What is normal?

[JDB]

Hey Guys
Question.....a brand new Merlin crate motor....572, 725 horse, naturally asperated motor.....what is "normal" for oil pressure? From 2,000 RPM and above it runs a constant 50 PSI....at idle, and below 1,500 RPM, it runs about 17 to 20 PSI. I am running straight 40 W oil.....and the max oil temp I am seeing is about 230 to 240 degrees. It has a 12 quart pan.....Is this normal??

[IMPATIENT 1]

Hey Guys
Question.....a brand new Merlin crate motor....572, 725 horse, naturally asperated motor.....what is "normal" for oil pressure? From 2,000 RPM and above it runs a constant 50 PSI....at idle, and below 1,500 RPM, it runs about 17 to 20 PSI. I am running straight 40 W oil.....and the max oil temp I am seeing is about 230 to 240 degrees. It has a 12 quart pan.....Is this normal??
10 psi for every 1000 rpms is normal, but i've seen alot of "loose" marine motor with 15psi at idle.once my oil temp is high, my idle pressure drops down to 20psi on the low end of my surge, and stays above 60psi when cruising with high oil temp. i'm also runnin a 12qt pan
i'm gettin a oil cooler over the winter, it helps keep pressure steady and seems to contribute to a long life in a marine motor.

[DMOORE]

JDB, the specs you posted look damn good. Including the temps.
Darrell.

[obnoxious001]

Hey Guys
Question.....a brand new Merlin crate motor....572, 725 horse, naturally asperated motor.....what is "normal" for oil pressure? From 2,000 RPM and above it runs a constant 50 PSI....at idle, and below 1,500 RPM, it runs about 17 to 20 PSI. I am running straight 40 W oil.....and the max oil temp I am seeing is about 230 to 240 degrees. It has a 12 quart pan.....Is this normal??
Do you have a mechanical gauge? I don't particularly like those pressure numbers , I would advise double checking pressure with a mechanical gauge, even just one temporarily screwed into the block. Perhaps your first step should be to contact the seller,, or World Products directly if you know your gauge to be good. The engine should live with those pressures,, but seems on the low side, even with just a stock Mellings oil pump. What's cold idle pressure?

[JDB]

Cold temps run 50+ PSI until I hit over 200 degrees on the oil temp.

[victorfb]

id have to agree, those numbers seem scary low to me. contact your supplier and ask them. when my oil pressure gets to those numbers i know i have waited too long before changing it. and yes ive done it, i will admit. im just thankfull royal purpal oil is sold at alot of places now. yippeeee.
oh, and the temp numbers seem real good. IMHO.

[cfm]

I'd call and ask if it's normal also. It may or may not be.
There are many oil pumps made for racing (sustained higher rpms) that sacrifice idle/low speed oil psi for smoother and more consistent oil flow at higher rpms.
Checking with mechanical guage is always the first thing to do.

[steelcomp]

IMO that's borderline for that much power. A better guide for oil pressure is 10# for every 100hp.
I don't know if this is the same as the GM 572, but check some other websites and you'll find more than one guy who ended up tearing his down only to find that the machining and clearances were far from acceptable. It usually starts with low oil presure. Don't mean to rain on your parade, just that you should be aware of this. It's why I won't buy a crate engine.

[WishIknew]

Is it a marine motor or a sprint car motor? where you get it and how much?

[uLtRADeNniS]

Heres my deal...
555ci 800hp+ n/a
idle 70-80psi
cruisin 60-70 3700-3900 rpms
hard pass 35-40psi at 6000+ rpm
running 50w Royal Purple

[victorfb]

35-40 psi at 6000rpm isnt what id like to see. who recommended the 50w oil? ive had great luck with royal purple, but i also run 5w30 or 10w40 at the most. clearances are tighter than some others run though aswell.

[uLtRADeNniS]

typo... the OP is at 40-45 at 6000rpm...set up by Dave Ebbert, he is also the one who recommended the Royal Purple. Motor runs fabulous.

[steelcomp]

typo... the OP is at 40-45 at 6000rpm...set up by Dave Ebbert, he is also the one who recommended the Royal Purple. Motor runs fabulous.Dave's a good engine builder, but that would bother me...the 40-45 part, Royal Purple or not. 50wt is costing you power.

[steelcomp]

35-40 psi at 6000rpm isnt what id like to see. who recommended the 50w oil? ive had great luck with royal purple, but i also run 5w30 or 10w40 at the most. clearances are tighter than some others run though aswell.The type of oil you're going to use definately plays a part in deciding on clearances. It's also good to know what oil temp you'll be running for the same reason.

[SmokinLowriderSS]

Hey Guys
Question.....a brand new Merlin crate motor....572, 725 horse, naturally asperated motor.....what is "normal" for oil pressure? From 2,000 RPM and above it runs a constant 50 PSI....at idle, and below 1,500 RPM, it runs about 17 to 20 PSI. I am running straight 40 W oil.....and the max oil temp I am seeing is about 230 to 240 degrees. It has a 12 quart pan.....Is this normal??
I am running a recently rebuilt 454, Mk-IV. Bearing clearances are on the wider 1/2 of the factory specs.
STOCK OIL PUMP!
54PSI cold idle.
58PSI WFO, for MILES AND MILES, 5,000 RPM (5,400 RPM on nitrous)
23PSI HOT, at idle, after those miles of WFO running, or tubing kids for a few hours.
I do not know my oil temp as I do not have instrumentation for that installed yet.
5 quart oil pan, filled with 5 quarts of Castrol 20W-50 Syntech 100% synthetic (not blend).
Your pressures look just fine to me.

[Badburn]

Hey Guys
Question.....a brand new Merlin crate motor....572, 725 horse, naturally asperated motor.....what is "normal" for oil pressure? From 2,000 RPM and above it runs a constant 50 PSI....at idle, and below 1,500 RPM, it runs about 17 to 20 PSI. I am running straight 40 W oil.....and the max oil temp I am seeing is about 230 to 240 degrees. It has a 12 quart pan.....Is this normal??
I like the 10 psi for every 1000 rpm rule, however the fact of the matter is that I have rarely had a motor that meets it at high rpm. I could not count the times I have looked down and seen 35 psi @6000 RPM. I dont like it, but thats what happens when the oil gets hot. Who knows if its from heat, areated oil, sucking the pan dry, or whatever.....Never have been able to pinpoint it.
Those pressures are similar to what I see in my boat.;)