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-   -   Possible New Renesis Engine Failure Theory? (https://www.rx8club.com/series-i-tech-garage-22/possible-new-renesis-engine-failure-theory-210194/)

rotarygod 11-07-2011 12:05 PM

I've had 5 rotary powered cars and have yet to have an engine failure. Of course none of them have been 3rd gen RX-7's or RX-8's!

shadycrew31 11-07-2011 12:39 PM


Originally Posted by rotarygod (Post 4119325)
I've had 5 rotary powered cars and have yet to have an engine failure. Of course none of them have been 3rd gen RX-7's or RX-8's!

I bet you I can find some members on this forum that can solve that issue for you!

PhillipM 11-07-2011 01:48 PM

Ship it over here, soon have it broken for you.

I've broken 3 now :(

shadycrew31 11-07-2011 01:52 PM


Originally Posted by PhillipM (Post 4119427)
Ship it over here, soon have it broken for you.

I've broken 3 now :(

3 RX-7 first and second gen engines?

PhillipM 11-07-2011 01:59 PM

:lol: No, RX-8's.

Although we can chalk up one RX-7 motor too...so I don't think it'd be too hard to make a few go pop ;)

1.3_LittersOfFurry 11-07-2011 02:31 PM

This is my forth Rotary (3- Fc's, 1-FE), not a single engine failure yet! :D

maxchao 11-08-2011 06:34 AM


Originally Posted by rotarygod (Post 4119253)
Nope. The S1 oil metering system was inadequate causing mixed results, power levels, mileage figures, and reliability between engines. The oil coolers have no fans so don't get any cooling while the car is not in motion or is moving slowly. The engine bay is cramped which doesn't allow air to easily get out. This leads to the engine running hotter. I'll remember a couple of other things but the point is that all of the issues with that motor are known and no new theories are needed.

I wonder if we could spray water on the oil cooler to cool the engine...It gets too hot in the summer that I don't have ac between runs of autocross...and that really tires me out.

rotarygod 11-08-2011 09:02 AM


Originally Posted by shadycrew31 (Post 4119432)
3 RX-7 first and second gen engines?

4 second gens and a first gen. One of the second gens was near 400 hp street ported and beat on pretty hard. Blew up 4 clutches and a few transmission synchros in that one. Engine lived. The first gen was a street port. No problems with the motor in it either. I've had ceramic from at least 2 spark plugs break off and fall into the motors. No problems. I've run one of them out of oil when an oil cooler line broke. Fixed the line and the engine kept running. I've overheated them. No problems. I've even gone with no oil changes only adding it when the oil metering caused it to get low. No problems. I've run everything from 20W50 to 0W20 oil, obviously synthetics and conventional. No problems. It's not to say that with the way I've treated engines that none of those motor didn't have any wear inside but none of them failed. I have never had a broken seal or a bad water or oil ring. All of those cars had over 100K on them with one of them topping 200K. I drive all of my cars hard. I don't believe in babying them. I bought them all used from owners who probably didn't take perfect care of them and I drove them like they should be.

Those cars had mechanical fans which pulled more air than the electric fans. The radiators were larger and the engines made less power, except for the turbo car. The oil cooler was in front of the radiator and always had air being drawn through it. The engine bay wasn't cramped and there was room for air to move and escape. As a result everything was easy to keep cool and there was cooling capacity to spare. Many people put very high powered engines in those cars with no issues. Those engines also had oil metering done in the center of each rotor housing as well as in the primary intake ports. No oil metering lubrication issues.

The third gen had a small engine bay much like the RX-8's that was cramped where air couldn't get out. They had oil coolers without fans. They had an inadequate radiator. Those engines made more power which produced more heat. The turbos were small and restrictive which didn't help things. Mazda changed the water o-rings and unfortunately they failed easily. Rebuilds used the old o-rings for reliability and added a metal heat shield for them. Those cars could overheat sitting in traffic! It's ecu was MAP based so when people increased flow through the motor it didn't take long for things to go bad. Those cars got a bad rep as a result of the way it was designed and because of owners not tuning them. Sadly Mazda didn't learn too much with the RX-8. They fixed a couple of mistakes but made a few more.

There are 2 things required to keep a rotary alive. It's got to be well cooled and it has to be well lubricated through the oil metering. They are amazingly tough if you can do those things.

tofu_box 11-08-2011 09:18 AM

^ in all honesty best one can do for lubrication is, up your OMP injector amount, SOHN adapter if you believe in it, Premix the tank.

