Oil pressure issue......
 

Okay.. now that I FINALLY have the distributor figured out, it looks like I may have an oil pressure issue.....


The engine is 555 cid 630hp N/A

Oil pump is a high volume Melling 10778.. . Main bearing clearance is .0028" on 1-4 .0030" rear main. Rods are .0027" Lifters are .0016"
Oil pan is a Summit Racing 11 quart.. have 10 qts in it currently to make sure aeration is not occurring.
-12 oil lines Mr cool MRC CPH-775 oil cooler with the thermostat bypass tube blocked. Fram HP6 Filter CP performance "extreme" oil filter adapter ..

Had cheap STP brand 20-50 in it...(long story.. been changing oil often due to a contamination issue)

Oil temp under 140 (not reading on the gauge)
55 psi @700 RPM
67 psi @ 3000 RPM
70 psi @ 3500 RPM
65 psi @ 4000 RPM

Ran a while.. oil temp stabilized at 170 degrees...
20 psi @ 750 RPM .
55 psi @ 2000 RPM
60 psi @ 3000 RPM
57 psi @ 4000 RPM
50 psi @ 4500 RPM
50 psi @ 5000 RPM


When I bring the RPM back down from say 4500 RPM to 3000 RPM the oil pressure comes back up in 20 seconds or so...


Do I have a mechanical issue or was it maybe the cheap ass oil I was running ?


THANKS !


Doug

i am sure you meant .0028 and .0030 on the main bearing clearance.try using brad penn oil and see how the pressure looks.

Why is the thermostat tube blocked?

Looks identical to my Melling 10778 pressures (with spring oilers) without spring oilers hooked up it was a bit better but not a whole lot.
I worried about it for years but never had a oil related problem.
Besides contaminant marks during assembly the bearings looked fine... (correct me if I`m wrong mike T)


Edit: noticed you have the big boy filters , I used to use Wix 51222R with a bypass.
I did some research and decided against the bypass filter. I believe it improved oil pressure at idle


https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

My initial test run, the oil thermostat wasn't working, allowing the oil to bypass the cooler..
5000 RPM oil pressure was 35 psi.. no idea of oil temp, didn't have the gauge installed yet but it was HOT !
So I plugged off the bypass tube to force all the oil through the cooler...

I'll look in to that one.. :)

So, dropping pressure at higher RPMs isn't an issue ?
Never had an engine do that before....

dropping pressure at higher rpm,s is an issue,that is when you need the pressure the most.

Do you know the clearance from the bottom of the pan to the pickup?

without a oil temp gauge how do you know if the oil is HOT?90% of the oil will bypass the cooler until the oil t stat opens sending the oil through the cooler.35 lbs oil pressure at 5000 rpm usually indicates lack of oil present at the oil pump pickup that can be caused by many reasons.

to answer your question,i doubt the issue is the oil but trying another oil brand might answer that question.

Try Valvoline Racing VR-1 20W50. Reasonably priced and carries good pressure hot. That will take the oil out of the equation.

My oil pressure has always dropped at WOT . Used to be worse with undersized oil cooler lines (40psi)
Again ran like that for years. As long as the volume is there it`s no ideal but does not cause any damage.
Now I run a Shumann pump and it still drops at WOT.

I`m open to ideas on why that is happening. Joes motors are rock solid at 75+ psi at wot.
I thought oil gets hot and thins out = lower pressure

I do NOT.. was the pickup that Summit calls for with that pan but didn't actually measure it...

My oil stat is built in to the cooler. when the temp comes up, it's supposed to expand and block off the bypass tube.. apparently it was failing to do that.
http://www.mrcool.us/mrc-cph-775.html (flow diagram on this page.. Can't seem to link it as a picture)

.
My initial test run, my oil pressure would drop to 35 psi at 5000 RPM. No oil temp gauge on that run, but I leaned against my remote filter in the bilge and about lost the skin off my arm ;)

I then plugged off the cooler bypass tube, got my oil temp gauge installed went out again with the same engine oil....
at 170 degrees I could hold my hand on the remote filter.. and came up with the pressure results shown in the first post... :)

Was thinking this may be my next step... :) Do they have a "street" and "racing" formulation of it or is the VR1 all the same ?

[QUOTE=Boatally Insane;4543265]Was thinking this may be my next step... :) They have both conventional and synthetic versions. I was speaking of the conventional and it runs under $5/quart in my area..

may want to pull the oil filter and dump it out,,see if anything is in there.hope there isn't.

