Penton Owners Group

General Discussion => Penton Talk => Topic started by: Mick Milakovic on June 07, 2011, 08:27:16 PM

Title: Intake Boot Length
Post by: Mick Milakovic on June 07, 2011, 08:27:16 PM
Hi All,

I'm converting my Harescrambler from the worn-out Bing to a Mikuni.  I've made the first cut on my carb-to-intake boot, and I know it's too long, but I was wondering if the length of the boot can affect power, and if so, in what way?

Thanks, in advance, because I know someone out there knows the answer to this question!

Mick
Title: Intake Boot Length
Post by: firstturn on June 07, 2011, 08:51:56 PM
Mick,
  Here is the theory I have operated under many years. To answer your question of the length you should be OK since you are not going after specific "all out High or Low range racing".  I use velocity stacks in some of my specific applications since I feel that gas "floats" around between 2 to 6 inches past the slide when the piston (or in 4 Cycle valve) closes.  Just for  some other information in "Theory" Velocity stacks are a Convergent Duct, meaning the air will increase in veleocity as it goes through the stack which is what I want.
  I hope Nelson makes a comment.


Ron Carbaugh
Title: Intake Boot Length
Post by: linglewn on June 07, 2011, 09:39:16 PM
Ron,
No additional comment needed. I agree with your explanation.

Nelson Lingle
73 Jackpiner
74 Jackpiner
71 DKW 125
Title: Intake Boot Length
Post by: firstturn on June 07, 2011, 10:00:48 PM
Thanks Nelson...you are the man with all the formulas and I respect that.

Ron Carbaugh
Title: Intake Boot Length
Post by: Mick Milakovic on June 07, 2011, 10:22:17 PM
Ron and Nelson, thanks, appreciate the feedback.

Mick
Title: Intake Boot Length
Post by: Paul Danik on June 08, 2011, 06:24:25 AM
Hi Mick,

   The old school guys that I hung with who did those types of conversions usually agreed that a little longer inlet tube would help with ease of starting and good bottom end response. If they were after high end performance and were willing to give up a little at the bottom they shortened the tube.

    Hope that helps, and hope to see you at VMD.

Paul
Title: Intake Boot Length
Post by: Mick Milakovic on June 08, 2011, 10:41:02 PM
Thanks Paul, I'm into easy starting!

Mick