FC3S Murray

iTrader: (7)

That is too bad man. I hope the new regulator fixes the problem for you, it didn't for me.

ViperDude152

Ya hope so too. I have been driving around with the oil pressure staying around 40 psi no matter what. Except on cold starts, then it hits near 60 and drops.

I replaced the oil pump, chain, front cover regualtor and the front cover o-ring. I have an oil leak under the oil filter pedestal but nothing that would release that amount of pressure.

Who knows, this engine was a rebuild that I removed from another rx7. I have no idea if it was rebuilt right. I have noticed somthing scary though. My oil level keeps getting higher. Its not milky and doesn't smell like fuel. Im stumped on that one.

I have my idle around 900 to keep the idle oil pressure up and the volts too since my FD alt is having a hard time at anything below that.

I will figure it out. I wish I could tear everything apart and do what I want and let you know but I have a feeling I will have to loose my job before I find time to work on my car. I have no spare vehical to use if I don't get my engine back together by 6 am the next morning

Mine is a n/a too. Not that it makes a big difference but i don't have the extra oil lines to the turbo.

This is something I worry about. I hope the oil jets on the e-shaft were not made larger. The original owner of the motor used to race it. Couldn't have been very fast with stock exhaust and S4 intake manifold .

I put the motor in when I had 167K miles. I know have 173K. The motor I think has around 30K. that is a plain guess since no one has told me how many miles the engine really had. The only whine I hear is from my alternator bearings.

FC3S Murray

iTrader: (7)

I am sorry to hear you are victim to this problem man. All we can do is drive around until rebuild time or take a weekend and rip into it.....but then you have the risk of problems after the rebuild.

Stuck between a rock and a hard place.

I am to the point of **** IT. I am just gonna enjoy driving this POS.

ViperDude152

So, I wonder if we really did have modified e-shaft oil jets, if we could use an external oil pump and get a sump oil pan if that would fix the problem?

Personally. I never want to tear my engine apart.

FC3S Murray

iTrader: (7)

Yeah I know, it is very possible that the E shaft has oil jet mods. All I know is the previous owner was BIG TIME into drag racing and this was his second rebuild. Matter a fact I am gonna call him now that he is back in the U.S.

I will keep ya posted.

halfast

Murray, just came across this thread, you poor bugger.....

1; I've built hundreds of engines with all MFR oil system mods and none have had similar symptoms.

2; Rule of thumb for ALL (not just mazda) engines is 10psi per 1000rpm

3; following on from that if it really is 30psi at 7k and full boost = ripped rotor brgs

4; I have seen big pressure drop with increasing rpm when oil lines were replaced with Hydraulic style lines, the actual I.D. is 3/8" instead of 1/2" and front reg blows off most of pump flow

5; I've seen engines with metering pump shaft removed and oil pressure still normal

6; Front regulator tests at around 140psi, never is a problem, if you have the correct spring you have to compress it to get the cap nut to start in front housing

7; The rear regulator to use is ser8 FD, 110psi, N3A1-14-230 $60 in Australia

8 Pressure at idle is not relevent, only check at 3k and 6k

9; Oil pressure on engine with window bearings/FD shaft will be low until waxstat bypass in front of Ec shaft closes.

Did you see the pressure rise and fall with throttle on the mechanical guage whilst driving? Or did you compare guages while stationary, then observe the electric guage only while driving?
I am not questioning your ability to compare guages, it is a very important point.

If you observed this with the mechanical guage, do a road test with the oil filler cap removed.
b.t.w. if you want to check for run rotor brg put your ear to the open filler and gently blip throttle, you'll know it when you hear it.
Cheers Bryan H. Bridgewater OZ

ViperDude152

I need to put a rev limiter on my motor if thats the case 4000 rpm is all I can go up too? That sucks.

Most of us have removed that thing and replaced it with the aftermaket thermo pellet

rogrx7

iTrader: (11)

Could the shaft have to much play?

Could be oil starvation at higher rpm. clogged oil strainer in pan or a hole in the pick up.

Some clearance is allowing the oil to drop when engine is at operating temp..

You can have a bad oil injector.

Did you check the oil pressure regulator valve?

Is the o-ring on the Oil metering pump all right. I had a bad one on my motor.

