f150rx7

I know there is a thread about some guy in the forum using a series 2 block but he's not utilizing the third oil injector. I wanted to see if anyone has done this and still utilized the third oil injector in the middle by using some kind of separate independent metering pump? Im rebuilding an engine and planning on purchasing new Series 2 rotor housings.

9krpmrx8

iTrader: (46)

No one that I know of has used it, they just blocked it off. It would also be a pretty useless endeavor.

200.mph

iTrader: (9)

had a long talk with mazda maniac dring a dyno day about this. yes he used s2 hosing in one of his builds and used all three oil injection holes

NotAPreppie

I wonder why Mazda's design uses two separate oil feeds for the injectors in the same housing. Theoretically, would it work to have a 2->3 split to feed the third injector?

(Yes, I know I'm ignorant. That's why I'm posing the question.)

TeamRX8

iTrader: (25)

To ensure specific flow to a desired point. Tied in together there’s no way to be sure flow is equally distributed or as intended, especially since the amount to the new center injector might be different than the amount going to the two corner injectors.


.

f150rx7

200.mph any info how he did it?

200.mph

iTrader: (9)

i dont remember how he said he fed all the oil nozzles, it was a very long very busy day. iirc someone else has used them before and plugged one hole

TeamRX8

iTrader: (25)

Or plugged them all and ran premix only (racing)

f150rx7

I know but does it hurt to have a third oil injector even if it's not working 100% ?

TeamRX8

iTrader: (25)

You seem overly fixated on something that you also don’t seem to have a good understanding on. S2 engines are failing early too. Seems like you might have something better to worry about than locating a magic bullet that doesn’t exist.

But since you feel compelled to do something, go buy one of the well documented premix suggestions and add 1/2 ounce per gallon of fuel with each fillup instead.



.

Mazda Sports Corner

Ryan rotary has started doing 3 oil injectors in the housing.That engine he is using a rx7 housing and mod it to take 3 oil injectors.

9krpmrx8

iTrader: (46)

Scott Rotary says that's a lot of wasted time and effort.

TeamRX8

iTrader: (25)

just go full-baller and use 5 or 6 instead ...

IamFodi

iTrader: (1)

Probably not. The problem is, it introduces a variable that is basically impossible to figure out how to work with. How do you know whether it's injecting enough? Or too much? How is that third line affecting the rest of the system? How does it all work at various loads/RPMs/temps? Etc. etc. Can't even begin to figure this out without a lot of very careful controlled testing and teardowns. Like, this is the kind of thing that makes cars take years to develop by whole teams of engineers with lots of resources.

An S1-style 2-injector setup is a known quantity. An all-OE S2 3-injector setup is a known quantity. A 3-injector hack job is not.

If you're just tinkering and want to run it for lols, then by all means have at it. If you're trying to decide based on what "will" or "won't" be beneficial/harmful, probably safe to say you'll never find an answer other than gut feelings.

f150rx7

If the S2 engines are failing early its still because of owner negligence and not informed enough about rotaries. I have seen an S1 RX8 with 214k miles before it started loosing compression because the owner monitored the engine.. coolant temp,oil temp, misfires and etc. My point is everyone talks of how bad this engine is when they don't take time to know why. There's a reason why Mazda added the third oil nozzle. It's not just about lubricating but also removing heat. I was planning on using the third oil nozzle with a separate tank of two stroke oil since it burns cleaner and separated from sourcing oil from the oil pan which can get dirty and not work as effectively. I wouldn't have to premix as much or worry when in a hurry. Rotary Aviation has the oilnmetering pump adapter so looking into how that works for the mean time and see if I can use that somehow with the third oil nozzle.

NotAPreppie

The Sohn OMP adapter won't help you. It's basically a block-off plate with an alternate feed source that gets sandwiched in between the engine and OMP. The factory OMP with its four outlets is retained.

