Oil pressure drop off

[USMC1812]

I am running a BBC 502 with a Melling oil pump. At start up the oil pressure is around 60 lbs, but after running it drops to around 10 to 0 lbs. I am running Valvolene 50 wt racing, with a 10 qt pan. I have move the gauge pick up to above the oil filter with no improved result. Any ideas? The boat runs great, but i don't want to blow this thing up!
Thanks
Doug

[stix818]

What are you running this motor in and have you had this problem with the engine before?
[ January 18, 2003, 01:48 PM: Message edited by: Stix818 ]

[USMC1812]

The boat it a Kona jet. The motor has run like this since i bought it last summer. The guy that i bought it from said that it was normal which i don't buy. Here some more on the motor. the engine is a 502 mark 5. here's what is suposed to be in it.
-ported & polished heads
-180lb valves springs
-670 lift cam
-all true roller rockers.
- j.e. pistons
-h.d. rods
-h.d. crank
-all new berings uper&lower.
-big h.d. melling oil pump with biger spring for more p.s.i.
Thanks for the help!
Doug

[stix818]

And this is happening even on the trailer? Or is it happening while you are decelerating or during acceleration? Sorry for the ?s, I'm just trying to understand more. It definately don't make since!!!

[USMC1812]

No sweat thanks for the help! I have not ran it that long out of the water. However once it losses pressure it does not seem to come back until it is off and has sat for awhile.

[Fiat48]

I am assuming what we are talking about here is that your oil pressure is 60 lbs when cold and basically goes away when the oil warms up. If we are not talking oil sloshing away from the oil pickup while driving, then here's some ideas:
1. Main bearing clearance problem or spun main bearings. Generally oil pressure gauge "flutters" but not always.
2. Oil pump pressure bypass stuck (doubtful).
3. an oil galley plug left out internally, or oil passage that has broken through and leaks internally.
4. If rod bearing clearance was that loose, I'd think it would knock.
Since you say it has always done this since you got it, you might suspect something done wrong when the engine was rebuilt. Like wrong bearings causing excess clearances or something like that.
You're right, it's not normal and certainly time to investigate.

[Rexone]

I'm going to mention this just so it's not overlooked.. if you have an electric pressure gauge, make sure it has the correct sender installed for the gauge. Incorrect readings are common with mis-matched senders.
Assuming that's not it, definately time to investigate before any more running. :)

[GofastRacer]

I'll add one more to Fiat's list. Melling makes a very good pump but, you might want to check the clearance between the gears and the cover. The reason I say this is because I seen one once that had almost .015 clearance and if that's the case, you will definitly have a drop in pressure when the oil gets hot...Just another thing to check!... :rolleyes:

[cookieman]

I have the same problem in my blown 509 at this time. I cracked open the oil filter and found metal in the filter. I took the blower off and looked under the intake to find #8 exhaust roller lifter without roller. I have a Isky cam w/ solid roller lifters. I wrote to Crane cams and to Isky cams, I got a reply from Crane which expain to me that to much spring pressure are used and the engine see idle and low speed running the lifter will not get enough oil splash to keep the roller cool. The lifter then burns the oil off and the axle burnishes, metal comes off and this will kill the lifter. I was told to make sure to not have any oil restrictors. I would start with the oil fliter first It will give some kind of clue if you have an internal problem. still working on mine at this time.

[Fiat48]

cookieman:
I buy everything but the too much spring pressure. How much spring pressure did they say was too much?
Also, there is a Comp cams roller lifter they say solves the oiling problem and supposed to be severe duty with more needle bearings. Part number is 866-16. Idling is a problem with roller cams.

[Infomaniac]

I put some new style lifters in mine this past season. Got them from Clay Smith but they are Crower. Pressure fed roller lube.
Holes in the body down low that line up with the oil passage when the lifter is up on the cam lobe.

[Fiat48]

Yeah, Info , I'm sure Comp's a similar deal. Comps are here: http://www.compcams.com/catalog/260.html
Makes you wonder why they never put that groove in there before. My stuff doesn't idle much so never had a problem, but a Daycruiser motor I built did. First time I had seen a roller lifter failure since the old Crane spring load lifters.

[Infomaniac]

Those look nice. Mine are installed or I would take a pic. They have a hole above the pin that directs oil pressure to the pin.
I wondered myself why someone had not done that before.

