I have a serious worry about low oil pressure on the pinto in my MK Indy. When the engine gets properly hot (like at a track session a Donnington last night) the oil pressure is dropping to around 1 bar. In warm weather it can even get to this sitting at 4000rpm on the road. However with slower driving and cooler weather the pressure holds up well above 2 bar.
I am using Duckams 20/50, the engine is a well modified 2.1 kicking out around 175bhp, I do not have an oil temp gauge, so I can't tell what kind of temp I am running, but the engine temp does not stray above 100.

It is all very worrying as the engine was only re-built about a year ago and I cant afford another disaster!

Anybody any ideas??

Have you fitted a competition oil pump and an oil cooler?
If not, you are asking too much of the engine.

I think an oil cooler is a bit extreme in this application, and more bling than use in my opinion anyway, but I would suggest a high pressure and high capacity oil pump for sure. Available from burtons and ebay. I have one fitted to my modified pinto.

David

High pressure oil pump fitted when the engine was re-built, also I dont think I am suffering with surge, I have a modified sump with some baffles. Colud I be getting some foaming of the oil?

It sounds like oil temp is the problem.

An oil cooler will reduce oil pressure in itself but would (marginally) cool your oil which in itself would thicken it up and increase pressure.

High pressure / high capacity pumps aren't really necessary, they can be a "sticking plaster" to cover up other problems. Not many wet sump competition Pintos use them.

I wouldn't want to see engine temp above 90. Is the rad up to the job? Is the ignition timing correct? Is the mixture correct?

Could be a combination of things. If the engine wasn't spotlessly clean when rebuilt the main bearings could have a problem (they are what in effect establish oil pressure) or the pump could be worn.

Whats the cold pressure?

Has the pressure changed recently?

Mechanical or electrical gauge?

Are you certain of the accuracy of the gauge?

Cheers

Andrew

The cold pressure is 4-5 bar. The situation is a bit worse than previous but the last time it had proper use was on a track day in the winter. Not sure about the gauge but the cold pressure reading is I think about right? It is a Racetec electrical gauge.

Anyone any views on the 'right' oil to use in a reasonably tuned pinto?

Thanks

James

Drop the sump stick a new set of big end shells in, clean the oil pump suction strainer.

Fit an oil cooler (with thermostat).

Ref oil - most people recommend a decent 20W-50. My local factors didnt have any (only a very cheap and crap bare oil) so i went for Valvoline turboV 15W 50 (£13 for 5l). i could have got Valvoline Racing 20W 50 (£25 for 5l) but dont believe my use or state of tune demands such an oil

Cold i get around 70 psi, hot it only drops to 60 ish. This is all just normal road running. Being spiritted i get a corresponding rise in pressure.

Ref temps, coolant runs between 93 and 98 typically (controlled by fan), but will rise to around 105 ish on track. Oil temps follow a similar pattern but of course temp reading is also dependant on location of the senders. i use my tepms mainly as a onparitor between std road use and track to gauge if a problem is occuring.


iirc 1 bar is around 14.5psi

Britishtrident and Darren are right, as was said, put a new set of big end shells in, its an easy job and costs little.

14 psi (1 bar) is not uncommon with a hot engine that is a bit tired, but its not great either if its got expensive bits in it then changing the shells makes sense.

An uprated pump is NOT necessary either, the std pinto one has MASSES of capacity and is quite up to the job as long as the strainer is clear and the casing is not worn.

Main bearing wear has a far greater impact on oil pressure than big ends

Orange Indy,
Not sure if you know Dave but id defo listen to him. He has masses of experience building race engines.

Just been out for a spirrited jaunt and took more notice. Gauge was showing high 60's / low 70's all the time. Datalogger recorded max of 85psi. I have seen over 90 recorded after a track day.
Water temp peaked at 99 deg, oil temp at 103 deg (as said before temps can be subject to sender location and gauge etc so take with pinch of salt).

ETB DD2

Oil pressure gauge is in std location. Water temp again in std location. Oil temp sender is in one of the oil gallery plugs. All senders came with dash.

[Edited on 7/6/07 by DarrenW]

Thanks very much guys that is really useful advice, sounds like a few jobs need doing, - new shells, change of oil type, maybe I should fit an oil temp gauge and possibly an oil cooler as well!?

Best get down to the garage and get that sump off!

Was a bit concerned about the oil pressure on my recently rebuilt crossflow after a good run , fitted an oil cooler with thermostat last night, now after a good run the oil pressure is approx 10 PSI higher than it was before and the coolant temperature is about 10 degrees cooler at 80 degrees.