Engine rebuild mods for reliability suggestions
01-14-2020, 12:58 AM
#1
Weekend Warrior
Thread Starter
Engine rebuild mods for reliability suggestions
Been lurking here for 2 years before buying an 05 6spd in pretty good original shape a year ago (other than a tired original engine with 185km on board.) Learned lots before and after purchase from many knowledgeable people here. Lots of trouble shooting with success but it is basically time for a rebuild and I want it to last. No I won't be doing this myself unlike the many threads I have read.
This project car is just planned to be a weekend warrior, not a race car or even a track car. It will be mostly original and well sorted in the end.
I want to know what components should be used and any good mods should be done as part of this engine build. I understand that most of my engine parts will not be able to be used due to the very high mileage on them.
The current engine is still starting and running really well with ample power for such an engine. Surprising really. It does however suffer from the dreaded 'hot start' issues and has known low compression of approximately 93 psi average at 250 rpm. This was bought as a project car expecting to put an engine in it sooner rather than later. I am wanting suggestions that are known to work rather than what someone has done and maybe worked or not. I have had older rotaries prior to this one but the last engine rebuild I had was 20 years ago.
By the way a reman is out of the question as I have never heard of one being purchased in AUS. A Mazda dealer did quote me $17k AU without fitting. This still used all of my own accessories! Wow. He assured me it was factory new however!
Thanks in advance for constructive suggestions from people far more knowledgeable than me.
Finally if this has been covered and I have not found this info in my many hours of searching then feel free to link me up.
This project car is just planned to be a weekend warrior, not a race car or even a track car. It will be mostly original and well sorted in the end.
I want to know what components should be used and any good mods should be done as part of this engine build. I understand that most of my engine parts will not be able to be used due to the very high mileage on them.
The current engine is still starting and running really well with ample power for such an engine. Surprising really. It does however suffer from the dreaded 'hot start' issues and has known low compression of approximately 93 psi average at 250 rpm. This was bought as a project car expecting to put an engine in it sooner rather than later. I am wanting suggestions that are known to work rather than what someone has done and maybe worked or not. I have had older rotaries prior to this one but the last engine rebuild I had was 20 years ago.
By the way a reman is out of the question as I have never heard of one being purchased in AUS. A Mazda dealer did quote me $17k AU without fitting. This still used all of my own accessories! Wow. He assured me it was factory new however!
Thanks in advance for constructive suggestions from people far more knowledgeable than me.
Finally if this has been covered and I have not found this info in my many hours of searching then feel free to link me up.
01-14-2020, 04:44 AM
#2
Best "reliability" mods are having an engine built by a reliable shop, and keeping up with regular maintenance. Coils, wires, plugs, etc. Drive it right. Don't sit and idle in your driveway to warm it up, start, fasten seatbelt and go. Warm up as you drive. Then, when she's good and hot, stomp on it. Best thing to a rotary is to wring it out every chance you get. A single redline a day won't keep the carbon away if you baby her the rest of the day. She loves BDSM, punish her! She'll only ask for more.
premix a half ounce per gallon if using the OMP. If not, more. Get rid of the cat, drive with a midpipe until you need to E-check. As far as oil goes, I used 5w20 conventional Pennzoil in my S1 for 86k miles and never had a problem. My R3 is getting 5w30 conventional Pennzoil. Think that's about it.
premix a half ounce per gallon if using the OMP. If not, more. Get rid of the cat, drive with a midpipe until you need to E-check. As far as oil goes, I used 5w20 conventional Pennzoil in my S1 for 86k miles and never had a problem. My R3 is getting 5w30 conventional Pennzoil. Think that's about it.
01-14-2020, 05:34 AM
#3
Weekend Warrior
Thread Starter
Thanks DannyR3. Im onto all the maintenance across the car and basically do all that you list. Im more of a 10/40 dino oil guy down here in Oz with 40 deg C here ATM and a ton of bushfires all around.
I'm more looking for add on's at time of rebuild. Basically a guess but things like high volume oil pump if that's even a thing with the RX8. What seals will take 9k rpm all day? Or am I ordering a stock standard engine with new SSV and vdi along with new or quality used housings?
As per OP I will be using a reputed builder but I want to be schooled before any discussions as to what I need rather that what he wants to sell me, let alone talking $$. I have got a top feeders stealers price on an all new engine, but no thanks.