[Badboat1]

You do have the tall lifter bodys I hope for the Gen5 or6 block or the tie bars will bottom out on the block.And you will have a pressure problem.
Badboat1

[stix818]

USMC if this is the case then I would recommend tearing that bad boy down and checking everything. Something is definately not right and will cost you if let it go.

[Thunderbutt]

I would go with what Rexone said first if you have an electric gauge. From one Marine to another. What does the 1812 stand for other then the war?

[GofastRacer]

Infomaniac:
Those look nice. Mine are installed or I would take a pic. They have a hole above the pin that directs oil pressure to the pin.
I wondered myself why someone had not done that before. Yeah, I wondered that too!, here's a cool tool for lifter bores. Saves you money if you already have good lifters, that's my next item for the tool box!...
Lifter bore tool (http://www.powerhouseproducts.com/store/merchant.mv?Screen=PROD&Store_Code=PH&Product_Code=POW351026&Category_Code=LIFTER)

[USMC1812]

Semper Fi!, 1812 is the MOS designator for M1A1 Tank crewman. Thanks for all of the great suggestions! The pressure gauge is mechanical. Where should I start the inspection process?

[Fiat48]

I would remove the oil filter, cut it open and look at inside. If it's nice and clean with no chunks, especially copper looking stuff, celebrate by go getting a beer! Odds are the bearings are o.k.
If there is bits of copper looking stuff, go get a beer anyway. There's trouble down below.
I am assuming that the engine runs pefectly, no noises and the mechanical oil pressure gauge is good.

[DansBlown73Nordic]

I would try another gauge to be sure its not a funny gauge. If the new gauge shows the same deal get the tool box out. eek!

[Liberator TJ1984]

I usually have no idea what the hell I'm talkin' about but have seen this happen before. The guy that put his engine together, a Caddy 472 ,great oil PSI at startup then went away ...he was a firm believer in putting Silicon Sealer on every gasket.all the excess had circulated down to the bottom end and was plugging up the screen and losing pressure after oil got hot due to lack of oil to pump. since you did not build this engine ????..my 2*
Gopherrr

[GofastRacer]

I've seen that more than once! eek!

[Rexone]

I have heard of this as well. Anything partially blocking the pickup OR clogging up the oil filter could contribute to what you say is happening. Check the filter first as mentioned above because it's easiest. It may hold the key as to what the problem is or may not. Not knowing the history of anything in the engine puts you at a disadvantage so you just have to start methodically checking everything until the problem is found.

[Hotcrusader76]

I agree. Not knowing the identification of the internal parts can always be a headache. Maybe a good refreshen is in order. Pull the pan, new gaskets, some paint :D ...

[gnarley]

USMC1812, if you are checking with an electric gauge pull it out & put in a mechanical to test it & if you can plumb them together in a tee so you can cross check the pressure! I had a similar problem & isolated it to the electrical sender for the gauge. YOU have to verify with a mechanical gauge!

[USMC1812]

I cut the filter apart, and found nothing, it was clean, drank a beer. Next I plan on trying another gauge, if this doesn't work then the motor will come out and I'll drop the pan. The oil had a fairly strong gas smell. I just changed out the intake and put a new MSD ignition on it, so I figure that the smell is due to the dialing in process. What do you guys think?

[gnarley]

If you smell fuel in the oil be careful. If I had any fuel in the oil I'd drain it! If you put a drop between your finger & thumb and rub it together & it doesn't feel smooth but instead feels kind of gritty change it! Then find out why it's getting into the oil.
When you try that other gauge make sure it's mechanical.

[Infomaniac]

Fuel in the oil. The oil pan might come off by itself if not careful.

