GregM Posted March 31, 2022 Share Posted March 31, 2022 2 minutes ago, Bruce K said: I owned a last-gen RX-7 and never once pre-mixed, nor did my dealer advise it. I agree that rotaries do not run as clean as conventional 4-strokes - the oil they bypass clogs the cats too quickly, which is why we have not seen exploitation by manufacturers of their other innate qualities. And the only 2-stroke that has passed Euro standards is the Langen, which is strictly a bike engine. Bear in mind that Euro standards, though nearly equal between bikes and cars, still heavily favor bikes because they are based on grams of emissions per mile, which favors featherweight bikes in comparison to ton-plus cars. I believe that you don't want to premix a rotary if your car has a catalytic converter. Also a premix-ed rotary won't pass emissions. Besides those two points, the rotary apex seals will last longer if using a premix. Link to comment Share on other sites More sharing options...
Bruce K Posted March 31, 2022 Share Posted March 31, 2022 16 minutes ago, GregM said: I believe that you don't want to premix a rotary if your car has a catalytic converter. Also a premix-ed rotary won't pass emissions. Besides those two points, the rotary apex seals will last longer if using a premix. GregM - I have no insights with which to deny your point about rotary apex seals lasting longer if rotary fuel is pre-mixed with oil, and the idea seems sensible. However, I am interested to know if engine power output suffers due to the oil added to the fuel. Diesel oil has a converted-from-cetane rating of 25 to 30 octane, so I presume that pre-mix oil would be similar, and would therefore lower the overall octane rating of the 93 octane fuel I ran in my RX-7. I also suppose that plugs would have a shortened lifespan. Are there other demerits, like carbon buildup? Link to comment Share on other sites More sharing options...
GregM Posted March 31, 2022 Share Posted March 31, 2022 Just now, Bruce K said: GregM - I have no insights with which to deny your point about rotary apex seals lasting longer if rotary fuel is pre-mixed with oil, and the idea seems sensible. However, I am interested to know if engine power output suffers due to the oil added to the fuel. Diesel oil has a converted-from-cetane rating of 25 to 30 octane, so I presume that pre-mix oil would be similar, and would therefore lower the overall octane rating of the 93 octane fuel I ran in my RX-7. I also suppose that plugs would have a shortened lifespan. Are there other demerits, like carbon buildup? All of this is most likely correct. Again, I’m no rotary expert but, from what I understand that premix helps with the seals (but might reduce the lifespan of other components). It is also advised to use higher octane with premix (to your point) Link to comment Share on other sites More sharing options...
fastg Posted April 1, 2022 Share Posted April 1, 2022 I am not sure why this is a surprise to people it's been common practice in the Rotary works for many years. All the later RX7/8 have oil injection anyway, your just augmenting that. The guys I know add about 4oz of oil per 10 gallons of gas. That amount is not going to change your octane by a measurable amount. There are some people that dump the oil injection system totally and run only pre-mix. The following web site has a nice review. https://rotaryperformance.com/blogs/news/84479876-to-premix-or-not-to-premix Adding oil in the fuel might not have the effect you might think. When we were racing 2-strokes the privateer teams would buy the latest and greatest oil that claimed the highest mix ratio 80:1 or higher, thinking they were getting more gas so more octane and more power. They just destroyed there engines. We would run as much oil as the plugs would fire 25:1 or lower. The latent heat of oil is much higher that gas. So just valorizing the oil require heat. The engine runs cooler, the combustion temps are lower, you could run more ignition advance. Our motors would run better longer, especially late in the race, and as a bonus they would last longer. Graham 1 Link to comment Share on other sites More sharing options...
coffee break Posted April 1, 2022 Share Posted April 1, 2022 Both Wankel and 2 cycle motors are "piston" ported devices. They both produce distinctive exhaust notes, in some cases ear splitting! As far as being clean or dirty in the exhaust emissions it depends. In the operational sweet spots of a specific RPM range the HCs could be lower because all the pressure waves are working together to make peak power. Real life operation doesn't always exist in the sweet spot. They have both had their place in time, and time moves on. That said, my 7 has Webers and they give the garage that "old car" smell that we don't get from FI and closed fuel systems. Link to comment Share on other sites More sharing options...
