Tuned pipe inlet dia. to engine size

[Ronnie Lerew]

I have boxes of nitro pipes but don't know what motors they match with. Is there a common inlet dia. To engine size? Like pipe inlet 7/8 is for a .67 engine.
Ron

 

[Mike Hughes]

You could post pics. We should be able to name them all. ID wont tell you what you need to know.
Mike

 

[Terry Keeley]

Generally, 1/2" I/D = 21's, 5/8" = 45's, 3/4" = 67's and up.

 

[Ronnie Lerew]

Thank you Terry,
That is what I was looking for. Being stuck inside I have time to root through boxes of unwanted stuff to post.
Ron