Making Tuned Pipes...

[oldlugs]

Hey gang, while thinking of fun projects to do with my new little toy lathe, I thought I'd make some .21 size tuned pipes and have a local guy weld up the cones for me. I'll probably make copies of the "shorty" Irwin pipe I have (at least I'll give it a try).

Will 6061 alloy work OK for a pipe?

Thanks, Duane

 

[Ray Sametz]

Duane, 6061 worked for me, wall thickness .050. Takes time from billet stock. Finding a good welder was hardest problem. Are you making copies or designing new. Ray B) B)

 

[oldlugs]

Ray, I thought I'd start with a good working pipe, and just make a copy for now. I really don't know enough yet to design.

Cheers, Duane

 

[Ken Retallick]

If you can get some 6262 it machines way better than 6061,

almost as good as 2011, but 6262 can be welded.

 

[Ron Jefferson]

Best place I've found for welding alluminum is a local radiator shop. Look for someone that specializes in race car rads. In a lot of cases they are custom fabricated and a guy that's building and welding rads all day usually can lay a real nice weld on a tuned pipe. Just a suggestion.

Ron

 

[jetpack]

Have you thought about carving or shaping one out of a wax candle and wrapping it in CF tow strands and hi-temp epoxy? Then all you do is boil it in water to melt the wax out. Wax is easy to work with. If you want to make more than one, make a plaster cast of the candle first, then go to town.

If you're looking for small lathe work, I have a bunch. LOL. How about making me a couple Aeromarine Flex Couplers with special pilot diameters. The only hard part is dialing in the ID threads so the pilot runs true. I have a couple old Webra marine flywheels that need them to run safely. I have no idea what Webra was thinking when they designed it, other than having their own special coupler or universal to go with it (which I have never seen). Actually, I could get away cheaper by using a smaller pilot and using a bushing to reach the flywheel bore, but it would have to be a special bushing/washer ring. A collar I guess you would call it.

 

[oldlugs]

Have you thought about carving or shaping one out of a wax candle and wrapping it in CF tow strands and hi-temp epoxy?...

Dave, I have thought about it... But I haven't researched materials yet. Do you know what resin to use?

Duane

P.S.- I've got as much lathe work as I can handle, just doing my own toys...

 

[RIGGERMORTISE]

Have you thought about carving or shaping one out of a wax candle and wrapping it in CF tow strands and hi-temp epoxy? Then all you do is boil it in water to melt the wax out. Wax is easy to work with. If you want to make more than one, make a plaster cast of the candle first, then go to town.

Good luck finding the right temp epoxy! Would be cheaper to buy one. Needs to be over 200f! and very hard. The wax system works very well for one off protot pipes.

regards

Dave

 

[tnrcboatracer]

To work at teh temps for a pipe, the epoxy would have to be a post cure type. You could use a eutectic metal for the mandrel, and melt it out at the last stage of the post cure. By the time you have all that invested, it would be cheaper to buy one of the SPP pipes.

 

[Jim Allen]

There are several good methods that can be used to make custom tuned pipes. They can be rolled from sheet steel, machined from steel & aluminum bar stock, nickel plated over an aluminum mandrel, spun or vacuum bagged over a teflon mold.

Of the methods listed, I have found the easiest to be, the rolling of the tapered sections, by hand. Sheet steel, in a thickness of .015 to .020 can be easily used, with the head pipe & stinger sections machined. A. Grahan Bell's, Two-Stroke Performance Tuning, second edition, pages 102 to 107 gives an easy to understand method that can be used to calculate the length & two IDs of any section. Sample pieces can be cut from stiff paper & taped together to ensure correctness.

For those wishing to build carbon fiber pipes, vacuum bagging over a two part teflon mold & then joining the two pieces is possible. Two high temperature resin systems that can be used are bismaleimide & cynate esters. Cynate esters are easy to use because of their low viscosity & their low working temperatures. They are four times more expensive than bismaleimide resins & would typically cost about $100.00/lb. Transition temperatures greater than 550 deg F are possible with this resin system. One problem found in sample pipes was maintaining a bond between the aluminum insert in the head pipe & its outer carbon fiber wall. An accurate temperature controlled oven will be necessary because of the multiple number of cure cycles required.

Jim

 

[Joe_Knesek]

This will work for carbon pipes.

 

[Jim Allen]

This will work for carbon pipes.

Polyimide resin systems certainly can be used, but not for vacuum bagged layups, since their cure cycle temperature is in excess of 600 deg F. The cynate ester resin's cure cycle begins at 200 deg F.

Jim

 

[Muddy]

Hi All,

I had a good mate of mine build me a pipe for my Chainsaw powered Top Fuel Rail (1/5th scale)

We used for the 2 x cone sections Lithographic plate (thin aluminium) for the mid section - wait for it - a beer can!!

And the stinger - an Air Conditioning fitting (automotive)

All joined together with plasterer's mesh tape and Devcon as the glue

You can play Baseball with the pipe, and it weighs bugger all

I used a poulon 44cc chainsaw engine - good for 8,000 rpm or so

New pipe should give me 16,000 rpm

Now it's a Grenade

 

[Joe_Knesek]

This will work for carbon pipes.

Polyimide resin systems certainly can be used, but not for vacuum bagged layups, since their cure cycle temperature is in excess of 600 deg F. The cynate ester resin's cure cycle begins at 200 deg F.

Jim

I would use high temp heat shrinkable tape instead of vacuum bagging.