FC3S Murray

iTrader: (7)

"Did you see the pressure rise and fall with throttle on the mechanical guage whilst driving? Or did you compare guages while stationary, then observe the electric guage only while driving?
I am not questioning your ability to compare guages, it is a very important point."

No, I havn't checked with a mechanical guage while driving. The one I had was only about 6 inches long so I couldn't get it to my window for observation. I know I should do this but I am almost 100% my factory guage is correct. It gives me almost the exact readings when just reading the pressure in nuetral at all RPM ranges. Plus ot worked fine before I swapped the engine and I didn't screw up the wiring in the harness and to the pressure sender. Plus I measured the resistance via the FSM for both the sender and went through all the shananigans for testing the oil pressure guage(think I tested the voltage or resistance to the guage while RPM increased. Kinda been a long time since I did the test).

"b.t.w. if you want to check for run rotor brg put your ear to the open filler and gently blip throttle, you'll know it when you hear it."

You mean worn main bearings right? I never tried that method but I will put my ear there and see what I can hear.

Thanks for the help halfast, it is nice to see some new intel. I just emailed the previous owner so I am waiting for his reply to see if any mods were done that he failed to mention.

eriksseven

iTrader: (6)

Yo Murray, I just read most of this thread, and I think that it's REALLY important that you ONLY trust an aftermarket mech. gauge...

Even if you trust the stock gauge, I think it's silly to be drawing such a negative conclusion from a somewhat untrustworthy source. Basically, I think you should in a sense "start over" in your diagnosis, and then come back with legitimate and irrefutable data from a mech. gauge.

I'm running a mech. gauge in my Turbo II, in conjunction with the stock gauge, and although both appear to be somewhat similar, it seems like the stock gauge is slow to respond and since it's not (linear?), you really have to guess at what it's saying...

I'll compare the two gauges tomorrow to see how different their readings are.

FC3S Murray

iTrader: (7)

erikseven, you read my mind. I am buying a mech gauge with 3 feet of hose so I can do a "drive test" but to be honest I am assuming the same readings.

Good news is I got back in contact with the engines previous owner and got some new intel.

1. The shop's name who rebuilt it is Vanna Racing in Japan.
2. The owner said he told the engine rebuilder it was exclusively being built just to drag. So drag racing modes were done to the engine, oil jet mods included(shot peened apex seals too ). PLUS the main bearings were replaced with brand spankin new ones as well!

3. So this tells me that either somewhere along the lines of the engine install I fucked something up in the oil system or the oil jet mods are the culpret.

I know this sounds desperate but my hybrid turbo was only on my old engine for maybe 15 mins before she blew. Could these pressure complications be caused from a turbo? I don't know how but I am still an amatuer mechanic, maybe someone knows something I don't(thought I had turbos figured out though, pretty basic platforms)

ViperDude152

I would say the oil jet mods are what is causing the problem.

What is this?

FC3S Murray

iTrader: (7)

Check out this thread: https://www.rx7club.com/2nd-generation-specific-1986-1992-17/apex-seals-shotpeened-what-does-mean-how-do-590346/

FC3S Murray

iTrader: (7)

SOOOO......re-reading this old thread because again I am pissed while driving my car with low pressure.

I know what the problem is and researched the benefit of oil jet mods in a rotary. I came across nothing informative BUT did come across warnings saying, " NOT RECOMMENDED FOR STREET USE." Have to love MazdaMotorSports

That makes me just warm and fuzzy inside.

What I want to ask you fine folks is what the hell is the point of this mod if you will not get higher pressure at higher RPM? it's not like I am getting 60PSI at 7Gs...****, the only time I get that reading is either coasting(you know that) or immediatly after I rod the **** out of it and the blow off valve is releasing the charged air.

I am assuming that this engine will last 50,000 maybe? What you gurus think?

patman

iTrader: (3)

did you ever check with a real guage? what you have sounds like classic symptoms of a sending unit with an air bubble in it. The air will compress, so that when you get a high pressure under load, it reads low, but the rest of the time it reads fairly normally. you can get a relatively accurate mechanical pressure guage for less than $20 at any parts store or even walmart.

i personally find it hard to believe that there is any internal problem. and if it has lasted 5k miles, it will probably last forever at least in respect to bearing lubrication and such.

