Author Topic: SRM recommends monograde?  (Read 2747 times)

Offline wilko

  • Resident Legend
  • *****
  • Join Date: Mar 2010
  • Posts: 681
  • Karma: 4
Re: SRM recommends monograde?
« Reply #15 on: 04.05. 2012 23:15 »
I drove an old Mk7 Jaguar across the Nullabor on  sump oil from garages all the way.It held 22 pints and burnt it all each fuel stop! Epic trip! I left with 50 bucks from Melbourne and ran out of money in Coolgardie!

Online muskrat

  • Global Moderator
  • Wise & Enlightened
  • **
  • Join Date: Jul 2009
  • Posts: 8924
  • Karma: 113
  • Lithgow NSW Oz
    • Shoalhaven Classic Motorcycle Club Inc
Re: SRM recommends monograde?
« Reply #16 on: 05.05. 2012 02:02 »
 Ha, when I sold my A65L to a mate in QLD he also took my HQ 1 tonner with a blown 308. It used 13 gal of oil from here to Brisy. *eek*
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
Muskys Plunger A7

Offline Rocket Racer

  • Wise & Enlightened
  • *
  • Join Date: Jun 2009
  • Posts: 1546
  • Karma: 16
  • A kiwi with a racing A10 rig and too many projects
    • NZ Classic Sidecar Racing
Re: SRM recommends monograde?
« Reply #17 on: 05.05. 2012 02:43 »
My 10 cents worth
In my race A10 engine I run morris castor, which is a straight 40. However I personally wouldnt ever run a straight 50 in a plain bearing crank motor. Straight 50 doesnt like colder climates and gets very thick in the mornings, so cant imagine it being kind to plain bush bearings at start up. It is however perfect for the B series which have heavy duty roller big ends and rely on splash. The straight oil is reputed to support the roller faces from scuffing.
I see nothing wrong for monograde 30 or 40 IF its changed each season.
If I lived somewhere very hot (I don't) I might have a different view.
The converted SRM engines are a bit different as the timing bearing is both non bush and pressure fed.
Got to compare apples with apples -climate/seasons, frequency of change, filtration, nature of use (long runs, pottering, racing).
In a road A engine I would use a multigrade 20/50 with a cartridge filter, whereas my B is on monograde 50 with no addition filtration.
A good rider periodically checks all nuts and bolts with a spanner to see that they are tight - Instruction Manual for BSA B series, p46, para 2.
New Zealand