What brand of oil do you guys use?
05-18-02, 06:47 PM
#51
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Originally posted by jeremy
there is one true statement, contamination. but if you can't tell this when you pull the dipstick then you need to follow the 3k order. otherwise no. ..3k was an idiot device for the blind and uninterested.
there is one true statement, contamination. but if you can't tell this when you pull the dipstick then you need to follow the 3k order. otherwise no. ..3k was an idiot device for the blind and uninterested.
So you're telling the only reason I change my oil every 3k (or less) is because I'm too stupid to be able to tell if the oil is contaminated by looking at the dipstick? So I defaulted to the "changing oil for dummies" method of every 3k miles? Plus I'm blind and uninterested?? I havn't learned anything in the 18 years I've owned my RX-7? Great. Don't I feel stupid.
I do appreciate the grin you supplied, though...
the weight 10w-40 has nothing to do with additives. all the 40 means is a heavier winter weight. it will not even affect you any different then 10w-30 at spring/summer temps. additives have to do with brands and lines within a brand.
10W40 DOES have to do with additives:
An example quote:
"10W-40 and 5W-30 require a lot of polymers (synthetics excluded) to achieve that range. This has caused problems in diesel engines, but fewer polymers are better for all engines. "
"Very few manufactures recommend 10W-40 any more, and some threaten to void warranties if it is used. It was not included in this article for that reason. 20W-50 is the same 30 point spread, but because it starts with a heavier base it requires less viscosity index improvers (polymers) to do the job. "
Hardly definitive, but an example. There remains concern about 10W40. Why not stick to the grades everyone agrees on?
Northern 7: Mazda does not recommend 10W30. They recommend various oils over a range of temperatures. That is too light for the summer. In the summer in Canada we are often beyond the upper range for 10W30 (~27c). The 20W50 range is from ~-8c and up. Nobody wants to use it to -8c though, for the same reason nobody wants to use 10W30 at the upper end of it's temp. range. That's why most people up here use 20W50 in the summer and switch to 10W30 in the fall.
Peejay: If you run 20W50 when it's cold, of course you're inviting problems.
"Personally I don't see the point of running thicker oil..."
I'm surprised you say that. It has nothing to do with oil pressure. The point of running thicker oil is to keep the oil within it's optimal temperature range, simply. Above 80F or so, nobody recommends 10W30. At least, nobody I've heard of.
I like Directfreak's idea, though I'd use Extra Virgin (How does that work, anyway?
)
Last edited by FJ; 05-18-02 at 06:49 PM.
05-18-02, 10:53 PM
#52
05-18-02, 11:47 PM
#53
FJ - I stand corrected !! However, my owners manual states up to 30 degree C (can you hear the hair splitting?), and the data is 20 years old - IMO oils have come a long way in the last 20 years and I feel safe using the lighter oil in Canada (but I change it often!). Also, 10W30 is whats in the car when you drove it off the lot (not 20W50) - so I ASSUMED this was the recommended oil. I know the 20W50 guys swear by the heavier stuff - I think the first thing I read on a RX7 forum was "Use 20W50", and I did for a couple of years but I found it too heavy for most of my driving season.
You made some good points - thanks for chim'in in on the 10W40 - I think a lot of people were not aware of the downside to this weight. The article on oil is very interesting - did anyone notice the Havoline numbers for viscosity and flashpoint were better than the castrol? I would think those two numbers would be critical in a rotary
You made some good points - thanks for chim'in in on the 10W40 - I think a lot of people were not aware of the downside to this weight. The article on oil is very interesting - did anyone notice the Havoline numbers for viscosity and flashpoint were better than the castrol? I would think those two numbers would be critical in a rotary
05-19-02, 01:11 AM
#54
Old [Sch|F]ool
The problem isn't oil contamination so much as the oil breaks down. The oil molecules are long hydrocarbon chains. With heat and shearing loads the chains get broken up and the oil wears out. And then, it needs changed.