I would like the option of a reman but the shipping cost would be ridiculous to my location.
I'm more looking for add on's at time of rebuild. Basically a guess but things like high volume oil pump if that's even a thing with the RX8. What seals will take 9k rpm all day? Or am I ordering a stock standard engine with new SSV and vdi along with new or quality used housings?
As per OP I will be using a reputed builder but I want to be schooled before any discussions as to what I need rather that what he wants to sell me, let alone talking $$. I have got a top feeders stealers price on an all new engine, but no thanks.
I would like the option of a reman but the shipping cost would be ridiculous to my location.
01-14-2020, 10:20 AM
#4
Smoking turbo yay
I'm more looking for add on's at time of rebuild. Basically a guess but things like high volume oil pump if that's even a thing with the RX8. What seals will take 9k rpm all day? Or am I ordering a stock standard engine with new SSV and vdi along with new or quality used housings?
Even the whole "a redline a day keeps the carbon away" is a bit debatable since there is little engineering evidence(so anecdotal evidence doesn't count) to back it up.
You can clean your existing SSV and VDI and there are some threads here showing how you can go about doing it.
And if you are set for a rebuild, you may as well get new housings.
01-14-2020, 10:29 AM
#5
Seal wear from high RPM is not a problem from the seal itself. It's more from the flexing of the e-shaft as well as the imbalance of the rotor itself. At 9k RPM the rotor might wobble enough for your seals to contact your housings. Holding your car at fuel cut or close to it does nothing good, and this applies to all engines(pistons or rotaries).
Even the whole "a redline a day keeps the carbon away" is a bit debatable since there is little engineering evidence(so anecdotal evidence doesn't count) to back it up.
You can clean your existing SSV and VDI and there are some threads here showing how you can go about doing it.
And if you are set for a rebuild, you may as well get new housings.
Even the whole "a redline a day keeps the carbon away" is a bit debatable since there is little engineering evidence(so anecdotal evidence doesn't count) to back it up.
You can clean your existing SSV and VDI and there are some threads here showing how you can go about doing it.
And if you are set for a rebuild, you may as well get new housings.
01-14-2020, 10:34 AM
#6
Here’s what I have done.
Remove the catalytic converter.
Reduce the temp the fans turn on.
gauges to monitor temp.( coolant seal can blow as early as 104C)
Oil pressure regulator mod.
Sohn adapter + JASO FC or FD rated 2 stroke oil for the seal
0W synthetic oil for the crankcase. As for 0W-XX, it depends on your oil temperature.
BHR ignition coil.
Tuning software to LARGELY increase the OMP rate
Remove the eccentric shaft thermal pellet( I haven’t but I suggest you do this mod) this can only be done when you have your engine out.
premix IMO is important, Eric used to point out the fact that the OMP system favors the side seal too much. So you need premix to sustain the life of your apex seal.
This engine mainly dies from overheating and lack of lubrication.
Remove the catalytic converter.
Reduce the temp the fans turn on.
gauges to monitor temp.( coolant seal can blow as early as 104C)
Oil pressure regulator mod.
Sohn adapter + JASO FC or FD rated 2 stroke oil for the seal
0W synthetic oil for the crankcase. As for 0W-XX, it depends on your oil temperature.
BHR ignition coil.
Tuning software to LARGELY increase the OMP rate
Remove the eccentric shaft thermal pellet( I haven’t but I suggest you do this mod) this can only be done when you have your engine out.
premix IMO is important, Eric used to point out the fact that the OMP system favors the side seal too much. So you need premix to sustain the life of your apex seal.
This engine mainly dies from overheating and lack of lubrication.
Last edited by Shaozhou Zhang; 03-13-2020 at 12:37 AM.
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01-14-2020, 08:18 PM
#7
Weekend Warrior
Thread Starter
Thanks Jinx and SZ for your info. I will look further into the thermal pellet as I am unaware of its effects. Also the oil pressure mod.
I get that fan temps and OMP are all software deals that I will look into this after the engine is set up and running well in the car. I know whichever route I decide to go with will be beneficial to neutralize decat codes and others as well.
Anyone suggest anything other than Mazda apex seals (or just go with a full standard kit)? I am leaning towards this way unless convinced otherwise.
I get that fan temps and OMP are all software deals that I will look into this after the engine is set up and running well in the car. I know whichever route I decide to go with will be beneficial to neutralize decat codes and others as well.
