Another Oil Pressure Question?

[jeffroe]

running a 468bbc w/871 intercooled blower, sunday running across the lake about 5000rpm (water was very rough 3' waves from all different directions no wind lots of big boat wakes) 70mph+ i looked down and the oil pressure(mechanical guage) had dropped to 30psi :cry: reduced rpm and settled down in the water and it came back back up to 40 at idle? i checked the oil very clean no stink or dark color from bearings and no motor knock either. could it have been bouching around so much that the oil sloshed away or foamed around the pump? i have a 8 quart oil pan with a tray and i run castrol gtx 20w-50 oil. fired it on the trailer a hour later at home and it sounded good w/40psi at idle? i thought about changing oil to sythetic moble1 15w-50 but the current oil only has 4-5 hrs on it. once again it was rough and had it under boost for atleast 3-4minutes 5000rpm range. thanks jeff.

[Wet Dream]

Sounds like you were probably running a little low in the pan. Add that to thinner oil due to higher temps while running that hard for that long. I'm not a big fan of Castrol in bigger engines, I like it just fine in 4 bangers and such. I use Valvoline VR-1 20-50 when the water temps are cooler in the beginning of the season, but through mid season and after, it gets straight 50wt.

[ERV JR]

I Would Say That It Is Due To The Choppy Water And The Fact That U Were Turning The Motor Hard Then Pumps The Oil To The Top End And There Is Less Oil In The Pan And The Pickup May Starve For A Bit And Then Grab Oil And So On. I Have Seen It Happen In Some Of Our Drag Cars When They Launch, Ure On The Trans Brake Hard @ 5200rpm Then U Leave Wheels In The Air And The Oil Pressure Drops Due To Oil Being In The Top End And Sloshing Away,same As Being In Chop I Think

[BRAWNY]

what size pan are you running?
might try a larger 10qt. pan.
brawny

[robsquezn]

try valvoline race straight 40 wt or 50 wt been running it in 2 jets with great success & its what tom papp told me to run....good luck

[beerjet]

I used to run multi-grade until oil pressures dropped .
Went to straight (valvoline) 50 and cold start it's in the 90 range and haven't seen it go below 60 since .
-beerjet-

[jeffroe]

put in mobile1 50w synthetic and idle pressure went from 40psi to 60psi, it's been raining here all week so i have to wait til this weekend to take it back out. think that the castrol GTX stuff must have broke down (still cheering for JOHN FORCE!!) i heard that oil temps in a jet are more of an issue than water temp and can break down alot of non synthetic oils under heavy loads.

[atxwrangler]

you had no mention of an oil cooler.do you run one??? you should!especially need one for those long distance runs with a blower motor!

[Devilman]

you had no mention of an oil cooler.do you run one??? you should!especially need one for those long distance runs with a blower motor!
How come you ain't at the lake, foo? :rollside:

[jeffroe]

no oil cooler? i came from car drag racing where a oil cooler can get some fresh air but how or what type do you use on a boat?

[don johnson]

Sounds to me like there could be a number of things going on, or combination thereof;
1. Oil control. Crank could be whipping the oil in the pan (windage) due to; Overfilled pan or no oil control (windage tray). This usually causes erradic oil pressure however where oil pressure will jump around. If your oil pressure was consistent then this is probably not the issue.
2. No oil cooler. I agree with atxwrangler that if you at WOT for extended periods an oil cooler is manditory. Especially in a blower deal. The tops of the pistons pass on intense heat to the oil in a blown motor. Actually the oil carries off most of the piston heat. If you are a little lean on the mixture that will make this affect even worse....
3. Not controlling the oiling to the upper end of the motor and you are pumping all the oil into the overhead. An 8 qt pan should be big enough so capacity should not be the cause. However, for extended WOT use i would recommend a larger capacity pan.
Most likely your oil is getting hot. 3-4 minutes at 5,000 RPM will get the oil plenty hot without a cooler. Especially in a blown motor. I suggest you invest in a good cooler from Teague or Dan Olsen. Either would make a huge affect on controlling your oil temperatures.
Just an fyi.... As a rule of thump you need to carry a minimum of 10 psi of oil pressure for every 1,000 RPM. Thus 5,000 RPM should have 50 psi oil pressure.
Good luck!

[don johnson]

no oil cooler? i came from car drag racing where a oil cooler can get some fresh air but how or what type do you use on a boat?
Water to oil type. You will need to plumb either;
1. a pickup from the pump/ bottom of the boat to run fresh water thru the cooler.
2. Run the cooler in line before the engine. This is the most typical installation.
Teague has a great stand alone unit that bolts to a stringer. Dan Olsen has a cool one the hangs off the side of the motor. If you have room the Teague unit is more efficient.

