Renesis OIL PRESSURE Discussion with Dealer Tech
11-30-2009, 08:44 AM
#726
To clarify--- I dont think we wanted an increased oil pressure? We wanted more oil flow. But the only way of accomplishing that without an engine teardown and blueprinting -is to modify the pressure relief valves/reduce the oil's pathway.
9K's work has shown the pump is capable of more flow(side affect is increased pressure) and so now it is about getting the system balanced which includes filtration.
We also --for those that track--need the latest baffles in the sump pain (ash--
)
I had front stationary bearing wear at approx 7oclock (facing the engine) almost through the copper at 50K. That was with using 30wgt oil most of that time. I am certain that wear in one particular spot through the engine balance off.
olddragger
9K's work has shown the pump is capable of more flow(side affect is increased pressure) and so now it is about getting the system balanced which includes filtration.
We also --for those that track--need the latest baffles in the sump pain (ash--
)I had front stationary bearing wear at approx 7oclock (facing the engine) almost through the copper at 50K. That was with using 30wgt oil most of that time. I am certain that wear in one particular spot through the engine balance off.
olddragger
Last edited by olddragger; 11-30-2009 at 08:47 AM.
11-30-2009, 02:09 PM
#727
SARX Legend
iTrader: (46)
I really wish I could have taken apart my previous two motors. I used 30wt as well and never went over 3,000 mile OIC on my second one (with all updated flashes) and it failed after 72k (90% highway). First engine ran Mobil1 10W30/5W-20 but it had the crappy OMP flash so I am certain that was the cause of it's failure at only 22k.
On average, this motor will not survive 100k without meticulous maintenance and I believe premix is a must. I believe the SOHN should be installed from the factory but that will never happen because many don't even change their motor oil as they should so there is no way they are going to premix gas and fill a SOHN adapter on a regular basis.
On average, this motor will not survive 100k without meticulous maintenance and I believe premix is a must. I believe the SOHN should be installed from the factory but that will never happen because many don't even change their motor oil as they should so there is no way they are going to premix gas and fill a SOHN adapter on a regular basis.
11-30-2009, 03:20 PM
#728
Super Moderator
Thread Starter
I think you have to keep it all in perspective...the engine "failures" are mainly due to Irregular Wear of either Apex Seals and or Broken Side Seal...poor compressions.
The Bearing wear has naturally surfaced when the motor is stripped.
As far as regions or countries go, seen more than a few in the USA, the only one I have seen pics of in England had this issue, as for Australia, Mazda here are renewing with all new engines and dealers do not get to see the insides. (Australian cars ONLY have One Oil Cooler). It would be interesting to pull a few dozen Aussie engines apart and see internals.
This is the factory spec for USA Oil pressure levels, but many are just not seeing this low number in S1...
Oil pressure (reference value)
[oil temperature: 100$C {212$F}]
(kPa {kgf/cm2, psi}
500 {5.10, 72.5} [3,000] Series II RX-8
350 {3.57, 50.8} [3,000] Series 1 RX-8
The Bearing wear has naturally surfaced when the motor is stripped.
As far as regions or countries go, seen more than a few in the USA, the only one I have seen pics of in England had this issue, as for Australia, Mazda here are renewing with all new engines and dealers do not get to see the insides. (Australian cars ONLY have One Oil Cooler). It would be interesting to pull a few dozen Aussie engines apart and see internals.
This is the factory spec for USA Oil pressure levels, but many are just not seeing this low number in S1...
Oil pressure (reference value)
[oil temperature: 100$C {212$F}]
(kPa {kgf/cm2, psi}
500 {5.10, 72.5} [3,000] Series II RX-8
350 {3.57, 50.8} [3,000] Series 1 RX-8
11-30-2009, 03:30 PM
#729
Super Moderator
Thread Starter
I am under the impression by some very talented people who are close to Mazda engine engineering that 9 out of 10 failures of Renesis engines in the US and are sent to the warranty rebuild facility in Virginia are low compression engines with Apex seal carbon deposit issues. Perhaps the bearing issue is absent, overlooked, unreported or these engines seen in Virginia have yet to experience this issue.
