Oil related questions

[1968Droptop]

My oil pressure drops to 49 after a hard run. Is that something to worry about ? it comes right back if I idle it, or shut it down. I've yet to see it drop below 49 to date, and I've made some long boost runs.
My oil temp is ice cold. When the engine was crispy new it ran about 180*. Now at 20 hours I can barely get the gauge to come off 140*. I'm taking the temp right off the pan, and no oil cooler.
Comments ?

[paradigm shift]

I would double check your oil temp gauge I think it is not correct. Hard to believe oil is that cold with no cooler. 49lbs is nothing to worry about but it sounds like once your oil cools pressure is back up. :idea:

[1968Droptop]

Yeah after it cools, which only takes a couple of minutes, it reads 60 at 5K. 49 at 5K after working the engine.

[78 propduster]

whats your set up? water temp.?
I'm running a jet, valve to restrict pressure, bypass valve set at 10psi, holds pressure to 13psi, water temp. at 160*, oil temp. at 240*. Will run there all day up to 3800rpm. I make one short run and at 9psi, 6000rpm and oil temp. jumps to 280*. I'm installing an oil cooler.

[cruser]

Drop,
If the pressure dropis heat related, it will take some time for the oil to cool off. It takes time to heat up, it takes time to cool off. If the comes right back once you let off the throttle, I would think you are getting oil up onto the spinning crank/rods. Letting to motor drop to idle and geting back on it again won't change the oil temp very much but will alow the crank to shed any oil picked up via windage.
Also, judging by your other posts, you don't stay in the trottle that long and shouldn't be heating the oil up all that much. Your temp guage is telling you that.
I could be wrong though.......

[Shadow1]

Yeah after it cools, which only takes a couple of minutes, it reads 60 at 5K. 49 at 5K after working the engine.
I thought the rule of thumb was 10 psi for every 1000 rpm. You are on the border with 49 at 5000 and if you require the oil to cool to regain pressure and your gage reads cool oil something is wrong with the gage?
What oil/wieght do you run??
I like shell Rotella, the old forumula, not the new J4

[1968Droptop]

Set-up; Dominator jet, 521 BBF, 8-71, .721 rollor w/ 1:8 Miller rockers, water pressure reg. (about 2lbs. at idle, 12lbs. wot), 160* t-stat, Lightning jacketed headers, 10qt. Armondo Racing oil pan, and 2 one qt. filters. I run 11qts. total in the oiling system. The water temp never goes over 160*, to which I'm very pleased. I'm running Valvoline Racing straight 50wt. This is the Off-Road use only oil, and still has Zinc in it.
I may of lead you down the wrong path. It takes like 5 minutes of idling or not running to cool the oil, not just a second or two. I never fire it up and peg the throttle, and I always let it idle for a couple of minutes b/4 shutting it down.
I'm just a little concerned I don't have quite enough oil pressure, as I too thought 10lbs. per 1K of rpm's. It runs like 65-70lbs. at 2.5K on initial start up (ice cold), then settles to around 60lbs. after the engine warms.
I also have read that peeps like to see 180* on the oil temp. I know it's getting warm, as the o/p drops a bit when running it hard. I also have a puke tank, whick collects about 1-2 tablespoons of water after a long day. There is no sign of water in the oil, or under the valve covers.
Cruser; I'm starting to run it harder and harder as I gain confidence in the boat/engine. I took a 10 minute run at 5.2K the other day (which was about 85ish on the speedo). The o/p stayed right at 49 and never dipped.
My oil pump came with a shim kit, and I was thinking about adding a little more pressure to it ??? Thanks for the input guys.

[Ralph Brunt]

have you talked to paul kane yet? we did some r&d about this verry issue, i will let him explain.
ralph

[cruser]

OK then, you may indeed be heating the oil up on those runs. However, I beleive that the fords are happy running a bit less pressure than the Chevys. ~50lbs sould be enough pressure regardless. The 10lbs/1Krpm is just an approximation and 49lbs @ 5200rpm seems close enough for me. I have the same issue with my oil temp gauge. The highest I've seen it is ~140. Got to get that figured out.....
Mine runs 85lbs cold and goes up from there until warm. After it warms up, it stays around 60-65 or so. I don't worry about it unless when I get off it, it drops really low at idle. Then I know it's gotten way to hot.
By the way, why do you run 50 wt? I started out with 20-50 at first and dropped to 10-40 now. Didn't really change the presssure much. Thinking of going to synthetic next year.

[1968Droptop]

By the way, why do you run 50 wt? I started out with 20-50 at first and dropped to 10-40 now. Didn't really change the presssure much. Thinking of going to synthetic next year.
That's the brand and weight oil reccomended by my engine assembler. He set up the tolorences loose, and told me to run the striaght 50. I checked with a couple other trusted local h/p engine assemblers and they agreed.