[78Eliminator]

Liberator TJ1984:
he was a firm believer in putting Silicon Sealer on every gasket.all the excess had circulated down to the bottom end and was plugging up the screen and losing pressure after oil got hot due to lack of oil to pump. since you did not build this engine ????..my 2*
Gopherrr No shit!? Same here. On my crotch rocket (94 Kawasaki ZX7R) I decided to open her up one night. I was at about 130 and hammered it and just about hit 160. When I let off the throttle, it sounded like I spun a rod brearing (that sound like a hammer is hitting the crank case). I nursed it home (I was very close having been going 160) and eventually pulled it apart. Yes, the rod bearing was toast, but why? I pulled off the oil pan and looked at the oil intake filter. It was COMPLETELY blocked with chuncks of silicone sealer. In fact it was trying to suck oil so bad, that the plastic oil intake was completely disfigured and melted to the case! What a dipshit the previous owner was. How irresponsible can you friggin be? Anyway, $1300 for a new short block and I'm running again as of last weekend......
ps Sport bikes don't have oil pressure guages. I would have seen this comming, had there been one.
[ January 22, 2003, 11:54 AM: Message edited by: 78Eliminator ]

[Fiat48]

Mechanical fuel pump diaphram bad can put lots of fuel in the oil. If you run one. You might check that, then clean oil, new filter. I'd think if there was a silicone problem you'd see some silicone in the filter. But not always.

[78Eliminator]

Fiat48:
I'd think if there was a silicone problem you'd see some silicone in the filter. But not always. Well, I would think that the oil has been changed a few times since the previous owner said the oil pressure drop "was normal". He was probably driving that way for a while. By now, all the stuff floating around is in a filter that's sitting in the trash and all the other fragments are bonded to the oil intake filter. In fact, before my engine blew up, I would inspect my filter and note how clean it was. Very misleading. It was clean because hardly any oil was flowing through it.....

[78Eliminator]

By the way, don't drive you boat till this gets figured out. Inspect your motor, fix what you think is causing the drop and go to the lake and dip the ass end in the water and start it. Note the oil pressure as it gets up to temperature. If it holds, tell you buddy, Zeke, to drive the truck up the ramp while you take a quick spin. If you come back after a lap and it's holding, have Zeke give you a silver to celebrate.

[AZKC]

I had almost the exact problem in my 454 and this is what happened soon after....
http://free.***boat.net/ubb/Avatars/Avatars/meltdown.JPG
3 and 4 rod bearings became a blob of clevite jawdrop
Take it apart and dont drive it anymore...
KC

[powerplay230]

What kind of oil, I remember having a problem years ago on a street engine with "bad" oil. When oil got hot it turned to a gel and didn't get back to where it belonged. Don't want to point fingers as this was a long time ago but it was a name that is also on oats...lol. boxed

[78Eliminator]

I hope you let us know what you find. If you end up mowing the lawn instead of working on the boat this weekend, you might be gay.

[stix818]

I know you probably have a haddle on things but I talked to my old man and he mentioned bearing clearances. He said that you may experience this problem if your clearances are are to wide.

[Thunderbutt]

Stix818:
I know you probably have a haddle on things but I talked to my old man and he mentioned bearing clearances. He said that you may experience this problem if your clearances are are to wide. I had a bearing clearance problem on a pickup truck but the oil pressure only droped at idle, when I accelorated the pressure came back and stayed there.
USMC1812 I loved thoes Tanks. They kept the bad guys away. Semper-Fi

[kojac]

We had a simialiar problem on my brothers 465 chevy. The oil pressure would go to 60# when cold. When it got hot or he would flog the motor the oil pressure would drop to 10#. We pulled the motor and found the oil pick up cracked. Put in new hi pressure pump and pressure problem resolved. One other time on 509 oil pressure dropped after engine ran for a while. When the motor was started the pressure was 60#. Figured the same problem. Pulled oil pan and found sludge pulling up around oil pickup. It would drain away when the motor was such. Could not figure where sludge came from because I am considered a nut by my boating friends when it comes to changing oil so frequently.(after every three or four outings) Actually they just consider me a
nut period. Kojac eek!

[hulshot]

OK I'll bite, I have had the same 540 for 5 years and have had it rebuilt 3 times because of the oil problem. I have never spun a bearing or suffered a rod knock. I run Valvoline 50-60 wt oil and when cold it will run 80-100psi and after running it hard and getting it hot it will drop to 40-45 psi while on it at 5k-6500 rpms and idle at 10-20 psi, when it idles for a while or if I just cruise for a bit the pressure will rise to 40 at idle and go to 60 -65 on it. I have had it pressure tested, have changed pumps 3 times went to a bigger oil cooler, (oil temp in is 198 and coming out is 157) and run a 14 puart pan. I have .080 side clearance on the rods, I think this may be the culprit but it does not seem to have affected it yet. I am going to run another oil pressure gauge directly off the filter housing to double check the gauge. I have also tried 2 different gauges with the same results. I run comp side bar rollers. and did find one of the rollers was cracked bad but did not come off the lifter. could this attribute to the oil problem also? Have never found bearing babbit in the oil filter but it has the occasionall metalic tint to it. I used to change oil every outing but now I change it every other time unless it is a long weekend.

