-stig-

hello guys!

i have a car in the garage that is giving me a headace...

The oilpressure going in to the engine is low, and a little unstable. about 30psi at 1000rpm idle and doesnt get any higher than about 70psi. ( a bit more at cold engine) it tops out at 4000 rpm, and stays there and then drops if more rpms are applied.

the gauge ( that is after the oilfilter) is proven to be correct, and pressure going in to the filter is spot on the same as going out of it.

but heres the problem, OUT of the engine, at the frontcover i get about double the oilpressure. it goes easy up to 140psi at cold engine, and are stable and calm, just at other rew's i've got. not the unstable jumpy pressure measured going in to the engine.

so i took of the oilcoolers and the piping, but cant find anything wrong. this is with the orginal twin coolers.

but, have anyone tried to measure the pressure at the frontplate? can it be that much pressure drop over the coolers?? are going to try to bypass all coolers and piping tomorrow, but doesnt really help that much..

and, the engine is a newbuild, with fresh pump/regulator.

thanks,stig

RotaryEvolution

iTrader: (30)

pretty sure the REW cooler has a thermal bypass same as the FC, which will cause pressure to change before and after the cooler.

as for the drop after 4k, probably due to an inefficient oil filter.

30psi idling is normal, 70psi while driving is normal.

in fact, you DO NOT want to try and increase the pressure as you seem to be wanting to do. pushing pressure up to 100psi can and likely will cause issues with the oil delivery system to the turbos and force oil past the seals and eventually damage them. more is not always better. the stock regulator seems to keep the pressure at around a max of about 70psi which is good.

DriveFast7

iTrader: (1)

While the oil coolers are out have them ultrasonic cleaned. There's more pressure drop than you think going thru the oil coolers, especially if they're plugged up with metal particles. It's a very good idea to clean the oil cooler after an engine failure.

Bypassing the oil coolers just to test pressure at the oil filter is a great idea.

The front pressure regulator bypasses at 150psi so I think you're okay with the pressure the motor is making.

-stig-

Im pleaced with 30psi idle and 70psi at 4000rpm, but i dont like it when the pressure drops over 4000rpm, hos rough the pressure is (jumps around å bit) and the fact that on a cold engine, when the coolers should bypass i have the double pressure before them than after.

I have buildt a couple of engines, but never æren this behaviour before.

It cant be the oilfilter, it has vern changed, and i have measured the pressure just before the filter, same thing there.

Thanks for the answears guys!

RotaryEvolution

iTrader: (30)

you're probably getting a little bit of pressure bypassing the front cover o-ring after the engine is warmed up, not uncommon but also not too much to worry about unless the o-ring has taken a vacation. then you will definitely notice an issue with severely low pressures all around.

honestly i think you're worrying a bit for nothing, just visually inspect the integrity of the oiling system. ie no ripped oil cooler lines, small punctures in the oil coolers dripping oil, no cheapo oil filters, oil level topped off, etc.

-stig-

the oilsystem is out of the car and inspected, all ok.

next step tomorrow is to bypass the hoses and coolers, but that will just confirm that its something off in the cooling system.

I cant have a system like this, when engine is hot the pressure is a bit lower, down to 44-50psi cruising, and it does not rise with the rpm. but i have not checked the pressure out of the engine when its hot, try that tomorrow as well.

its not normal behavior for a rew.

maybe the regulator that was put in is wrong/for a older 13b with lower oilpressure? then i get all that pressure difference over the coolers? 5bar difference is a bit...

RotaryEvolution

iTrader: (30)

do what you want then.

-stig-

so you really think that so much differential pressure is normal? and 50psi at 4000rpm, not rising any higher?

just to be clear, those measurements in first post is on pretty cold engine.

RotaryEvolution

iTrader: (30)

if the engine is original, yes. if rebuilt then it could have many used parts which will attribute to it. it's still not anywhere remotely near a critical level unless you are pushing it to extremes and often, like say it was a tracked car and oil temps were becoming high.

-stig-

its a new build engine, the last one seized up due to oil problems, this engine is just run in at low rpms. most parts in the engine is new, bearings, pump, regulator, plates and shaft. last time the symptomes where much the same, but with more pressure drop on top. car made approx 400 rwhp.

that too is a reason why i just want to get the pressure ok. not my car this, so would like to get it ok before i return it.

I didnt build the engine, so all i know about it is what the owner tells me.

RotaryEvolution

iTrader: (30)

if so then did you have the coolers checked and flow tested? this is something most people neglect when a motor has a lack of lubrication massive failure. all that debris usually winds up scattered through the whole system.