So they don't press out/renew the bearing tubes.
11-30-2009, 09:33 PM
#730
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9k, did you premix on your old engines?
I'm also curious as to what rev range and gears people drive in around town <50mph. Unless I'm creeping along, I don't let revs go below 2,500 rpm, and will downshift at least a gear if I try moderately accelerating.
I'm also curious as to what rev range and gears people drive in around town <50mph. Unless I'm creeping along, I don't let revs go below 2,500 rpm, and will downshift at least a gear if I try moderately accelerating.
11-30-2009, 09:43 PM
#731
SARX Legend
iTrader: (46)
The first engine I did not premix at all and on the second very little towards the end (when I learned). I also believe many who do not push their cars are driving around on bad engines. My second engine ran fine (for a normal person) under 5,000 RPMS. It was bogging above 6k and then eventually started stalling (same as first motor).
12-01-2009, 03:14 AM
#732
Ayrton Senna Forever
I think the same. Mazda advertised that the Renesis has more accurately balanced rotors, and e-shaft, against older rotaryes. I think we partly loose this balancing advantages with this kind of bearing wear.
Last edited by ayrton012; 12-01-2009 at 03:16 AM.
12-01-2009, 03:56 AM
#733
Ayrton Senna Forever
Something more on the front and rear regulators.
Some rotary experts said that the front regulator has to be very high opening pressure in the Renesis too, so it is only for emergency reasons in the oil system.
It is strange, if we look at the official european datas.
Front regulator: 64-71 PSI
Rear regulator: 78-92,5 PSI
Our max oil pressure in the original two OCs systems is corresponding to the front regulator data, as our max pressure is about 72-75 PSI.
But If we see the modified single OC's max pressure, it corresponds to the rear regulator data, as it is close to 90 PSI.
I will try to check the front bypass reg data in this weekend, but IF THIS DATAS ARE RIGHT:
Why the rear regulator determines the max oil pressure in the modified 1 OC systems, and why the front regulator in the 2OC's system?
Maybe Mazda measured the front regulator opening pressure with the 2 OC's system on. I don't see any other explanation why is this strange difference.
Don't tell, that the front regulator can't limit the max oil pressure in the lower resistance 1 OC systems, because the front regulator has the same diametered bypass (to pan) hole, than it's oil feeding hole. So the front regulator's bypass hole is able to drain even the hole amount of the oil coming from the pump.
Some rotary experts said that the front regulator has to be very high opening pressure in the Renesis too, so it is only for emergency reasons in the oil system.
It is strange, if we look at the official european datas.
Front regulator: 64-71 PSI
Rear regulator: 78-92,5 PSI
Our max oil pressure in the original two OCs systems is corresponding to the front regulator data, as our max pressure is about 72-75 PSI.
But If we see the modified single OC's max pressure, it corresponds to the rear regulator data, as it is close to 90 PSI.
I will try to check the front bypass reg data in this weekend, but IF THIS DATAS ARE RIGHT:
Why the rear regulator determines the max oil pressure in the modified 1 OC systems, and why the front regulator in the 2OC's system?
Maybe Mazda measured the front regulator opening pressure with the 2 OC's system on. I don't see any other explanation why is this strange difference.
Don't tell, that the front regulator can't limit the max oil pressure in the lower resistance 1 OC systems, because the front regulator has the same diametered bypass (to pan) hole, than it's oil feeding hole. So the front regulator's bypass hole is able to drain even the hole amount of the oil coming from the pump.
12-01-2009, 04:20 AM
#734
Something more on the front and rear regulators.
Some rotary experts said that the front regulator has to be very high opening pressure in the Renesis too, so it is only for emergency reasons in the oil system.
It is strange, if we look at the official european datas.