[Rexone]

hulshot:
OK I'll bite, I have had the same 540 for 5 years and have had it rebuilt 3 times because of the oil problem. I have never spun a bearing or suffered a rod knock. I run Valvoline 50-60 wt oil and when cold it will run 80-100psi and after running it hard and getting it hot it will drop to 40-45 psi while on it at 5k-6500 rpms and idle at 10-20 psi, when it idles for a while or if I just cruise for a bit the pressure will rise to 40 at idle and go to 60 -65 on it. I have had it pressure tested, have changed pumps 3 times went to a bigger oil cooler, (oil temp in is 198 and coming out is 157) and run a 14 puart pan. I have .080 side clearance on the rods, I think this may be the culprit but it does not seem to have affected it yet. I am going to run another oil pressure gauge directly off the filter housing to double check the gauge. I have also tried 2 different gauges with the same results. I run comp side bar rollers. and did find one of the rollers was cracked bad but did not come off the lifter. could this attribute to the oil problem also? Have never found bearing babbit in the oil filter but it has the occasionall metalic tint to it. I used to change oil every outing but now I change it every other time unless it is a long weekend. While your situation might not quite be ideal at 40-45 lbs, I don't think its a problem. And it certainly isn't the same situation as the topic starters who is running at 10 to 0 lbs warm (not idling at 10-20 like your's). The fact that your's rises significantly as the oil cools off indicates a pretty normal condition. I've run motors hard at 40-45 lbs without problems although I'd prefer more psi. And you might in fact be giving up some with the side clearance.

[kojac]

hulshot:
OK I'll bite, I have had the same 540 for 5 years and have had it rebuilt 3 times because of the oil problem. I have never spun a bearing or suffered a rod knock. I run Valvoline 50-60 wt oil and when cold it will run 80-100psi and after running it hard and getting it hot it will drop to 40-45 psi while on it at 5k-6500 rpms and idle at 10-20 psi, when it idles for a while or if I just cruise for a bit the pressure will rise to 40 at idle and go to 60 -65 on it. I have had it pressure tested, have changed pumps 3 times went to a bigger oil cooler, (oil temp in is 198 and coming out is 157) and run a 14 puart pan. I have .080 side clearance on the rods, I think this may be the culprit but it does not seem to have affected it yet. I am going to run another oil pressure gauge directly off the filter housing to double check the gauge. I have also tried 2 different gauges with the same results. I run comp side bar rollers. and did find one of the rollers was cracked bad but did not come off the lifter. could this attribute to the oil problem also? Have never found bearing babbit in the oil filter but it has the occasionall metalic tint to it. I used to change oil every outing but now I change it every other time unless it is a long weekend. You don't say what type of cam you have. If you have a rollor you might check to see if you have restrictors for the valve train. Without the restrictors the oil will pump up to the valve covers and most of the oil will be in the block and not in the pan for recirculation. This may especially true if you have a hi pressure hi volume oil pump. hopes this helps. Kojac...

[USMC1812]

Ok, I pulled the motor and took off the pan. Nothing other than a little sludge. There were a few small pieces of gasket on the pick up but other than that, it was clean. Looking into the motor everything looks good. It runs great, no noises. Ideas?

[Infomaniac]

Change the pump while you have the pan off. Look at the relief valve and gear clearance in the old pump.

[78DiMarco]

Has anyone mentioned OIL COOLER? Do you have one? It sounds like you don't and that could explain 60psi cold and 10psi hot. The oil may be getting hot and hence no oil pressure. You mentioned that presure comes back after you let it sit for a while. :confused:
Do you have an oil temp guage? This would help to know how hot the oil is....

[gnarley]

78DiMarco:
Has anyone mentioned OIL COOLER? Do you have one? It sounds like you don't and that could explain 60psi cold and 10psi hot. The oil may be getting hot and hence no oil pressure. You mentioned that presure comes back after you let it sit for a while. :confused:
Do you have an oil temp guage? This would help to know how hot the oil is.... Yeah, what he said. I've said the same thing before and couldn't say anymore here excpt it happended to me too, 10 psi hot without cooler :confused: & 50 PSI hot with a cooler :D

[USMC1812]

any sugestions on a cooler?

