1/25 scale Transtar 4300 exhaust: Part 1 - pipe from engine to back of cab

Kit supplied parts don't always work for exhaust system components...especially when you mix-n'-match parts between kits such as I have done with projects using a Cummins, taken from a AMT White Road Boss kit, to replace stock Transtar 4300 kit's International V800.

0:34 One thing I like to do is drill centre of turbocharger to take a 1/16" dia. (1.5 mm) brass wire pin. This provides a stronger connection when exhaust pipe is glued in place, and consistent alignment for test-fitting during assembly.

0:50 Suitable exhaust pipe material can come from a variety of sources. Over the years I have bought a number of Revell's "snap kit" Peterbilt 359's and Kenworth W900 Aerodynes for use as parts kits. A lot of good parts can be found in these kits...

1:04...for exhaust systems the stacks offer 90 degree elbows at the bottom and a long straight pipe at the top, both solid rather than hollow.

1:20 This pipe is essentially 3/16" diameter (.188" or 4.75 mm) styrene rod and long enough to be quite useful for bending up your own exhaust pipe.

1:35 At first the task of getting the long straight pipe to fit between turbocharger, along frame, and under the cab may seem difficult but it is actually quite easy to do...

1:45...with a little bit of heat. A small votive candle, in addition to making the workshop smell nice, has the safety feature of glass jar to prevent tipping and contain the melted wax. Getting the "pipe" to bend properly does require a bit of trial and error, practice with parts runner material from kits is helpful to develop a "feel" for the process.

2:03 If required, small adjustments can be done after the the bends are made by re-heating the required area. It is important to use solid rod for this heating-and-bending process as tube will collapse if the heating-and-bending approach is tried. Two stack pipes were used to make the pipe from engine to back of cab with joint drilled and pinned with 1/16" brass rod.

2:30 A easy detail to add to any truck exhaust system is clamp where pipe attaches to turbocharger.

2:42 This is basically a metal band with bolt at bottom to lighten it.

2:55 In model form it can be represented by taking a piece of aluminum tube that fits over exhaust pipe (in this example, 7/32" or .218", 5.5 mm in metric) and cutting a piece .060" (1.5 mm) long. Two pieces of .040" (1.0 mm) diameter styrene rod are used for the bolted connection at bottom.

3:12 Glue the rods to tube, then use a bolt head casting with some of the shank left on the represent projecting thread. Glue a short piece of the same bolt head casting shank material between the two styrene rods to fill in the area and look like the rest of threaded fastener.

3:30 With a coat of silver paint, this small "clamp" is convincing enough for scale model purposes.

3:40 Slip this clamp onto exhaust pipe before gluing the pipe to turbocharger, remembering to locate "bolt" so that a 1/25 scale mechanic would be able to reach it.

That completes "Part 1". Next instalment will cover the exhaust stack and brackets.

#scalemodelling
#scalemodeltrucks
#modeltrucks
#modeltruck