The oil pressure on my pinto seems to be dropping significantly when the engine is hot to the point that when i pull up sharply or take a tight corner the oil pressure light comes on. Ive got a gauge and it runs about 50psi when driving drops to about 30psi on tickover. Ive a shortened sump with a box on the side to make up the capacity with a standard oil pump. Ive got a 2nd hand oil cooler but ive read that a standard engine shouldnt need a cooler for normal running. Do i need a cooler, a high pressure oil pump, extra baffle in the sump ????Anyone any advice and also what temperature the oil should get up to for best use etc
I would say Baffles in the sump
The pressure is the same as mine for a standard pump 50 cold /30 hot
Similar pressues to mine during normal driving but my light doesn't come on during corners, have you got your oil pick up pipe low enough? Thats
what I'd be checking anyway.
Cheers
Rich
in my experience if the oil pressure is dropping significantly just because the engine is up to temperature (oil could easily see 100 degrees). then
its usually a worn oil pump? when the oil thins out the pump cant cope.
however, losing pressure when cornering or sudden stopping suggests oil flying round in the sump and the pump drawing air.
Needs more oil
Sorry for hijack, my pinto has a slightly shortenned sump and the dipstick has a mark hand cut into the side of it.
However 3l of oil goes above the mark (filter is filled), running it with 3l of oil in I get 4bar (60psi) when cold at idle, which drops to just under
2 bar (25-30psi) when hot at idle. Under load from 1200rpm it sits at 4bar, and increases to 4.5bar by 5000rpm.
Does this sound about right. Alternatively if I drop the sump to check the dipstick, am I right in thinking the oil level should be just below the
base of the crank?
As a rough guide the oil temp should be about 20 degrees hotter than your water temp, with a limit of around 120C or so.
Oil pressure is not really a problem on idle or high RPM, it is the capacity you need. Oil pressure on the big ends is hundreds of PSI due to the
centrifuge effect, this is why you need a pump to supply enough oil to supply the crank. I have seen race engine with oil pressure down in the 40 lbs
at 8,000 RPM with no drama. If you "up" the engine oil pressure to excess all you do is create more heat and engine drag.
Your problem with the oil surge is something you need to address quickly, perhaps a couple more litres of oil and a baffle or two would correct the
problem, its cheaper than an engine.
quote:
Originally posted by Hugh_
Sorry for hijack, my pinto has a slightly shortenned sump and the dipstick has a mark hand cut into the side of it.
However 3l of oil goes above the mark (filter is filled), running it with 3l of oil in I get 4bar (60psi) when cold at idle, which drops to just under 2 bar (25-30psi) when hot at idle. Under load from 1200rpm it sits at 4bar, and increases to 4.5bar by 5000rpm.
Does this sound about right. Alternatively if I drop the sump to check the dipstick, am I right in thinking the oil level should be just below the base of the crank?
Hmm bugger, mine doesnt appear to have any additional capacity. Maybe time to think about a different sump 
Jacko, just short of 5 litres? the capacity in haynes for the pinto is around 3.5 litres i think, doesnt putting too much oil in risk causing the seals to spring leaks (mind you i suppose if you monitor the pressure it doesnt matter if theres a bt more than recommended does it....???)