Then pray to the rotary gods.

rotarygod 11-08-2011 09:32 AM

If you have an S1 RX-8, even a sohn adapter doesn't fix the problem with the oil metering. Only an S2 engine does that. Pre-mixing addresses the issue better but it comes with it's own downsides as well. Cooling (water and oil) is something everyone can address though.

tofu_box 11-08-2011 09:36 AM

thats why i included the praying part :P

Hesselrode 11-08-2011 07:39 PM

https://www.rx8club.com/series-i-do-yourself-forum-73/diy-clean-your-omp-mop-injectors-225253/

Cleaned my OMP/MOP injectors. Here is a DIY for it.

https://www.rx8club.com/showthread.php?t=225253

stinksause 11-09-2011 01:07 AM

Good to see that you are still around!

Originally Posted by rotarygod (Post 4120109)
Those cars could overheat sitting in traffic! It's ecu was MAP based so when people increased flow through the motor it didn't take long for things to go bad. Those cars got a bad rep as a result of the way it was designed and because of owners not tuning them.

Can you elaborate?

thanks

rotarygod 11-09-2011 12:25 PM

Yeah I'm still here. I've always been here. I just don't post much anymore. I'm more of a tech person and I think I've pretty much run the course on those topics so I haven't really had much to post. I got a bit burned out on cars for a while too. I'm still a mod here though so I've got to clean things up here and there.

Tamas 11-09-2011 12:40 PM


Originally Posted by rotarygod (Post 4120137)
If you have an S1 RX-8, even a sohn adapter doesn't fix the problem with the oil metering. Only an S2 engine does that. Pre-mixing addresses the issue better

So perhaps the Sohn adapter plus premixing 6-8 oz per tank may be the best solution for S1... eventually together with an increased MOP rate compared to stock.

plain ole wanker 11-09-2011 05:33 PM

Nice to see you posting again RG not to many I trust here on rotor topic including me. I consider myself like Sergeant Schultz from Hogans Heros's "I know nothing" that's why I keep my ear to the ground and wait for some good ol' info from the few I trust around here.

ASH8 11-09-2011 08:16 PM

Yep, always great to see RG still around and posting great info....
Pity Mazda does not harness his many Rotary Wankel talents.;)

rotarygod 11-09-2011 08:48 PM

Many talents? I'm back to driving a bone stock '90 n/a FC (when I'm not driving a Camry)! I do have a bunch of goodies lying around though. I might have a Vortech V5G sitting around here somewhere.

ASH8 11-09-2011 09:10 PM

:) WELL...I think you are and have engineering skill, and talent.
Always enjoy your talks here Fred..

You should do more..:puke:

jk.....;)

jsight 11-09-2011 09:11 PM


Originally Posted by rotarygod (Post 4120137)
If you have an S1 RX-8, even a sohn adapter doesn't fix the problem with the oil metering. Only an S2 engine does that. Pre-mixing addresses the issue better but it comes with it's own downsides as well. Cooling (water and oil) is something everyone can address though.

What are the downsides of premix?

stinksause 11-09-2011 11:48 PM

it lowers your octane rating and may clog the fuel system

rotarygod 11-10-2011 12:14 AM

It doesn't affect your octane enough to matter but it may cause problems with fuel filters clogging. It never seemed to be a problem on the RX-7's but RX-8 owners have reported potential problems.

jsight 11-10-2011 10:04 AM


Originally Posted by rotarygod (Post 4121739)
It doesn't affect your octane enough to matter but it may cause problems with fuel filters clogging. It never seemed to be a problem on the RX-7's but RX-8 owners have reported potential problems.

Good to know... Thanks!

dannobre 11-10-2011 10:21 AM


Originally Posted by stinksause (Post 4121729)
it lowers your octane rating and may clog the fuel system


These are both close to "urban myths". They started when a few cars were having fuel problems..and found dirty fuel pickup socks. I think this was more due to dirty fuel than the premix

shadycrew31 11-10-2011 10:37 AM


Originally Posted by dannobre (Post 4122044)
These are both close to "urban myths". They started when a few cars were having fuel problems..and found dirty fuel pickup socks. I think this was more due to dirty fuel than the premix

I never cleaned my sock and premix regularly for the past 40k.


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