Anyone suggest anything other than Mazda apex seals (or just go with a full standard kit)? I am leaning towards this way unless convinced otherwise.
01-14-2020, 09:49 PM
#8
Smoking turbo yay
honestly I don’t really trust the theory. When going WOT the car runs super rich, the excessive fuel not getting burned may contribute to the carbon build up theory. If we hold WOT at lower gear it will eventually cut fuel, if we are holding at redline with partial throttle then there’s not enough heat to break the carbon.
And RPM isn't the only factor, engine load also plays a role as well. This means you have to do a few WOT redline runs in a few gears to maybe get to that temperature to break the carbon deposits apart. I say maybe because there aren't any exact numbers to use.
Realistically, if you don't want any carbon in a rotary engine, the only options are running a water/meth injection kit and/or use E85. The former has a chemical reaction that will clean away the carbon while the later has less gasoline to leave deposits behind.
01-14-2020, 10:46 PM
#9
SZ I'm not sure where you get your info but it has some strange notions. The OMP system specifically targets apex seals, and one of the benefits of premixing is more lubrication for side seals. Side seals are where compression is lost just as often as apex seals.
The engine doesn't run particularly rich at WOT, low 13s?
As Unknown points out, it's all about temperature and pressure, and temperature is a function of engine load. You don't need to hit redline but you need to have high load for as long as possible.
The engine doesn't run particularly rich at WOT, low 13s?
As Unknown points out, it's all about temperature and pressure, and temperature is a function of engine load. You don't need to hit redline but you need to have high load for as long as possible.
01-15-2020, 11:28 AM
#10
You can run E85 but you would need to increase your injector rate by 30-35% to keep the same power as regular pump gas (E10 or E15), The real benefit to using E85 for power is its higher octane number (110 versus 84-93 for pump gas) which allows you to run at higher compression ratios than gasoline without worrying about pre-ignition. This is why it is used for turbo setups as you can run at higher boost pressures (i.e., more power). E85 use in a stock engine really offers no advantage over pump gas. I would recommend running Top Tier detergent gasoline instead which is what I do.
01-15-2020, 12:47 PM
#11
Smoking turbo yay
And I think in daily driving there is no possiblity to reach that level of temperature. You will have to hit a track for that.
You can run E85 but you would need to increase your injector rate by 30-35% to keep the same power as regular pump gas (E10 or E15), The real benefit to using E85 for power is its higher octane number (110 versus 84-93 for pump gas) which allows you to run at higher compression ratios than gasoline without worrying about pre-ignition. This is why it is used for turbo setups as you can run at higher boost pressures (i.e., more power). E85 use in a stock engine really offers no advantage over pump gas. I would recommend running Top Tier detergent gasoline instead which is what I do.
I am not saying Top Tier is complete BS, but at the same time, I don't think it helps with carbon buildup issue significantly. It's not like the rotors and seals are directly sprayed by the gasoline like the intake valves of a port injection piston engine. Again, you need to get the engine real toasty before these detergent will actively start to clean off the carbon.
Also know that there are some brands meet the Top Tier requirements but don't bother to get the stickers because they have to pay a fee. Just saying.
01-15-2020, 02:55 PM
#14
SZ I'm not sure where you get your info but it has some strange notions. The OMP system specifically targets apex seals, and one of the benefits of premixing is more lubrication for side seals. Side seals are where compression is lost just as often as apex seals.
The engine doesn't run particularly rich at WOT, low 13s?
As Unknown points out, it's all about temperature and pressure, and temperature is a function of engine load. You don't need to hit redline but you need to have high load for as long as possible.
The engine doesn't run particularly rich at WOT, low 13s?
As Unknown points out, it's all about temperature and pressure, and temperature is a function of engine load. You don't need to hit redline but you need to have high load for as long as possible.
It's in Page 6, posted by EricMeyer
As for the engine load, I agree. But having a high load at low rpm is bad and having a consistent high load in not so low rpm, let's say 5000 in 5 or 6, if I got pulled over I am dead lol.