9krpmrx8

iTrader: (46)

That is the excuse everyone makes for rotaries and every noobie who comes into the RX-8 world from the RX-7 world thinks they have the answer. And if you saw an S1 RX-8 with 214k is was one of maybe two and who knows it could have been on it's third engine or more and even if it were true and still running, it is probably making 100WHP at best. We have had a few new guys come into the group thinking they had a high mileage original engine only to show them the blue reman tag in their engines. My first engine lost compression at 22,000 miles, bone stock, on time oil changes, babied during break in, etc. and over the past 10+ years I been apart of many Renesis tear downs that were meticulously maintained, premixed, etc.

For me personally it has been a toss up, my factory engine lasted 22k (loss of compression), my first reman lasted 74k (loss of compression, premixed, but found faulty oil injectors when tested), my second and last reman lasted lasted 27k (coolant found in oil during routine test, was pulled before it had a chance to fail). And lastly my current and only professional build (pineapple racing on a very low (8k IIRC) mileage 2008 core) has lasted me about 40k and still has good compression and it has been turbocharged since day one.

One of our long time local guys is a tech at Mazda, has been for many years, and the S2's have been rolling in for a couple of years now. They are lasting a bit longer but the they also sold in much much lower numbers. He said the most common failure modes as far as they can tell (they can't tear them apart) are the same, just a loss of compression. But he has seen quite a few failed cats so it's obvious Mazda never fixed that issue either. The S2 is better but they still fail more often that they should and the same reman plant that makes S1 remans is making S2 remans so it doesn't really matter how many injectors they have.

f150rx7

You just explained what I thought no one takes the time to figure out why is it a toss up between really low mileage and high mileage.. I didn't believe either.. I bought two non running S1 rx8s both original owners. 214k and the other 134k that's pretty good I think, I couldn't find reman tags( pls inform me of what they look like to make sure)carfax checked and you can usually tell if the engine has been pulled once. Both owners were the original owners shows in carfax as well and both said it is the original engine.

f150rx7

Notapreppie thanks for the info I just saw it but it was giving me ideas the way it works. I also like the idea of having a separate oil tank purely for the oil nozzle.

9krpmrx8

iTrader: (46)

Carfax is probably accurate on the owners but not the engine replacements. And mileage doesn't mean **** I am on my fourth and know plenty of other RX-8 owners with high mileage who are about the same. They could have had five engines each for all you know.

TeamRX8

iTrader: (25)

N00bs gotta n00b ...

f150rx7

Wow they're that bad huh? why do you guys even own rx8s? You guys always shut noobs down? Maybe I should just join the LS bandwagon...I bet they would be more supportive at least. But nah I still like these engines good or bad...I was just trying to see the root cause of these engine failures and maybe find a way to make it better even if it's a long shot.. what's wrong with that? I guess I'll get help somewhere else and I did call racing beat in aneheim and even they've seen 200k renesis and it is possible...What they say makes more sense but thanks anyways guys sorry for being a noob I thought it was a valid question and idea.

TeamRX8

iTrader: (25)

No, you’re talking about something you don’t understand to people who do. You ask a question and then argue against sound information and advise. We know and love are car for what it is. Some of us for 12 - 13 years now. You’re not doing a very good job of presenting yourself in any favorable form of understanding or enlightment. I chose to call you a n00b just to cap off the blah-blah-blah of trying to reason with you, plus we’ve seen people carrying on this way come and go here like birds on the wind. We’re having a discussion and you’re part of it. Participate and learn if you want, or not.

NotAPreppie

I own it because it's worth it. It's a car I can take to work on Monday but won't be financially burdened if I stuff it into a wall at the track on Saturday.

So, I have to shell out roughly $1.2k a year to keep it running (assuming reman/rebuild every 3 years). That's far less than a car payment.

f150rx7

Anyways...So you guys don't believe 200k plus is possible? You don't think 22k miles on that factory motor you had not worth digging into? There's got to be a reason for that.....