Do no believe people who will sell you expensive filtration systems that allow extended oil-change intervals because "oil doesn't wear out, the additives get depleted". The oil wears out too.
Do no believe people who will sell you expensive filtration systems that allow extended oil-change intervals because "oil doesn't wear out, the additives get depleted". The oil wears out too.
05-19-02, 02:51 AM
#55
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Hmmm, so the oil goes in **** colored, and after 2000 miles (on my new engine) it came out almost black... I am going to change my oil again in 1000 miles to make sure it's getting all the nasties out... something's up.
05-19-02, 07:27 AM
#56
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New, and newly rebuilt engines are different. The black stuff is steel. Parts are wearing together (seating), steel is being scuffed away minutely at the hi points, and burnished. You should change it according to color these first few changes, and here's why I think so...
Though the oil itself probably is'nt all broken down or filled with contaminents or otherwised used up to its limit, but it is filled with a microns-sized abrasive. The steel dust is probabaly not too abrasive (therefore not too harmful) to most of the components because they are different steel - harder steel and tempered as well.
However, the miniscule bronze coating on the inside of the main bearing (s?) sleeve is soft.
The abrasive (more like rouge polishing) qualities in your new-engine oil are probably also wearing on things like the OMP. This abrasive is so tiny that your filter is'nt going to catch it. But it would be alot of fun for this post if you would yank that baby off after engine break-in, cut the cover off it and show us pics of the paper inside!
Hey...This is all a guess on my part. I have yet to even tear an engine down. But you have to agree that it all makes perfect sense. Why take the chance with a new engine. Just toss the oil when it gets crappy looking.
Northern 7
- IMO oils have come a long way in the last 20 years and I feel safe using the lighter oil in Canada (but I change it often!).
I totally agree. Oil is alot different than the stuff yer daddy used to buy. I feel plenty safe using the lighter oil because I change it frequently as well. However, I do have two more cases of 20-50. (Bought 5 cases at once. It seemed like a good idea at the time!)
Oil is yer engines blood. The filter is its liver.
...Very important organ; The liver is. I still don't see anyone talking about what filter they use and how often they change it.
Though the oil itself probably is'nt all broken down or filled with contaminents or otherwised used up to its limit, but it is filled with a microns-sized abrasive. The steel dust is probabaly not too abrasive (therefore not too harmful) to most of the components because they are different steel - harder steel and tempered as well.
However, the miniscule bronze coating on the inside of the main bearing (s?) sleeve is soft.
The abrasive (more like rouge polishing) qualities in your new-engine oil are probably also wearing on things like the OMP. This abrasive is so tiny that your filter is'nt going to catch it. But it would be alot of fun for this post if you would yank that baby off after engine break-in, cut the cover off it and show us pics of the paper inside!
Hey...This is all a guess on my part. I have yet to even tear an engine down. But you have to agree that it all makes perfect sense. Why take the chance with a new engine. Just toss the oil when it gets crappy looking.
Northern 7
- IMO oils have come a long way in the last 20 years and I feel safe using the lighter oil in Canada (but I change it often!).
I totally agree. Oil is alot different than the stuff yer daddy used to buy. I feel plenty safe using the lighter oil because I change it frequently as well. However, I do have two more cases of 20-50. (Bought 5 cases at once. It seemed like a good idea at the time!)
Oil is yer engines blood. The filter is its liver.
...Very important organ; The liver is. I still don't see anyone talking about what filter they use and how often they change it.
05-19-02, 07:52 AM
#57
Old [Sch|F]ool
Originally posted by Sterling
[B]Oil is yer engines blood. The filter is its liver.
...Very important organ; The liver is. I still don't see anyone talking about what filter they use and how often they change it.
[B]Oil is yer engines blood. The filter is its liver.
...Very important organ; The liver is. I still don't see anyone talking about what filter they use and how often they change it.