Front regulator: 64-71 PSI
Rear regulator: 78-92,5 PSI
Our max oil pressure in the original two OCs systems is corresponding to the front regulator data, as our max pressure is about 72-75 PSI.
But If we see the modified single OC's max pressure, it corresponds to the rear regulator data, as it is close to 90 PSI.
I will try to check the front bypass reg data in this weekend, but IF THIS DATAS ARE RIGHT:
Why the rear regulator determines the max oil pressure in the modified 1 OC systems, and why the front regulator in the 2OC's system?
Maybe Mazda measured the front regulator opening pressure with the 2 OC's system on. I don't see any other explanation why is this strange difference.
Don't tell, that the front regulator can't limit the max oil pressure in the lower resistance 1 OC systems, because the front regulator has the same diametered bypass (to pan) hole, than it's oil feeding hole. So the front regulator's bypass hole is able to drain even the hole amount of the oil coming from the pump.
Some rotary experts said that the front regulator has to be very high opening pressure in the Renesis too, so it is only for emergency reasons in the oil system.
It is strange, if we look at the official european datas.
Front regulator: 64-71 PSI
Rear regulator: 78-92,5 PSI
Our max oil pressure in the original two OCs systems is corresponding to the front regulator data, as our max pressure is about 72-75 PSI.
But If we see the modified single OC's max pressure, it corresponds to the rear regulator data, as it is close to 90 PSI.
I will try to check the front bypass reg data in this weekend, but IF THIS DATAS ARE RIGHT:
Why the rear regulator determines the max oil pressure in the modified 1 OC systems, and why the front regulator in the 2OC's system?
Maybe Mazda measured the front regulator opening pressure with the 2 OC's system on. I don't see any other explanation why is this strange difference.
Don't tell, that the front regulator can't limit the max oil pressure in the lower resistance 1 OC systems, because the front regulator has the same diametered bypass (to pan) hole, than it's oil feeding hole. So the front regulator's bypass hole is able to drain even the hole amount of the oil coming from the pump.
Also determining where the restriction is would be a good point in redesining this oil system for us who have different needs.
12-01-2009, 04:35 AM
#735
Ayrton Senna Forever
It would be nice to hear from some engine rebuilders if there's a great different in bearing damage\engine life from the 2 oil cooler models and the 1 cooler ones.
Also determining where the restriction is would be a good point in redesining this oil system for us who have different needs.
Also determining where the restriction is would be a good point in redesining this oil system for us who have different needs.
12-01-2009, 04:38 AM
#736
I know, there should be a fairly good share of information with stock single oil cooled ones though!
Guess time will tell...
Anyway can we summarize what are we trying to achieve, how are we trying to achieve it and what the expected results should be?
After 30 pages of reading and mixed comments i think that it is pretty much time!
Guess time will tell...
Anyway can we summarize what are we trying to achieve, how are we trying to achieve it and what the expected results should be?
After 30 pages of reading and mixed comments i think that it is pretty much time!
12-01-2009, 05:52 AM
#737
Ayrton Senna Forever
I know, there should be a fairly good share of information with stock single oil cooled ones though!
Guess time will tell...
Anyway can we summarize what are we trying to achieve, how are we trying to achieve it and what the expected results should be?
After 30 pages of reading and mixed comments i think that it is pretty much time!
Guess time will tell...
Anyway can we summarize what are we trying to achieve, how are we trying to achieve it and what the expected results should be?
After 30 pages of reading and mixed comments i think that it is pretty much time!
1. We are trying to increase the oil pressure.
2. We are trying to increase the max oil pressure ( for instance we can't take the technically minimum 10PSI/1000 rpm rule)
To get the 1., we have to decrease the flow resistance of the oil system (pump-coolers-filter) system. Our pump capacity seems to enough, so the resistance decreasing can help in itself (to 92,5 PSI).
To get the 2., we have to modify the front or rear oil pressure regulator's opening pressure, but if we do the 1. mod, that can be enough to 92,5 PSI max pressure.