Bruce K Posted April 1, 2022 Share Posted April 1, 2022 5 hours ago, GregM said: All of this is most likely correct. Again, I’m no rotary expert but, from what I understand that premix helps with the seals (but might reduce the lifespan of other components). It is also advised to use higher octane with premix (to your point) GregM - a lot to absorb and evaluate regarding your new DSK purchase. I'm reading all these opinions and facts, and you haven't even driven your car a mile yet! Please be sure to provide updates and progress reports - I'm now really curious regarding DSK performance, especially your rotary-powered model. 1 Link to comment Share on other sites More sharing options...
GregM Posted April 1, 2022 Share Posted April 1, 2022 (edited) 8 hours ago, Bruce K said: GregM - a lot to absorb and evaluate regarding your new DSK purchase. I'm reading all these opinions and facts, and you haven't even driven your car a mile yet! Please be sure to provide updates and progress reports - I'm now really curious regarding DSK performance, especially your rotary-powered model. I will. But first is to get the car here to NC. Edited April 1, 2022 by GregM Link to comment Share on other sites More sharing options...
fastg Posted April 1, 2022 Share Posted April 1, 2022 Nothing is more visceral than the hit of a big 2-stroke. It blubbers, turns into a gurgle, then a wail, the horizon jumps up, grab the next gear and it does it again. Graham 2 Link to comment Share on other sites More sharing options...
Bruce K Posted April 1, 2022 Share Posted April 1, 2022 That video is CRAZY! How do those pilots keep their concentration at such extreme speeds for so long! Really worth the watch. Link to comment Share on other sites More sharing options...
Cueball1 Posted April 1, 2022 Share Posted April 1, 2022 (edited) Had an rz350 back in the day. Yamaha 2 stroke cafe bike. Ton of fun. Definitely wish I still had it. Very much collectible now. What are those bikes in the vid? Isle of Mann TT has always been insane! Edited April 1, 2022 by Cueball1 Link to comment Share on other sites More sharing options...
Croc Posted April 1, 2022 Author Share Posted April 1, 2022 Diva 7 on Bringatrailer LS1-Powered Diva Roadster for sale on BaT Auctions - ending April 8 (Lot #70,055) | Bring a Trailer Link to comment Share on other sites More sharing options...
Anaximander Posted April 1, 2022 Share Posted April 1, 2022 (edited) Wow, Thanks Croc. I couldn't remember the name of that Queen song and some of the first stanza lyrics until you posted the BaT ad. "Fat-bottomed girls you make the rocking world go round". I am a bit surprised at some of the hate postings on the comments section on the BaT Diva auction suggesting that the sevenesque tent is too small for the Diva or even such dastardly cars as my Storkers. Thank goodness that my fellow se7enesque brothers and sisters don't exclude us other folks that don't own the exact car that Colin Chapman designed. I think about the 1962 Lotus 7 I almost bought in high school and cringe when I think about using it as a daily driver on the streets/freeways of Los Angeles where I grew up. My red TR4 was fun enough at the time and I still darn near drove it off a cliff with my girlfriend in the passenger seat racing an MGB (I was in the lead hehehe) and coming up on a stretch of road under construction and graveled on Tuna Canyon Road between the San Fernando Valley and the Pacific Ocean near Malibu. The car came to a rest with the right front tire freewheeling in thin air with the undercarriage preventing us from going over about a 200 foot cliff. That would have really dampened the end of my senior year in HS that was coming to a close about 3 weeks after this experience. Edited April 2, 2022 by Anaximander Link to comment Share on other sites More sharing options...
Bruce K Posted April 1, 2022 Share Posted April 1, 2022 (edited) On 4/1/2022 at 5:22 PM, Croc said: Diva 7 on Bringatrailer LS1-Powered Diva Roadster for sale on BaT Auctions - ending April 8 (Lot #70,055) | Bring a Trailer The Diva is a really attractive roadster - reminds me of an LS-powered, fiberglass version of the Ford-powered Panoz AIV roadster. Personally, however, I am no fan of older automatic transmissions in sports cars. I do enjoy the paddle-shift DCT in my Alfa 4C, and the new 10-speed automatic offered by both Ford and Chevy are brilliant and work very well inside Mustangs and Camaros. But, in general, automatics are heavy, and inconsistent with the Seven ethos. Edited April 3, 2022 by Bruce K Link to comment Share on other sites More sharing options...