K guys, first off I only know what I've experienced. Our team's experience is in a race environment. Here is how I define race environment:
-5,600 to 8,700 rpm pretty much every time the car is operated on track
-1,500F+ EGT's pretty much every time the car is operated on track unless it's a yellow flag in which the EGT's are still over 1,000F
-Constant load. This is coming off the various corners in 3rd gear at 60 mph or whatever and then running wide open throttle (WOT) up through the gears to 5th or 6th at 120+ mph. Brake. Repeat process. Load, load, load, load. Basically I've got the throttle pegged at 100% for the majority of each lap for either a 15 minute qualifying session or an 8 hour enduro.
-About two dozen motors worth of rebuilds and observation
-.89 and .93 Lambda data (google if you don't know what Lambda is).
-With and without OMP function
-Various amounts of premix
-Lots of data collection
-The greatest number of hours we've seen is 25 as after that our power slowly falls off (side seal spring).
When running in the above environment WITHOUT the OMP function we have experienced huge, huge, side seal spring failure. Huge. Please note that I did not use the word "Apex" anywhere in the previous sentence. We've had newly refreshed motors last 6 hours. We've had refreshed motors last 2 hours. Side seal spring failure with no OMP function.
This has been my experience and leads me to MY THEORY of the coorelation of OMP to the #1 failure mode of the engines (which was the original post of this thread). To my knowledge (and I could be totally off here), the failure mode that leads to low compression that leads to warranty rebuilds at Mazdas facility in Virginia has to do with carbon buildup in and around the apex seal groove which prevents apex seal travel which restricts the apex sealing function which causes compression loss which leads to low power and/or inability to start the car. And I could be way wrong here but this is my understanding.
Apex seal wear is (according to all the smart RACE engine guys I've talked to) is actually much more of a rotor housing wear which is caused by the bowing of the center of the apex seal during its normal function and this over time wears a groove in the softer aluminum housings and this makes for an escape or compression leakage. This is very much like a scored piston engine cylinder bore which lets compression escape around the rings. This groove decreases the engines ability to retain higher compression and therefore higher power.
Again, I could be wrong and our experience with the OMP has and does have a huge coorelation to side seal spring failure. Not apex seal or corner seal. At all. We've been reusing the stock apex seals for a lonnnng time. We've also tried ceramics and they last so damn long its crazy (in our operating environment).
It would appear that the new S2 oiling location to the Apex seal area (not pointed only to the side irons) is to address something specifically with the apex seal function. I would suggest this is an effort to both lubricate, reduce friction and reduce heat (the beneficial byproducts of lubrication). I would feel confident in saying that this is to reduce wear and friction of the apex seal to the rotor housing, reduce the rate of housing wear and therefore give the engine a longer ability to make higher compression.
Now......isn't this different than gummed up Apex seals? It is my understanding that the gummed up apex seals are the main reason why the street motors end up in warranty. Pulling a poorly combustionable motor oil from the engine and then trying to burn it in a combustiion process leads to some nasty, nasty, nasty deposits. Two stroke oil is preferred----why? Because it has better combustion properties. Why don't people premix with motor oil? Because there is a better product for this. The motor oil deposited via the S1 side irons lubricates but also leaves a nasty residue which gums up sealing grooves. A seal needs to freely travel to operate properly. We have replaced our source of lubricant to a remote reservoir and use two stroke oil and the resultant deposits are much less. They're still there but they are much less.
If one were to dissconnect the side iron lubrication function of the S2 motors and retain the new apex seal squirter location (using or not using premix) I'll suggest to everyone that the failure mode of these engines would still be side seal springs. Which is the basis of my theory of what the S1 OMP was designed for----prevent side seal friction/spring failure----not to reduce apex seal wear.
In summary, I don't think the S1 OMP function was to address apex seal wear. It was to address side seal spring/seal wear. Again, this has been our experience under our operating parameters. Perhaps long term street wear is different.
I was hoping that someone who has cracked open many, many, many high mileage engines could clarify this. It is pretty common knowledge that when replacing apex seals one should also strongly consider replacing the rotor housings too. Why? Because they have been grooved or scored. Just about every engine builder I know will demand new rotor housings to start with and I hope people think about that for a bit. Even if the initial failure modes are apex seal wear related, that does not overrule (IMO) that function of the OMP is for Apex seals. Removal of the OMP toasts the side seal/side seal spring function and this is the hands down weak link of the motor without OMP.
I believe the only people who can add value to this theory are those who have seen numerous high mileage street engine teardowns and I encourage everyone to abstain from comment or speculation until they can contribute their findings of RENESIS high mileage failure. Speculation and "my brother in law opened one of these one time and he told me XYZ" is what we don't need right now. Neither is 3rd party here say.
