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Old 03-28-2008, 12:36 PM
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I wonder the percentage of renesis engines that make it over 100,000 miles?
Old 03-28-2008, 01:09 PM
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Originally Posted by Evolv
It is true, I am a troll. but I don't have an EVO...

It is also true that you can get 200K out of your rotary, but by that age it is heavily burning oil and if you tear the engine apart you will see that the end plates are badly scored, the apex and side seals are just about worn to nothing and there will be a nice hop skip and jump scar on the rotor housing located just south of the compression point.

I know there are a lot of first time rotary powered owners here, spewing **** out both ends of their bodies, boasting about how great their 8's are.

Keep in mind that most of those 8 owners have never seen the inside of a rotary engine, except in photos and if I were to guess, 99% of all members on this forum have never rebuilt a rotary engine.

I owned my first rotary powered car in 1983, wrote my Engineering Thesis on the Wankel engine and I have personally rebuilt many 12A's and 13B's. I have seen the inside of several dozen rotary engines and I know that, what I speak is the truth.

Say what you like, but the reality is, these engines do not have a long life expectancy.
It is true that I've never seen a rebuild Rotary engine in person. But I've seen TONS of piston engines in person with over 150K miles.

Wow, it looks like **** inside, the piston looks like it got beat up so much that its about to make a hole in the center. and of course most of them can barely be able to hold compression.

The good thing about piston engines is that, u have so many pistons, sometimes if one of them failed, the others still work. Thats why the engine can still run.

Rotary on the other hand, if one apex seal fails, it actually effects at least 2 combusion chambers, and the fallen part might just tear up the whole housing. then the whole rotor is pretty much useless.

I seen a lot of older rotary can go over 150K miles. I just havent had a chance to look at the motor (hey, its still working, the owner not gonna let anyone to tear up their car u know)

You rebuild it b4 does not mean u know it all. Not to mention if a person knows how to build piston engine, Im sure the person will know how to play with a Rotary engine.

Jeeze I should really get a dead core from Paul or whoever so I can play with one.

Last edited by nycgps; 03-28-2008 at 01:11 PM.
Old 03-28-2008, 01:13 PM
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Originally Posted by TALAN7
I wonder the percentage of renesis engines that make it over 100,000 miles?
some people did without any problems.

Not to mention, this forum represents like what maybe 1/100 of the whole RX-8 community. im sure there are people out there with over 100K miles. Its just that we dont know, does not mean they never exist.
Old 03-28-2008, 01:20 PM
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Originally Posted by StealthTL
Unless you pre-mix from day one.....

S
Absolutely!! This is THE key to a long life rotary.
Old 03-28-2008, 01:21 PM
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Originally Posted by Jax_RX8
Absolutely!! This is THE key to a long life rotary.
Thats not really possible

Cuz Day 1 happens @ the factory ... so ...
Old 03-28-2008, 01:29 PM
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Originally Posted by nycgps
Thats not really possible

Cuz Day 1 happens @ the factory ... so ...
Hey, the days it's in Mazda's womb do not count
Old 03-28-2008, 02:00 PM
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Originally Posted by Evolv
It is true, I am a troll. but I don't have an EVO...

It is also true that you can get 200K out of your rotary, but by that age it is heavily burning oil and if you tear the engine apart you will see that the end plates are badly scored, the apex and side seals are just about worn to nothing and there will be a nice hop skip and jump scar on the rotor housing located just south of the compression point.

I know there are a lot of first time rotary powered owners here, spewing **** out both ends of their bodies, boasting about how great their 8's are.

Keep in mind that most of those 8 owners have never seen the inside of a rotary engine, except in photos and if I were to guess, 99% of all members on this forum have never rebuilt a rotary engine.

I owned my first rotary powered car in 1983, wrote my Engineering Thesis on the Wankel engine and I have personally rebuilt many 12A's and 13B's. I have seen the inside of several dozen rotary engines and I know that, what I speak is the truth.

Say what you like, but the reality is, these engines do not have a long life expectancy.
Old 03-28-2008, 02:41 PM
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Anyone who believes their rotary engine should outlast the "average" piston motor needs a serious reality check. Simply put, the rotary is fragile, gets crappy gas mileage, produces zero torque, and is severely outclassed by most modern piston engines. The RX-8 would be much better off with a piston engine. Yes, I said it... and yes it hurt when I came to the realization of that too. There is a reason no one else is using these engines... it's because they aren't nearly as well developed as their piston counterparts and can't hold up to the competition. The rotary is a liability and not an asset.
Old 03-28-2008, 03:02 PM
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Originally Posted by nycgps
some people did without any problems.

Not to mention, this forum represents like what maybe 1/100 of the whole RX-8 community. im sure there are people out there with over 100K miles. Its just that we dont know, does not mean they never exist.
While I believe people are getting over 100,000 miles, I'd like to see maybe in a couple of years some stats on the average life expectancy of the Renesis before it needed rebuilding. Is it 1/2 that don't make it? A 1/3? 1/4, whatever. I'd like to know this. Overall, in my experience this car reuires too much maintenance att too much money. I mean, when you have Mazda techs telling you to get out of the car it's bad.