[78DiMarco]

Check with Rexone. Rex Marine and many other suppliers carry what you will need. Olsen is one brand that is popular. There are coolers that are remote and some that attach to the block directly at the filter.
I bet this will fix your problem. At the same time add the temp guage then you will really know what is going on.
Good luck! :)

[hulshot]

I thought it fit into the subject somewhat, not the exact same concern but close. Yes I do have the restricters in the cam feed gallies. I thought since someone had mentioned lifter oil feed bleed off that I might have a problem in this area but I dont know exactly where the feed hole lines up in the oil gallies. how whould you determind if this was a problem. I have just never herd of this but am curious.

[Fiat48]

Infomaniac:
Change the pump while you have the pan off. Look at the relief valve and gear clearance in the old pump. Absolutely. I've never seen 50 weight oil so hot that oil pressure would drop 0 to 10lbs. If it was diluted by gas, maybe that's possible. But since the engine is out, better do some more investigation.

[USMC1812]

how do I check to see if the restrictors are installed?

[gnarley]

At the rear of the block above the cam are two oil galley's at 10:00 & the other at 2:00, they are threaded in & should be checked by removeing them. The OEM's look just like allen pipe plugs that threads into the holes and is about 3/8 inch long & if memory serves me the restrictors are about 1.5 inches long, they are very different in length.

[USMC1812]

Here is what I have found so far. The oil pump is a standard OEM replacement pump and not the high volume as I thought. So, I ordered the HV model. I am going to check the restrictors today. I also will check the tolerances of the bearings. what should I be looking for.
Thanks for the great help!
Doug

[USMC1812]

Gnarley Charlie,
Checked the restrictors like you said and they are only about 7/16" long. But there are 3? One at 10 and 2 like you said and then another at 11? Ideas? :confused: I ordered the new oil pump today. The boat is getting painted so I will not have an opportunity to run this thing for a few weeks. But, I want to get as much done as possible before the motor goes back into the boat.
Thanks,
Doug

[gnarley]

Doug sounds like stock galley plugs, depending what you run for valvetrain & rockers, that may make the decission to restrict or not. So IMHO from what I have read I'm leaning to say the oil just got to Damn hot! I'd still look closely at the bottom end, main & rod clearence & rod side clearence also Crank thrust. I personally think you'll be fine when youget an oil coller installed, it made a world of difference for me!
I only use Wix or NAPA marine oil filters.
[ February 06, 2003, 04:11 PM: Message edited by: gnarley ]

[Brewer]

I battled that exact problem a while ago on same motor (fresh 454 LS-7). Three times apart for inspection, clearances all good, very frustrating. Racing Ray, who used to frequent these boards (very knowledgable), mentioned he had same problem, turned out to be Fram oil filter. I always used Frams, but decided to try something else, guess what, with no other changes, not even the oil, problem went away. Something else to think about.

[USMC1812]

funny you mention the fram filter, that is what it had on it! I put a K@N but have not run it yet.

[bmff]

I have a 460 in a Ranchero. After 2000 miles and before 3000 miles the Fram filters would lose prime after it warmed up. A little rod knock when it started. Changed to Motorcraft and no more problems. Needless to say , I changed the ones in the boat too.

[GofastRacer]

Unless I missed it, there's one question that has not been asked yet!. How much clearance do you have between the pickup and the bottom of the pan???. I like to have a minimum 3/8", I've sucked the pan at a 1/4" before!. If this has been asked, please disregard!!... :rolleyes:

[HalletDave]

Brewer,
What brand of oil filter are you using on the BBC now? I have never been a fan of Fram.
HD

[Brewer]

HD, I'm using either the WIX or Baldwin. I still use the Frams on my truck, but only because they sent me a case!

[Bajajet]

Just some info on oil filters.
http://www.frankhunt.com/FRANK/corvette/articles/oilfilterstudy/oilfilterstudy.html#acd-pf2
Craig

[USMC1812]

What about the pan? It is a 10 qt pan made by Dooley. The pan is divided into compartments with a spring loaded door separating them. I checked the pan to oil pump pickup clearance and it is about 3/8". I see jet boat pans advertised what are these?

