Salisbury Power Pipes
EQ 7000
Designed for 60cc through to 74cc engines
EQ 6000
Designed for 55cc through to 65cc engines, and to sleeve over the header
silicon.
EQ 5000
As per EQ 7000, for engines of 40cc to 55cc.
These pipes are similar to our very popular pattern range of EQ (Extra Quiet) pipes. The pipes have high torque characteristics, making for superb performance at low rpm (say 6,500 to 7,500) and very low noise levels.
All Salisbury EQ Series Pipes have an optimum 'operating length'. This length is
quoted as a distance in mm from the exhaust (piston face) via any curves in the
alloy header pipe to the first baffle inside the pipe. The system's length is
varied by shortening the header (preferred as it is heavier than the C/F), or
lengthened by adding a spacer to the system... usually by inserting a length of
header cut-off, inside a longer piece of silicon
To find the pipe's first baffle, insert a rod inside the pipe until it contacts the baffle. Mark it's position on the outside of the pipe. .... Caution.... the first baffle has a hole in the centre, double check that you haven't found the second baffle.
The EQ-6000 uses a different system where the silicon is sleeved over the header, and the neck of the pipe then goes over the silicon. Use 2 metal hose clamps to secure. Depending on the header diameter, the silicon may require careful sanding (on the OD) to find the correct diameter. This system is cooler and lessens vibration levels.
This pipe / muffler should be rubber mounted at or near its C of G. Excessive heat and vibration are the biggest destroyers of exhaust systems (metal or composite).We use the Bolly 'Tuned Pipe Mount' combined with a Iso-Mount & a cable tie for the rearward attachment.
These pipes will work at any reasonable length, however only trial and error will find the best combination of pipe length, prop size, head clearance and fuel etc. Below are the recommended lengths from our development testing. Use only as a guide as there are literally thousands of possible combinations.
60 74cc engines EQ 7000 @ 750mm - Bolly 24 x 12 or 22 x 12 3B 7000 rpm
55 65cc engines EQ 6000 @ 730mm - Bolly 22 x 12 or 21 x 13 3B 7300 rpm
40 55cc engines EQ 5000 @ 710mm - Bolly 21 x 12 or 20 x 12 3B 7600 rpm
Low rpm = longer pipe ; Higher rpm = shorter pipe. When in doubt, use the pipe long. It is a safer option than being too short.
Pipe too short: = frequent blowing of plugs Pipe too long: = prone to burbling rich running
= overheating engine = low power, low noise levels
= sags under load - ie in climbs
= harsh and / or lean running despite taking off with a good needle setting.
Please note: The symptoms of being too short may also occur if the engine is over compressed (often the case when using a pipe on an engine not specifically designed for pipe use) ..... Using a pipe will increase the effective compression ratio of an engine. (as will adding more nitro to the fuel). Add a .1 to .2mm shim under the head to decrease the compression.
Beware: We have found that some of the larger 2 stoke engines have very low exhaust timing (below 145 degrees), and do not respond as they should on a pipe. If the engine is too low on exhaust timing, the pipe may cause poor throttle response or even inhibit the engine performance. Such engines will usually go rich with throttle transition from idle to full power. In these cases, use a very long pipe (it will now act like a muffler) and a hot plug.
Caution: Petrol / spark ignition engines run much hotter than methanol versions. Engine, header and pipe cooling are very important. The silicon joiner provided will suffer if a petrol spark engine is run hot (ie too lean) or when stressed (bent). Large single cylinder engines are often suffer severe vibration, hence careful pipe and engine mounting is paramount.