7 replies to this topic

[johnnysti]

Right

Today my father-in-law fitted my new fuel pump and i decided to remove (for the time being) my oil cooler. The reason behind this being that the dizzy cap is hitting the cooler. I do have the flat dizzy cap fitted aswell.

Now before its removal it idled at 50 or just below and while in motion would sit at 75 or just below.

From cold it mirrors the above but when its warmed up it will idle at 25-30 or just above and in motion will sit at 75 or just above.

Ive checked the oil level and all is fine. I checked it from cold before removal of the cooler and again when i put the pipe on. I then checked it after a running time of 5 mins and again fine. There are no leaks and im using millers CTV 20w50 that has only covered a few hundred miles.

When its driven from cold it runs really well, very keen and willing to go but after about 10 mins there seems to be flat spots almost. I can notice the difference between hot and cold driving.

I know nothing about cars/engines but at a guess what i think/hope it is that the oil when hot, is to thin. When it drops to 25 the low pressure oil light comes on but goes off and on with the rough idle the cam generates. if i tap the throttle the oil pressure goes up and the light goes off.

The only other thing i havent done is blanked off the mech fuel pump but that shouldnt have anything to do with the above should it?

Please help

Johnny

[minislapper]

There was obviously a restriction somewhere in the pipework to the cooler or in the cooler itself and sounds like you are better without it !! The pressures you quote after removing the cooler are plenty !!

[johnnysti]

Even though the pressure light is coming on?


Johnny

[johnnysti]

Can anyone else shed any light on this?


Johnny

[mini13]

I strongly suspect that your oil was never really getting up to the proper operating temperature, on my own 1380 when properly hot the oil pressure is about 20 psi at idle(1000 rpm), meaning my 22 psi oil light is on/flickering,

as long as you get about 40psi above around 3k revs (although opinions differ!!) thats fine.

Best thing to do is fit an oil temp gauge an see how hot the oil actually is, I bet its cooler than you think!!

Oil should run around the 100degc mark, I have real trouble getting my oil to this heat even in the summer on the motorway.

[mini13]

also i recomend not running the shitty bit of pipe with the bolt through it, I use one braided pipe from an oilcooler setup, much less restrictive.

[johnnysti]

Thanks mini13.

Im using the longer one of the two cooler pipes i have. My pressure light does exactly what you say on idle on around 1k.

Doing 3k and about 45-50mph my pressure reads just under 75.

[mini13]

Sounds fine then, my engine will only make about 55 psi hot tops, it might not hurt to lower it a tad from 75psi the extra pressure just heats the oil more and wastes a bit of power. I'd especially lower it if running a belt drive, less stress on the belt see,

the std oil pressure light comes on at about 7 psi, the uprated one about 22 as std the oil pressure is set to about 40psi running.