Interval? My intervals were kinda funny - oil change every month and filter change every other month. That worked out to 2500mi for the oil and 5000mi for the filter. I figured that with mainly highway driving (low load, most of the drive time spent at operating temp) I was being especially kind to the engine. The main reason I'd change the oil at 2500 instead of doing both at 5k was because the oil level would raise one quart in that time. Gasoline diluting the oil.
05-19-02, 10:21 AM
#58
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Originally posted by peejay
The main reason I'd change the oil at 2500 instead of doing both at 5k was because the oil level would raise one quart in that time. Gasoline diluting the oil.
The main reason I'd change the oil at 2500 instead of doing both at 5k was because the oil level would raise one quart in that time. Gasoline diluting the oil.
The only way I can see that as being remotely possible is if you run pre-mix (because you have the OMP blocked off), you have absolutely no crank ventilation, your seals are completely shot, and you're running an air fuel ratio of about 1:1!
Please explain, or I shall be forced to raise the ole flag upon your statement!!!
05-19-02, 01:41 PM
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Originally posted by Northern 7
However, my owners manual states up to 30 degree C (can you hear the hair splitting?),
However, my owners manual states up to 30 degree C (can you hear the hair splitting?),
I had looked at the factory manual chart and the arrow tapers from 27 to 30; I played it safe.You, along with Peejay and Sterling, may well be right about 10W30 year-round being sufficient. But when it does get above 30C and I'm sitting in traffic, I'm more comfortable knowing the heavier oil is in there, in the middle of it's temperature range and not thinning out too much.
Although oils have improved, I don't think the recommended temperature ranges have changed much. For the summer, I pick an oil based upon the peak temps. For me, that means 20W50.
That's my story, and I'm sticking to it.
Peace of mind, as much as anything, I guess.
As to filters, I use OEM or Purolator Pure One. Usually every oil change, at least on the second.
-John.
05-19-02, 02:14 PM
#61
That's my story, and I'm sticking to it.
05-19-02, 02:23 PM
#62
Old [Sch|F]ool
Why? Because the oil was being changed not because it was dirty, but because it was diluted with gasoline.
I used to cut my old filters open. Even after 5,000mi the filters still had no particles in them.
I used to cut my old filters open. Even after 5,000mi the filters still had no particles in them.
05-19-02, 04:29 PM
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By me
That's my story, and I'm sticking to it.
That's my story, and I'm sticking to it.
Originally posted by Northern 7
Yeah, I figured you would.
Yeah, I figured you would.
Even for our climate, I'd rather stay in the middle of the temperature range of the oil than at the upper limits. Same reasoning as changing the filter every oil change, to my mind. It may not be necessary, but it can't hurt.
-John.
05-19-02, 11:27 PM
#64
thanks fj, didn't know that about 10w-40.
sorry you fit in the blind or uninterested category. don't get pissy, its not my fault. if you read the article, normal driving=7500, hard driving=3000. now tell that to mr average joe. point being you can generally look at the oil and tell whether or not it needs changed. how thick is the goo on the stick and what color is it? like i said before, but you forgot to qoute. car companies are putting in sensors because your car doesn't always need an oil change at 3k. some sooner and some later. personally i would use the vinegar and not have to worry about the hole mess.
sorry you fit in the blind or uninterested category. don't get pissy, its not my fault.
if you read the article, normal driving=7500, hard driving=3000. now tell that to mr average joe. point being you can generally look at the oil and tell whether or not it needs changed. how thick is the goo on the stick and what color is it? like i said before, but you forgot to qoute. car companies are putting in sensors because your car doesn't always need an oil change at 3k. some sooner and some later. personally i would use the vinegar and not have to worry about the hole mess.
05-20-02, 12:18 AM
#65
I used to cut my old filters open. Even after 5,000mi the filters still had no particles in them.
Originally posted by Northern 7
Yeah, I figured you would.
