From:Mark Hill
Subject:RE: RE: RE: RE: RE: RE: RE: Shower Head Pic Date:Fri Mar 22 20:05:12 2013
Response to:4674

Oil pressure is a non-issue for us. The big boy KJ's that use the new crankshafts were drilled and modified exactly how Ian has described the mod he makes (late model Indian Four). We also left the tail hole open as it was originally. When starting some of the first of those engines up, we saw pressures on the gauge as high as 125 psi. No B.S. Actually, taming the oil pressure was a real problem. We used late model KJ pumps with restictor orifices. All of our bikes ran external filters. One or two oil filters were blown off the crimps and a hell of a mess was made on the shop floor before we tamed the pressure by drilling the orifice. The new crankshafts are fully cross drilled with four more orifices in them than the factory crankshafts had from day 1. The fabled brass restrictor jets(stock cranks) were never used either. That tiny wire EDMed orifice is miniscule in comparison to the spotty workmanship of the shim placement from the factory. If anything, the KJ's and probably the Deluxes are over pumped. Back to hydrodynamically floating the mainshaft, I am going to pressurize it. Half a dozen new special main shafts that are drilled and orificed providing lubrication are being gun drilled as I write this. I am going to float the shaft and it will be end of story(I hope)that part anyways. Careful attention was paid during the disassembly of key test engines and several of the pack engines survived with no wear whatsoever in the transmission area. The mods that we are making are for longevity, well beyond 4000 miles. You can not ask oil to find its way into randomly places oil holes in the plain bearing bushings with a centrificly rotating shaft that is trying to push it out just by the nature of the shaft turning. Look at the oil path of BMW's RR 1000 crankshaft it end oils rather than side oils like most everthing else on the street. You can spin a shaft so fast it will resist pressurized oil flow. Yah thats not our case here but we are working with random chaos that oil will want to enter one of those three holes in the spline shaft bearings. I am going to float it then loads can be calculated properly. I will post pics of the shafts and my mods when the shafts are ready. We are Gunning up for the next time if there is one . I love the look of demoralized H.D. riders.

If the standard Henderson pumps are set up with about .002 end clearance on the gears in the housing (including the gasket thickness) there is plenty of oil. Our .005 inch thick gasket requires that the gears protrude .003 above the surface of the pump body. Billk

I could have sworn I remember seeing a Henderson with a HD
type oil cooler mounted on it. Would be a simple enough
modification. I affixed a filter on mine but I doubt it adds
enough surface area to provide any effective cooling.

John,It seems even the smaller Delux pump produces enough
pressure and flow initially it,s the heat that needs
controlling to be able to supply the extra oiling needed in
Marks modification to make it successful.It would be
interesting to hear from some of the guys running external
oil filters with enough surface area or exposed tubing to
affect cooling if they have noted better viscosity in those
machines under the same conditions.Many questions?

Sounds like the next step is to upgrade the oil pump with a
spacer and some wider, re manufactured gears. Can only hope
to boost pressure though as the 3/8" tubing is only going to
flow so much oil.

Mark ,Have been following your progress on this immense
undertaking.The question comes to mind of what is the effect
of bleeding off the pressure in the crankshaft?particuliarly
in a motor at full operating temperature?I have found that
plugging the tailshaft and forcing the oil thru the side
hole as in the Indian engine will increase the viscocity and
length of time it takes to reduce it.but it does not
eliminate it and a pressure drop ensues when running the
type of miles you guys were running on the cannonball
particuliarly at high altitudes.It seems a transmission that
has enough oil mist and pressure to drive or pump the oil up
the shift tower to cause a leak should be sufficient to
lubricate the plain bronze bearings or in the case of the
cluster babbitt or aluminium of the Henderson.Short of a
modification to run a roller or ball bearing not sure if
there is a way out of this one.Looking forward to seeing
your mod on the mainshaft. Ian>>>>>>>>>>>>>


The Cannonball exposes weekness that can only be learned on
that type of brutal, non-stop competition. I watched three
of the Wolfpack Hendersons run wounded. Bramwell's was the
worst(he could only cruise about 75mph). Cutter, you got
the video that day in Iowa when we were smoking the entire
line of bikes. See if you can get it to Dave H. It would
be cool if he could add it as a link. It was great smoking
those HDs.

We had torn up some mainshafts on some of the bikes due to a
materials compatibility issue. During one of our gas
station engineering sessions, we began talking about taming
the Henderson transmission.

Our modern motorcycles and dirt bikes all shower and
pressurize the transmission. With the type of power we are
making now, and on long, sustained pulls, it became apparent
we were not cycling enough oil through the transmission.
This was probably partially due to the line boring process I
employed. The shims that I use between the bearing halves
get bored 360 degrees along with the bearings.

Originally the Henderson shims were not set up like this.
They stood back off the edges of the shafts which probably
allowed for some oil in the rear bearing to effectively
"puke" back around the small bevel gear (to use an
engineering term)- completely inadequate in its own design
as the lack of a 360 degree bearing is kicking the hell out
of the hydrodynamic lubrication of the shaft itself.

Discussion of our situation led to the topic of the late
model Indian Fours having a drilling off the pinion support
bearing, showering the bevel gears with a jet of oil (1940 -
1942). Yes, Barry, I updated your '36 to this spec. We
were pushing these bikes hard, and they let us know what
worked and what didn't.

It would be very difficult to achieve the Indian style
shower effect with a Henderson case due to the differences
in geometry of the saddle support of the case. Everyone was
in agreement that we needed to figure out how to get oil
from the tail stub of the crankshaft to the transmission.

Mike Fockler (#65) offered up one of the suggestions that we
think will yield big results. We would wire EDM, an oil
hole, through the pinion gear at an angle to provide a
shower effect to move more oil back to the transmission
area to cycle oil through the system. This gets us a shower
on the gears but it still does not address the lack of
hydrodynamic lubrication of the main shaft. Wait until you
see what we are doing with the main shaft.