[jeffroe]

called teague asked about oil cooler and they said jets run so cool that there really not needed? i don't have a guage on my oil temp but has anyone ever checked befor and then after oil temps (on a blower motor) after adding a cooler? i need to set-up a remote filter also and was going to ad a cooler at the same but not sure what to do now :220v:

[SmokinLowriderSS]

Teague is mistaken on that one. I can't first-hand my oil temps, but next year when my remote filter goes on, so does a temp gauge. There are lots of others here, both with and without jets who have found oil temp problems, and needed a cooler. The stronger the motor, the higher RPM you spin, the more heat you put in the oil, both from piston under surface heat and the shear forces in the bearings. I have not had any temp symptoms yet, but am still nudging the motor stronger each year. I just wonder at what point it's going to come up.

[Mike D..]

called teague asked about oil cooler and they said jets run so cool that there really not needed? i don't have a guage on my oil temp but has anyone ever checked befor and then after oil temps (on a blower motor) after adding a cooler? i need to set-up a remote filter also and was going to ad a cooler at the same but not sure what to do now :220v:
I have a 540 with 10# of boost 1st season oil would hit 250 plus after a hard pass, with an olsen oil cooler beginning of summer wouldn`t get over 210 (water temp)at middle of summer hits 220 maybe 230 but cools down to 180 very quickly. I am running oil temp and oil pressure gauges. water temp seems to be a constant 140 block gauge reads same

[jeffroe]

i assume you are running water thru the oil cooler from the feed line on the jet befor it goes into the motor.
where do i find a gary olsen cooler, i looked at teagues and hardin's not sure who's is better?
oops it's dan olsen found it :crossx:

[don johnson]

I run the big Teague coolers on my twin GT 572 blower motors. Each motor makes 1,100 HP and my oil temps never exceed 210 degrees. Even after 6,000 RPM sustained runs. The Teague cooler is supposed to be the best, at least that is what I was told.... It is a stringer mount type. Available in chrome finish and when plumbed with braided and nice fittings show very nicely...

[jeffroe]

are you running thermostats on the cooler or the remotes are they needed?

[Hallett19]

what size pan are you running?
might try a larger 10qt. pan.
brawny
yeah, you need a bigger pan, 8qt for a blown motor turning that many rpms.... bad idea :rolleyes:

[jrork]

All good points given already. For what it's worth, I'm running a 10qt pan on a weeny motor compared to you and if I run for any length of time, I can see the oil pressure begin to drop off. Number of other guys I run with have the same issue.
Cooler is next in line for my boat. Heres a link to some. REXMarine has em too but the online link didnt work. Give them a call though too. Good guys.
http://www.cpperformance.com/products/Oil/oil-coolers.htm

[bp]

here's the rexmarine address.
http://www.rexmar.com/sectiono.htm

[Hallett19]

All good points given already. For what it's worth, I'm running a 10qt pan on a weeny motor compared to you and if I run for any length of time, I can see the oil pressure begin to drop off.
Yeah, me too jrork, I run a very very mild 460, setup more for economy than power and I run a 10 qt. I run an oil temp guauge which is IMPERATIVE for jet boats and I am being lazy on getting a cooler but I run 260-280 degree oil temps sometimes (15W-50 Mobil 1 Synthetic) when running full bore (4500rpm) for a few min.
You need a bigger pan bro !!

[jeffroe]

ran the boat sunday and she's hurt :cry: down to 20-30 psi under power 60psi at idle. well summer is almost over, yank it out put in bearings this winter might be a good time to upgrade to a set of alum heads :rolleyes: going to put on a cooler for sure when it goes back in (that might have been why it puked in the first place) with a oil temp guage. i did race another daytona sunday 300hp outboard 21' cat hull pulled him on the top end w/20psi oil pressure :crossx: what the hell!!!!!
thanks for all the info. jeff

[jeffroe]

tore the motor apart and found not only did i have water in the oil (warped intake manifold) but also (no surprise) the bearings are all worn from the lack of oil. i bought this motor complete from a local speed shop just befor july 4th and have been fighting one problem after another sense. took the motor back to the speed shop and he was looking it over and asked me how many quarts of oil did you run? i said you told me 8? he filled the pan with oil (off the motor shitty looking back yard welded junk pan) and it held 14 qrts :mad: sh*t!!!! i ran it out of oil :argue: this is what happens when you buy used parts :cry: he is cool about it and agree's to rebuild w/new bearing ect and get me back on the water (just in time for winter :yuk:) oh well next year "thats when i'll really start having fun right" live and learn.
Milodon oil pan on the way 10qrts.