Too late now my friend :) If I don't end up swapping in a REW I will be purchasing as many new (freakin' expensive) hard parts as possible. Finding pristine used stuff is getting very hard.

I was lucky to find an engine that had less than 1000 miles on it for this latest rebuild :)
Have you had enough experience with the oil pressure mod to say that it helps with no drawbacks ? IE issues with the pump or overheating the oil etc .

I have it and we have installed it in on a couple of engines we have rebuilt locally. With my pineapple modification I get a maximum of 100psi or so, with the mazmart I would see about 120psi max running the same oil (0W-40). I'm not sure how feeding oil to my turbo affects that. To me it's a no brainer. And my last engine had zero oiling or bearing issues when it was torn apart by Pineapple after about 30k or so.

About the only downside is that if you are turbocharged you should not put full pressure to the turbo, most turbo should not get more than 30-35psi or so of oil pressure. I am working on a solution to read and regulate pressure to the turbo now.

Is that available to purchase or is it just a mod to the mazmart mod ?

Nah, just get the Mazmart one, Pineapple doesn't really sell a "kit" like mazmart does. The mazmart one comes with everything you need and it's simple to install.

Mine were fine when I rebuilt at 125k. I now have 158k? I think they have about 30k on them and are starting to show smooth copper.

It's all a learning game, so long as the OMP is up and you are premixing housing wear should be minimal. If you catch it before you pop an apex seal its not to costly to experiment :).

basically every racing engine since the late 70's has run an oiling system like the FD or a renesis with an FD regulator. its pretty well proven.

Easy oil pressure mod

Get a 3/8"-16NC Bottom Pipe Tap

Tap the hole on the end of the regulator, Then use a 1" long 3/8"-16 Bolt with a backup nut.

Measure the depth of the cone on top of the regulator, Set the screw depth Just slightly under that depth.

I have 5-20 Oil on a cold start up I see pressures as high as 128 PSI, but once it warms up they are steady at 96PSI Max.

What does this mod do - physically ?

Anyone got any suggestions for resolving the exhaust port wear issue ?

there is much more to proper lubrication than replacing the pressure regulator. A lot. I am not an expert, but i do listen to others.
For example my engine ( with redline 5W 30W) my max psi is 93 -95psi. My MINIMUM cold or hot is 48-50 psi. You cant get that by just a regulator change.

"No overheating" uhhhhh--old buddy--sorry to port out you were having some localized overheating---big time. Look at the trailing and leading sparkplug sites. Now whether the gas leakage marks came before the cracks--I dont know.

Team IMHO is correct about the detonations. I think Harlan's work is showing that this engine is having more detonations than a lot think? The gas leakage marks on your rotors could also suggest that. Very possible. Makes me paranoid--lol.

After learning some additional things recently--i do know if I ever have to build another engine i will use ceramic seals.

Sure looks like you have clean gas where you live.

I think you may have more turbo back pressure than you think? Maybe? Pressure/expansion under the seals could cause the seal to catch on the exhaust port.
Also when the cracks appeared at the plug sites I will bet you have a patch of metal around that area that "sticks out" from the rest of the housing. Get a true straight edge and see...now that protrusion can cause the rotor to "wobble' more than it normally would and it may be enough at times to catch a corner seal edge on the exhaust port?.

Brettus,

I would suggest reconsidering your reduction of OMP injection next time around. The oil injection into the combustion chamber does more than just lubricate, it also provides some heat dissipation.

RX8 Engines

Reading the pettit blurb about it in the above link , I'm more inclined to think they were right on the money all along ......Yes Team ..... I know .

Another possibility for the extra bearing wear is preignition. The E-shaft bends under load, more pressure at TDC would bend it more. Does the bearing wear correspond to opposite of tdc or opposite of 45-55ATDC?

Also of interest is the fact that the end of the apex is not wearing into the steel ,yet it has an even smaller surface area than the corner seal .

That plus the reduced wear on the non ported ports (that have less land area) makes me think there could be something to gain from reducing spring pressure on the corner seal ..........................

Centre of wear patch corresponds to approx. opposite 20 degress before TDC .

So you turn up your omp on your current tune yet?

can,t - still on the ecu that has reached 100 flash limit . Plus I'm not convinced that is an issue here after re-reading that Pettit blurb and seeing that the exhaust port thing is the exact same issue I have..

It puts additional pressure on the spring and causes it to open at a higher pressure.

It is like shimming it with washers but this makes it adjustable. Just like a a welding Regulator.

It does not relive any pressure out of the end. The flow path is out of the side ports so It does not restrict flow. Just increases the spring tension.

cool . thanks for the suggestion .

When I get 500 Miles on my car I'll drop the oil pan and take a pic of it. IT is the same as crushing the top that Pineapple racing says. I didn't want to risk buggering up the threads on the bottom and It is completely reversable, just remove the bolt.

Remember to shim the relief in the front cover also.

"These conditions also can cause the minute film of protective lubricant, (from the OMP), to vaporize resulting in elevated friction and wear, which generates more heat and wear eventually causing hard starting and / or a weak idle on hot engines"

so you turned minute level of lubricant to near non existent, the uneven wear can be from the oil squirters not injecting the same.....

You missed my point . The issue is not unique to my car and is the most common failure mode of the renesis engines that Pettit rebuild .

And the whole quote in context:

And this referencing the pic showing damage identical to what I have on my ports.
Plus : we are talking about an engine that ran at higher whp than most AND survived longer than any turbo renesis I've yet heard about on this site .

interesting. there are three corner seal springs. the wire type (1202-11-323A), used from the beginning until the early 90's.

with the JC cosmo engines they introduced the NF01-11-C24 seal spring, its much stiffer, and much more durable.

interestingly with the Rx8 they have a 3rd spring, N3H1-11-C24B, which is like the FD spring, but apparently with less tension.

so perhaps Mazda already gave the Rx8 less corner seal spring, and when you up the power more, it wants even less?

yeah, I have read the article several times, I get what your saying.