Aaron Cake

iTrader: (1)

More cooling oil flow to the inside of the rotors.

RotaMan99

I know the thread is long, but start from the beginning. Everything was covered and discovered.

RotaMan99

Wouldn't you wan't more pressure which would mean that the oil will get pushed through the rotors faster then if you had lower pressure?

FC3S Murray

iTrader: (7)

Did the mechanical gauge while driving. 20 psi at idle and 38-42 psi at 3000rpm. PSI should read a little higher if my oil wasn't so saturated with gas, way to much blow by because of some daily driving I have had to do.

What do you think about this? When I purchased this engine it was a S5 short block. While I was assemblying the necessary components I realized that the front cover did not have the extended flange for the turbo drain tube. I remember two years ago when I was swapping my blown engine with a used JDM clip engine I had to replace the front cover with my old S4 front cover because of this very same issue. With out the old front cover the turbo oil return line was to short to bolt to the front cover.

I had to do this same step for this current motor. Is there any possibilty that there might be a small clearence issue with the S4 front cover. I also noticed when installing the turbo before I dropped the engine in that the side housings had entrance to the coolant passenges for the turbo coolant lines. This means N/A housings right? I CAREFULLY dremmeled into the passage ways with a diamond bit so my turbo would remain water cooled.

I don't know....that is all that I can remember that was out of the norm. I have heard of using N/A housings in turbo applications but don't know if there are some small percedures you need to keep in mind.

patman

iTrader: (3)

40 psi at 3k isnt too bad, but not great. does it get higher at 5k or so?

NA rotorhousings are fine to use in turbo motors, but the exhaust diffuser has to be removed. this can either be ground off or the whole sleeve can be replaced. i doubt anyone would put a turbo motor together with those in there, but if they did, it would just make a little less power, it wouldnt grenade or anything.

s4 and s5 front covers should be totally interchangeable.

if your oil is really majorly saturated with gas, you should change it mroe often, gas really hurts the lubrication of the oil.

patman

iTrader: (3)

a faster moving fluid often does not lubricate or cool as well as a slower moving one. what you want is more volume, not speed or pressure. also it is a common misconception in the rotary world that higher oil pressure is better period, which is not true. there is a certain point at which increasing oil pressure is actually bad for the engine, not good.

RotaMan99

Alright, well how about if I run my engine to 7000 rpm and im only seeing 30-40 psi?

VIOLATAZ

hey.. i had the same prob,so i replaced both regulators (front and back) i also put a little build-up (2/3washers)under the spring of the front regulator.. The problem was the o-ring in front though,,, BUT now i got to hi pressure, so i tried to remove the washers in the front regulator.. and this lowered the pressure a bit maybe u can try the opposite::: just a tip.. my experience in these engines is low, so i hope u take this as just an (why not try tip section)

rob86rx-

My engine has a similar problem but I think it oil temp related. When cold I have 15psi at idle, 60psi above 3k. But when driving on the highway I only have 35psi. If I coast in neutral down a long hill, I have 60psi again at the bottom but only for a minute until oil heats back up. I did not check the oil control spring when I rebuilt my engine and think that it is a little weak.

Also how can oil become gas saturated in a rotary? Any input? I am still learning about rotaries.

scathcart

The jet mod reduces the size of the rotor jets. This restricts the flow of oil to the rotors, not increases it. The purpose of this is when you have double the stock oil pressure (120-130 psi compared to 65-70 psi), you don't need such a large jet to deliver all of the cooling that the rotor needs. So, by making the jet smaller, you deliver more oil flow to the bearings. Hell, it's possibly to simply weld the stock jets shut, and then redirll them with a NOS jet drill to the same size as the jet upgrade, and then keep the ball and spring in there for high oil pressure below 3000.

This mod has nothing to do with power levels. It has to do with RPM levels. If you are spending a lot of time above 7000 rpm, you do this mod to help your bearings. If you are doing a turbo engine, with an 8K redline, you don't need to do this mod, since it reduces oil pressure at low rpms.

This is a RACING ENGINE mod. If you daily drive it, there is no point in doing it.