Pond Skipper

Update - I have sourced 1/2A pipes for $55 ea.

New PROFI Rambler .8cc tuned pipes

ALBERTO CABALLERO, FLA / USA
Ebay contact; speeddomingoe

Note the length is actually a hair bit under 9in . / 9.6mm OD up front and the stinger ended up at 6.8 mm OD

Mr Cox

You can't just resize the pipe like that...

The length would be about the same if you want about the same rpm. There are very few engines available that are timed for a pipe too. Apart from Fora or Profi I don't think there is anything available...

Pond Skipper

From MACS Products:

We resized one of our standard racing 3.5cc boat pipes to a 6 3/4" 2.8cc custom-racing
pipe.the head pipe (5/8" od) is about 1" long. The front
cone is about 2 5/8" long the high point is 1 1/4"od, the back cone is about
2 5/8 long and the stinger is about 1/2" long and is .333"id.

As an example Norvels, Cox and CS engines have been able to run on a pipe with an increase in rpm.
Other possible RC engines AP .06 , CS Sport .061.
Show me a 1/2A pipe design you think will work this thread needs positive information and solutions.
The header pipe can be used to adjust the length to suit whatever timing an engine has.
It may be dirty and not ideal but could add extra power or for some neat sounding muffler, exhaust
diverter.

Pond Skipper

Some adapted changes to suit using a pipe- first pic the sleeve was rotated and the back case drilled out for the exhaust.

Pond Skipper

Cox muffler unscrews into two parts the end was removed to use coupler




Aluminum header was fabricated.

Pond Skipper

https://www.youtube.com/watch?v=F6HqdIVUaTo

Pond Skipper

Spotted this post:

I have a throttled .061 norvel that I attached a cs/gz pipe to. I made a header pipe adapter on my lathe and I think I did a proper job on it. There are no leaks between it and the exhaust port. The engine is turning a ducted fan impeller in a little Kamdax Mig. With open exhaust and 40% nitro I was turning 23.3k rpm. When I added the pipe and did my tuning I got it up to 24.3k rpm

Pond Skipper

More info on the other thread...

http://www.rcgroups.com/forums/showthread.php?t=2391197

MJD

My Feedback: (1)

Just so I get it - each person pays the $37.50 once, plus pipe cost x number of pipes? So three 35 dollar pipes would be $142.40 + shipping?

aspeed

Just wonder if $150 an hour sounds reasonable to you. With a good print, someone may be able to make the tooling much cheaper. Maybe even freeish. My one lathe will not cut tapers, and the other Taig is kind of small to hold anything too big.

combatpigg

My Feedback: (3)

I'll bet Japanman [Stephan] built that....?

Pond Skipper

As an example (some variables)

The machine cost will be 37.50 per pipe for the first 8 pipes - then the pipe itself will be about 28 + shipping.
I know they sell the .10 to .15 pipe for 28 bucks as I bought one so playing it safe with the pipe cost.
I would think 65 / 70 total cost out the door - more that get in on this the price will drop"

This is the minimal order possible to make it remotely reasonable. If 16 pipes went on order 18.75 base price for tooling is now becoming very reasonable.

I know a new Russian 1/2A pipe goes for $95 plus shipping from very far away you can guess about 140 bucks for one pipe.

Pond Skipper

Ya if anyone knows a method to make them at a reasonable cost I am all ears.

Looking at my MACS pipe for the 10 to 15 size engines the stinger has thicker walls then the other end - you can tell they used Swaging machine.

The largest dia of the pipe is the constant the swaging machine spins both ends down to a given shape leaving circular marks on the metal
I had to use my buffing wheel to polish out the marks.

Cross Check

Hi All,

Back in the day when model mags had useful information, there were pipe dimensions for a TD.049.
American Aircraft Modeller, FF Duration section, mid 70s I'm guessing.
It was made of brass sheet and tube.

Mid 90s I was going to make one, but never made it past figuing out how to make a header that sealed one of the exhaust ports.

