Renesis OIL PRESSURE Discussion with Dealer Tech
10-03-2009, 04:49 AM
#126
Super Moderator
Thread Starter
Yes, as far as I am aware on a cold engine the Pellet restricts the oil flow through the eccentric shaft, the pellet allows enough oil to lubricate front and rear stationary gear bearings and the two rotor bearings/journals, but the pressure is not great enough for the two E-Shaft Jets to actually squirt oil over the inside of the rotors, this as we know assists in a faster engine warm up time frame, the oil not sprayed inside rotors is by passed.
10-03-2009, 05:04 AM
#127
Ayrton Senna Forever
I think, when we are seeking the causing factor of the Renesis bearing wear, we have to seek what is the difference between the oil system of a piston engine's crankshaft, and the e-shaft of the Renesis. The pellet is a difference.
Why there aren't bearing wear in the conventional engines using any viscosity oil? As I know there are bigger forces on the bearings.
Why there aren't bearing wear in the conventional engines using any viscosity oil? As I know there are bigger forces on the bearings.
10-03-2009, 05:05 AM
#128
Since Ash has been so kind to let me post some pictures here about the pellet etc here they are, for reference. I hope this helps making the subject clearer for the less experienced and who never saw an engine open 
Please forgive my horrible working area but that's the only table i can dirty and soil while disassembling engines Then off to the working table 
Please forgive my horrible working area but that's the only table i can dirty and soil while disassembling engines
Then off to the working table
10-03-2009, 05:33 AM
#129
Super Moderator
Thread Starter
GOOD pics G 
I see that nice NA RX-7 oil pump there too, the E shaft looks like it has Rust on it??? NAAAAaa must be dirt?
What is the mileage of the engine...."G"
I see that nice NA RX-7 oil pump there too, the E shaft looks like it has Rust on it??? NAAAAaa must be dirt?
What is the mileage of the engine...."G"
Last edited by ASH8; 10-03-2009 at 05:37 AM.
10-03-2009, 05:38 AM
#130
Super Moderator
Thread Starter
I think, when we are seeking the causing factor of the Renesis bearing wear, we have to seek what is the difference between the oil system of a piston engine's crankshaft, and the e-shaft of the Renesis. The pellet is a difference.
Why there aren't bearing wear in the conventional engines using any viscosity oil? As I know there are bigger forces on the bearings.
Why there aren't bearing wear in the conventional engines using any viscosity oil? As I know there are bigger forces on the bearings.
The S1 RX-8 shares the same Oil Pump and Bypass Valves as a 1986 NA FC RX-7...
10-03-2009, 05:51 AM
#131
I like it 
Anyway that engine had a broken side seal spring on the rear rotor, and a stuck corner seal on the same side. Barely 1000miles per the owner. Surely less than 10.000 even if the rotor is not so clean, considering bearing wear etc.
The eccentric shaft has got some light rust that can be cleaned by hand, long story why it is rusting... i took everything inside my box for storage this summer but i forgot the shaft in the balcony. Dunno if it is reusable, guess i'll try to clean it and see how deep the rust is. What do you suggest that i do? Trash it?
10-03-2009, 02:05 PM
#132
Super Moderator
Thread Starter
G! First Charles, then the whole BHR crew and now you I like it
Anyway that engine had a broken side seal spring on the rear rotor, and a stuck corner seal on the same side. Barely 1000miles per the owner. Surely less than 10.000 even if the rotor is not so clean, considering bearing wear etc.
The eccentric shaft has got some light rust that can be cleaned by hand, long story why it is rusting... i took everything inside my box for storage this summer but i forgot the shaft in the balcony. Dunno if it is reusable, guess i'll try to clean it and see how deep the rust is. What do you suggest that i do? Trash it?
I like it Anyway that engine had a broken side seal spring on the rear rotor, and a stuck corner seal on the same side. Barely 1000miles per the owner. Surely less than 10.000 even if the rotor is not so clean, considering bearing wear etc.
The eccentric shaft has got some light rust that can be cleaned by hand, long story why it is rusting... i took everything inside my box for storage this summer but i forgot the shaft in the balcony. Dunno if it is reusable, guess i'll try to clean it and see how deep the rust is. What do you suggest that i do? Trash it?
Its a 4 port job..
