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More shop work

Started by playdiesel, August 02, 2020, 06:08:53 AM

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playdiesel

#15
A weekness in any twin is the #2 pump cam has zero lubrication. This is not strictly an India problem, Listers have the same issue that must be addressed in work engines. There are several ways to do it, this is how I fix them. I drill a 1/16" hole through the rotation stop screw. Then drill deep enough to tap at 1/8"npt and add fittings and valves as shown. The feed line valve is only slightly opened. Also shown is a pressure gauge and snubber valve. The oil pressure pulses with pump operation and is very hard on guages. I use a needle valve to snub the pulses and a quality liquid filled guage. However a person could get by with a cheap guage and a ball valve. Once the operator has verified oil pressure at start up he then isolates the guage with the valve.  There are many variations of the top plug in the pump, some are blank. I drill and tap the blank plugs to a 1/4"NPT , The ones with the additional plug such as the one pictured are drilled out to accept a 3/8" NPT tap and then bushed down to 1/4
Fume and smoke addict
electricly illiterate

playdiesel

The oil inlet screen,, more reasons to assume nothing with a Listeroid .
Fume and smoke addict
electricly illiterate

Henry W

#17
 :o ::) Wow! That picture definitely enforces the reasoning to tear an engine apart if your not sure of the condition of the engine from sitting outdoors all those years.

BruceM

Cam failures were not uncommonly reported on India twins and some originals.  Do you think that was due to cam shaft warping from cam pin installs with resulting stresses, or some other cause? 

I love this simple fix for the twin dry cam.


playdiesel

The cam drive on a twin is identical to a single and has  over double the loading and twice as many lash reversals every revolution, short life should be expected I think? The camhaft is the same diameter, operating twice as many valves, twice as many fuel pumps AND driving the oil pump. I have no means to measure torsion but can offer a guess, Lots. On paper I have designed a single cog belt drive for singles and dual cog belt drive for  twins but it will likely never see the light of day due to lack of engines that actually get a lot of hours on them.
Fume and smoke addict
electricly illiterate

playdiesel

Stacking a twin Listeroid is complicated by loose fits and tolerances. If not down right You will have leaks and can also break the manifolds. After squish is set and before the heads are torqued down I install the water manifolds and just snug the nuts. You want them to hold the cylinders square let allow some up and down movement as the heads are torqued. You must torque both heads in sequence I start at 25 ft lbs and every 25 to 150 on the four big studs.
Fume and smoke addict
electricly illiterate