Oil Press Ques.

[Hallett19]

does that rhyme ? anyways, I run 20-50 mobil 1 in my 460, it has a lifter tick which causes rpm drop at high R's. My question is, if I am at 4000 rpm's, and it reads a little over 30 psi on the guage, is that bad considering I run synth. oil ?

[Allan Gorneault]

I have had a problem with oil pressure on my ford 460 engine. Oil pressure started at 60 psi @ 4600 rpm in the begining of the year , dropped to 40 mid season and finally to 20 psi at 4600 rpm at the end of the year. Problem was the pressure relief spring broke in 4 pieces. Melling told me it was a metalergical problem with the spring .

[mister460]

It is VERY bad juju if you don't have at least 10lbs of pressure for every 1000rpm. Find the problem and fix it!

[Hydro-Thunder]

mister 460 do you think I can get away with a stock oil pan with a high volume pump or will it suck the pan dry while running some RRRR's?
Thanks for the help
Jesse
[This message has been edited by Hydro-Thunder (edited February 20, 2002).]

[Hallett19]

same thing happened to me with the pressure drop, it kicked ass at first, then started tapering off, now I think that might be what is causing the lifter tick if they arent getting enough pressure, because could a lifter being callapsed and/or messed up cause a drop in oil press. ??

[1quickjet]

Hallet19, Last year in my 19' Eliminator Sprint with mildy built 460 Ford, I launched the boat and started to cruise up river (Parker AZ). About a mile or two up river when the motor warmed up, the oil press started dropping slowly. The farther I drove, the more it dropped untill finally about 20lbs, when I shut it off. I let it cool down and restarted, and the press was back up. I got back to the the trailer safely and when I got it back home, I called Steve at ProBoat. He suggested I drain the 20w-50 and use a straight 50 weight. I took his advice and used Valvoline (I think) 50 weight racing oil (not synthetic). From then on I never had a problem (60-70lbs). My Chevy in the new boat doesn't seem to have a problem. I don't know exactly what went on that day, but running that straight 50 weight fixed it and it had great idle and speed press from then on. Just a suggestion you might try, or look into more. Good Luck!

[77charger]

mine starts off high when cold but drops about 10 pounds when warm and is at 40 at idle.never a problem.My old motor never had more than 60 when warm and dropped to 20 at idle but that motor i had machined with more clearance but i followed the 10 pounds per 1000 rule 5k with 60 pounds of oil=s ok.

[timitunnel]

I strongly recomend aginst strait weight oil.The Extra wear during start up is not worth it. If your motor is mechanicly sound multi weight oils are far supirior. Tim

[77charger]

btw i run 20-50

[spectras only]

I ran Penzoil 40 for the last 13 years ,engine still running 55 pounds pressure at cruise , 65 pounds at WOT . BTW I have a high volume oil pump.
[This message has been edited by spectras only (edited February 22, 2002).]

[LVjetboy]

Three things:
1) Oil Temperature
2) Oil Weight
3) Oil Condition
Oh ya and clearances.
First of all, jets running for extended time at full throttle put a LOT of load on the bearings, which really heats up the oil...more than I would think. This is why lower pressure. I measured 260-270 F oil temp on my jet after full throttle cruising just about 1/2 mile on a hot day.
I used to run 10-30 mobil syn before, but now run 15-50 mobil syn (don't know if they make straight mobil synthetic) After a fresh oil change and higher viscosity, now pressures are back to normal.
Frequent oil changes are good. Especially if you've had a flooding episode. I'm bad at regular oil changes, but diluted or contaminated oil I'm sure is a bad mojo.
jer

[mister460]

Hydro:Is it a Ford or Chev? Then no problem. Olds engines have a problem with oil drainback. Fords and Chevs don't. HV pumps are fine with a normal oil pan. Usually an HV pump isn't all that necessary though. But cheap insurance.

[Hallett19]

1quickjet, did your boat tick at all from the lifters while psi. was low ? mine does the same thing, the psi. will be fine at start up, around 60psi, then drop and an imediate tick, if I turn it off and then back on,full psi again, but a few min. later, sure as hell, psi drops. I am going to try the 50 weight again, but I remeber it STARTED doing this when I first put in Kendall 50 weight, from then on went to 20-50 valv. synth.

[skeepwerkzaz]

Hey guys,
I work on light aircraft. It is fairly commonplace for a 500 plus cubic inch engine to produce between 300 - 450 horsepower. Not bad considering they ar air cooled six cylinders that make rated power for thousands of hours. Both super-charged and normally aspirated. These engines are ALWAYS broken in with straight weight mineral oil. Usually 50-60 wt. This is maintained for the first 50 hrs of flight time to aid the engine in break in. The oil is then switched to a multi-grade, usually 20-50. The river though in the summertime is really hot, a switch to a higher weight oil would probably be warranted. Just for shock value a normally aspirated 300 horse six cylinder sells for about $25,000 new. 350-450 horse blown motors are in the 40-50K price range.
Clay

[1quickjet]

Hallet19, Yes, it did "tick" a lot when the psi dropped. Very hard to hear with the boat being as loud as it was. All the noise came from the right bank for some reason (?). Anyway, this only happened the one time. After the 50wt all was cool.