The thought of getting rid of my 8 hurts me so though. I can't do it.
Old 03-28-2008, 03:06 PM
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Anyone who believes their rotary engine should outlast the "average" piston motor needs a serious reality check. Simply put, the rotary is fragile, gets crappy gas mileage, produces zero torque, and is severely outclassed by most modern piston engines. The RX-8 would be much better off with a piston engine. Yes, I said it... and yes it hurt when I came to the realization of that too. There is a reason no one else is using these engines... it's because they aren't nearly as well developed as their piston counterparts and can't hold up to the competition. The rotary is a liability and not an asset.
My previous RX-7s proved otherwise. Rotary engines are used in aviation-nuff said.
Old 03-28-2008, 03:37 PM
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Originally Posted by max5roadster
My previous RX-7s proved otherwise. Rotary engines are used in aviation-nuff said.
+1

drive them right, maintain them right(with a little common sense and knowledge), and you're looking at a long happy life for NA rotaries.
(no i am NOT saying that boosted rotaries are ticking time-bombs either!)

my parents had a 1st gen 7 when i was a kid... years later, they found the new owner... 265,000 miles and NO major repairs by either of the owners. nothing more than fluids/brakes/clutch/etc, not a single ounce of motor/tranny work(minus clutches)
Old 03-28-2008, 04:06 PM
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Originally Posted by max5roadster
My previous RX-7s proved otherwise. Rotary engines are used in aviation-nuff said.
Yeah.. in experimental aviation. There are no certified rotary aircraft engines. (And for good reason) In order for a rotary engine to legally be installed in any aircraft certified in the Normal, Utility, Aerobatic, or transport category it would have to meet the requirements documented in FAR 33.

This means that any airplane operating with a rotary engine currently falls into the experimental category and must be operated under the limitations provided in FAR 91, section 319.

Essentially below are the highlights of the limitations:

1) You cannot fly the aircraft for compensation or for hire.

2) You cannot fly the aircraft over densely populated areas (though this isn't really enforced in practice)

3) You must inform any passengers of the aircraft that it is not a certified aircraft and is being operated under an experimental certificate.

4) Notify the controller when operating in and our of airports which have a control tower that you are operating an experiential aircraft. (This isn't a big deal either, you just preface it in your radio call such as "Fort Myers tower, experimental 123 bravo delta...."


In other words... the FAA does not endorse or recommend the use of these engines for use in aircraft. Anyone using a rotary engine powerplant in a aircraft is doing so (legally) in an experimental airplane which typically means homebuilt.

As a pilot I would not personally fly any aircraft (experimental or certified) with an experimental power plant.
Old 03-28-2008, 04:11 PM
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What is the point of raining on the parade of people who have accepted the Renesis(or other rotaries) for all of its faults and are doing so willingly?
Old 03-28-2008, 04:13 PM
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Originally Posted by paulmasoner
+1

drive them right, maintain them right(with a little common sense and knowledge), and you're looking at a long happy life for NA rotaries.
(no i am NOT saying that boosted rotaries are ticking time-bombs either!)

my parents had a 1st gen 7 when i was a kid... years later, they found the new owner... 265,000 miles and NO major repairs by either of the owners. nothing more than fluids/brakes/clutch/etc, not a single ounce of motor/tranny work(minus clutches)
The 1st gens tend to be exceptions. They do tend to run for a long time. The problem is as the horsepower has increased the life expectancy has gone down. Go to the Toyota, Ford, GM, BMW, Honda, Lexus, whatever forums and see how many threads are discussing engine replacement. VW doesn't count... they suck :-)

Also for what it's worth my IS300 has never had a check engine light and currently has 143k miles.
Old 03-28-2008, 04:16 PM
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Originally Posted by Charles R. Hill
What is the point of raining on the parade of people who have accepted the Renesis(or other rotaries) for all of its faults and are doing so willingly?
Just saying you have to take the good with the bad. Anyone who thinks it's "better" than a piston engine is mistaken. The rest of the car is a DREAM to drive and I absolutely understand why people like them and buy them. They are a ton of fun, and there aren't many cars that just "feel" as good to drive as an RX-8. Just don't fool yourself into thinking the engine is somehow magically superior in reliability to a piston engine. That's all I'm saying
Old 03-28-2008, 04:22 PM
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Where did one get the idea that we hadn't already considered all that you are saying.........long before we had a chance to welcome you to the forum? Please accept my personal welcome to our Club and if you ever need to learn the details about the RX-8/Renesis, I'd be happy to share my own experiences with you.
Old 03-28-2008, 04:34 PM
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Thanks for the welcome... though technically I've been here almost as long as you have, just not very active. :-) Just saw the discussion of piston engines being "beat up" at 100k+ miles being compared to the rotary lasting hundreds of thousands (kinda rare). In my experience being around and owning rotary powered cars for 11 - 12 years the piston engines do tend to hold up much better for normal daily driver use.

