How much volume is delivered by a "High Volume" oil pump?
How much volume is delivered by a "High Volume" oil pump?
(OP)
I am building a 1.8L motor with many new mods that require extra oil (Turbo, lifter spray bar) and I am trying to decide if my pump can deliver enough volume to do the job. What I am looking for are some benchmark numbers (Gpm,Lpm,...) . The words "High Volume Pump" are so often thrown around in the V8 world, but what does it really mean? What kind of volume are we talking about? I have looked everywhere for oil pump performance numbers, but with no luck. Obviously every motor has different requirements, but I am curious to know where my 4 banger oil pump stands relative to a V8's.
Thanks
Thanks





RE: How much volume is delivered by a "High Volume" oil pump?
Oil pumps are oversized so that they put out more flow than the engine requires under most conditions. The excess flow is bypassed by the relief valve, otherwise the pressure would be excessive. It is possible that your pump could work as is with the engine modifications. If it produces rated pressure with hot oil, it is probably ok. If the pressure does not come up to rated, or if it is really low at idle, then you would need a larger pump. Note that if the pressure does not come up to the rated value, shimming the relief valve spring is not going to do any good since the relief valve is not opening. The additional downstream flow paths would not be offering enough resistance to build up the pressure.
I don't know if this is making any sense. You are looking for some actual numbers so hopefully someone else will reply.
John Woodward
RE: How much volume is delivered by a "High Volume" oil pump?
Oil squirters usually have a ball and spring check valve located inside each squirter. A typical release pressure might be around 30psi, so if idling oil pressure drops below that, the squirters each shut themselves off.
Turbos can vary quite a lot, but the old sleeve bearing Garretts have two approximately 1mm metering holes in the thrust bearing which allows typically around half a gallon per minute of oil flow at typical full (hot) oil pressure. These old turbos use the oil to cool the turbo, so that amount of flow is required.
Modern water cooled ball bearing turbos typically have a single restrictor of around 1mm. I have never seen a specification for oil flow, but a wild guess might be around one litre per minute.
The standard oil pump in the stock engine should give you a rough idea of what you need, and then increase the capacity to feed the extra goodies you plan to add.
It really comes down to your planned idle speed, and minimum oil pressure at that speed. If you are building a racing engine with a planned 1200 Rpm idle, the stock pump might work fine. If it is a road car with twin turbos and 600Rpm idle, a larger volume pump might be a very good idea.
RE: How much volume is delivered by a "High Volume" oil pump?
RE: How much volume is delivered by a "High Volume" oil pump?
Better fuel economy, more power, lower oil temps---seems like what the hot rodders were doing 40 years ago.
Rod
RE: How much volume is delivered by a "High Volume" oil pump?