My black RX-7 pics
Discussion
Thanks all! There's about 3.5 hours of elbow grease invested there (though it's filthy dirty already, I hate winter!)
RX-7 residuals have been in a bit of a freefall of late, possibly because there are too many on the market at the moment. But for whatever reason you can now pick up a decent early running example for £5k which is a lot of performance for peanuts. People still baulk at the petrol/insurance costs so that does at least keep it a rare sight and out of the hands of chavs.
I must say though, in the 10 months I've had it, I've only had to pay out £230 for a service and a few quid for some cheap mineral oil so in that respect it's actually been cheaper than my old Escort to run!
RX-7 residuals have been in a bit of a freefall of late, possibly because there are too many on the market at the moment. But for whatever reason you can now pick up a decent early running example for £5k which is a lot of performance for peanuts. People still baulk at the petrol/insurance costs so that does at least keep it a rare sight and out of the hands of chavs.
I must say though, in the 10 months I've had it, I've only had to pay out £230 for a service and a few quid for some cheap mineral oil so in that respect it's actually been cheaper than my old Escort to run!
The seven, including that one, is a gorgeos car, stunning.
As for oil, only the latest reneis rotary is allowed to have normal synthetic, but most dont. Mazda actualy did spend ages developing a good synthetic for the 787b and sold it to tue public as rotary 1 oil for a while but I believe it dissapeared in the mid 90's
One day I may have an RX7, most beutiful jap car ever.
As for oil, only the latest reneis rotary is allowed to have normal synthetic, but most dont. Mazda actualy did spend ages developing a good synthetic for the 787b and sold it to tue public as rotary 1 oil for a while but I believe it dissapeared in the mid 90's
One day I may have an RX7, most beutiful jap car ever.
RobDickinson said:
As for oil, only the latest reneis rotary is allowed to have normal synthetic, but most dont. Mazda actualy did spend ages developing a good synthetic for the 787b and sold it to tue public as rotary 1 oil for a while but I believe it dissapeared in the mid 90's
That's interesting. What is it about synth that the rotary doesn't like?
Mr E said:
That's interesting. What is it about synth that the rotary doesn't like?
Simon-oilman said:
Whilst on my cyberspace travels I found this which really only adds to what I said in SPIN 2 but nevertheless a good interesting read!
Mazda worked with Idemitsu Kosan Co., Ltd., to create a special synthetic oil for its racing rotaries, specifically the 900-hp 26B 4-rotor used in the 787B racer that won the Le Mans 24-hour race in 1991. Under the rules in effect then, that was the last year the rotary was eligible for competition in the class of cars that was likely to win the race outright, as opposed to winning just in a particular class. However, I must note that any 24-hour high-speed race is grueling, and just to finish Le Mans at all is an accomplishment. On the long straight, speeds of well over 200 mph (320 km/h) are usual.
The racing oil is described in detail in SAE paper 922375 of 1992, "The development of lubricating oils for rotary racing engines" by Takao Yabe et al. of Idemitsu Kosan. This paper is available from SAE.org and is well worth reading in full. Considerations in developing oil for the 26B included minimizing what the paper calls "spitback", which is leakage of combusting fuel-air mixture past an apex seal that is sticking because of oil-related deposits, and minimizing fuel consumption.
Mineral oils were out because they and their detergent inhibitor (DI) package created the problem deposits. Against mineral oil, Idemitsu Kosan tested polyol ester (PES), polyalphaolefin (PAO), and 3 different blends of polybutene (PB) synthetic oils. PB had advantages in minimizing deposits, hence the emphasis on PB variants, but in the end the company decided to use PAO for thermal stability and high viscosity index. Extreme pressure (EP) additives were considered but rejected in favor of small amounts of a DI package meeting API SG specs (which were current in 1991). A moly compound was added as a friction modifier. To minimize bearing wear required a viscosity of SAE 40.
In 1996 Mazdaspeed, which is Mazda's factory performance outfit, released a street version of the oil as "Rotary 1" in 10W40 viscosity meeting API SH (then the current spec). It came in rectangular 1-liter and 4-liter metal cans painted in the same green and orange colors as the 787B Le Mans winner.
The Mazdaspeed news release of 3 June 1996 said that Rotary 1 is "tuned to suit road cars" and "can be used in all MAZDA rotary engines (non-leaded hi-octane or regular gas versions)". This raises interesting questions concerning Mazda's long-standing warnings against using synthetics in its rotary engines in North America, though I understand from other BITOG posts that the RX-8 seems not to have this same prohibition. The release said that advantages of using Rotary 1 included minimizing "sludge" (carbon) formation and creating a more stable film for the seals.
>> Edited by RobDickinson on Monday 14th February 14:47
I've been using 76 Racing Oil in mine as the guy who rebuilt the engine (Pip Gardner @ WGT) uses it and has done so for long enough to trust it.
It's pretty pricey thiough - 7.8 litres cost me £39.95 but will do an oil change (~5.5 litres) plus top-ups until I need to do another one.
Also picked up a pile of filters in a group buy a while go so at $6 each it's going to cost me 46 quid for 3000 miles of motoring!
Like most turbo'd cars the 7 should be changed regularly. Mine actually overshot it's 3k by a bit... well, 1k miles and the oil was in good nick - still viscous and not too gunky!
Iain
PS. Looking great Steve! I can;t bring myself to give mine a proper clean at the moment... too depressing as it gets dirty so fast!
It's pretty pricey thiough - 7.8 litres cost me £39.95 but will do an oil change (~5.5 litres) plus top-ups until I need to do another one.
Also picked up a pile of filters in a group buy a while go so at $6 each it's going to cost me 46 quid for 3000 miles of motoring!
Like most turbo'd cars the 7 should be changed regularly. Mine actually overshot it's 3k by a bit... well, 1k miles and the oil was in good nick - still viscous and not too gunky!
Iain
PS. Looking great Steve! I can;t bring myself to give mine a proper clean at the moment... too depressing as it gets dirty so fast!
Mr E said:
As for oil, only the latest reneis rotary is allowed to have normal synthetic, but most dont. Mazda actualy did spend ages developing a good synthetic for the 787b and sold it to tue public as rotary 1 oil for a while but I believe it dissapeared in the mid 90's
That's interesting. What is it about synth that the rotary doesn't like?
I vaguely remember reading something on the mazdarotaryclub's forums that fully synth dries out gaskets or somesuch...
Mr E said:
As for oil, only the latest reneis rotary is allowed to have normal synthetic, but most dont. Mazda actualy did spend ages developing a good synthetic for the 787b and sold it to tue public as rotary 1 oil for a while but I believe it dissapeared in the mid 90's
That's interesting. What is it about synth that the rotary doesn't like?
I vaguely remember reading something on the mazdarotaryclub's forums that fully synth dries out gaskets or somesuch...
IIRC, there was also the question of burn deposits left by the synthetic oil. As oil is injected into the chamber in the combustion process, if the fully synthetic oil left ash or deposits upon combustion. not good for the tips .eek
I do not know who true that this is now, given the development of oils, but it is trully a can of worms and you get strong supporters of both pro and anti synthectic for rotary camps.
I do not know who true that this is now, given the development of oils, but it is trully a can of worms and you get strong supporters of both pro and anti synthectic for rotary camps.
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