LubeDude
Admiral
- Joined
- Oct 8, 2003
- Messages
- 6,945
My wife drives an 87 Mazda RX/7. Now Im not saying that I havnt recieved great results doing what Im doing, as the car has 290,000 miles on the original engine, but I have a question. What oil would you think would be the optimum oil for a rotary, as they have an oil injection system, and actually burn some oil like a two stroke?<br /><br />My guess would be an aircraft oil.<br /><br />Ive also always wondered what would happen if I just poured a TC-W3 oil in the crank case. 
Never had the guts to do that though. Only three moving parts though. I didnt do it mostly because I didnt know the actuall wieght of a TC-W3 oil and there are gears inside the rotors that I figured would shear the oil too quickly.<br /><br />Background:<br /><br />Bought the car with 120,000 miles, no Idea what oil was used previously but started using Castrol 20W-50. I immeadiatly started having severe carboning issues, it evidently was carboning around the exhause ports. I then in my infinate wisdom decided to use Dello 400 15W-40. (Even thoughI knew it was a higher ash oil), It fixed the carbon problem. I attributted that to the detergents in the diesel oil. However had to clean the carbon off the plugs every oil change. I ran this oil with no problems up to the 280,000 mile point, changing at 2000-3000 mile intervals. I then thought I would try a Synthetic even though I was advised against it, Thats just me, (15W-50 Mobil 1), This didnt work out too well, as it smoked more at start up, and actually carboned the plugs worse than the Dello did. (Go figure), I also had flooding problems, I think just because the oil ran away from the rotors overnight. I am now running the NAPA 20W-50 High mileage oil and it seems to like it fine.
Never had the guts to do that though. Only three moving parts though. I didnt do it mostly because I didnt know the actuall wieght of a TC-W3 oil and there are gears inside the rotors that I figured would shear the oil too quickly.<br /><br />Background:<br /><br />Bought the car with 120,000 miles, no Idea what oil was used previously but started using Castrol 20W-50. I immeadiatly started having severe carboning issues, it evidently was carboning around the exhause ports. I then in my infinate wisdom decided to use Dello 400 15W-40. (Even thoughI knew it was a higher ash oil), It fixed the carbon problem. I attributted that to the detergents in the diesel oil. However had to clean the carbon off the plugs every oil change. I ran this oil with no problems up to the 280,000 mile point, changing at 2000-3000 mile intervals. I then thought I would try a Synthetic even though I was advised against it, Thats just me, (15W-50 Mobil 1), This didnt work out too well, as it smoked more at start up, and actually carboned the plugs worse than the Dello did. (Go figure), I also had flooding problems, I think just because the oil ran away from the rotors overnight. I am now running the NAPA 20W-50 High mileage oil and it seems to like it fine.