[Scapegoat1]

I run 50 w torque full synthetic and it seems to reed around 48-50*
I run 790 horse motor with an offshore cooler and under hard runs it will get up to 180* but when I come down to an Idle it drops to 140*

[Sleeper CP]

My oil temp is ice cold. When the engine was crispy new it ran about 180*. Now at 20 hours I can barely get the gauge to come off 140*. I'm taking the temp right off the pan, and no oil cooler.
Comments ?
"Taking the temp right off the pan" :confused: Do you have a temp sensor in the pan? If so I would check it. I can't see you running under boost for any amount of time and not getting the oil above 140*. It is better for the engine for the oil to be at or above 180*. Depending on the type of oil your engine will make max power between 200-225* typically.
You should be able to get, and you want to get your oil above 215* from time to time. It is at this temp and above that you will burn/evaporate the water condensation out of you oil. If you never get it this hot you will have a lot of moisture in your oil:( .
It has been discussed I think in Just Jets(you can do the search) about oil over and over. You can take this input for what it's costing you, which is nothing: I would dump the 50wt and run a top grade multi-viscocity synthetic. That straight 50wt is about as "old school" as you can get. There is a reason every Nascar,F-1,Indy-Car& Moto-GP team's run synthetics and I don't think you'll find a top Baja 500&1,000 team that don't/doesn't either. :idea: Just my .02
But get the temp up, something is not right. And remember volume is more important than the pressure. About the best oil pump you can have for that engine is the Mellings HV pump. Great price and the best built pump on the market.
Our 565" runs at 140* water temp 190* oil temp under most conditions. It will hold those temps on a 14 mile run at 50 mph at 3,900 - 4,000 rpm's. With an oil cooler and 10-11 qrts of Mobil One 15-50.
Sleeper CP
Big Inch Ford Lover

[1968Droptop]

"Taking the temp right off the pan" :confused: Do you have a temp sensor in the pan?.......
..........That straight 50wt is about as "old school" as you can get. There is a reason every Nascar,F-1,Indy-Car& Moto-GP team's run synthetics and I don't think you'll find a top Baja 500&1,000 team that don't/doesn't either. :idea: Just my .02
Sleeper CP
Big Inch Ford Lover
As always I thank everyone for they're input !
I do indeed have a temp sensor in the pan (Autometer). One bung is used for my hard-lined oil drain, the other has the sensor.
The 50wt being 'Old School' may be the case, and I know all those race teams run synthetic oils. One thing I thought about though, those guys rebuild they're engine after every use. They do indeed run 'em hard and long, but the engine is all new time every time they go out :idea:. The only reason I'm running 50wt is that's what the engine assembler recommended using, and he's got a good rep around here. My local boat shop, Skagen Marine, also runs it with good results.
P.S. I'm yes I'm running an ARP o/p drive shaft.

[Sleeper CP]

FYI:
F-1 teams have to run their engine's for two complete weekends or they get a 10 postition qualifing grid penalty. That's quailifing and racing a 18,000 rpm 150 cu/in 800+ hp engine(nothing else like it) for two weekends. Granted they probably get to change the oil(i'm just guessing) but there is no way in hell petroleum oil could live under those conditions.
Sleeper CP
Big inch Ford Lover

[Shadow1]

Why are the motors run so cold?? To prevent detonation? Gas doesn't atomize properly until 185 degrees. Wear at 160 is 4 times as great as at 190
Power is heat so why don't you guys run hotter were the motor runs more efficently?
I run 15-40 Shell rotella and idle hot at 50 and anything above an idle is 60 plus. I run the high volumn pump

[Sleeper CP]

68DropTop,
Check out the GearHeads thread " Which Oil" I just bumped it for you.
Sleeper CP

[Sleeper CP]

Why are the motors run so cold?? To prevent detonation? Gas doesn't atomize properly until 185 degrees. Wear at 160 is 4 times as great as at 190
Power is heat so why don't you guys run hotter were the motor runs more efficently?
I run 15-40 Shell rotella and idle hot at 50 and anything above an idle is 60 plus. I run the high volumn pump
Shadow you didn't state at what temp you run your engine.
I can only speak for my self on the low water temp. Because of the way the jet pump produces(moves) water thru the system we have to balance the water flow at idle and the flow at 4,000 rpm's. If I try to run the engine at 170-180* at 4,000(with alot of flow and force) the valve will be shut down so much at idle there won't be any water flowing thru the engine. The temp will go to 240*. Since jet boats are a pain in the a$$ to run a thermosat on most just run a pass-thru open system which caused yet another problem.
The pass-thru open cooling systm isn't realy telling you the engine temp. It is telling you how hot the water got passing thru your engine before you dump it out. There is a difference. It would be the same as running your garden hose across your stove and saying your stove(heating element) is 140* after the water ran across it for 4 seconds. No it's not.
So my brother and I decided to run an oil cooler and an oil temp gauge more than 15 yrs ago. If the oil is 200* then the working parts in the engine are 200 degree's or somewhat hotter since the cooler shed's some heat out. It may not be correct, but we can control a fixed amount of liquid and can regulate it.
If the water leaving the engine is heated up to 140* then the engine is running hotter than that... how much hotter I don't know.
Sleeper CP
Big Inch Ford Lover