Author Topic: Rocker oil feed on OHV  (Read 4820 times)

0 Members and 1 Guest are viewing this topic.

Offline Ian

  • Master Member
  • ****
  • Join Date: Jul 2004
  • Posts: 1287
  • Location: The Oaks, NSW, Australia
Rocker oil feed on OHV
« on: 07 Jun 2005 at 06:57 »
My OC600 motor had its first run on the test bench on Sunday - sounds fantastic (no pipes fitted yet !!). One question I have is how the oil feed to the rockers should be set up. It has the alloy reservoirs which are presumably filled with oil - but should there be felt wicks or something in there to stop oversupply ? Also what thickness oil should be used ?

Offline Doug

  • Administrator
  • ****
  • Join Date: Mar 2004
  • Posts: 4315
  • Location: Glen Mills, PA, USA
Rocker oil feed on OHV
« Reply #1 on: 08 Jun 2005 at 01:35 »
Ian,

There should be wicks installed. They work on capillary action, not as restrictors, so the end down in the rocker spindle needs to be lower than the end in the reservoir.  They do not use oil, this would wick at all times till the reservoir was empty regardless if the engine was in use or not.  Rather they used grease, once the heat from the cylinder head got to it would start to wick.  Obviously you do not want to use modern high temperature grease; it would rather defeat the function!  There should be grease fittings fitted to the tops of the reservoirs to replenish the supply.  

Douglas specified using the same grease gun as applied to the fork links, the hubs, gearbox, clutch thrust bearing, etc.  This was called out as Castrol X.L. “…twelve turns every 500 miles.”  Probably the same benefit as for the gearbox would apply to the rockers, and that is to cut the grease with some 600W oil to make the grease just barely ‘self-leveling’.  This would ensure more reliable lubrication without the containment problems of going with straight oil.  

I use pipe cleaners for oil cups on old metal working machinery and will probably do so my DT/SW rockers.  When Douglas went to the fully enclosed o.h.v. in about 1931, they dispensed with the reservoirs and just had straight pressure grease fittings feeding to the rockers spindles.  On my 1934 I would give it a shot every time I took it out whether it needed it or not.

-Doug

Offline Ian

  • Master Member
  • ****
  • Join Date: Jul 2004
  • Posts: 1287
  • Location: The Oaks, NSW, Australia
Rocker oil feed on OHV
« Reply #2 on: 08 Jun 2005 at 03:13 »
Thanks Doug. Would semi-fluid grease be still too runny do you think ?

Offline Doug

  • Administrator
  • ****
  • Join Date: Mar 2004
  • Posts: 4315
  • Location: Glen Mills, PA, USA
Rocker oil feed on OHV
« Reply #3 on: 08 Jun 2005 at 12:30 »
Quote from: "Ian"
Would semi-fluid grease be still too runny do you think ?


It will probably be fine, that is basically what mixing wheel bearing grease and 600W gear oil will give you.  Just so long as it gets runny when hot!  The "groil" I mix for use in vintage Dougie transmissions will just barely pour; or a index viscosity of five.  If you drag a index finger through the surface at room temperature it takes about five minutes to level out!   :)

-Doug