In this moment there are different pressure datas about the regulators, so we are not really sure in which one determines the max pressure.
The 3. oil pressure related mod would has to be plugging the e-shaft thermo pellet, because it decreases the oil pressure very much, under 60C oil temp.
--------------
Giorgio, we took out the e-shaft pellet from my spare engine. That was a hard one, so if the engine is in the car, I'm sure we can do this only then if we remove the gear box first.
Last edited by ayrton012; 12-01-2009 at 07:00 AM. Reason: language
12-01-2009, 11:09 AM
#738
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To me, it still seems like this:
There is an issue where low oil pressure (only at low RPM) combined with low visc oil can cause bearing wear, as many performance shops are unaware of this issue in cars that are being driven hard on the track.
It also looks like the stock oil cooling circuit is restrictive to the point where it forces open the front oil bypass, which according to various mazda documents has a lower opening threshold than the rear. Mazmart mentioned that the front bypass opening threshold is actually set really high, but with all due respect, I believe they may have made a mistake and confused the renesis with older rotaries where in fact they did have a much higher opening pressure.
I think the increase in OP between the S1 and S2 was to boost low RPM flow (@3k rpm, ~50% more flow) and still maintain use of 5W-20. Until we see OP data from the higher rev range in the S2 cars, it's just speculation that they increased the OP there.
There is an issue where low oil pressure (only at low RPM) combined with low visc oil can cause bearing wear, as many performance shops are unaware of this issue in cars that are being driven hard on the track.
It also looks like the stock oil cooling circuit is restrictive to the point where it forces open the front oil bypass, which according to various mazda documents has a lower opening threshold than the rear. Mazmart mentioned that the front bypass opening threshold is actually set really high, but with all due respect, I believe they may have made a mistake and confused the renesis with older rotaries where in fact they did have a much higher opening pressure.
I think the increase in OP between the S1 and S2 was to boost low RPM flow (@3k rpm, ~50% more flow) and still maintain use of 5W-20. Until we see OP data from the higher rev range in the S2 cars, it's just speculation that they increased the OP there.
12-01-2009, 01:10 PM
#741
no we are not trying to increase oil pressure---we are trying to increase oil flow. Since we are not opening the engines and have to tolerate the clearances(pun--pun) the only way to achieve an increase in flow is too increase the pressures. Its a minor point but important to note.
I have received a report now that my second engine has the same bearing wear (front stationary gear) as my 1st. What is the chances of that--unless there is a real problem?
OD
I have received a report now that my second engine has the same bearing wear (front stationary gear) as my 1st. What is the chances of that--unless there is a real problem?
OD
12-01-2009, 02:22 PM
#742
Registered
News flash readers digest version:
I spoke with Daryl Drummond at length today. Daryl has been involved in Mazda engines for Mazda in various racing applications over the past 30 years. He specializes in race engines, has more Mazda racing championships as an engine builder then probably anyone else in the states (or close to it). Basically he is a very, very, very credible source. He continues to build and support commerical and professional rotary appications, builds several road racing motors, specializes in custom intakes using fuel injection and validates everyone on his engine dyno. Our Renesis engine dyno chart to follow in another post for reference. Neat stuff. I digress.
Daryl did some Mazda supported race team R&D many years ago when his rotary powered off-road motors would see one race before needing rebuilds. 9,200 rpm (and we are NOT talking Renesis here) would cause excessive heat and this would lead to bearing failure. Heat led to bearing failure. Bearing failure led to engine failure. Engine failure = DNF. DNF not good.
So an investigation was performed and it was determined that the entire oiling system was restrictive particularly the path from the rear to the front of the motor. The stock pumps are capable of 8 gal/min flow yet the internal restrictions of the oil path and gallies do not allow proper lubrication and cooling. Cooling was the issue as it melted part of the bearing. This was resolved by enlarging the oil passages (an aftermarket mod he does to his race engines and I beleive others do but can not confirm this) and stepping up the oil pressure reg (mentioned several times in this thread). He offered that many years ago he measured 90 psi at the rear @ 8,500 rpm and 60 at front same rpm with the stock 13 oil pump.