[Rexone]

USMC1812:
What about the pan? It is a 10 qt pan made by Dooley. The pan is divided into compartments with a spring loaded door separating them. I checked the pan to oil pump pickup clearance and it is about 3/8". I see jet boat pans advertised what are these? All correct except I've never seen a "spring loaded" door. They are free moving trap doors that capture the oil around the oil pickup. Dooley in my opinion is one of, if not the finest marine oil pans built.

[USMC1812]

i replaced the Melling oil pump with the high volume model. I was told that i might need to replace the timing gears to handle the increased stress. Is this right? The cam was made by Ultradyne.
Thanks,
Doug

[gnarley]

USMC1812:
i replaced the Melling oil pump with the high volume model. I was told that i might need to replace the timing gears to handle the increased stress. Is this right? The cam was made by Ultradyne.
Thanks,
Doug What type gears are they & how's the chain?

[USMC1812]

not sure but i assume that they are new and good?

[gnarley]

USMC1812:
not sure but i assume that they are new and good? Single tooth-single chain, double teeth-double row chain (tru-roller style) & hopefully not a nylon gear? that would certainly break. You need to put the gear & chain back on and see how tight the chain is. A little deflection is fine & if you don't know ask someone to look at it who does know.

[USMC1812]

Should I change to a gear drive to avoid the hassle? I was looking in the summit catalog the have a Pete Jackson for about $160. Advantages/ Disadvantages?
http://free.***boat.net/ubb/Avatars/Gearhead_Garage/Motors_and_Drives/pjj-327-1c.JPG
Thanks again for all of your help guys!
Doug

[Liberator TJ1984]

I've got a "Quiet" P Jackson and its been working well for me 3yrs. now...Gopherrr

[USMC1812]

was it easy to put in?

[GofastRacer]

I've been using a jackson for years and never a problem!, they are simple to install, just line up the dots and make sure the idler is not jammed between the cover and the block, done deal!.. :cool:

[cdaspeed]

has anyone used K&N oil filters?
hey usmc, where do you go boating around moscow?

[USMC1812]

We usually go to the snake or below lower granite dam, but have had some problems with the sheriff because of noise. Dworshak is great but they were releasing a ton of water. We were also on Pend Oreille last Labor Day. What about you? What kind of boat do you have? Where are you located?

[cdaspeed]

we run the cda river alot, we also go into cda lk mostly between Carlin bay and Rockford bay.
We have a 21ft daycruiser 455 berk
Are you going to show up a Carlin bay Jul 12&13?
there should be a alot of hot rod style boats there.
Mark

[USMC1812]

I am planning to. What is it like?

[cdaspeed]

Carlin bay is a great place! Good water,good food,good bar,GREAT VEIWS! They have cabins, camping, showers,everything you need.
The people that own the place are great.Very accomodating.Its also a great place if you have kids.
If the lake is to rough you can go up the Cda river all the way to Rose lk, or you can go up the St joe river all the way to St maries or even Calder if your boat has a shallow draft.
You can also get into half a dozen of the chain lakes from the Cda river.
You could boat for a week and still not see all the shoreline available,without ever taking your boat out of the water!
MARK

[eliminator777]

I read the things people have to say and it makes me wonder.I was doing a engine for a friend and I pissed every auto parts store where I live went thru 14 BBC oil pumps all hi volume none with tight enough clearance to be a runner.Let alone the gears not being the same height.none of the oil pressure springs the same length I guess thats what you get for 30.00 dollors. Years ago I was taught,an engine is like your body and the oil pump is the heart it circulates the blood (oil) thru. Makes no sence A guy spends a lot of money. Good crank(backbone)Good rods(arms)and then puts a junk oil pump. Because its new and it came out of a box.How many people out there took the oil pump apart and checked it.THINK ABOUT IT!!!!!!!!! :D :D :D :p

[steve@kps]

good suggestion..
My engine builder for my dragster does take the HV77 apart and increases the spring pressure and checks everything out. Weld on the pickup tube and off we go!

[Infomaniac]

You mean like this?
Step by Step Oil Pump Prep (http://www.havasubarney.com/cgi-bin/ikonboard.pl?s=3e554b42052cffff;act=ST;f=25;t=42)