Brian, can you comment here?
Paul, can you comment here?
I'm sure other qualified engine builders are much more well versed than I on this and apologies in advance for not mentioned you if you've got a ton of experience in this field.
Cheers, and always looking to learn something.
See you at the track.
Eric
-5,600 to 8,700 rpm pretty much every time the car is operated on track
-1,500F+ EGT's pretty much every time the car is operated on track unless it's a yellow flag in which the EGT's are still over 1,000F
-Constant load. This is coming off the various corners in 3rd gear at 60 mph or whatever and then running wide open throttle (WOT) up through the gears to 5th or 6th at 120+ mph. Brake. Repeat process. Load, load, load, load. Basically I've got the throttle pegged at 100% for the majority of each lap for either a 15 minute qualifying session or an 8 hour enduro.
-About two dozen motors worth of rebuilds and observation
-.89 and .93 Lambda data (google if you don't know what Lambda is).
-With and without OMP function
-Various amounts of premix
-Lots of data collection
-The greatest number of hours we've seen is 25 as after that our power slowly falls off (side seal spring).
When running in the above environment WITHOUT the OMP function we have experienced huge, huge, side seal spring failure. Huge. Please note that I did not use the word "Apex" anywhere in the previous sentence. We've had newly refreshed motors last 6 hours. We've had refreshed motors last 2 hours. Side seal spring failure with no OMP function.
This has been my experience and leads me to MY THEORY of the coorelation of OMP to the #1 failure mode of the engines (which was the original post of this thread). To my knowledge (and I could be totally off here), the failure mode that leads to low compression that leads to warranty rebuilds at Mazdas facility in Virginia has to do with carbon buildup in and around the apex seal groove which prevents apex seal travel which restricts the apex sealing function which causes compression loss which leads to low power and/or inability to start the car. And I could be way wrong here but this is my understanding.
Apex seal wear is (according to all the smart RACE engine guys I've talked to) is actually much more of a rotor housing wear which is caused by the bowing of the center of the apex seal during its normal function and this over time wears a groove in the softer aluminum housings and this makes for an escape or compression leakage. This is very much like a scored piston engine cylinder bore which lets compression escape around the rings. This groove decreases the engines ability to retain higher compression and therefore higher power.
Again, I could be wrong and our experience with the OMP has and does have a huge coorelation to side seal spring failure. Not apex seal or corner seal. At all. We've been reusing the stock apex seals for a lonnnng time. We've also tried ceramics and they last so damn long its crazy (in our operating environment).
It would appear that the new S2 oiling location to the Apex seal area (not pointed only to the side irons) is to address something specifically with the apex seal function. I would suggest this is an effort to both lubricate, reduce friction and reduce heat (the beneficial byproducts of lubrication). I would feel confident in saying that this is to reduce wear and friction of the apex seal to the rotor housing, reduce the rate of housing wear and therefore give the engine a longer ability to make higher compression.
Now......isn't this different than gummed up Apex seals? It is my understanding that the gummed up apex seals are the main reason why the street motors end up in warranty. Pulling a poorly combustionable motor oil from the engine and then trying to burn it in a combustiion process leads to some nasty, nasty, nasty deposits. Two stroke oil is preferred----why? Because it has better combustion properties. Why don't people premix with motor oil? Because there is a better product for this. The motor oil deposited via the S1 side irons lubricates but also leaves a nasty residue which gums up sealing grooves. A seal needs to freely travel to operate properly. We have replaced our source of lubricant to a remote reservoir and use two stroke oil and the resultant deposits are much less. They're still there but they are much less.
If one were to dissconnect the side iron lubrication function of the S2 motors and retain the new apex seal squirter location (using or not using premix) I'll suggest to everyone that the failure mode of these engines would still be side seal springs. Which is the basis of my theory of what the S1 OMP was designed for----prevent side seal friction/spring failure----not to reduce apex seal wear.
In summary, I don't think the S1 OMP function was to address apex seal wear. It was to address side seal spring/seal wear. Again, this has been our experience under our operating parameters. Perhaps long term street wear is different.