Matt535

I have personally seen a "rebuilt" 13B-REW probably with something jammed in the relief spring in the oil pump (well I assume that was what was wrong) hit 210psi oil pressure at 7000rpm. The autometer oil pressure gauge in the vehicle actually ruptured and filled with oil at that point.
It was a shoddy rebuild, but once the oil pump was removed and a stock spring assmebly was put in, it had 30psi/70psi as the OP describes.
And apart from the exploded gauge (and oil everywhere) the engine lives happily to this day

-stig-

time for a little update...

with engine semi-hot (water & oil at 80degre celsius) i get aprox 20psi at idle(1100rpm), and it peaks with 58psi@3000rpm but doesent go any higher. this is going in to the engine at the oilfilter. OUT of the engine i get about 60psi at idle, and peaks with 150psi @ 3500rpm and stays there steady and fine.

this is after i have changed the oilcoolers.

Next thing I'll try is to bypass the coolers. but i doubt its them..

but im banging my head against the wall here...

-stig-

the next thing i did was to change the system from a other car i got in my garage that i know is working. same thing...

then i tried to loop the entire oilcooler system with a new hose i got made, but still not more than 88psi max pressure in to the engine.

sooo i guess i have lift the engine out of the car next.. damn...

-stig-

so!

i lifted out the engine today and found nothing really wrong.

tested the rear regulator to about 110psi, and the front spring where 71.3mm long, it should be 73mm according to the manual, but still no big difference.

the oil pickup where a bit close to the bottom of the pan, but i cant see that it would be the issue due to the good pressure out of the pump.

stuck again!

RotaryEvolution

iTrader: (30)

stuck on what?

your pressures are still within range. i'm not sure what you're looking for but those #'s will not cause an oil system failure. i can only assume you had a critical failure with something on the last engine and now you're paranoid that this one will have the same issue.

it only takes 5 seconds of no oil pressure to kill a motor, no one watches their pressure gauge indefinitely.

-stig-

i have never seen a REW engine with a top oil pressure of only 58psi. This is a 400rwhp engine, and needs a bit more. It peaks at 3000rpm at said, and it begins to go down if i rev it hard. normal?

the last engine seized the front stationary bearing, and took out the rest of the engine.

the new front bearing still looks fine, checked that too today.

RotaryEvolution

iTrader: (30)

then modify the rear oil pressure regulator.

your previous failure wasn't due to that oil pressure, i can assure you. the front bearing seizes first when there is a real lack of lubrication, as i mentioned something else caused it or the bearing was severely worn to start with.

-stig-

but i tested the rear regulator, its a shim-able regulator. it opens at 110psi as it should, just like a orginal REW regulator. i get just over half that pressure on the engine.

RotaryEvolution

iTrader: (30)

assuming it is the race regulator with the 2 shims, are the shims installed? if not then it likely will bypass at lower pressures, as i'm not sure how you're testing it's breach pressure. the 115psi it's rated at iirc is with the shims installed.

the stock regulator bypasses at about 65-70psi but it is a 110psi regulator(as per the factory service manual).

was the oil pump reused? if it ate all that debris then the pressures are likely to suffer from the wear on the pump.

-stig-

i use this to test them: http://www.pineappleracing.com/oilregulatortool.aspx

yes, its the racing regulator and it got its shims installed.

just cant get my head around this on, sorry to bother you!

i'm really appreciate the help!

RotaryEvolution

iTrader: (30)

and the pump? used? was there any scoring on the faces of the gears? it's pretty common with all the turbo motors but ideally you want scoring to be minimal for the highest volume which sounds like your issue is low volume causing slightly lower pressures.

is the thermal pellet also still installed or did you put in a solid one to block the front shaft bypass port? a failed thermal pellet will cause the front bearing to eventually seize because it bypasses a large amount of oil from the front half of the engine.

any modifications to the rotor oiling jets? this has a HUGE impact on oil pressure and eats up a ton of the volume that the system pushes.

-stig-

sorry, forgot about the pump!

the pump is brand new!

solid thermal pellet, so no blowby there.

the e-shaft has its orginal oil-jets, REW e-shaft.

the o-ring behind the front cover was fine and like new.. was hoping that was it

but then again, the pressure i measure out of the frontcover from the pump is fine, high and stable.

Thansk for the inputs!

DriveFast7

iTrader: (1)

So to summarize:

New oil pump: CHECK
Oil exiting the engine peaks at 150psi: CHECK
Rear oil pressure regulator bypasses at 110psi: CHECK
Low oil pressure above 3000rpms measured at the oil filter


Wonder if theres blockage after the rear pressure regulator and before the oil filter. Like in the oil gallery between the two. And, how close to the pan is the oil pickup tube? Shouldn't there be at least an inch of clearance? Is the pickup screen clogged?

kensin

iTrader: (22)

Mine has high pressure,40 at idle and 60 above while cruising and 110 plus at wot !!!