I remember it being small compared to 'other' pipes. Perhaps it was set up for 10 second FF runs?

Any estimates on what a pipe/header combo would weigh?

Take care,
Have fun,
Dave'crosscheck'Fallowfield
Maac 6437
Unabashed Combat Team

MJD

My Feedback: (1)

Dave - check this out.. recognize the engine?

https://www.youtube.com/watch?v=FOd2wrE0vP8

I'll scan Gene Hempel's article on his piped TD speed model and post it.

aspeed

My speed partner in crime used a TD with the blank cylinder carved out to a schnuerle configuration with a stack brazed on. It may have been Gene Hempel. Someone did the motor for him. He soldered up a brass pipe. I believe from my fading memory that it did slightly over 100 MPH, which was a record in this country at the time. I know it wore out quite fast, and he replaced the piston a couple of times, but it was finished fairly quickly. A couple methods of making pies are lathe spinning, which is done with a flat piece of soft aluminum that is spun and forced over a form with a hardwood stick that is lubed, or a roller. There are videos on Youtube showing this. It is a bit hard to get a long skinny taper for a pipe. Easier for a bowl. Tubing can be used. I tried it once, and could not hold it in the jaws without deforming and getting loose. It is hard to find thin wall tubing too. Another method is to turn a candle on a lathe, and lay up some fiberglass or carbon fiber with a high heat resin. There is always the mousse can. The F2D motors used a silicon muffler for a while. Kind of like a thick balloon. Another way is to use a grease gun and make an internal form to the shape desired. Flare the ends and pump it up until it fills the cavity. You would need to search for some thin wall tubing and likely soften it first. An extreme bulge may pose a problem. There may be some K&S tubing that could work?

MJD

My Feedback: (1)

This article mentioned 132 mph. And that the engine occasionally ate glow plug elements and scored itself up. Talk about a pile of work and the risk involved - holy technogeek sport! At least when off the shelf powerhouses aren't available as they are now.

Pond Skipper

Here a 1/2A pipe set up on the Norvel heli engine I have one of these lager fin types -heli engine as I recall made more rpm / ran thru a clutch and geared to the main rotor.

Pond Skipper

FYI

There is an article in the Aero Modeller annual 1968-69 on page 41 -42 for those that are interested .Results were between22,000 and 29,000 rpm .Also used front and rear intakes ( from Space Hopper ).The pipe was made from brass tube and .003 copper sheet .

Mr Cox

Do you have any experience yourself with a tuned pipe on an engine?

Pond Skipper

Yes I used them on planes and out rigger hydro's. 1 Pattern plane, 1 Speed plane and 2 hydro's. 25 to 40 size engines. I currently own 3 aluminum tuned pipes.
How about yourself Kris?

Mr Cox

Good to know, this doesn't show in any of your posts, that's why I'm asking. You also only show pictures and movies from other peoples work and it seems that you may have underestimated their efforts.

I have experience mostly with pipes on .10 -.15 engines. One thing that I have learnt is that there is no gain over an open exhaust, unless the engine is timed for it with a longer exhaust timing (>150°). So for our typical sport engines it is much better to use a muffler with a low internal reflection. This way you can get near open exhaust performance but with a very quiet, good throttling, engine. This can be done by using a header and an aftermarket muffler, from Merker for instance. On a stock OS .10FP this gives more power than with the Macs pipe and header.

Pond Skipper

This is a who wants 1/2A pipe thread I dont own one hence no photos of my own ~ do you want on the list?

MJD

My Feedback: (1)

On that subject I can tell you that I'm thinking about it PS, but have to consider what I really need them for. Very tempting, but I know I won't be modifying TD's, and I already have three Profis, one piped.

I am prone to temptation.. how does it go again..?

"And lead me into temptation, for verily I am a total sucker for cool shiny things that I think I might possibly use some day". Or something like that.

Pond Skipper

Yezzzah chance by a company who can math down a quality 1/2A pipe and willing to do so which is key.

Will be a reduced version of their 2.5cc pipe -