I was hoping that someone who has cracked open many, many, many high mileage engines could clarify this. It is pretty common knowledge that when replacing apex seals one should also strongly consider replacing the rotor housings too. Why? Because they have been grooved or scored. Just about every engine builder I know will demand new rotor housings to start with and I hope people think about that for a bit. Even if the initial failure modes are apex seal wear related, that does not overrule (IMO) that function of the OMP is for Apex seals. Removal of the OMP toasts the side seal/side seal spring function and this is the hands down weak link of the motor without OMP.
I believe the only people who can add value to this theory are those who have seen numerous high mileage street engine teardowns and I encourage everyone to abstain from comment or speculation until they can contribute their findings of RENESIS high mileage failure. Speculation and "my brother in law opened one of these one time and he told me XYZ" is what we don't need right now. Neither is 3rd party here say.
Brian, can you comment here?
Paul, can you comment here?
I'm sure other qualified engine builders are much more well versed than I on this and apologies in advance for not mentioned you if you've got a ton of experience in this field.
Cheers, and always looking to learn something.
See you at the track.
Eric
Last edited by Shaozhou Zhang; 01-15-2020 at 02:59 PM.
01-15-2020, 03:14 PM
#15
Weekend Warrior
Thread Starter
I have looked into the thermal pellet and it appears some people remove it and some keep it, some go for a modified Atkins. Some modify OEM but some OEM fail closed which is big problem.
Can anyone elaborate on above?
If it is removed what potential issues can I expect?
Also love to hear about seal kit recommendations for solid weekend use NA engine rebuild.
What is the 'high oil flow' mod and is this worth looking at?
Only mods to this car are: catless, BHR new style coils and a catch can. Otherwise bone stock. Always use 98 RON fuel and premix, of course done all fluids.
Can anyone elaborate on above?
If it is removed what potential issues can I expect?
Also love to hear about seal kit recommendations for solid weekend use NA engine rebuild.
What is the 'high oil flow' mod and is this worth looking at?
Only mods to this car are: catless, BHR new style coils and a catch can. Otherwise bone stock. Always use 98 RON fuel and premix, of course done all fluids.
01-15-2020, 03:22 PM
#16
I have looked into the thermal pellet and it appears some people remove it and some keep it, some go for a modified Atkins. Some modify OEM but some OEM fail closed which is big problem.
Can anyone elaborate on above?
If it is removed what potential issues can I expect?
Also love to hear about seal kit recommendations for solid weekend use NA engine rebuild.
What is the 'high oil flow' mod and is this worth looking at?
Only mods to this car are: catless, BHR new style coils and a catch can. Otherwise bone stock. Always use 98 RON fuel and premix, of course done all fluids.
Can anyone elaborate on above?
If it is removed what potential issues can I expect?
Also love to hear about seal kit recommendations for solid weekend use NA engine rebuild.
What is the 'high oil flow' mod and is this worth looking at?
Only mods to this car are: catless, BHR new style coils and a catch can. Otherwise bone stock. Always use 98 RON fuel and premix, of course done all fluids.
The high oil flow mod, if you are referring to the oil pressure reuglator mod, is to raise the maximum pressure of the oil system from factory 70psi to about 100 psi. Means more oil flow at high RPM, higher flow at startups (if you are using thick oil at cold temperature). Just be careful with your oil cooler lines, mine has blown up after several days of install. Not sure if it is coinencidence or not, but mine was pretty rutsy.
01-15-2020, 03:28 PM
#17
Smoking turbo yay
However, unburnt fuel does cool the cat, assuming there is little to no oxygen in the exhaust. If your ignition system is busted, that can leave a lot of oxygen in the exhaust to react with the fuel when it gets to the cat, which can melt it.
Here's the source Loki https://www.rx8club.com/series-i-tec...-210194/page6/
It's in Page 6, posted by EricMeyer
As for the engine load, I agree. But having a high load at low rpm is bad and having a consistent high load in not so low rpm, let's say 5000 in 5 or 6, if I got pulled over I am dead lol.
It's in Page 6, posted by EricMeyer
As for the engine load, I agree. But having a high load at low rpm is bad and having a consistent high load in not so low rpm, let's say 5000 in 5 or 6, if I got pulled over I am dead lol.
WOT at 5k RPM in 5 and 6th gears require you to live in Autobahn to pull it off legally, and if you are at that speed, you should worry more about your own safety over cops.
01-15-2020, 05:15 PM
#18
Eric is operating in a race environment, which is how side seals die: heat and distortion. His findings are valid, but his dataset is biased toward one type of engine regime. Useful if you're in that regime (in which case, premix?), not useful on a street car which accumulates carbon during low load, low temp, low airflow operation. Which camp do you fall in?