Croc Posted April 3, 2022 Author Share Posted April 3, 2022 Week beginning April 3, 2022 NEW Replica Marketplace - 1962 Lotus Locost clone | Facebook Lotus 7 S2 1961 Lotus Super Seven | eBay Diva 7 LS1-Powered Diva Roadster for sale on BaT Auctions - ending April 8 (Lot #70,055) | Bring a Trailer Diva 7 Diva Roadster kit car (similar to Lotus Super 7 / Caterham 7) - cars... (craigslist.org) REPEATS Elfin 7 2018 Lotus Seven Replica for Sale in PALMETTO, FL | RacingJunk and here 2018 Lotus #2566420 | Hemmings Lotus 7 S2 1962 Lotus Super 7 for Sale in CHATSWORTH, CA | RacingJunk Lotus 7 S4 71 Lotus Series 7 for Sale in LAKE LEELANAU, | RacingJunk and here Marketplace - 1971 Lotus Series 7 | Facebook Caterham Marketplace - 2008 Lotus Caterham R400 Superlight | Facebook RM 8 Marketplace - 2000 Lotus Seven | Facebook Mitsuoka Zero 1 Marketplace - 1994 Lotus mitsuoka zero1 | Facebook Replica Marketplace - 1974 Lotus - Chevy 7 | Facebook Caterham 2006 Caterham Super 7 Caterham Super Sprint 1700 #2526905 | Hemmings Lotus 7 S2 1962 Lotus Super 7 | eBay and here 1962 Lotus #2534446 | Hemmings Replica LocostUSA.com • View topic - FS: Bike Engine Book Chassis For Sale Caterham Caterham Inventory — Beachman Racing Caterham INVENTORY (rockymountaincaterham.com) Caterham 2011 Caterham Super 7 - cars & trucks - by owner - vehicle... (craigslist.org) Caterham Lotus Super 7/Caterham Super 7 S3 - cars & trucks - by owner -... (craigslist.org) Caterham Lotus Super 7/Caterham Super 7 S3 - cars & trucks - by owner -... (craigslist.org) CANADA Deman SR7 Turbo 2013 Caterham Super 7 Open roadster - Edmonton (autotrader.ca) Replica Project Locost super7 | Cars & Trucks | Calgary | Kijiji MCC 7 LocostUSA.com • View topic - MCC 7 for sale Link to comment Share on other sites More sharing options...
Croc Posted April 9, 2022 Author Share Posted April 9, 2022 Stalker on Bringatrailer - ex-MightyMike LS3-Powered Brunton Stalker 6-Speed for sale on BaT Auctions - ending April 15 (Lot #70,715) | Bring a Trailer Link to comment Share on other sites More sharing options...
Cueball1 Posted April 9, 2022 Share Posted April 9, 2022 That car was sold by RNR on BAT less than a year ago for 45k. Huge money for a Brunton. Granted the finish work inside and out is exceptional. That interior is amazing but it is also the older design suspension and sans independent rear end. Link to comment Share on other sites More sharing options...
Anaximander Posted April 10, 2022 Share Posted April 10, 2022 7 hours ago, Cueball1 said: That car was sold by RNR on BAT less than a year ago for 45k. Huge money for a Brunton. Granted the finish work inside and out is exceptional. That interior is amazing but it is also the older design suspension and sans independent rear end. Cueball1, You are absolutely correct on all counts. The new suspension on the M-Specs has a lot more adjustability and rides better than the original Brunton Stalkers. However, I really, really enjoyed my last Classic Stalker with the supercharged 3800 in it. It was very nicely built, tuned up by Scott Minehart when I brought it home and gave me several years of absolute joy. Link to comment Share on other sites More sharing options...