I guess I am saying your motor could have lasted even longer?
but you are correct you did have the longest going turbo Renisis, and that desires high honors!
you set a high bar :)

are you running esmiril seals in your current block?

so why did the engine loose power and then recover?

Been mulling this over . I notice there is carbon in behind the corner seal . This implies there is also combustion gas behind the seal as well . So we have gas at extremely high pressures (much higher than an NA engine) pushing the corner seal (like a piston) into the side iron . Then it passes over this overheated , underlubricated and small surface area land at the exhaust port .
It's a pretty bad recipe .....

Totally stumped on that one . I originally (before tearing the engine apart ) thought it was the apex seals wobbling around in the groove and getting stuck .

I think this is why so much attention needs to be taken when cutting the seals. Did you use precut seals on this engine when it was rebuilt last time or were they cut by the builder?

No - this one has the deeper RX7 ALS brand seals . Knowing what I know now - I think i should have saved my $ and stuck with the esmerils

Don't actually remember if he cut them or not - I suspect not .
I don't see a connection to this issue though?

Well it seems to me if they were not cut to tight tolerances then carbon could build up where you don't want it and then cause the side seals to stick and cause damage and wear out prematurely. :dunno:

I actually meant to say 'corner seal' above (now corrected) but yeah I see what you are getting at now .

The factory pre-cut side seals have very loose tolerances, the side seals shrink slightly as well which contributes to compression loss.

"I think you may have more turbo back pressure than you think? Maybe? Pressure/expansion under the seals could cause the seal to catch on the exhaust port."

Ahem..........cough, cough, cough")

Don't dismiss the hot spots around the plugs. That has to be addressed if you want longevity. There are specific things that you can do to increase the cooling to those areas.
Omp has to be used to get the max out of the side seals--pre mix doesnt fix the lack of omp injection---i feel like I am preaching to the choir here....bret knows these things already--sorry man.

I hear ya OD .But the pressure I was alluding to is the combustion pressure not the back pressure from the turbo.

Do you have details of what can be done around the spark plug holes and the exhaust port to improve cooling?

I havn't done it myself. But I will get what details I can to you. My engine rebuild has had it done.
I will Pm you Brett.

You can grind out little slots in the coolant jacked around the plug holes. The theory is that this causes turbulence around the plug area so the water cools a touch longer.

I'll take pics of it for you tomorrow if I remember. Pineapple does this, mazmart does a variation as well. Shoot even the factory casts have some cut out that dip on an angle to slow water flow... Basically we just improve on what the factory was going for.

I have pics of the exhaust ports as well if you want to see them ill try and upload them.

if i can make a recommendation, its to tap a fitting into the exhaust manifold and look at preturbo backpressure.

you don't need anything fancy to do monitor it, a boost gauge works fine.

i did it on the last car i really went after methodically, and its very informative.

The only problem with all of this is if he wasn't to reduce manifold pressure he will need to get a larger turbine which will increase spool times.

The 20G greddy turbine wheel is almost perfect, as far as size spool times goes.

The only other opportunity to gain more flow would be to convert the downpipe to a true 3" setup. I am still working on that but wont have anything done till the end of the year.

well the point is to find out what the preturbo backpressure actually is before you guess about having to change stuff

Yea I get the point, I'm just saying if there is an issue he wont wanna fix it.

I already know there is a LOT of backpressure due to the lengths i had to go to to get decent boost at high rpm . I'm not 100% convinced that this issue is caused by the backpressure or whether it is just a factor that exacerbates it . The main factor could be high pressure in behind the corner seal - IE from boost. We need a high mileage teardown from a SCd car to verify that they don't have it as well.

Gunna just throw this out there

The blurb from pettit suggests that they see this a LOT . They also say the cause is from turbos set to run at much higher boost than the stock 'assume Greddy' system was designed to run therefore backpressure blah blah blah.
I will put it like this - very few Greddy kits ever ran anywhere near the boost level (particularly at high rpm) that I ran on my car or got the miles i did for that matter . I wonder how many of the engines they see saw track time ? Maybe that was a big factor in the failure rates ?

I was holding 10psi from 4k to 8500 at fuel cut. That seemed decent enough for me, but then my engine went boom LOL.

Sounds like you had a very quick car on your hands :) Are there any signs of the kind of wear I have on your ex. ports ?

I still am not sure what wear you were talking about, on my end everything looked the same as my previous NA tear down. Identical wear minus the chunks of apex, I'll get some pictures for you to compare.

This -notice the big gouge at the outer edge of the exhaust port . Is there any sign on yours of scuffing or abnormal pressure from the corner seal ?

https://www.rx8club.com/attachments/...s-p1010172-jpg

Yea mine didn't have anything close to that...

But then again most of its career was NA.

Pettit has seen a LOT of turbo renesis engines. Not high mileage ones, but the ones from the Diaso track cars. Pettit is the supplier of engines to this model. He identified this issue back in 2008? Maybe?
I know my engines were not high mileage under boost engines (25000miles max)--but none of mine had any markings like that. My engines were ran pretty hard due to multiple track sessions--even in 105F ambient weather. SWEAT:)
Cam even recommends to not wrap or ceramic coat your header ( oem or aftermarket). He told me that the rear rotary exhaust port has more trouble cooling and a coating or wrap would make the exhaust ports run hotter.
Pettit does cooling mods for the lead/trail sparkplug area through an access they drill between the two sparkplugs. I now have a sealant plug between those two areas. like a water jacket plug.

Did you actually inspect the irons yourself ?