Fast forward. The Mazda dry sump has a 12 gal/min flow rate. Modifications to the pump allow for 15 gal flow combined with opening up the galleys has solved this issue. He does this on our Renny race engines and those built for Pro Formula Mazda (spec engine with Motec engine mngt.). Note: This series is running the new 09 motors and currently a hard cut of 8,700 rpm I beleive. 04-08 motors had a 8,500 rpm limiter (so i tell everyone once again---don't drive your dumb engines at 9,000 thinking there is good power there----there is not).
Summary: It appears there has been a long history of oil flow issues with the 13b. Heat reduction, increased flow and higher psi all help to solve this.
Daryl offers this oil modification service along with an extensive balancing of components. His other offerings are beyond a typical street car owner and/or above the budget most of this forum wants to spend on their engines.
One other thing: Heat can be generated in the combustion chamber by inadequate tuning. Combine this with high rpms and less than adequate cooling and the probability of bearing failure is increased.
It would be interesting to see what conservative tuning, improved water cooling, improved oil cooling and increased oil pressures would do to an engine subjected to many, many hours and miles of operation.
I guess it all comes back to "how much do I want to invest in my engine to avoid potential bearing failures"?
Happy rotoring
Renesis Engine dyno (flywheel hp): http://gallery.me.com/meyermotorspor...&bgcolor=black
Mazda Dry sump: http://gallery.me.com/meyermotorspor...&bgcolor=black
daryl@drummondengines.com
I spoke with Daryl Drummond at length today. Daryl has been involved in Mazda engines for Mazda in various racing applications over the past 30 years. He specializes in race engines, has more Mazda racing championships as an engine builder then probably anyone else in the states (or close to it). Basically he is a very, very, very credible source. He continues to build and support commerical and professional rotary appications, builds several road racing motors, specializes in custom intakes using fuel injection and validates everyone on his engine dyno. Our Renesis engine dyno chart to follow in another post for reference. Neat stuff. I digress.
Daryl did some Mazda supported race team R&D many years ago when his rotary powered off-road motors would see one race before needing rebuilds. 9,200 rpm (and we are NOT talking Renesis here) would cause excessive heat and this would lead to bearing failure. Heat led to bearing failure. Bearing failure led to engine failure. Engine failure = DNF. DNF not good.
So an investigation was performed and it was determined that the entire oiling system was restrictive particularly the path from the rear to the front of the motor. The stock pumps are capable of 8 gal/min flow yet the internal restrictions of the oil path and gallies do not allow proper lubrication and cooling. Cooling was the issue as it melted part of the bearing. This was resolved by enlarging the oil passages (an aftermarket mod he does to his race engines and I beleive others do but can not confirm this) and stepping up the oil pressure reg (mentioned several times in this thread). He offered that many years ago he measured 90 psi at the rear @ 8,500 rpm and 60 at front same rpm with the stock 13 oil pump.
Fast forward. The Mazda dry sump has a 12 gal/min flow rate. Modifications to the pump allow for 15 gal flow combined with opening up the galleys has solved this issue. He does this on our Renny race engines and those built for Pro Formula Mazda (spec engine with Motec engine mngt.). Note: This series is running the new 09 motors and currently a hard cut of 8,700 rpm I beleive. 04-08 motors had a 8,500 rpm limiter (so i tell everyone once again---don't drive your dumb engines at 9,000 thinking there is good power there----there is not).
Summary: It appears there has been a long history of oil flow issues with the 13b. Heat reduction, increased flow and higher psi all help to solve this.
Daryl offers this oil modification service along with an extensive balancing of components. His other offerings are beyond a typical street car owner and/or above the budget most of this forum wants to spend on their engines.
One other thing: Heat can be generated in the combustion chamber by inadequate tuning. Combine this with high rpms and less than adequate cooling and the probability of bearing failure is increased.
