new gas pipes under construction

[Jim Allen]

The posted photos are of two new gas pipes for 27 cc & 35 cc engines under construction. Some sections are rolled from .018" sheet steel & some are machined from steel tubes. Tapered sections are generated from a computer program, spot welded & then silver soldered. All sections are silver solder in the final assembly making disassembly for modifications possible.

Jim Allen

 

[john bass]

Mr Allen...I am not having good luck in my quest to fabricate the new pipe.....I will call you later and see if i can get one of yours for my new 35cc zenoah....I hope that you can part with one for me....cost is not a factor...thanks

 

[Jim Allen]

John,

I sent you an email because the phone is not working. The slip roller we talked about is still available, but the price is much higher for the exact same model I purchased several years ago.

Precision Slip Roller

The Precision Roller, a long time favorite of the Accucutter® product line, has been significantly upgraded. The rollers are now manufactured from precision ground and polished tool steel, and the gears have been strengthened and fully enclosed for safety. Wire grooves have been added, and convenience items have been incorporated like easy to use knurled knob adjustment screws and a handle to assist in lifting the movable top roller. Stainless steel rollers are available as an option.

The Precision Roller is used to form metal into an infinite variety of rolled shapes. By adjusting its three rollers, different shapes may be made and different thickness materials may be used. The Precision Rollerhas many applications in making custom awards and trophies as well as other industries.

Accucutter® also offers a dedicated Column Maker. Before extruded column blanks, trophy makers formed the columns for their trophies. Many used Accucutter®'s Column Maker. It is an inexpensive, easy to use device that enables you to accurately and repetitively form columns. Five formers are available to make round columns. The material opening is 12" wide. Now the Column Maker is used primarily for special projects, repair of older trophies, and scroll making. The base and formers are purchased separately.

Operator's Manual
An Operator’s Manual is included with the PR12W. A copy of Accucutter®'s "Guide to Basic Trophy Forms" is included with the Column Maker.

PR12W Capacity:
Maximum material thickness is .040". Recommended capacities are: Aluminum - .040"; Half Hard Brass - .030"; and Mild Steel - .020". The wire grooves are for the following wire sizes: .063", .125", and .156"

Column Maker Capacity:
Maximum material thickness is .040". Recommended capacities are: Aluminum - .025"; Half Hard Brass - .020"; and Brass Plated Steel - .015".

Size & Weight:
· Size: 23"L x 6"W x 7"H
· Roller Size: PR12W - 1" Diameter
· Weight: PR12W - 18 lbs.; Column Maker - 10 lbs.

Availability & Ordering
Please check for current availability and delivery. At the time of ordering the Column Maker it is necessary to specify which former or formers you prefer.

Model PR12W, $435.00
Column Maker & Formers, Call

 

[john bass]

thanks Jim...I have been looking online for this company...do you have a phone contact for Accucutter???

 

[john bass]

I have also seen one made in China for less than 200.00 but I am sure the quality is not as good as a 500.00 tool...but do you think that the less expensive tool will work for what i am trying to do??

 

[john bass]

found the company and ordered the tool 3 week wait though ....thanks for all your help

 

[Terry Keeley]

Incredible work as always Jim!

 

[Jim Allen]

Some more photos of what is done to make a tuned pipe. Tapered sections come from computer generated pieces that are printed out to size. They are then glued to heavy paper, cut & then transferred to the .018" thick cold rolled sheet steel. A slip roller is used to roll the tapered sections. I use a shear to cut straight lines & metal snips to cut curved lines. 050" extra material is added where any straight line joint or curved section is to be spot welded with a Miller resistance welder before silver soldering.

JA

 

[Wally Duarte]

Looking great Jim !

 

[Jim Allen]

Both tuned pipes in the photo would measure the same length from the side of the piston to the end of the flat section. However their tuned lengths are not the same because the tuned length is measured from the piston face to half of the entire length of the baffle cone. They also have very different total volumes which will determine the maximum length & inside diameter of the stinger section. Stinger length & inside diameter will effect the engines operating temperature. Different baffle cone angles not only effect the total volume of a chamber, but they effect the width & amount of power boost obtainable. Notice that the unpainted chamber does not have a flat flex section in its diffuser, but is tapered from its connection point at the engines header pipe.

Jim Allen

 

[Mike Whitney]

Next level stuff as always. Good job, anxious to see real world results.

 

[Tom Foley]

Some more photos of what is done to make a tuned pipe. Tapered sections come from computer generated pieces that are printed out to size. They are then glued to heavy paper, cut & then transferred to the .018" thick cold rolled sheet steel. A slip roller is used to roll the tapered sections. I use a shear to cut straight lines & metal snips to cut curved lines. 050" extra material is added where any straight line joint or curved section is to be spot welded with a Miller resistance welder before silver soldering.[/size]

JA[/size]

Old world craftsmanship from cradle to grave on the part !Keep up the good work !