Pickup could be too close if you didn't measure, also what fittings are you using? Sharp 90 or sweep? I ran sharp 90's in past with no issues (stock brass Merc) but with new builds I went all long sweep or straight for flow.

Also did you run these coolers before? Maybe the stat in cooler is restricting it?

I run melling select pumps with mains at .0032-.0035 1-4, and rear is .0040 rods .0026-.0027 lifters .0020 I have 78 cold even at idle, 75 hot running And 40 idle hot..

They're full flow 90's... but there are 6 of them.. Don't know if it's worth going to straights ? Would have to use longer hoses...


I didn't put the oil stat back in..
I plugged the bypass tube by cutting a 1/4" carriage bolt to the right length held in by a plug so, no restriction there... :)


http://i130.photobucket.com/albums/p...pscaa5kmqo.jpg

maybe because you have spring oilers a lot of oil is in the valve covers and not keeping the oil pickup submerged in oil.did you try adding an extra quart of oil?

Is that a HP Fram? or regular? I have sucked a regular fram enough to restrict, guys say they have with HP filters but I never did, for chits and giggles swap to K&N or Wix racing and see, could be simple as that

I was going to bring the same thing up, try a wix or napa gold filter, if that does not change it, might try plugging the spring cooler lines(think that what was said you were running) and see if that changes it, if you are loosing OP at WOT throttle usually a pan, drain back, lines issue. what pan are you running, smitty(articfriends) had the same issue recently on his dyno engine he's flogging and came down to drain back/pan

try adding the 11th quart of oil. there could be so much that hasn't made it back to the sump yet that the level is low.

His issue sounds diff than the issue im having with my junk ass canton pans. Mine starves for oil at 6000, oil pressure starts dropping from 80 or so to 35 or 40 at a very quick, erratic rate. You start adding oil it goes away but its NOT steady when it does it

What is your thought that the Canton oil pan is causing oil pressure loss on the dyno?

Ive seen similar issues to these though, it always comes down to volume of oil needed/supplied vs oil temp/hot viscosity vs what requirements dictated by . all clearances/controlled leaks motor has
Example: my 540 had similar clearances as described, i had some 5 w 40 or something to that effect in after dynoing at crocketts. Was only in for last couple pulls so i left it in motor. Going down river w oil at 220 degrees ehen you would lean on it it did EXACTLY what dougs oil pressure does. Took a couple rides though before i saw it, cruising at 55/60 psi at 3400, lean on it to 5000 u der boost and watch oil pressure steadily drop (not erratic at all). Cut filter open, changed oil, no metal, went to 20/50 and nomlonger did it unless i ran oil too long.
Ran oil too long cause oil pressure drop? In MY case motor was procharged, tune was fat, oil got gassed up and thinned out. I think thats why it did it with the thinner oil but not right away. Stuff was gassed up when i changed it so was even thinner than rated. I started doing my own tuning and got tune better and never saw much contamination in oil after that.

Your setup is just like mine except for the pan and block. I use a block adapter that does away with the relief valve then I use a filter with a relief valve in it. What block adapter are you using?

Oil pickup is becoming uncovered and sucking air, i previously ran 14 qt hardin and would run 11 or 12 qts and never had a issue. If a pan is a 10 qt pan, and manufacturer says put 9 in pan plus filter and you need 10 in pan to not starve motor, literally 1/2 qt less oil and your turning bearings to copper? Im perplexed by it, the trap doors are fairly stiff and barely open 1/4 or less of their swing. I left it like that as i figured it was how it was designed but i feel now that the oil is having hard time getting to the pickup. When i first ran this engine with this pan problem was worse, pulled heads and doubled size of drain back path, it was small but i had previously ran this rngine with same bearing clearances, lifters, pump, heads etc with only thing being different was the pan. Again, a good pan shouldnt starve motor the minute oil is 1/2 quart below max full, no way all of a sudden top end of motor is holding ALL of the oil. Going to mod a pan soon and try it with 8 qts oil, if mods work ill keep the pans, if not they are going down the road

My pan is
this one from Summit Racing..
Has a couple trap doors but nothing all too fancy...

https://www.summitracing.com/parts/sum-g3607/overview/
https://static.summitracing.com/glob....jpg?rep=False
Pickup...
https://static.summitracing.com/glob....jpg?rep=False
https://www.summitracing.com/parts/sum-g3623/overview/

Yeah.. mine too..

http://www.cpperformance.com/images/...e/625-7914.jpg
http://www.cpperformance.com/images/...e/14597_4_.jpg

http://www.cpperformance.com/p-14597...gen-4-bbc.aspx

and I AM running an HP filter.. Cut the last one open.. couple metal flakes still (long story) but looked ok....
hopefully it IS just the cheap STP oil causing it.. ;)

Do you have a gen4 or gen 6 block? They take different adapters.

