oil pressure question

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I wonder what the longevity is on an engine that has lost significant oil pressure after warm up.
Only the bearing or bearings loosing clearance knows.
I don't believe there should be that much pressure drop with a HV pump feeding it.
 
My understanding is that his oil pressure is dropping 52 lbs after it's up to temperature from cold to hot right, Furyus2 I'm only 50 miles from you do you guys have a car show at Hwy 50 and 19 on some Saturday nights.
 
I wonder what the longevity is on an engine that has lost significant oil pressure after warm up.
Only the bearing or bearings loosing clearance knows.
I don't believe there should be that much pressure drop with a HV pump feeding it.

Shouldn't be that much of a difference, but he also said that he built the engine quite a bit back... So yeah, starting to get loose. 25 at idle is still good, goes up with RPM is good, as long as running a quality oil, I wouldn't throw the towel in on it yet.
 
My 440 when cold has 70 psi at 750 rpm. at 190* it drops to about 25 psi. I know the whole 10 psi per 1000 rpm, but my concern is the Difference in pressure from being cold to hot. Does this indicate worn bearings? These readings are with a high volume pump, and a bottle of STP.
I built this engine 20 years ago.

For what is worth, my teener 50 years old and over 100 thousand miles cold fires at 60 PSI after it warms up guess what; it drops to 20 PSI at idle. Perfectly normal? who knows but it still runs like a rabid dog. My 76 Shovelhead after rebuilding the top end; guess what 65 PSI cold, At idle 10 PSI whatermellon whatermellon whatermellon: no worries."Loose and wet" in my opinion trumps "tight and dry":confederateflag:
 
Thanks for the input. I just want to be pro active, and not put holes in my head, pan, block, etc. A block around here is expensive.
 
My understanding is that his oil pressure is dropping 52 lbs after it's up to temperature from cold to hot right, Furyus2 I'm only 50 miles from you do you guys have a car show at Hwy 50 and 19 on some Saturday nights.
There isn't a cruise night at 50 & 19 on Saturdays. There's one on Thursday, but it's dying. Dade city has a Saturday cruise in the first Sat. of the month. Plant City has one I think it's the 3rd Saturday. Lakeland should be having the Lake Mirror show next month.....
 
The factory service manual gives oil pressure specs at a given RPM, I've seen 2000 RPM a lot. But it's not given at idle and it does not specify a difference from hot to cold. As long as you have X amount of oil pressure at X RPM, you meet the spec. Of course I realize your engine is no longer stock, but you have to have a baseline somewhere and that gives you one. It sounds to me like your engine has worn normally, but is still well within spec for good oil pressure.
 
First, stop using the STP. Normally, additives should be used only as a last resort, not a matter of routine. That's probably giving you that really high cold PSI.
Second, use an oil with a higher viscosity index. You'll get less pressure drop with temperature increase. You should be able to get the pressure you want with Rotella T6 5W-40, which has a viscosity index just under 170, or Mobil1 15W-50, VI of 160. They will thin less, and consequently hold pressure better than oils with lower VIs. Both also have ZDDP levels above 1200 PPM, which is a good anti-wear package for stiff valve springs. They are synthetics, which will cost a little more, but both are readily available, and often on sale in 5 quart containers at Wally World.
 
There isn't a cruise night at 50 & 19 on Saturdays. There's one on Thursday, but it's dying. Dade city has a Saturday cruise in the first Sat. of the month. Plant City has one I think it's the 3rd Saturday. Lakeland should be having the Lake Mirror show next month.....
Yes sir I know all of them I just thought you guys had one up that way Crystal River meet on Saturday Nights too.
 
First, stop using the STP. Normally, additives should be used only as a last resort, not a matter of routine. That's probably giving you that really high cold PSI.
Second, use an oil with a higher viscosity index. You'll get less pressure drop with temperature increase. You should be able to get the pressure you want with Rotella T6 5W-40, which has a viscosity index just under 170, or Mobil1 15W-50, VI of 160. They will thin less, and consequently hold pressure better than oils with lower VIs. Both also have ZDDP levels above 1200 PPM, which is a good anti-wear package for stiff valve springs. They are synthetics, which will cost a little more, but both are readily available, and often on sale in 5 quart containers at Wally World.