It would be interesting to see what conservative tuning, improved water cooling, improved oil cooling and increased oil pressures would do to an engine subjected to many, many hours and miles of operation.
I guess it all comes back to "how much do I want to invest in my engine to avoid potential bearing failures"?
Happy rotoring
Renesis Engine dyno (flywheel hp): http://gallery.me.com/meyermotorspor...&bgcolor=black
Mazda Dry sump: http://gallery.me.com/meyermotorspor...&bgcolor=black
daryl@drummondengines.com
12-01-2009, 03:19 PM
#744
12-01-2009, 03:19 PM
#745
Super Moderator
Thread Starter
Yes, intereseting...
All goes to show what many of us thought...
The Renny 1 needs higher OP (B Pass and Relief Valve adjustments), I don't think a street Renny needs any E-shaft gallery changes, oil jets etc and bearings are FC and FD RX-7 .....just more flow with higher OP should be enough IMO.
Heat...our rotaries enemy..like carbon...IMO it is imperative if you have a stock RX-8 to open up the Rear Oil Cooler Splash Shields to allow more air flow, hence Cooler Oil for Summer Temps at least...cooler oil has to help Coolant temps....and Engine Bearings..
All goes to show what many of us thought...
The Renny 1 needs higher OP (B Pass and Relief Valve adjustments), I don't think a street Renny needs any E-shaft gallery changes, oil jets etc and bearings are FC and FD RX-7 .....just more flow with higher OP should be enough IMO.
Heat...our rotaries enemy..like carbon...IMO it is imperative if you have a stock RX-8 to open up the Rear Oil Cooler Splash Shields to allow more air flow, hence Cooler Oil for Summer Temps at least...cooler oil has to help Coolant temps....and Engine Bearings..
12-01-2009, 04:22 PM
#746
seems like i have a correct recipe?
1- coolant and oil temps under control---VERY rarely over 200 for either.
2- water methanol injection--for all the benefits you get from it--especially on boosted apps
3- my redline is 7.5K (boosted does help here i admit)
4- relief valve mod will be done asap. .....PAUL!!!!!! Christmas presents are needed!
By the way Racing Beat will be releasing SS oil cooler lines in Jan 2010. That should help some of the outside restrictions.
Again glad I have a Rick E engine--he does some "things" in this regard or so I am told
Thanks Eric!
OD
1- coolant and oil temps under control---VERY rarely over 200 for either.
2- water methanol injection--for all the benefits you get from it--especially on boosted apps
3- my redline is 7.5K (boosted does help here i admit)
4- relief valve mod will be done asap. .....PAUL!!!!!! Christmas presents are needed!
By the way Racing Beat will be releasing SS oil cooler lines in Jan 2010. That should help some of the outside restrictions.
Again glad I have a Rick E engine--he does some "things" in this regard or so I am told
Thanks Eric!
OD
12-01-2009, 04:26 PM
#747
Good recipe Denny, can i have some?
Charles R. Hill's engine also has some oil pump porting. I did that in an engine but the user doesn't have gauges so i really don't know how much it works. For sure the stock design is a restrictive one. Bevelling and enlarging the holes should help.
Anyway that is useless in this discussion since we're talking about easily achievable mods for our current engines
Charles R. Hill's engine also has some oil pump porting. I did that in an engine but the user doesn't have gauges so i really don't know how much it works. For sure the stock design is a restrictive one. Bevelling and enlarging the holes should help.
Anyway that is useless in this discussion since we're talking about easily achievable mods for our current engines
12-01-2009, 06:03 PM
#748
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I have a hard time understanding how mazda wouldn't have seen this issue if it's inherently related to low OP at high RPM. The renesis was surely tested at full tilt. 
12-01-2009, 08:00 PM
#749
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It would be interesting to see how many engines might have lived if only water/meth injection had been used, considering most failures were supposedly related to carbon buildup.