 

[Jim Allen]

This is what one of the finished chambers looks like. It will be used in a mono hull with a 35 cc engine by Performance Unlimited. The photo does not show the tuned pipe at its running tuned length! This chamber has two sections in the diffuser compared to three in the latest chambers shown.

JA

 

[Jim Allen]

The type of simple fixture shown allows not only straight section ID's but also tapered section ID's to be easily machined to the exact length needed. It is held in a collet & repeats within .0005". Tapered sections are then mounted on a tapered mandrel for OD machining. Stinger & head pipe sections are typically .040" thick while other sections in the pipe are .018" to .020" thick. Thick walled, A 513 - type 5 steel tubing DOM (drawn over mandrel), can be purchased in 12" lengths from OnlineMetals.com. The carbon steel tubes have a uniform grain structure which is a seamless consistent structure. They also come in various OD & ID combinations & make it easy to machine any tapered section if the beginning ID & the ending OD are known. A 513 DOM steel tubing welds & silver solders extremely well.

JA

 

[Jim Allen]

Tuned pipe construction continues with the use of the fixture shown in post #5. The completed pipe shown mounted between centers was silver soldered with Aufhauser Silver Alloy #45 & Nokrode Black soldering flux. Mounting the pipe sections between centers, with interlocking sections, gives a chamber that is straight & true. This flux works with all metals, except aluminum, at both low & high temperatures, (1000* F to 1700* F) without glazing. The paste should be brushed on all areas adjacent to the soldering joint as well as the joint area. After soldering, any flux residue left can be washed off in hot water with a steel wire brush. I clean the inside of the pipe by sand blasting & washing with hot water. In the photo, the center section is made of A 315 Type 5 DOM steel & both ends are # 303 stainless steel. Notice how smooth the silver solder has flowed over both pieces. White silver soldering fluxes will not give this result!

Jim Allen

 

[Jim Allen]

This is part of the four section diffuser being built. The diffuser will be tapered from the engines exhaust window to the mid-section. There is also a possibility that the baffle cone will have two angles. The section's tapered ID is machined first, then the OD. A .010" deep X .050" wide relief is cut into the OD at both ends before parting off. Matching diffuser & baffle sections also have a similar relief cut into their ID's. This allows the entire chamber to be assembled between centers before silver soldering because all the pieces interlock. Since the wall thickness of any section is .020" to .022", the thickness of any relief area is .010" to "011" thick. This would at first appear to be a weakened area, however silver soldering make these joints as strong as any other part of the tuned pipe.

Jim Allen

 

[Jim Allen]

The photo shows the next section of the diffuser before it is parted off. A .010" deep X .050" long undercut will be machined before the piece is parted off. One more section after this & the chamber will be ready for silver soldering. Notice the heavy, water soaked brown rapping paper inserted "tightly" inside when machining the OD. It changes the chatter frequency & allows the piece to be machined down to a .022" thick wall without any chatter.

Jim Allen

 

[Jim Allen]

Machining of the third section's ID is done with a 3/4" X 10" boring bar. This section has the same .010" deep X .050" wide relief inside to enable interlocking with its mating second section. The OD is machined by mounting the piece between centers because of it's long length (4.100"). After final machining all pieces are shown interlocked for easy silver soldering. Next comes the all steel header & its 5/16" thick steel mounting flange, which are also silver soldered together. No type of rubber "O" ring or gasket is used between the engine's crankcase & the steel mounting flange. There is no leakage at this point!

Jim Allen

 

[BobHorowitz]

Jim,

I like your technique of packing the ID with wet paper. I bet that works really well. I often use rags myself. Rubber bands on ODs. One thing that surprises me though, is your use of a piston type tool post as opposed to a wedge lock Aloris type. I picked up a piston lock many years ago and I was never happy with it.

Regards,

Bob

 

[Jim Allen]

Bob

Either heavy wet paper or a wet shop towel seem to work well when packed tightly. I use tightly wrapped 1/8" thick X 1/2" wide X 12" long silicone rubber strips in place of rubber bands, when necessary, on thin walled ID turning. I've used both types of tool post as well as the old four way types. All perform well providing the clamping areas are kept clean.

The final header section, which is also tapered, is being test fitted before final silver soldering. A special aluminum cradle, with clamping device, will be mounted beneath the mid section of the pipe. It will have a soft neoprene rubber nest for the mid section of the pipe to rest in. Several different length center sections have been machined to allow tuning of the tuned length without shortening of the head pipe area.

JA