25 replies to this topic

[Guess-Works.com]

On a freshly built engine using the standard pressure relief valve I would expect the idle to be a little more than 20psi when hot, and upwards of 50 when cold, but it's not the end of the world... only be concerned if it starts dropping into the teens when hot and on idle...

 

Likewise my 1330 I ran with an adjustable pressure relief valve and set it @ 50psi when running and 20psi when at idle running a 10/40 oil. There is no need to push high pressure oil, you just need a consistent supply.

[Morry Stu]

Higher pressure does not equal higher performance. In fact higher pressure uses more power to turn the pump leaving less for the wheels. It can also heat up the oil and burst seals in some cases.

As Guess works says.." you need consistant supply "

[cian]

Thanks guys putting me at ease here lol does a lumpy cam influence pressure? 

[IainStallard]

My oil pressure when hot is about 40-45lbs on idle and 60lbs when driving. After a motorway drive it drops down to 30lbs on idle but then returns to 40lbs after a few minutes. That's on my 1275 with 50000 miles

[Gremlin]

Thanks guys putting me at ease here lol does a lumpy cam influence pressure? 

Only if its a used cam and the bearings are worn

[cian]

Hummm well the pressure sits rock solid at 50 when hot and driving but about 70 when cold I'm happy with that but it just seems low when idle but my idle is lumpy an the rpm fluctuatesfrom 900 rpm  down

[Morry Stu]

Personally..I would only start to panic if it gets to 15psi. Oil lights in general come on at 7psi.

If its at 20psi hot at idle then you can sleep easy.

These motors have there own idiosyncracies when it comes to oil pressure. They will flucuate a bit at idle and this has more to do with oil type,grade,temprature etc.

Learn to live with it. And DONT be of the view you need really high oil pressure when you dont. The factory designed them to work at 40-50psi hot.

You also need to remember that modern oils are different & better to those used 40yrs ago. Just dont use friction modified oil and make sure you use the correct weight for your climate.

I use this
http://www.penriteoi...1&id_products=4

But here our climate is a lot hotter so we can get away with heavy oils.

[cian]

Thanks a lot morry stu great advice 

[racingbob]

if its any help my oil pressure is  75 to 80 on start up cold

when hot its drops back to 70 at 3000, time to start worrying is when

its drops down to 50 at 3000 shows worn bearings

 

I can always remember on my race engine ran at good 75

but when started to drop back to 50, when the engine was stripped

main bearings were worn

 

so it seems when there is a fair difference from cold to hot

shows something not right

[Morry Stu]

Why do you run it so high ?

There is no advantage. Especially on a street motor. Your only wasting power driving the oil pump.

Edited by Morry Stu, 05 June 2014 - 11:17 AM.

[cal844]

my standard 1275 sprite engine runs at 60 cold 40 hot, both at idle