I assume this is the cold start wear argument, but unless you always take short trips, wear at operating temperature is much more of a concern - regardless of how cold it is outside. I drive my car in 20 F conditions all the time. Furthermore, the viscosity of any oil in these engines thins so fast (if you drive the car hard) that even with racing oil you're equivalent to a 10w-40 or even 10w-30 within a few hundred miles anyway, and I've got the test results to prove it.

 

moconner is actually right about the apex seals and coolant seals going before showing extreme wear of the bearings. Keep in mind that this is the 3rd gen section. Where not talking NA rotarys in this thread which can go 100,000-200,000k. My personal Fd original engine lasted over 108k and blew from me over boosting it. Good luck finding 10 more people on this forum with 3rd gen engines that has lasted as long as mine has. This is not me being cocky, but it does prove a point. Fact is 99% of the fd original engines blowing has been due to blown apex or coolant seals. Those are the facts! The factory 3 piece apex seals are a ticking time bomb in higher mileage situations.


Oh yea, when I tore my engine down, the bearings where flawless. I did nothing but regular oil changes 10-40W. Castol, Penzoil, Quakerstate. I used them all!

My biggest thing was making sure I put on a good quality oil filter.

 

Yes it does refer to the cold start argument. Which is supported by just about anything I've read or heard since ~1970. And cold start is where a significant amount of wear occurs. Some stuff involving piston engines suggests as much as 80%.
If you've got tests that show fuel dilution is really bad after just a "few hundred miles", then you've probably got tests that indicate seals are worn or not clearanced properly. I get some fuel dilution true enough, but nothing close to significant in that short of time.

To borrow a phrase used earlier in the thread, straight 60w oil in 20 F. ambient for a streeted car is NOT necessary, and "dumb". Straight 60w oil at 20 F. has got to have the consistency of something akin to grease. Maybe if you have dedicated race engine with looser clearances MAYBE...I'd invite anyone else running that heavy of an oil in below freezing temps (20 F.) to chime in. But I'd hope no one else in a street car is running that.

 

All I can say is, my wear metals dropped significantly with the heavier weight oil - anything else is pure conjecture. I believe cold start wear is vastly overrated in rotaries. It's when you're boosting at 15 psi that wear occurs. My engine may still be breaking in, and I'm running 3 mm seals.

Also, you don't know what your fuel dilution level is until you get it tested. The "sniff test" means essentially nothing.

 

Why do you believe that cold start wear is vastly overrated in rotaries? I just would like to know your basis for that.

In my thinking I don't know what about a rotary would make it less of an issue than a piston engine so I thought I'd ask.

 

Metal wear factors can be numerous. You can't compare metal wear on an old engine to metal wear on a new one. That test "means essentially nothing".

If you can smell gas, the sniff test actually does mean something

A person's reputation on this forum is really all they have. Some people come here thinking they have to argue everything ............ right or wrong. It's much better not to be thought of as one of those people.

 

It was the same engine. The only thing that changed was the oil type/viscosity. I ran four consecutive tests. wear metals dropped across the board with heavier racing oil. "Cold start wear" (which, to clarify, I believe is overrated in general, but especially considering relative wear with a turbocharged rotary) wasn't a factor.

It indicates you have fuel dilution, but that's about it - anything more than 2% is "cautionary"

 

I have been running 10W-40 Royal Purple in my FD for the past 4-5 years and during that time have put on ~90k KM with the majority of it being extensive track abuse (as in every other weekend during summer) and daily driven as well. During this time I have rebuilt the engine 4 times and my bearings have never shown any real sign of wear according to my engine builder and he is the one who suggested NOT to use the 20W-50 knowing very well what I do with the car. I now make it a routine to rebuild every winter anyway to avoid any possible downtime during the summer and will start doing my own rebuilds next year.

Other thing to note is I have a fully vented catch can which I can see smoking/venting cruising down the highway through my vented hood once the car is up to temperature. This catch can also drains back into the oil pan and never needs to be emptied.

I honestly don't think I need a thicker oil given my own experience and you can take that with a grain of salt as everything should be on the forum. However, every time I see an oil thread, i just face palm every time.

Also, I tow my tires and equipment to and from the track and have on occasion used it to tow **** for my friends that don't fit in cars. Image included to get an idea... Mentioned this cause I figure that puts more load on the engine and have occasionally boosted with the trailer on ^_^



thewird

 

Why have you had to rebuild your engine so many times?

 

Unless you can cite something, THIS^ sounds like conjecture. Rotaries may not have cams, rods, and valve trains like a piston engine, but they have bearings, oil pumps, oil pump chains, control rings and turbos. When a warm engine is shut down, the hot oil drains off into the pan. A straight 60w at 20 F. then turns into some big heavy goo that the pick-up and pump have to somehow get to those bearings etc. at cold start-up.
Correlation is not causation. As I mentioned earlier, I believe the "Race Oils", VR and some others are able to retain their ZDDP content. This is in contrast to the reduced/eliminated ZDDP in the 'normal...non-racing oils'. If you really are seeing less wear I suspect it's due to that, not the heavy viscosity.

 

1) Low compression when I got the car
2) My BNR's blew and I Ignored OEM oil pressure gauge as I assumed it had failed and 10 minutes later engine locked , aka everything was fucked but the housings
3) Blew engine on purpose seeing at what point the engine would blow, new housings and ceramic seals yeah (it took 18 PSi, 11.9 AFR and 16 degrees of timing if anyone is interested and this lasted for 4 laps around Mosport)
4) winter rebuild, nothing wrong

There would have been a 5th rebuild this winter but there is just no time due to all the changes I have to do before DGRR >.<

thewird

 

A 'best oil' thread in the 3rd Gen section? Something new for a change!

