I'm sure this has been asked before, but the search aint searchin', so....

I have a mystery '73 440 I just stuffed into the R/T. The guy I bought the engine from claimed it was rebuilt, but I suspect it was 'rebuilt' with four cans of paint.

Anyway, after fiddling with the middle carb, the engine roared to life...and has 75 psi at idle! Step on the gas a bit, and it goes past 80. Yep, oil pushing past the filter. Replaced the new filter. Removed the oil pump and the bypass is fine. No markings on the pump or spring, so I don't know if they are stock. Look it, though. Changed the oil to a lighter grade (10W30 now). I'm sure the engine was NOT rebuilt, so I'm eliminating tight clearances.

Anything else I should consider and look for?

As always, my many thanks!

Jer


seeing that the engine is a transplant, and your comfy with your findings regarding the pump, (may be a high pressure pump?)......check the sending unit, is it correct? for the gauge your using?......if it is, double check pressure using a mechanical gauge plumbed directly into the blocks sending unit passage,....also if your having dash voltage regulator issuses, your dash gauge could be reading high?.......lot of variables to consider?

I thought the same thing, so I plumbed a trusty mechanical gauge directly to the engine. All that did was confirm the first high readings.

The pump might be a high pressure, or perhaps the spring is, but they look stock. A new spring and perhaps new pump are on the list for tomorrow (no auto parts stores open at 11pm here!)

I'm sure I'm just overlooking something simple...I hope!

My motor is a brand new crate engine.
When i first started it up it made nearly 100psi on 20/50.
Changed to 10/40 and now it makes 80-85 running and 55-60 at idle hot.
i believe the crate motors have a hi-vol pump.
Maybe you engine got a hi-vol pump as part of it's 'rebuild'

Thanks, Connie-bee. I might have, and will likely change it out to a stock one tomorrow.

Any issues you have had with the high psi?

The high volume pumps can also have the high pressure relief spring in them. It's generally not needed. If you have an old original pump lying around you can take the spring out of that, clean it and replace the high presure one, or you could grind a 1/16th of an inch off the relief spring, then debur and re-install it. Check your pressure again, repeat the process once or twice more. They also make an adjustable oil pressure relief spring.

i've had no problems,watching the gauge was a bit scary to begin with...my old 383 only made 40psi cold.
I don't know anybody else with a crate 500 so i can't say if mine is typical,
i do have a friend with a stroker motor built by FBO Systems and his makes similar pressure to mine

Yah, better to reduce it if you can. The relief spring will bleed off pressure to a point, but it can only do so much. Building all that pressure robs horsepower and unnecessarily increases the strain on your timing chain, intermidiate shaft etc. The general rule of thumb is what? 10 psi per 1000 rpm?

My 440 did the same thing fresh with a high volume pump. 15-40 oil and it made 50 lbs hot idle in gear.

did you let it get warm by actually driving it? or did you fire it up, see high oil pressure and shut it off?

my recently built 383 makes 75 psi cold on 15w40 oil..at idle.

once it is driven for a bit though and it warms up, my oil pressure drops to around 30 at idle. I'd consider a lighter oil, but I don't want to loose too much oil pressure at hot idle, 30 is about as low as I want to go.

My son's 400 runs 60+psi at cold idle, 30ish hot idle, and 80+ depending on RPMs. No problems here...

My oil pressure was over 100 at startup and never blew a filter or anything and when hot would never go under 85 except 60 at idle. I changed oil(straight 50 wt to 20/50)and put a stock spring in the HV pump and it went to 58 cold..45 hot...30 at idle..changed the spring back to the original and now I have 80 at start...65 to 70 warm and 40 at idle.I'm happy with that

when I rebuilt my 440, I put an 80psi manuel gauge in. it would peg the gauge and stay there. I changed to a 100psi gauge, and it woud hit 95.
never had oil pushing past the filter though.

Personally I wouldn't worry about a cold reading like you have. What is it warm (operating temperature)? It will drop off quite a bit. My duster after just about 5 seasons still has 80 cold and 55 hot idle at about 1000.

My untouched 440 pushes 75-80 at cold start-up, but at a hot idle it comes down to around 20. If I back the idle speed all the way out and get a 550rpm idle in gear it'll go down to more like 10-15. That's with 10w-30. Oil temp makes a huge difference.

The 383 in my 67, all warmed up and driving at a constant 3200 RPM for hours at a time on a 90 degree day, put's out 65-70 PSI, with engine temps in the 185-195 degree range.

Stone cold it idles at 80-85 psi...
Hot idle is way down there... Been that way forever.

I don't see that you have a problem

When you start to blow filters off and split filter cases wide open that's when you have to much presure.