I fell really stupid for asking this, but..

Is there an easy way to measure equal length?

Or do you all have any tips on keeping it all equal while fabbing up say a topmount manifold?

Pull a string thru and measure?

Thanks for your suggestions and time,
DK

 

Fill each runner with sand, pour into measuring cup, bake for 30mins on 450.

 

Calculate the arc length and the length of the straight for all 4 runners.

 

Matlab/Solidworks

 

i seen a copper tubing trick that looked really easy.if you google kammini or midlana that is where i found it.its a build blog of a carbon mini cooper.so you figure out what you primary lengths are then cut 4 pieces of copper tubing and bend to match the radius you will be using.then you cut paper discs the size of your tubing to slide over the copper tubing to check for clearance.pretty good idea i thoght

 

so this wont work if your actually trying to find a specific measurement assigned to length, but to just get runners the same. a quick and dirty way is to just assign your 90's and 45's a # value, say 2.5" for 45's and 5" for 90's. i'm sure with some research you could find the equivilant length of each fitting, whereas a 1 1.5" long radius 90 might equal 4" of straight for example(not that it does, just using that as an example). then just keep track of the length of straight in each runner, add that to your 45's and 90's in that runner and that will at least give you something to work with and will get you super close.

 

The numerical value would be arc length. Not that hard to calculate. Just need to keep it consistent throughout the center of the runner.

 

i measure the centerline of the runner. it isn't hard to do. just imagine a string going through the runner that is exactly in the center from flange to flange and figure out a way to measure that. i usually do it in sections. the straights are easy. for the elbows, just measure from weld joint to weld joint along the side of the elbow. be sure to follow the imaginary center line of the arc of the elbow where the string inside the center of the runner would be. does this make sense?

 

Thanks everyone for the detailed responses.

I really like Speeddave's and weiRtech's suggestions.

I these methods would be more than sufficient for what I need.

I'm also curious, do you all make your runners out of 1.25" or 1.5"? I noticed that 1.5" 304 sch 10 90's are alot cheaper than 1.25" 304 sch 10 90's.

Thanks again for your time,
dk

 

Radius or diameter?

 

i used 1.5" diameter for my b-series topmount w/a hx35. i think 1.5" is pretty common for a bseries setup.