Also consider this: how would OMP oil climb toward the center of the engine against the centrifugal force of the spinning rotor and seals, to cover the side seals? That's where premix helps.
The oil injector dribble pattern isn't exactly all-encompassing.
Also consider this: how would OMP oil climb toward the center of the engine against the centrifugal force of the spinning rotor and seals, to cover the side seals? That's where premix helps.
The oil injector dribble pattern isn't exactly all-encompassing.
Last edited by Loki; 01-15-2020 at 06:06 PM.
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01-15-2020, 06:02 PM
#19
Registered
Been lurking here for 2 years before buying an 05 6spd in pretty good original shape a year ago (other than a tired original engine with 185km on board.) Learned lots before and after purchase from many knowledgeable people here. Lots of trouble shooting with success but it is basically time for a rebuild and I want it to last. No I won't be doing this myself unlike the many threads I have read.
This project car is just planned to be a weekend warrior, not a race car or even a track car. It will be mostly original and well sorted in the end.
I want to know what components should be used and any good mods should be done as part of this engine build. I understand that most of my engine parts will not be able to be used due to the very high mileage on them.
The current engine is still starting and running really well with ample power for such an engine. Surprising really. It does however suffer from the dreaded 'hot start' issues and has known low compression of approximately 93 psi average at 250 rpm. This was bought as a project car expecting to put an engine in it sooner rather than later. I am wanting suggestions that are known to work rather than what someone has done and maybe worked or not. I have had older rotaries prior to this one but the last engine rebuild I had was 20 years ago.
By the way a reman is out of the question as I have never heard of one being purchased in AUS. A Mazda dealer did quote me $17k AU without fitting. This still used all of my own accessories! Wow. He assured me it was factory new however!
Thanks in advance for constructive suggestions from people far more knowledgeable than me.
Finally if this has been covered and I have not found this info in my many hours of searching then feel free to link me up.
This project car is just planned to be a weekend warrior, not a race car or even a track car. It will be mostly original and well sorted in the end.
I want to know what components should be used and any good mods should be done as part of this engine build. I understand that most of my engine parts will not be able to be used due to the very high mileage on them.
The current engine is still starting and running really well with ample power for such an engine. Surprising really. It does however suffer from the dreaded 'hot start' issues and has known low compression of approximately 93 psi average at 250 rpm. This was bought as a project car expecting to put an engine in it sooner rather than later. I am wanting suggestions that are known to work rather than what someone has done and maybe worked or not. I have had older rotaries prior to this one but the last engine rebuild I had was 20 years ago.
By the way a reman is out of the question as I have never heard of one being purchased in AUS. A Mazda dealer did quote me $17k AU without fitting. This still used all of my own accessories! Wow. He assured me it was factory new however!
Thanks in advance for constructive suggestions from people far more knowledgeable than me.
Finally if this has been covered and I have not found this info in my many hours of searching then feel free to link me up.
maybe upgrade the starter and make sure coils en, plugs and wires are good, it might solve hot starts
01-15-2020, 06:22 PM
#20
Weekend Warrior
Thread Starter
Thanks Sinkas. I had the compression test results before purchase and knew they were low according to charts I have seen on here.
I have done new plugs/ leads/ BHR coils and although it is smoother and a little more power, there was no difference to the hot start issue.
I may try a S2 starter for this? Still preparing for my rebuild after 185km tho! My 07 spare parts car with dead engine only lasted 120km.
I'm also thinking of replacing engine mounts at time of rebuild after lots of reading about them.
I have done new plugs/ leads/ BHR coils and although it is smoother and a little more power, there was no difference to the hot start issue.
I may try a S2 starter for this? Still preparing for my rebuild after 185km tho! My 07 spare parts car with dead engine only lasted 120km.
I'm also thinking of replacing engine mounts at time of rebuild after lots of reading about them.
01-15-2020, 06:47 PM
#21
When running rich the catalytic converter is running hotter on any engine because of the unburned fuel. Running lean will heat the engine which can heat the exhaust manifold if that's what your referring to. Running MILDLY rich CAN have a cooling effect on the engine, BUT will cause the catalytic converter to run hotter because of the unburned fuel and increased work load.