The aviation topic I just get caught up on... :-)
Old 03-28-2008, 04:36 PM
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Sorry about that, Bri. I saw the low post numbers and not the join date. My bad.
Old 03-28-2008, 05:01 PM
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what i think as a mechanical engineer is... any and all mechanical devices are unreliable.

which makes rotory a beautiful thing. the thing is soo simple it allows for easy diagnostics and easy rebuilds.

it also feature the best hp to size/weight ratio. if you drop a piston into rx8, the handling will be bad =/ the power to weight ratio is also why ppl use em on aviation.

the only bad part is 1 seal go bad, the motor goes bad. u can run piston with 1 piston not working =D


there is the saying, being consistently bad is better than being inconsistently good in the engineering world
Old 03-28-2008, 05:11 PM
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Originally Posted by Brian_TII
Yeah.. in experimental aviation. There are no certified rotary aircraft engines. (And for good reason) In order for a rotary engine to legally be installed in any aircraft certified in the Normal, Utility, Aerobatic, or transport category it would have to meet the requirements documented in FAR 33.

This means that any airplane operating with a rotary engine currently falls into the experimental category and must be operated under the limitations provided in FAR 91, section 319.

Essentially below are the highlights of the limitations:

1) You cannot fly the aircraft for compensation or for hire.

2) You cannot fly the aircraft over densely populated areas (though this isn't really enforced in practice)

3) You must inform any passengers of the aircraft that it is not a certified aircraft and is being operated under an experimental certificate.

4) Notify the controller when operating in and our of airports which have a control tower that you are operating an experiential aircraft. (This isn't a big deal either, you just preface it in your radio call such as "Fort Myers tower, experimental 123 bravo delta...."


In other words... the FAA does not endorse or recommend the use of these engines for use in aircraft. Anyone using a rotary engine powerplant in a aircraft is doing so (legally) in an experimental airplane which typically means homebuilt.

As a pilot I would not personally fly any aircraft (experimental or certified) with an experimental power plant.
As an Air Traffic Controller I like to hear the words "Experimental" This way I am prepared in advance and ready in an instant to hit the "CRASH ALARM" and get the firetrucks moving.

I understand that the rotary engine is making its way into UAV's. With no one on board, and if shot down by the enemy, all they get is Japanese parts with German technology... LOL
Old 03-28-2008, 05:50 PM
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Originally Posted by xsnipersgox
it also feature the best hp to size/weight ratio. if you drop a piston into rx8, the handling will be bad =/ the power to weight ratio is also why ppl use em on aviation.
You state this like the rotary is a popular engine in aviation. Let's be clear about this - The rotary engine is NOT popular in general aviation. It is "somewhat" popular among the homebuilt RV series of experimental aircraft, but even most of those still use traditional aircraft engines. The manufacture of the RV kits (Vans) even recommends against using auto engines in airplanes. Why you may ask...?

1) Aircraft engines (specifically the Lycoming IO-360 which is commonly used in the same RV series of experimental aircraft) weigh about the same as the rotary conversation.

2) An IO-360 typically makes between 180 - 200hp in factory stock form, the Mazda tends to make about 160.

3) The IO-360 uses a dual fully redundant ignition and a mechanical fuel injection system which have ZERO dependency on the aircraft's electrical system.

4) The IO-360 has been tested and certified for aircraft use. Do you REALLY think that Mazda ever intended to see their engines running WOT for hours on end @ 14,000 feet?

5) The IO-360 is air cooled, no need for plumbing, and much less risk of over heating due to a busted coolant line, bad water pump, stuck thermostat, etc.

6) No need for the Lycoming to premix oil with the fuel, it's a normal 4-stroke engine.

The ONLY legitimate reason that I can see for these guys using a rotary over a Lycoming is the price. A Lycoming will run you about $25,000 give or take, a rotary can be found in a junk yard for $500.

Personally though... when I'm at 200 feet AGL on a hot day climbing out and see a sea of trees at the end of the runway in front of me. I want to know that the engine I'm using is DESIGNED for this. At low levels like that an engine failure means that the ONLY place you can go is directly in front of you... typically into the trees and many pilots don't survive those accidents. Pulling off to the side of the road is one thing, an off airport landing is in a totally different realm.
Old 03-31-2008, 01:21 AM
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got the code pulled today before my appointment Monday with Mazda (I don't trus tthem), and I got a P0302 code only. No cat code. Misfire. The guy from SEars said I need a tune-up. I told him I just paid $738 last week to Mazda for a tune-up where they also told me I needed a cat.

Would a bad cat cause a P0302 code and rough idle for about 30 seconds. My understanding is that with a bad cat the car would run bad all the time not just when starting her up.
Old 03-31-2008, 03:35 PM
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When my motor webt with 65k on the car mazda would not do anything to help me out, Go to wayne mazda though and talk to tony they did a good job had the car back in 2 days
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