Another BBC oil pressure question
 

Got my big block running and been having some issues with the oil pressure gauge. I am running an Autometer electric, and I am losing trust in the gauge, Put a second sending unit in, and then the gauge seemed like it was sticking at first. Anyway now it is showing around 20 psi at idle, and about 35 psi at 3000 rpm. Went to 4000 and it didn't go any higher. This is with Valvoline 10W30 oil. Does this seem like a safe amount of oil pressure? I may get a mechanical oil pressure gauge after all of this.

Re: Another BBC oil pressure question
 

How many miles on it? Mine was rebuilt a couple of decades ago (~100k miles on it since then), and pegs the gauge when cold. I don't like that, but it's been that way since the rebuild. It now runs about 30 PSI at hot idle, if the gauge max is 80 PSI. If the gauge max is 60 PSI, then the hot idle is about 25 PSI. 20 PSI isn't that bad, I would think. I run 10-40, though. Truth is, the lighter the oil you run, as long as there is a film present, you should be good to go.

Re: Another BBC oil pressure question
 

cold pressure or hot.

20 at the low end is a bit low but with 30 wt warmed up it might be normal for an older engine.

the high pressure at higher rpm is a bit more concerning.

change to a 40 wt and see what happens when its warmed up.

next fix would be to put a high volume hi pressure pump in there and see what that does to psi hot at high rpm but watch that cold pressure on start up.

may be just tired old truck engine

Re: Another BBC oil pressure question
 

I would try a mechanical gauge just to be sure.

Re: Another BBC oil pressure question
 

Newly rebuilt motor. Hot. I am going to change the oil filter to make sure it is not plugging up with assembly lube first. Then I will try 40W. Already ordered a mechanical gauge.

Re: Another BBC oil pressure question
 

Be careful of the 40 weight,don't rev when cold,you could blow out the rear seal,other problem would be oil not travelling fast enough on start up and starving rods and cam bearings, 10 w 40 would be better,

Re: Another BBC oil pressure question
 

O'rielly has a $14 mechanical gauge... shows in stock. I'd hafta know TODAY.

I have 25-30k miles on a .40 over 454 in the Blazer. I run 20/50 and the mechanical gauge shows a tad over 60lb at 2000 rpm cold and a little over 40lb at a 700 rpm idle. It looses about 10lb over all when it warms up. Not sure if my gauge is dead accurate but it's consistent.

Re: Another BBC oil pressure question
 

Took off the break in Wix and put on a K&N filter, and now I have 30 psi at idle and about 45 psi at 3500 rpm. Feel a lot better. Not completely warmed up.

Re: Another BBC oil pressure question
 

GOOD NEWS!!! Did you cut the break-in filter open to see what it had caught?

Re: Another BBC oil pressure question
 

Don't have a cutter to open it up. If I hack saw it open I don't think I would be able to tell much.

Re: Another BBC oil pressure question
 

You can cut it with a big set of wire cutters on the flange. That doesn't make too much of a mess.

Re: Another BBC oil pressure question
 

yes that is good news