Elan Sprint oil Pressure

[rgh0]

You need to raise or lower the engine with the jack to get the pump to clear the chassis flange

cheers
Rohan

[512BB]

I tried that not that long ago. It was impossible to either raise the engine high enough or lower it enough to get the pump out.

Leslie

[alan.barker]

Well same result as last time when this subject came up " entente cordial" mon ami.
Alan

[promotor]

Hi,

I took a car out for a test drive on the weekend and the oil pressure was showing at around 65 when driving. I believe the norm is only around 40 so I was just wondering if 65 is acceptable?

If not, what should I look for as the cause?

Thanks

Chris

65psi isn't unusual for a high pressure pump.

I've just had an engine dyno'd and the oil pressure was reading 30psi with hot oil @ an idle of 1000RPM and 70psi above approx 1500rpm with both hot and cold oil. This was on an original genuine Ford pump with an uprated oil pressure relief valve spring fitted. I fitted a high pressure one as I just wanted to be sure of getting more than adequate oil pressure on the new engine. Now that I know the engine is good and the oil pressure is decent at low revs (ie 1000rpm) a standard oil pump should also return similar psi on hot oil.
Once it's done some run-in miles I expect pressure might drop to 25psi at idle regardless of the type of pump fitted which is still extremely good.
Both standard and high pressure pumps will make similar pressure at idle - the difference in pressure will be from around 1200-1500rpm upwards.

As mentioned 65psi isn't really required - a maximum of 35-40psi is more than adequate providing you are getting at least 15psi with hot oil at idle.
If fitting an uprated pump it's better to fit a standard pressure high capacity pump IMHO rather than a high pressure one.
The higher the oil pressure the more load is put on the jackshaft and oil pump skew gears so a happy medium is the best approach.

[alan.barker]

On a Cortina Twincam i had a high capacity/flow rate Pump
Alan

[promotor]

On a Cortina Twincam i had a high capacity/flow rate Pump
Alan

Hi Alan,

I hope you are well.

I remember having a high pressure & high capacity one on my mk2 cortina (1500 but not a twincam!) - the longer pump end plate of the high capacity unit hit the chassis rail when I wanted to remove the pump. I had to remove the endplate and outer rotor to give me enough room to take the pump out! I was miffed but I suppose I'd got off lightly compared to those with an Elan who want to remove even a standard pump!

[alan.barker]

On a Cortina Twincam i had a high capacity/flow rate Pump
Alan

Hi Alan,

I hope you are well.

I remember having a high pressure & high capacity one on my mk2 cortina (1500 but not a twincam!) - the longer pump end plate of the high capacity unit hit the chassis rail when I wanted to remove the pump. I had to remove the endplate and outer rotor to give me enough room to take the pump out! I was miffed but I suppose I'd got off lightly compared to those with an Elan who want to remove even a standard pump!

Hope your well too.
On my 1968 Cortina Twincam i tuned it using my David Vizard book. Gas flowed with my Rotary Files, fitted Piper FY2 Cams. Then drove it all the way down to Costa Brava on national roads, crazy drive but great fun.
Thought i was a Rally Driver
Alan

[2cams70]

The oil pressure needed is related to the maximum RPM your engine will be operating at. If you are not going racing or operating the engine for sustained periods at high RPM you don’t need a high pressure pump. You also don’t need a high volume pump unless you have a lot of internal oil leakage going on due to running large bearing clearances.

Driving a modern car with an electronic controlled variable pressure oil pump it’s interesting to watch how the oil pressure changes according to operating conditions. It seems that the optimum oil pressure at any one time is determined by calculating the bearing loads. The bearing loads are determined by a combination of the pressure acting in the combustion chamber and the engine RPM. For example you can watch the oil pressure increase rapidly under high turbo boost low RPM operation to around 60 - 65psi. Under high RPM light load operation the pressure will drop and under idle conditions it’s maintained at a steady 25psi.