If the E shaft has no damage on it from the bearings then I would try the following, Rub clean engine oil all over the shaft and leave it sit there for a few weeks and then wipe it off, rust may just come off clean, though hard to tell from pic you don't really want any pit marks on the journals, I would see how it cleans up.
10-03-2009, 04:54 PM
#133
The engine in my case is a 6 port but that really doesn't matter imho.
No rust signs after the shaft is cleaned by the way, i think i will just oil it with gun oil to preserve it and see what the next guy that'll need engine needs
No rust signs after the shaft is cleaned by the way, i think i will just oil it with gun oil to preserve it and see what the next guy that'll need engine needs
10-03-2009, 09:29 PM
#135
Super Moderator
Thread Starter
Yep, how silly of me I was looking at the end plate...derrr..
But, I remember you talking about the broken side seal spring ages ago..
Good on your G
10-04-2009, 05:06 AM
#137
Super Moderator
Thread Starter
So any experimentation with the springs size (thickness or length) could be hit or miss, and then I would have to ask what are you trying to achieve, you really don't want to up it's heat range from 65C, only lower it, and if that is the case you might as well put a sold pellet in to stop any oil flow restriction.
10-04-2009, 11:58 AM
#138
MMmm, trouble is G, there is only one type of Pellet Spring used by Mazda for all rotaries made from the FC RX-7 onwards...
So any experimentation with the springs size (thickness or length) could be hit or miss, and then I would have to ask what are you trying to achieve, you really don't want to up it's heat range from 65C, only lower it, and if that is the case you might as well put a sold pellet in to stop any oil flow restriction.
So any experimentation with the springs size (thickness or length) could be hit or miss, and then I would have to ask what are you trying to achieve, you really don't want to up it's heat range from 65C, only lower it, and if that is the case you might as well put a sold pellet in to stop any oil flow restriction.
10-05-2009, 01:34 AM
#139
Ayrton Senna Forever
Are the e-shafts the same, and mainly the oil passages of it? There are xxw-20, xxw-30 oil users in earlier 13B-s. Have they got bearing wear problem?
What are the differentces between a crankhaft's and an e-shaft's oiling system? One is for sure, the pellet, but what are the others? The higher temp?
As I wrote earlier, the pellet cause pressure fluctuation while the oil is warming from cold start up, and because of the pellet, the oil can drain out from the e-shaft as it cools under 140F, which is a matter at the next start up.
We need the experts of this forum.
10-05-2009, 01:43 AM
#140
If you write it 1000 times again, it won't help to find the answer.
Are the e-shafts the same, and mainly the oil passages of it? There are xxw-20, xxw-30 oil users in earlier 13B-s. Have they got bearing wear problem?
What are the differentces between a crankhaft's and an e-shaft's oiling system? One is for sure, the pellet, but what are the others? The higher temp?
As I wrote earlier, the pellet cause pressure fluctuation while the oil is warming from cold start up, and because of the pellet, the oil can drain out from the e-shaft as it cools under 140F, which is a matter at the next start up.
We need the experts of this forum.
Are the e-shafts the same, and mainly the oil passages of it? There are xxw-20, xxw-30 oil users in earlier 13B-s. Have they got bearing wear problem?
What are the differentces between a crankhaft's and an e-shaft's oiling system? One is for sure, the pellet, but what are the others? The higher temp?
As I wrote earlier, the pellet cause pressure fluctuation while the oil is warming from cold start up, and because of the pellet, the oil can drain out from the e-shaft as it cools under 140F, which is a matter at the next start up.
We need the experts of this forum.
There were xxw-30. But most owners were smart enough to use something better than that.
As for e-shaft, size is the same, you can use a MSP e-shaft into a EGI, no problem. Material about the same, its about 0.6 lbs lighter than the old one. a bit more balanced. Thats all I can think of right now.
10-05-2009, 02:27 AM
#141
Super Moderator
Thread Starter
When it come to Mazda Parts...I think I should know what I am talking about, It has been half my life..if it is the SAME it is the SAME it is the SAME..
Sure when it come to a Mechanic or Tech at a Dealer replacing said parts most know how to Remove and Replace.....and that is about ALL..
When it comes to the actual Parts, I will back ANY long Term Mazda Parts guy Any-day, because Techs know JACK ****... most of them are are Lawn Mower mechanics that happen to be a grease monkey's too at the same time...and that is most of them.
My sincere apologies to all the great Mazda Techs who actually work on the Product and Know what they are about and take an interest...and that includes many on this and other forums.
