Board index Flathead Power-Technical Questions, Answers, and Suggestions Indians tuned length .. and bore on exhausts

tuned length .. and bore on exhausts

Post Fri Feb 16, 2007 4:09 am

Posts: 78
Location: highlands of scotland

Getting to the stage where i'll need to make up exhausts for my Stroked Scout, any pointers as to length and bore I should use, for fast road and track use?

Post Tue Feb 20, 2007 7:09 pm

Posts: 124
Location: Glenmoore, Pa. USA

Steve,
You need to have more info to make an eucated guess as to where to start in size and length.
Rocky

Post Wed Feb 21, 2007 5:29 am

Posts: 614
Location: Roxboro, North Carolina, U.S.A.

Steve -

This is in no way the solution to your problem. Calculating pipe length is complicated. However, there starting points. This was taken from an aviation site that posted a formula for calculating pipe length. It is greatly simplified, compared to what it would really take. But, it may get you there:

http://www.terra-glide.net/pgms/ExhPipe.exe

Jack

Post Thu Feb 22, 2007 2:59 am

Posts: 78
Location: highlands of scotland

It gives me a start, thanks Andrew, just a couple of starter questions, never having ridden an Indian, at what sort of revs would a Stroked Scout get its maximum power. I know.... it depends on the state of tune, if its lightened etc etc, but i'm talking about a starting point.

Post Thu Feb 22, 2007 6:53 am

Posts: 39
Location: Paris, France

steve_blackbob wrote:
It gives me a start, thanks Andrew, just a couple of starter questions, never having ridden an Indian, at what sort of revs would a Stroked Scout get its maximum power. I know.... it depends on the state of tune, if its lightened etc etc, but i'm talking about a starting point.


take a look here : http://virtualindian.org/archstrokerdata.htm

Post Thu Feb 22, 2007 3:51 pm

Posts: 124
Location: Glenmoore, Pa. USA

Steve, All I can say at this time without knowing your cam and engine internals is that in 1948, Paul Giambonni came down from Springfield to Daytona at the beginning of the week prior to the races and instructed most Indian teams to run these new cams and set them at 3/4 inch BTDC on the rear cylinder. All during the week as the hot shoes would run thru Daytona and terroize the HD's with the poor idle and then walk away from them at high RPM. My father figured that they were getting 4800 to 5000 RPM, about 200-300 more than the HD's on the straight sections.
Rocky
1957S/VG

Post Fri Feb 23, 2007 11:38 am

Posts: 78
Location: highlands of scotland

Rocky, I'm going to pull the motor out of the frame this weekend, and set it up on the bench, check all of the dimensions and try and figure out which cams are installed. The original "bung it all together and hope it runs plan" is quickly turning into a quest for speed :lol:

excuse my ignorance on all things Indian, I'm in the process of weaning myself off Triumphs :D

Post Sun Feb 25, 2007 2:22 pm

Posts: 124
Location: Glenmoore, Pa. USA

Steve,
You will need a device like this with a "Triumph" degree wheel or you can send your cams to me and I can plot them for overlap amd opening.
Or you can send them to me and I can plot them in about an hour
Rocky
1957S/VG
Image
Image

Post Tue Feb 27, 2007 5:33 am

Posts: 78
Location: highlands of scotland

thanks for the offer Rocky .... but the boy gotta learn :D ... engine is on the bench, wassell timing disc on its way and notepad ready 8)


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