Does anyone know what the oil pressure should be for a warmed up and running 200 blocked cosworth engine? is 15lb to low when hot and running?

 

way too low!

what oil you using?standard pump in the ideal world you want at least 25-35psi on tick over!

 

I would also say this is way to low as well.
tabetha

 

the oil is 10w 40 castrol off the top of me head.

 

how to check the oil pressure as follows;

the oil pressure level depends on a variety of factors (engine speed ,oil temperature, oil pump rotor clearance etc.) the measurement should always be carried out with the oil at a temperature of 80degc. the oil pressure should be 1.8bars at idle speed and 2.4bars at 2000rpm. however, the maximum pressure should not exceed 5bars at engine speeds in excess of 2000rpm.

follow this and if its still only 15ibs then you have problems

 

done test today again it starts up at cold start with 74lb/ 75lb cold start oil pressure.

the problem is its not maintaining this pressure, once you've driven it and left it to idle you will see the pressure at idle around 25lb.

then after say 5mins more driving the pressure needle will start dropping to 15lb and thats when i have just switched it off as its getting far too low for my personal liking.

could the pump fail that easily? would and external oil leak cause this say if the oil filter was abit loose and the car was drawing in air?

cheers in advance

 

The above checking procedure is a load of crap to be honest with a USED engine as the most important area here is the wear on the crank/shells etc, as you can lose it all here.
It is however overlooking one major influential factor and that is the oil you use.
10W40 is WAY TOO THIN, in a worn hard worked engine, personally I wouldn't use this stuff on my door hinges let alone a car engine.
I suggest you try a thicker oil first, tests have shown oil to run at 30C hotter than the engine(water) itself, on average.
The same tests have also shown the biggest problem with some oils was thier complete breakdown under pressure, CASTROL RS being the worst culprit.
I really would not concern yourself with the oil pressure at idle, as no great amount of pressure is needed, I would be more concerned about it as boost starts, as this puts the crank in particular under increased load.
It is all very well FORD quoting oil pressure, but we live in the real world.
Another point may be the accuracy of the oil pressure gauge/sender.
I would not be too quick to do anything, some engines have a LOT less pressure at idle.
Change the oil for Silkolene PRO S 10W50, or if mega high mileage MILLERS 10W60.
tabetha

 

what speed was it idleing at?

 

idleing at approx 900rpm, the engine has done approx 10k now its a wrc bottom end 200 block.

the cold starting oil pressure does this sound correct at about 74/75lb?

cheers again

 

10 thousand miles should be better than that by a long way.
Initial oil pressure sounds high but does show relief valve on pump to be working ok, if ok by say 2000rpm I really would not worry.
Try a thicker oil like 50 or 60 weight.
If you want to be ultra safe put on a oil/air cooler, the cooler oil will keep better pressure.
tabetha

 

changed the oil with millers 10 60 and its crystal now oil pressure on cold start is about 75lb/76lb and one warmed up idles it shows 26 28 on idle.

after abit of a pasting it dropped down to 20 but is staying there and is not going any lower at all.

think its ok now, and theres no smoking or anything amazing what oil change can do, lol

 

could also be turbo related. oil pressure reading are normally taken from the same place as the turbo oil supply. a worn turbo can cause a low reading