01-23-2020, 03:40 AM
#22
Weekend Warrior
Thread Starter
Some interesting suggestions here to take on board. Well my well known builder (that has been in strong business for many years) in my area only wants to do standard specs along with a street port. I was more thinking standard porting for the reliability factor after the tons of reading I have done.
Be great if someone that has built many engines could definitively chime in and say this following combo works for a weekend car that is only driven on country back roads and always with plenty of revs, and has a drinking problem!
Don't get me wrong, many thanks for the ideas, and engine data stats under the specific loads. I am learning heaps and loving the read.
At this stage I'm looking at basically a stock standard engine and chuck on a alloy rad and a new hose kit! Well I'm definitely glad Mazda got this design 100% sorted for the 8 and I won't need to change any specs all these years later!! Also it will last indefinitely!! Jk but wishful thinking.
Calling on any builders for any input for my benefit and also for others no doubt.
Be great if someone that has built many engines could definitively chime in and say this following combo works for a weekend car that is only driven on country back roads and always with plenty of revs, and has a drinking problem!
Don't get me wrong, many thanks for the ideas, and engine data stats under the specific loads. I am learning heaps and loving the read.
At this stage I'm looking at basically a stock standard engine and chuck on a alloy rad and a new hose kit! Well I'm definitely glad Mazda got this design 100% sorted for the 8 and I won't need to change any specs all these years later!! Also it will last indefinitely!! Jk but wishful thinking.
Calling on any builders for any input for my benefit and also for others no doubt.
01-27-2020, 05:36 PM
#23
New rotors with the apex seal grooves slotted for deeper Rx7 apex seals will allow them to be reused in subsequent rebuilds and they’ll also go longer before losing compression. Two of the biggest mistakes people make here imo is
1. Reusing used unmodified OE rotors. The unmodified apex seal slots are almost always sloppy. If they’re still in spec they won’t be for long in your rebuilt engine. Mazda putting the shorter apex seal on the Renesis was a big mistake.
2. Reusing rotor housings. Just a bad idea with new apex seals. It will cost you in the long run imo.
.
1. Reusing used unmodified OE rotors. The unmodified apex seal slots are almost always sloppy. If they’re still in spec they won’t be for long in your rebuilt engine. Mazda putting the shorter apex seal on the Renesis was a big mistake.
2. Reusing rotor housings. Just a bad idea with new apex seals. It will cost you in the long run imo.
.
01-28-2020, 02:48 AM
#24
Weekend Warrior
Thread Starter
Thanks Team. This is the kind of information I was looking for. Although I was kind of hoping to use known very good housings for my rebuild, of course new housings would always be the way to go.
The RX7 apex seals is if great interest to me. It makes perfect sense this areally.Is it a common thing among good builders? Or more experimental? How involved is it for a reputable builder to modify the rotors to take the RX7 apex seals?
Also I would imagine the costs involved may be offset somewhat by the $$ that were not spent on porting?
Can you or anyone else elaborate on the preferred seals used (latest gen I assume), and no I don't intend to tackle this job myself at all.
Although I intend to replace original OEM radiator with a quality aluminium one, is there any issues keeping the own fans if still kicking in at the set temps? Would the aftermarket fans discussed elsewhere here work just like OEM at the set pcm temps or not?
The RX7 apex seals is if great interest to me. It makes perfect sense this areally.Is it a common thing among good builders? Or more experimental? How involved is it for a reputable builder to modify the rotors to take the RX7 apex seals?
Also I would imagine the costs involved may be offset somewhat by the $$ that were not spent on porting?
Can you or anyone else elaborate on the preferred seals used (latest gen I assume), and no I don't intend to tackle this job myself at all.
Although I intend to replace original OEM radiator with a quality aluminium one, is there any issues keeping the own fans if still kicking in at the set temps? Would the aftermarket fans discussed elsewhere here work just like OEM at the set pcm temps or not?
02-29-2020, 12:41 PM
#25
Registered
As far as carbon buildup... I am never below 4k RPMS if not idling. I don't hit sixth until about 70 mph. She burns a lot more oil but I feel like she has been running smoother as well. As far as fuel consumption, well its **** anyway so who cares. Every time I drive it she sees at least 1 redline and generally I am quite spirited and liberal in my use of throttle.
I wanted to echo what someone said about the cat. I would toss that pronto.
I wanted to echo what someone said about the cat. I would toss that pronto.