Croc Posted April 10, 2022 Author Share Posted April 10, 2022 Week Beginning April 10, 2022 NEW Stalker LS3-Powered Brunton Stalker 6-Speed for sale on BaT Auctions - ending April 15 (Lot #70,715) | Bring a Trailer Caterham Caterham 7 Lotus 7 - cars & trucks - by owner - vehicle automotive... (craigslist.org) Replica Lotus 7 replica- bike engined - cars & trucks - by owner - vehicle... (craigslist.org) REPEATS Lotus 7 S2 1961 Lotus Super Seven | eBay Replica Project LocostUSA.com • View topic - FS: Bike Engine Book Chassis For Sale Elfin 7 2018 Lotus Seven Replica for Sale in PALMETTO, FL | RacingJunk and here 2018 Lotus #2566420 | Hemmings Lotus 7 S2 1962 Lotus #2534446 | Hemmings Lotus 7 S4 1971 Lotus Seven for Sale in LAKE LEELANAU, | RacingJunk and here Marketplace - 1971 Lotus Series 7 | Facebook Lotus 7 S2 1962 Lotus Super 7 for Sale in CHATSWORTH, CA | RacingJunk Caterham 2006 Caterham Super 7 Caterham Super Sprint 1700 #2526905 | Hemmings Caterham Caterham Inventory — Beachman Racing Caterham INVENTORY (rockymountaincaterham.com) Caterham Marketplace - 2008 Lotus Caterham R400 Superlight | Facebook Mitsuoka Zero1 Marketplace - 1994 Lotus mitsuoka zero1 | Facebook Replica Marketplace - 1974 Lotus - Chevy 7 | Facebook Replica Marketplace - 1962 Lotus Seven | Facebook and here Lotus Seven (locost) clone - cars & trucks - by owner - vehicle... (craigslist.org) RM 8 Marketplace - 2000 Lotus Seven | Facebook Caterham 2011 Caterham Super 7 - cars & trucks - by owner - vehicle... (craigslist.org) Caterham Lotus Super 7/Caterham Super 7 S3 - cars & trucks - by owner -... (craigslist.org) Diva 7 Diva Roadster kit car (similar to Lotus Super 7 / Caterham 7) - cars... (craigslist.org) Caterham Lotus Super 7/Caterham Super 7 S3 - cars & trucks - by owner -... (craigslist.org) CANADA Replica Project Locost super7 | Cars & Trucks | Calgary | Kijiji MCC 7 LocostUSA.com • View topic - MCC 7 for sale Daman SR7 Turbo 2013 Caterham Super 7 Open roadster - Edmonton (autotrader.ca) Link to comment Share on other sites More sharing options...
Donnie Posted April 11, 2022 Share Posted April 11, 2022 Please PM me prior to responding to an ad which is appearing in several auction sites for White 1962 Seven Series 2. Asking about $35,000. Don Link to comment Share on other sites More sharing options...
Croc Posted April 17, 2022 Author Share Posted April 17, 2022 Week Beginning April 17, 2022 NEW Caterham Caterham Super Seven SV for sale on BaT Auctions - ending April 23 (Lot #71,426) | Bring a Trailer REPEATS Replica Project LocostUSA.com • View topic - FS: Bike Engine Book Chassis For Sale Elfin 7 2018 Lotus Seven Replica for Sale in PALMETTO, FL | RacingJunk and here 2018 Lotus #2566420 | Hemmings Lotus 7 S2 1962 Lotus Super 7 for Sale in CHATSWORTH, CA | RacingJunk Lotus 7 S4 71 Lotus Series 7 for Sale in LAKE LEELANAU, | RacingJunk and here Marketplace - 1971 Lotus Series 7 | Facebook Lotus 7 S2 1962 Lotus #2534446 | Hemmings RM 8 Marketplace - 1962 Lotus Seven | Facebook Replica Marketplace - 1974 Lotus - Chevy 7 | Facebook Mitsuoka Zero 1 Marketplace - 1994 Lotus mitsuoka zero1 | Facebook Caterham Marketplace - 2008 Lotus Caterham R400 Superlight | Facebook Caterham Caterham Inventory — Beachman Racing Caterham INVENTORY (rockymountaincaterham.com) Caterham Lotus Super 7/Caterham Super 7 S3 - cars & trucks - by owner -... (craigslist.org) Caterham Lotus Super 7/Caterham Super 7 S3 - cars & trucks - by owner -... (craigslist.org) Diva 7 Diva Roadster kit car (similar to Lotus Super 7 / Caterham 7) - cars... (craigslist.org) Replica Lotus 7 replica- bike engined - cars & trucks - by owner - vehicle... (craigslist.org) Replica Lotus Seven (locost) clone - cars & trucks - by owner - vehicle... (craigslist.org) CANADA MCC 7 LocostUSA.com • View topic - MCC 7 for sale Link to comment Share on other sites More sharing options...
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