 

It's not conjecture because use of heavier oils showed significant drop in wear metals, why is this not clear? If all of a sudden cold start-up wear went through the roof, I would have seen it in the analytical report, but Fe was basically nothing. ZDDP additive is not that much with Valvoline VR1, so I doubt that was it. Furthermore, the oil thins out fast when exposed to fuel dilution, that was my whole point. The 'racing oil' is equivalent to 10w-40 or 10w-30 in short order.

Use of a vented catch can is a different issue, and I think it's a good idea, but I don't think you eliminate fuel dilution by just improving ventilation, since gas mixes with the oil when it gets past the seals under boost in the combustion process with a rotary. Rotaries don't seal as well as a piston engine and never will, it's just a fact of life. Forced induction piston engines have fuel dilution as well, some more than others. Until I see a used oil analysis pre- and post-catch can install, I'll remain skeptical, but open minded. Not sure why people on this forum are so resistant to oil testing, it's $25 - "just do it".

 

This is exactly what I want to avoid, the rebuild hamster wheel (and depleting bank account that goes with it). I have 30k miles on my motor and compression is excellent

 

There's a big difference between a necessary rebuild and an unnecessary rebuild.

This isn't rocket science guys..... have the engine built right, set the car up right, don't overheat it, and don't run it out of oil. My FD isn't that freaking special, and it's been dead reliable the last five years. I've ramped up the track time recently and it's handled it without a hitch.

 

If your getting that much fuel dilution in a "few hundred miles" something is wrong. Never had 3mm seals, so I can't say if that has anything to do with it. Otherwise (assuming a decent tune) you need new side seals or someone new to clearance them next time. Straight 60w oil at anything less than 80 or 90 F. ambient is a bandaid, not preventative medicine. Let alone at 20 F.

 

Almost all of these engines when boosted hard have excessive fuel dilution (> 2%). Fritz reported some as high as 10% (!). Running a thicker racing oil is not a "band aid" it's standard practice when you know it's going to occur. http://www.motorsportsracingfuels.com/50wBradPenn.html

Again, for anyone who can prove how to reduce or eliminate the problem in these engines with actual analysis, not just conjecture, I'm all ears.

 

This.

I have had reports of up to 1500 miles with little to no fuel dilution but certain people suggested it was my "driving style", then later on said turbo rotarys will dilute oil fast regardless lol

Something is def wrong if you have a strong fuel smell in your oil after a few hundred miles.

 

I will back you on the cold start wear being over rated. With my engine I allowed the AWS to do it's thing during every cold start. I didn't do it because of how it was designed to warm up the cats faster, I did it because it had another benefit. Not only are you heating up the exhaust faster but you are also heating up the combustion chamber faster. The extra heat generated in the combustion chamber burns the excessive fuels that get dumped in during a cold start. This greatly reduces the amount carbon that gets built-up. Your not helping your engine at all when you blip the throttle. When I blew the engine at 108k, my bearings were perfect. So anyone saying that AWS is bad for your engine is talking out of their ***!

 

That's a good way for FD owners to waste their time.

David

 

Fuel dilution in a rotary is a direct result of fuel/air mixture blowing past the oil control o-rings during the compression stroke. Side plate wear and oil control rings play a huge part in this. You have to remember that unlike the piston engine, the rotarys combustion chamber has numerous locations for blow by with all the hard seals that are used to make compression. The reason turbo rotarys are worse is because you have more pressure under boost (aka more dilution). Lapped/re-nitrated plates and new oil control rings will greatly reduce the dilution however, you can never completely eliminate it. This is an inherent rotary related design flaw we will just have to deal with.

 

^Correct

Which is why everyone who owns these cars should get an oil analysis done, if nothing else to see if their OCI is reasonable

In context I was talking about relative oil performance, I realize most reports never see the kind of fuel dilution these cars do - heck, my S2000 is always zero after 5k miles (10w-30)

 

*shakes head* You admitted originally that you very rarely get into boost because you're afraid your motor will pop. You can try to deny that all day long now, I know what you said. You don't get fuel dilution if you stay out of boost, it's a direct cause-and-effect

Nothing is wrong. I drive the car like it was made to be driven, you drive scared. You lost this argument about six months ago but you're still dancing.

 

My stock R1 w/original motor w/36-45k miles had 10% fuel dilution in the oil back in 1998-2000 time frame. Oil was tested by Royal Purple (via Southwest Spectro Chemical) 3 times.

I changed the oil every 1500-2500 miles, engine died from coolant seal failure @ 68k miles. I didn't crack it open for inspection.

 

It has already been stated our engines get fuel dilution. I knew that. You know that. Tvon has said it gets it by design. You even said it gets it regardless. Its the inevitable.

So you saying I don't get it cause im "out of boost" then go about saying these engines get it regardless throws your credibility out the door.

Wait actually you lost your credibility 5 forum names ago. I wonder how much you paid the admins to get this old forum name back. Lol. This is what? Your 6th forum name now? At least its one of the originals.



You drive the car the way it was meant to be driven yet you're alone in your vast wonders of what's right and wrong. We're not blind, you post your rants about your reports and driving habits and people are like ??. Doesn't that give you a hint. I may drive less aggressive than you but my car has less problems than yours. Hey I gotta be doing something right then.