My engine builder used a Melling 55 high volume pump. I left the specs up to him. He has plenty of experience with performance engines. The oil pressure at break-in was 60 psi warm. Is this too high and should I look to use 10w-30 oil? A repected person on this board suggested I use Delo 15w40 for the old high compression engines. Does the engine need time to loosen up a little? What are your thoughts?

What RPM? 60 psi at idle (warm) seems a little high. My 302 with Z28 hp pump is around 40 psi at idle. It does jump to about 60 at 2000 rpm.

What RPM? 60 psi at idle (warm) seems a little high. My 302 with Z28 hp pump is around 40 psi at idle. It does jump to about 60 at 2000 rpm.


I have about 60 psi at 2000 rpm. About 70 psi at cruise. What oil do you use? Thanks!


Update: I seem to be throwing oil from the front seal area. Could excessive oil pressure do this? Have I blown that seal out now?

I think the Delo oil is a non detergent oil,, I think and in case of new engine break in I would say its ok .. The high oil psi is a little hi, the oil pump bypass isnt plugged is it? Did your builder say if clearances were on the hi or low side?
Oil blowing out front seal is either bad seal to balancer snout, or no crank vents... i am also thinking no front slinger but I dont have one either. Remember the engine is basically an air pump,, In this case of new engine,, you need lots of breathing area
Need to keep eye on that hi pressure ,, gonna be a bogger in the winter..but you live in CA
You could finish the break in with some 5w30? Let it break in with this and dont jazz the throttle for a few hundred miles,,, allow temps to come to reasonable level and cool off. I will guess he used moly rings so they will seat quickly..

It's leaking at the front pan to timing cover seal. If I have to replace that I might want to go with a std oil pump. Is there a certain orientation for the spin on filter adapter? Maybe it is plugged. Delo 15/40 is detergent type oil. It is favored by many diesel (hi compression) owners. I think I will change for sure to lower weight oil.

If its for diesels , its should be non detergent but i am sure technology has changed. Its good for breakins...Being that you are gonna have to take pan off , try one of those felpro blue one piece gaskets,, they are more money but they can be pulled many times and still hold..

As for oil pump,, that Mellings 55 Hv is all I have ever run.. The oil filter adapter has a little brown flapper that is spring loaded,, while oil filter is off ,, look at it and see if someone has put a pipe plug in there. That would force all oil constantly thru the filter,,, sounds good but you could )1 over load that pump and in turn throw extra load on dist gear that is being driven by cam and thus wearing it prematurely, 2) when its cold , your oil is thick and oil pump can build enuff pressure to rupture that oil filter. Check it out first... dont jump into this.

I know the bypass is not plugged. I installed it and pushed on the spring. The engine builder stands by that pump and says 70 psi at cruise is not too much. I should say the leak is a different matter because there is no pressure there. Does the 1 piece gasket need to be sealed? Is it contour fitted so it will stay in place while working upside down? What weight oil do you use?

Felpro blue gasket comes with some screw in dowels to hold in place until you get pan on... Use no sealer unless u are skeered. and if so just a dab on front and rear oil pan lip but these gaskets do not leak.

I have changed cams 3 times and dropped the front part of oil pan and each time i was skeered (sp), but they hold... They also have little block in bolt holes to keep you from overtightening... gofeit

Mine starts up at 70 psi but settles down after warmed up to 40-45 psi at idle with 20-40 penns and i am in 90-100 weather,,, Cruise at about 58 psi at 2400 rpm