Help! oil pressure very low

[cletracboy]

Does anyone have any experiance or suggestions on my problem.  The oil pressure on my Oliver BD is very low when it gets hot, at half throttle it is on or around the needle rest, it only manages 15 - 20 when flatt out, I've tried adjusting the oil pressure, the guage seems ok it shows high when cold and drops as the oil thins.  Could it be the bigend or oil pump? I wanted to take it to a ploughing match next weekend

[Blake Malkamaki]

What weight of oil are you running?

My OC-12 acts the same way. My gramps said it was common for these engines to suffer low oil pressure. He said all you need is 5 psi for sufficient lubrication.

[cletracboy]

I'm using 30 weight oil.  Is that 5bar at tick over or with the engine revving hard, I'm planning to strip the  pump of the engine tommorow morning.  I figure if the bottom end was that worn it would be noisy and it isn't.

[cletracboy]

I've had the sump off now and the oil pump appears ok there is a lot of backlash on the gears, but the caseing isn't scorred or worn looking.  The bigend shells and the main bearings have some deep scores in them and they appear to be a red metal (looks like copper!) I would expect white metal?, so I dropped a shell out another BD I have and there the same colour.  Is this normal, did hercules use unusual materials in there shells and main bearings? can some one help!:(

[peter de vries]

I have many hercules bearings in the garage, both new and old. when new they have a thin coating of what appears to be whitemetal, but it is only very thin, and under that is the remainder of the babbit alloy which is a copper colour. I wouldn't be too worried about the odd  score, even if it is deep, rather the actual diameter of the bearing when it is in the rod or the main bearing housing and the diameter of the big end and main journals. these old motors can tolerate quite a bit of wear and still run quite acceptably. i have a dd and ddh that i was running yesterday and the dd runs at 60 psi cold and 25-30 psi hot at full rpm. at moderate speeds it sits around 15-20 psi and down to around 5 psi at hot idle. i have a feeling i may have a set of bd big end bearings in the shed thet are new( still in boxes). i will have a look tonight as they are no use to me but may be of use to you

[RLH]

I have some new bearings for for my bdh engine that I am rebuilding, I know the rod bearings have a copper look, not sure about the mains.
Randy:)