Not anymore. Since a few years back, none of the diesel oils have the high levels of Zinc they used to because since 2004, diesel trucks now have catalytic converters. So if you use diesel oils for high zinc with a flat tappet, be warned. It doesn't have enough zinc anymore.
 
Not anymore. Since a few years back, none of the diesel oils have the high levels of Zinc they used to because since 2004, diesel trucks now have catalytic converters. So if you use diesel oils for high zinc with a flat tappet, be warned. It doesn't have enough zinc anymore.

Yes, in general diesel oils have less ZDDP now than 15 years ago for the reason you stated. But I'm not speaking of diesel oils in general, but specifically Shell Rotella T6 5W-40. Others may be similar.
T6 5W-40 has around the same amount of ZDDP as many of the old SE, SF, and SG oils did back in the era of the OEM flat tappet engines. It has about 30% more than is allowed in modern API SN and ILSAC GF-5 oils. In other words, enough.
If the furyus2's engine has open spring pressure above 350 PSI, and is living at high RPM, he needs racing oil, and everything that comes with (and without) it. My impression is that it's a street engine, and my recommendation stays the same. Readily available, relatively cheap, and better than any oil on the market when 440s were new.
 
Rusty, and s'cuder, Thanks for the excellent answers. As for the oil, I am currently running the Rotella t4 with the stp additive. The reasoning is the Rotella reduced the zddp, and the stp has it, so, just tryin to keep the zddp levels up. And the oil pressure....
 
Yes sir I know all of them I just thought you guys had one up that way Crystal River meet on Saturday Nights too.
Yes, there is the Crystal river cruise night. Forgot about that one. I was going to go last Saturday, but the love bugs were insane. don't forget the Garlit's show in ocala. it's usually big. If you are in Lakeland, I hope you realize these cruise nights at Crystal River, and Weeki Wachee, are a couple hour drive.
 
Yes, there is the Crystal river cruise night. Forgot about that one. I was going to go last Saturday, but the love bugs were insane. don't forget the Garlit's show in ocala. it's usually big. If you are in Lakeland, I hope you realize these cruise nights at Crystal River, and Weeki Wachee, are a couple hour drive.
Yes my brother has a house on the Homosassa river plan on going to his house then cruise up there and Garlits we are going to that show also. I drive my car every where anyway it likes the cold weather.
 
Rusty, and s'cuder, Thanks for the excellent answers. As for the oil, I am currently running the Rotella t4 with the stp additive. The reasoning is the Rotella reduced the zddp, and the stp has it, so, just tryin to keep the zddp levels up. And the oil pressure....

I had 32 years in the motor oil business, so I stand by my recommendation. But it's your car so you need to be comfortable with what you're doing. So, if you want that much ZDDP, try to get an oil with it already in there. I don't want to go into a long dissertation, but additives can do more harm than good, and are best avoided.
Valvoline VR1 is a high ZDDP oil, and is probably the most widely available. Others are sold by PennGrade/Brad Penn, Joe Gibbs Driven, Amsoil, Lucas. Maybe Redline and Royal Purple.
 
It's probably worn - bearings and the pump itself. It's also probably fine. If you're nervous, buy a new pump, disassemble and clean it and make sure the bypass works, and install it. My impression is it might help a little in terms of your confidence. But that's about it.
And yes - lose the STP. Chances are the 20 year old camshaft will be just fine with any racing oil, or the fleet 15-40.
 
Had a freshened 446 on the dyno last week.
New std M63 oil pump.
All warmed up after making several full power pulls...... around 50psi for the whole pull.
3000-5800rpm.
10/40 Driven HR oil.

I prefer a little higher pressure than that.
Swapped in the spring from a HV pump...... brought it up to about 65psi.
Idles at 30psi....... depending on the idle speed.
 
I solved my worries by not having an oil-pressure gauge with numbers on it.
When I start the engine,sometimes I might look at the factory gauge, and see it come alive but most of the time I just jump in and go.Been that way since 1999 and for 125,000 plus miles. If it blows up, I'll stick out a thumb and catch a ride.
Don't hate me, but I install just about whatever dyno oil is on sale. But I do splash a bit of ZDDP in it for the FTH cam.
Course if you didn't have a gauge, you might worry worse,lol.
I know,I know; more useless mutterings ........ I couldn't help myself.......
 
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