In my time so many of the Mazda service staff could not give a dam about the Customer or the Service...they just want a pay check.
As for "Experts" what is it you are actually after?..What do you 'want' to hear?
As you well know the "Internet" like the "Telephone" can't always Diagnose an issue you may have with your (a) car...it needs to be Physically Presented.
Well lets see...
1. The E shaft Jets are the same as a 1986 FC RX-7 the Springs from a 1971 RX-2, one would think all being equal (including Pellet) that the oil passages in the e-shaft are the same...Wouldn't You?.
2. Have the 13B E-Shaft SG Bearings got wearing problems, not according to guys here who assemble naked 13B's, nothing I can see on RX-7 Forums...Have you looked?
3. Who Bloody Cares about CRANKSHAFT Bearing Wear with the same oil, we are talking Rotary, go and chase all the other 287 car forums that have Banger Engines and use the same oil, I can see some of it's relevance, but they ain't a rotary are they?
4. As for "alleged" Oil Pressure Fluctuations when engine oil is warming, it has been said before and on the RX-7 Forum that the Bearings are NOT Starved of OIL, if they were do you think Mazda would have stayed with the SAME set up for the past 23 Years? So what, the oil can drain out of e-shaft when turned OFF under 65C until next start up.. what do you think happens on a Banger engine with Overhead Camshafts???, Piston Pins??? at Start Up.
You are the one who keeps asking oil pressure questions and don't like the answer(s)...try somewhere else then..
NO we Don't need Experts on this Forum we need some Comprehension.
Sure when it come to a Mechanic or Tech at a Dealer replacing said parts most know how to Remove and Replace.....and that is about ALL..
When it comes to the actual Parts, I will back ANY long Term Mazda Parts guy Any-day, because Techs know JACK ****... most of them are are Lawn Mower mechanics that happen to be a grease monkey's too at the same time...and that is most of them.
My sincere apologies to all the great Mazda Techs who actually work on the Product and Know what they are about and take an interest...and that includes many on this and other forums.
In my time so many of the Mazda service staff could not give a dam about the Customer or the Service...they just want a pay check.
As for "Experts" what is it you are actually after?..What do you 'want' to hear?
As you well know the "Internet" like the "Telephone" can't always Diagnose an issue you may have with your (a) car...it needs to be Physically Presented.
Well lets see...
1. The E shaft Jets are the same as a 1986 FC RX-7 the Springs from a 1971 RX-2, one would think all being equal (including Pellet) that the oil passages in the e-shaft are the same...Wouldn't You?.
2. Have the 13B E-Shaft SG Bearings got wearing problems, not according to guys here who assemble naked 13B's, nothing I can see on RX-7 Forums...Have you looked?
3. Who Bloody Cares about CRANKSHAFT Bearing Wear with the same oil, we are talking Rotary, go and chase all the other 287 car forums that have Banger Engines and use the same oil, I can see some of it's relevance, but they ain't a rotary are they?
4. As for "alleged" Oil Pressure Fluctuations when engine oil is warming, it has been said before and on the RX-7 Forum that the Bearings are NOT Starved of OIL, if they were do you think Mazda would have stayed with the SAME set up for the past 23 Years? So what, the oil can drain out of e-shaft when turned OFF under 65C until next start up.. what do you think happens on a Banger engine with Overhead Camshafts???, Piston Pins??? at Start Up.
You are the one who keeps asking oil pressure questions and don't like the answer(s)...try somewhere else then..
NO we Don't need Experts on this Forum we need some Comprehension.
Last edited by ASH8; 10-05-2009 at 02:30 AM.
10-05-2009, 02:42 AM
#142
Super Moderator
Thread Starter
Forgot to add..it is not relevant to Oil Pressure, but the Needle Bearing and Oil Seal at the Gearbox end inside the Eccentric Shaft is also the SAME as a ALL Rotaries over the past 35 years so I guess the hole it fits into is also the same.
10-05-2009, 04:29 AM
#143
Ayrton Senna Forever
2. Have the 13B E-Shaft SG Bearings got wearing problems, not according to guys here who assemble naked 13B's, nothing I can see on RX-7 Forums...Have you looked?
3. Who Bloody Cares about CRANKSHAFT Bearing Wear with the same oil, we are talking Rotary, go and chase all the other 287 car forums that have Banger Engines and use the same oil, I can see some of it's relevance, but they ain't a rotary are they?