FJ - That wasn't meant to be a patronizing remark - I realize most RX7 owners use the 20W50. I use the lighter for the opposite reason you use the heavier... I'm more worried about cold start friction. I may be wrong, but it sounds like you are more concerned with your oil failing at higher temps. IMO the heat range of 10W30 is higher than 30 degrees today - Have a good weekend !
05-20-02, 12:34 AM
#66
Originally posted by peejay
Oil dilution IS a problem with all rotaries! I even had it as a problem with the OMP active.
Oil dilution IS a problem with all rotaries! I even had it as a problem with the OMP active.
05-20-02, 01:17 PM
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And quite possibly if you use MMO in the gas tank...
Originally posted by mar3
I was running Mobil1 synthetic 10W50 before she was totalled. It went 27,000 miles with no problems, but did seem to start going down on power. I was converted to the MMO flock about 2 months ago and that one addition corrected all the problems the engine seemed to have developed. It now sits in my driveway with 28,600 very hard miles and doesn't smoke at all. The engine will very likely see its third body in the very near future. All of the theories and conjecture around synthetics haven't panned out so far in this engine, but it could very well be that the MMO is keeping the seals from getting stuck by the oil. Who knows?
I was running Mobil1 synthetic 10W50 before she was totalled. It went 27,000 miles with no problems, but did seem to start going down on power. I was converted to the MMO flock about 2 months ago and that one addition corrected all the problems the engine seemed to have developed. It now sits in my driveway with 28,600 very hard miles and doesn't smoke at all. The engine will very likely see its third body in the very near future. All of the theories and conjecture around synthetics haven't panned out so far in this engine, but it could very well be that the MMO is keeping the seals from getting stuck by the oil. Who knows?
05-20-02, 01:21 PM
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Originally posted by peejay
Oil dilution IS a problem with all rotaries! I even had it as a problem with the OMP active.
Oil dilution IS a problem with all rotaries! I even had it as a problem with the OMP active.
05-20-02, 01:50 PM
#71
Originally posted by mar3
Gentlemen, it's called blowby and I guarantee you're letting at least 8% of your compressed charge escape past the seals to contaminate the oil...
Gentlemen, it's called blowby and I guarantee you're letting at least 8% of your compressed charge escape past the seals to contaminate the oil...
If you have oil dilution through this method, your o-rings must be very worn out, which means you would also be seeing huge clouds of smoke if you ever use the engine to brake, and small clouds when you don't because of the vacuum in the chamber pulling oil past the seals. Your oil consumption would greatly outweigh any oil dilution that may occur.
05-20-02, 03:51 PM
#72
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Well Im going to hear it now from you guys but I just got my engine from pineapple racing. They say for the first 4,000 miles, put 10/40 oil in it. I have been puting Quaker State 10/40 in it and after 4,000 miles switch to 0-30 synthetic. I am now putting in mobile one 0-30 synthetic. I am still not sure why people dont put synthetic oild in there rotary engines but I guess Pineapple Racing knows what they are talking about.
05-20-02, 04:10 PM
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Originally posted by nimrodTT
...design of the seals on a rotary, I'd guess that maybe .5% gets past the side seals...
...design of the seals on a rotary, I'd guess that maybe .5% gets past the side seals...
05-20-02, 04:13 PM
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Originally posted by 82mazdarx7
Well Im going to hear it now from you guys but I just got my engine from pineapple racing. They say for the first 4,000 miles, put 10/40 oil in it. I have been puting Quaker State 10/40 in it and after 4,000 miles switch to 0-30 synthetic. I am now putting in mobile one 0-30 synthetic. I am still not sure why people dont put synthetic oild in there rotary engines but I guess Pineapple Racing knows what they are talking about.
Well Im going to hear it now from you guys but I just got my engine from pineapple racing. They say for the first 4,000 miles, put 10/40 oil in it. I have been puting Quaker State 10/40 in it and after 4,000 miles switch to 0-30 synthetic. I am now putting in mobile one 0-30 synthetic. I am still not sure why people dont put synthetic oild in there rotary engines but I guess Pineapple Racing knows what they are talking about.