anything else not in the plans, for that matter) would be difficult for anyone to figure out that is not standing next to your airplane to see what is there. The starter ring is usually the same but the alternator pulleys can be of many different types as well as the alternator brackets/setup. The clues we will give you are based on what we have on our Magic Carpets and might be exactly what you needed to know.........or not help at all! 😉
 
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