You are the one who keeps asking oil pressure questions and don't like the answer(s)...try somewhere else then..
Last edited by ayrton012; 10-05-2009 at 07:07 AM. Reason: language
10-05-2009, 07:12 AM
#144
Ayrton Senna Forever
But I haven't got e-shaft's temperature datas.
10-05-2009, 07:54 AM
#145
Frankly, I’m surprised by some of the comments in this thread. Particularly those that state that it’s a pressure problem, not a viscosity problem.
In Shigley and Mitchell’s Mechanical Engineering Design (a reference/bible for Mechanical Engineering) they state that hydrodynamic lubrication does not depend on the lubricant being introduced under pressure, although it is critical that an adequate supply is present.
That is why the oil is pressurized – the pressurization is a by-product of the need to flow oil through the system and remove heat. But wear is prevented by the presence of a film of oil between the journal and the bearing, and the thickness of that film is dependent on viscosity, not pressure. If you are getting metal to metal contact it is because the oil is not presenting a thick enough film, which means a thicker oil is called for.
Of course, if there is a cold-start issue where for some reason the bearing is nearly dry for longer than a moment or two, then that is a different problem. But I am reluctant to believe that is true.
Yes, this is armchair engineering, and I’d be happy if an experienced lubrication engineer chimed in and explained why basic hydrodynamic theory doesn’t apply to the bearing wear problem on the RX-8. But until that happens, I’m inclined to believe that the bearing wear problem is a viscosity problem. Of all the various theories & solutions I’ve seen posted here relative to engine wear issues, this is the only one that seems like a slam-dunk to me.
Now, what effect the higher viscosity would have on the seal wear is another question.
In Shigley and Mitchell’s Mechanical Engineering Design (a reference/bible for Mechanical Engineering) they state that hydrodynamic lubrication does not depend on the lubricant being introduced under pressure, although it is critical that an adequate supply is present.
That is why the oil is pressurized – the pressurization is a by-product of the need to flow oil through the system and remove heat. But wear is prevented by the presence of a film of oil between the journal and the bearing, and the thickness of that film is dependent on viscosity, not pressure. If you are getting metal to metal contact it is because the oil is not presenting a thick enough film, which means a thicker oil is called for.
Of course, if there is a cold-start issue where for some reason the bearing is nearly dry for longer than a moment or two, then that is a different problem. But I am reluctant to believe that is true.
Yes, this is armchair engineering, and I’d be happy if an experienced lubrication engineer chimed in and explained why basic hydrodynamic theory doesn’t apply to the bearing wear problem on the RX-8. But until that happens, I’m inclined to believe that the bearing wear problem is a viscosity problem. Of all the various theories & solutions I’ve seen posted here relative to engine wear issues, this is the only one that seems like a slam-dunk to me.
Now, what effect the higher viscosity would have on the seal wear is another question.
Paul.
10-05-2009, 08:42 AM
#146
Ayrton Senna Forever
10-05-2009, 09:15 AM
#148
Nope. Maybe in an engine with close to 200k miles. All the engines that ran 20W50 back in the day never showed this bearing wear so we should be able to say rotaries aren't all that prone to cold start lubrication issues (Is that due to slow shaft speed? 
).
Paul.
).Paul.
10-05-2009, 09:18 AM
#149
To be honest, one day the bearing wear will reach copper.
its just that in the older days most owners (smart ones that is) would not even touch anything lower than 10w40. most run 20w50 and they all got good results.
Thats why whenever I see those "omfg u need 5w most wear happens at start up blah blah blah." makes me sick. cuz seriously, I seen more dead engines these days than older times. and the engine these days supposed to be "better and and last longer" correct? no ?
Search, learn, Happy. Not on this forum of course, go other 7 forum. Oh yes Im a 7 guy too
its just that in the older days most owners (smart ones that is) would not even touch anything lower than 10w40. most run 20w50 and they all got good results.
Thats why whenever I see those "omfg u need 5w most wear happens at start up blah blah blah." makes me sick. cuz seriously, I seen more dead engines these days than older times. and the engine these days supposed to be "better and and last longer" correct? no ?
Search, learn, Happy. Not on this forum of course, go other 7 forum. Oh yes Im a 7 guy too
Last edited by nycgps; 10-05-2009 at 09:20 AM.
10-05-2009, 09:19 AM
#150
Paul.