I have a 68 400 MT bird and am wondering what typical oil pressures are for this motor at idle and at increased RPM (when hot). I've looked through the FAQ's but can't seem to find the actual typical pressure numbers. Any info on this is much appreciated. Thanks.

Dave

Dave , I think mine is pretty much typical...my 400 starts up cold at 80 psi, while driving and warm its at 45-60 psi dep. on rpms, at idle 20 psi when hot.

Ditto here for the most part. When it changes a little I know theres an oil level problem.

Dave,

Also keep in mind that the sender unit and gauge itself play a big role in what you see of course. If either is a little off or old or whacky you could get wierd readings. The console gauges that came with my car when i bought it would periodically read ZERO Pressure unless I was at high RPM. Check out all pieces if you are getting LOW readings.

Thanks for the help. I'm getting readings as Bjorn described, about 20 at idle. I just broke in a new cam with 30 weight oil. Prior to this I had Mobil 1 20W-50 and the pressure at idle seemed higher, I think due to the higher viscosity. Thanks again, as always. I'm always amazed at the wealth of knowledge and accessibility here on FGF.

Dave

I am running 20W-50 in mine and get 80 psi cold, then when hot I have between 18-20 at idle and up to 70 at higher rpms.

It may also depend on where your sending unit is attached. I've heard that a sending unit attached at the distributor pad may read differently than the same sender mounted at the filter housing.

Dave, Typically you should see about 10 - 20 psi per 1,000 rpms as a rule of thumb.

20 psi = 750 - 1,000 rpms
40 psi = 2,000 rpms
60 psi = 3,000 rpms

Just as a loose rule of thumb that is. Anywhere in this range seems to be about normal?

I agree, you can get almost any answer your looking for here, and if Bjorn, Q or Nash answer... even a few you weren't looking for!

Brett - 67 Drop Top 455!