Oil Pump

[Matt306]

I have replaced the bearing mains and Big ends on my Herald. Pressure when cold has risen, when hot though its not much better than before.

I took the oil pump to bits when the sump was off, the rotors were within tolerance but there had certainly been swarf through the pump as it was marked. I lightly rubbed it down and replaced. I think this was a mistake.

Looking at oil pumps for the herald like at rimmers https://www.rimmerbros.co.uk/Item--i-GLP145 mine doesnt look like that its a long tube with no gauze on the pickup. http://www.mevspares.co.uk/OIL-PUMP-Triumph-Herald-1959-71.html  Canleys has a bent pipe illustrated on there pump mine isnt bent. None of the pumps at Paddocks have straight pipes with no gauze over the pick up.

Has anyone any knowledge of this type of pump?

[JumpingFrog]

The long straight pipe, no strainer pump is the type I've found fitted to most of the Herald engines I've seen. More than likely the straight pickup with gauze is the type usually fitted to later 1500 engines, they do fit... But be careful as for me the pump body fouled slightly on the block (preventing the pump from seating), only a few strokes of a file to fix though.

The 1500 oil pump also has a bigger rotor (as pictured). I'm pretty sure the angled pipe was initially fitted but later switched over to the straight pipe pump, the angled pipe perhaps has issues with starvation on long descents? The reproduction pump bodies aren't meant to be the best in terms of tolerance. I've seen it mentioned somewhere that buying new rotor kits (only available for the 1500 oil pump AFAIK) and fitting to an old body can give better tolerances... The 1500 pumps usually have alloy bodies, which coupled with a steel rotor will increase the clearance when hot, reducing oil pressure, so clearances on the low side are recommended.

[nang]

I note you replaced bearing shells but did you have the crankshaft measured ? If the shaft is worn oval the oil pump won't help increase oil pressure. Sorry.
Tony.

[Clive]

I can't remember, so apologies if mentioned earlier.
Have you checked the pressure relief valve is seated correctly?
What oil are you using?

And what pressure are you getting when running at 2-3000rpm (ish) and idle, hot and cold

I have not had any issues with used 1500 pumps, they are indeed a higher capacity type, so preferable. Though I have also heard they are often out of tolerance when out the box..... A good used one may be a better bet.

[Matt306]

Didnt measure the crank, as i have a 1600 engine to replace the 4pot lump. I need to refurb and rebuild this one so the change of bearing is a quickish fix.


Getting 50 PSI at 3000 RPM so not worried at speed.