If oil is 20 50 the only way switching to a different 20 50 will change anything is if oil is diluted by fuel/contaminated or its foaming and new stuff has better properties

It's a mark IV style Dart block...:)

Don't have much dilution... A/F ratio runs high 12's to 13.0 cruising @ 3500 to 12.5 WOT.. :)

I had an engine that was overfull and aerated the oil.
difference in that was the engine had to sit for a while 'till the air got out of the oil before the pressure would come back up...
This one will come back up after a few seconds at a lower RPM

You may need a oil pan with a kick out and better baffle's in it. 4.250 stroke can whip up the oil on a straight side pan.

So, I changed the oil to Valvoline VR1 20-50 and the filter to a Wix racing 5122R. Took it out today..
Don't have exact readings as my dash gauge is off a bit and my buddy dropped my "work" digital gauge in the lake.. (started working again now that it dried out.. phew....)

However, the pressure WAS dropping on the dash gauge once I got over 5000 RPM.. Oil temp was steady at 150 degrees measured at the oil pump outlet...

Cut the filter open AGAIN.. no big flakes this time but it was a little sparkly (maybe 3 hrs run time)

SO, now I need to decide if I'm throwing the stock engine back in and tearing this one down AGAIN or throwing some boost at it and run it 'till it pops... :cool:

Guess on a positive note.. If I HAD the blower installed I wouldn't be running over 5000 RPM all too often. :grinser010:

If you have run it some and changed the oil, after the 1st time seeing metal is not good...

So here's the deal.. Sorry if it's a little long winded.....

When I got this engine together, I fired it up in the garage before heading to dyno.. I cut the filter open and found a substantial amount of metal in it..
I figured, no biggie.. left over stuff from assembly. Put another filter on it and ran it some more.. STILL a bunch of metal.. Started investigating and found my timing chain was TOO TIGHT and it wiped out the lower portion of the cam bearing and my front upper main..

When I was assembling the engine I noticed that the timing chain seemed tight.. I had to start the sprocket on the cam dowel and rotate the engine to walk it up on the nose of the cam to get it on.. I contacted the manufacturer (Rollmaster) and was assured that was normal for their timing chain sets. Well, OBVIOUSLY they were WRONG.. It would appear my timing set was mis-boxed and was for a line honed block.. Rollmaster makes the gears slightly larger for line honed engines to take up chain slack.. UNFORTUNATELY they do NOT mark the bigger gears in ANY way.. :angry-smiley-055:
(have a cheap Comp chain on it currently)


So, anyhow, I had vacation and dyno already all scheduled so I replaced the cam bearings, rod bearings, and mains. Cleaned everything best I could but didn't completely disassemble the engine.. I then went to dyno... Made GOOD power.. Engine ran GREAT !

I installed it in the boat (less blower) Ran it for a couple outings but STILL kept finding metal in the filter.. I pulled the engine, COMPLETELY disassembled it.. Inspected and found where some debris had gone through the bearings, but did NOT find a source of the metal.. Cleaned EVRYTHING thoroughly !
Flushed the cooler and lines with mineral spirits 'tll not a single speck of debris came from it..

I installed the engine back in the boat.. Went out and managed to break the gimbal ring and spin the boat at 85mph.. Pulled the engine from the Corsa, put a stocker back in then Bought a Velocity 290sc and just got done installing the engine.....

I've run the engine now maybe 10 hours in the Velocty.. Changed the oil 3 times... First filter had a couple brass & a few steel flakes with some fine shavings. Second filter had a couple steel flakes, fine shavings but no brass. 3rd filter had less run time.. NO flakes but is STILL sparkly looking...
AND am dropping oil pressure above 4500 - 5000 rpm..... but it comes right back up when I back out of it..


I'm involved in this hobby 'cause it's FUN.. :Whatever:

I had this problem last year with oil pressure drop at high rpm on a pair of 489s. Mine was anything over 4800. Ended up being a windage issue.

So, how did you fix it ?

Changed the miloden pickup to a mercruiser. Also had truck pan last year. This year running 8 qt mercruiser with windage. My problem was most likely the pickup.