[Hallett19]

well, I don't feel to bad, so we must have had a similar prob, 50 weight it is, and I will tell you the results.

[not guilty]

Had problems with our 460 stern drive last year.Same thing , started out with 40-50 pnds oil pressure but after running up over 4200 rpm for a while it would drop. WOT at 4800 it would get bellow 30 (didnt run there long ).Tore the engine down last week after aprox. one long season (upper midwest)bearings are trash ,cranks scored & pistons are scored.Dont know where the problem came from but where changing everything from the pan to the pump incl.cooler and lines.Moral of this story is if you think its a problem dont play the oil wt. game like I did to correct it, Steel cranks & bore jobs arent cheap.Better get inside and see whats up! NG

[Hallett19]

THANKS ALOT NT!!! Now I am super paranoid, would'nt it have an adverse affect if there were bearing problems, like knocking or somthing ? Shit, they better not be bad, but I am thinking about pulling the motor out soon anyway, I need it running before havasu !

[squirts]

I run vavoline racing 50wt. in my olds 455 but I also have had journels pluged a 10 qt. pan and high volume oil pump. Had a problem like your have now. 1 you will know if its in the bottom end real soon if you keep running it. Wait to you feel the boat start to shake and the motor loose power and then the bearings freeze up and oh well you get the picture. Just hope your up river so you can float home. Good luck and lets just hope its the oil.

[Hallett19]

oh hell, you guys got me SUPER PARANOID NOW, this thing better not have any probs or I am going to open a can of whoop ass on ....... Valvoline....no, Clevite.... no no no, Ford 460 V8's.....shit, now I am mad !!

[Banshee]

Hi All, I suggest that a lot of you go back to what Lvjetboy said in his post. #1 TEMPERATURE. Most of the time if all else is normal temperature will have major effect on oil pressure. And as LV said, running at WOT puts a lot of heat into the oil. The heat mostly comes from the friction generated in the bearings. I rough rule of thumb is to think of it this way. If you are running at 3000 rpms and go to 6000. The amount of pressure being exerted on the bearings goes up not just double- but 10 times. Yes there is roughly ten times the amount of force on a bearing when the speed doubles. I work for a company that manufactures high-speed radial expansion turbines. They look very similar to a turbocharger for a motor but are much much larger. Our machines run at an average of 30-40krpms with our smallest units running right around 100krpm. In our test lab we see the direct correlation between oil temperature and oil pressure everyday. But we don’t have a ten qt. oil pan we have a 500 gallon oil sump. Assuming that there are no internal problems with the motor an oil cooler may be the best bet for keeping up the oil pressure at high rpms.

[not guilty]

Banshee, 30-40krpm huh,hhhmmmmmmm,,how much room does this thang require under the hatch??
Didnt mean to scare you HALLET, just lettin you know what happen on my end.Were still not exactly sure what caused my problem,looking at a couple different possibles.For sure we know there was a o-ring not in place on the external oil adapter this was letting some oil bypass the filter and cooler, probably the main culpret!
You do have an oil cooler dont you ??NG

[Wet Dream]

Don't blame it on the Ford. How do you think I feel knowing that the bottoms of Olds' motors are weak at high revs? I keep one eye looking ahead and the other bouncing between the oil pressure and tach.

[Banshee]

Hi, Okay I knew that the 30-40 krpm would raise a few eyebrows. No kidding that’s an average speed for the equipment we manufacture. The huge difference between a car engine and our turbines, or any turbine for that matter, is that there is only one rotating assembly that revolves together as a single part. There are no pistons, rods or any other reciprocating components. As far as size goes, our smallest and highest speed units would fit in the trunk of a car and our larger units would fit on a small flat bed truck. Actually the tolerances on our shafts are not all that much tighter than that of a precision race crank. But they are balanced too much closer tolerances on much more precise balance machines than automotive equipment is. Also the bearings we use, while still being constructed of Babbitt, are much more sophisticated that a crank or rod bearing. Unfortunately my company doesn’t have a lot of info about them on our web site but here is a link to what is there. Feel free to email me directly if you want to know more.
http://www.airproducts.com/cps/support_equip.htm#turbines
Scroll down to near the bottom of the page under the section called Expander Turbines.

[Hallett19]

oh, yeah, oil cooler, uhhhh, sure I have one of those, are you kidding me.....JEEEZ, do you think I am stupid ?!?!? HAHAHAHAHAH!!!! (I really don't have one)but I run synthetic, that should make up a little bit, and my motor dosnt rev anything over 4500 r's

[Banshee]

I meant no disrespect Hallett19. You probably know more about motors than I do!

[Hallett19]

no disrespect taken Banshee, I am really interested how those motors work !!

[not guilty]

Do most jets not have an oil cooler ? Ours is stern drive , come in here a lot because seems to be some good info on BBF, dont know a hell of a lot about jets so I didnt mean to ask a stupid question.Sorry NG