Mazda Rotaries

[johnbirchjar]

Hi guys,I was under the impression that Mazda had given up on rotory engines,but apparantly not .In the motoring column in todays Daily Mail is a report that they are developing an "efficiant rotory engine" for their MX7 "Vision" prototype,anybody else add to this? J.B.

[Charles Wilson]

A year or so ago, one of the suits 'splained that they would have to sell 100,000+ a year to commit to it and no study they had told them that they could sell that many over the Long Haul, so, no RX-Y for the future. However, they keep allocating funds for more research.My guess is an internal corporate war like GM, which had the engine numbers for the GM Rotary in the Dealer's catalog (as an Option), a new car designed around the engine and so on. Was it Ed cole who became CEO and finally killed the project? In any event, GM had the car, which now needed a V-8 to "round out the line". It was such a tight fit that you had to raise the engine out of bay in order to change the spark plugs.Last I heard, the Mazda Rotary had met all emission Targets with semi-direct - but not Sky-Activ - Injection Technology - They have an SAE paper on it and I'll get the number of the paper for you if you're that lazy. So, on the one hand, you don't allocate precious funds and build Concept Cars every 3 weeks if you're NOT going to produce but if the Big Man says "NO!" in no uncertain terms, it's anybody's call."Mazda Rotary Powered Drones killed more people than all other Drones combined" doesn't make for good ad copy.CW

[Charles Wilson]

Sorta' wished I'd put this in...Mazda's SAE paper explored a Pilot/Main Injection Series. It was decided that the Pilot Cavity was to be 12 ccm firing through a 5 mm shoot hole. The fuel would shoot into the chamber with a vaporization of enough of the fuel in the cavity to ignite and carry the plume of fire into the chamber. Such a Pilot Cavity had a number of "self correcting" features that would allow a good burn during low rpm, during throttling (for getting the exhaust temp UP at low rpm and also superior working in the high rpm ranges.The Main Injector would inject more fuel in time for the fuel to be shot downstream and was positioned to be finished before the Apex Seal passed the injector at any rpm. Whatever Mazda et.al. does, it will involve a Pilot Injector System with Main Injector placed...somewhere. It's a very workable System.CWPS: AAI (Louthan, author, SAE) has already examined a Pilot Injector System for the Norton - with Turbocharging!

[FloridaMike]

My guess is an internal corporate war like GM, which had the engine numbers for the GM Rotary in the Dealer's catalog (as an Option), a new car designed around the engine and so on. Was it Ed cole who became CEO and finally killed the project? In any event, GM had the car, which now needed a V-8 to "round out the line". It was such a tight fit that you had to raise the engine out of bay in order to change the spark plugs.

My recollection (which I do not guarantee for total accuracy) was that the car the GM rotary was going to go into was the Chevrolet Vega (and somewhere I read that it was also going to go into the AMC Pacer). Just before the engine was to be introduced, OPEC got their act (or their scam) together and the price of gasoline skyrocketed - and that killed the engine, leaving GM with a small car and nothing to make it go.The response was to design a "modern, lightweight, advanced" four cylinder engine using an aluminum (unsleeved IIRC) block, and put that into the car.A Chevrolet dealer in New York state (I think) decided that the four cylinder was too anemic, and (unlike everyone else, who had already reached the same conclusion), they did something about it by stuffing a small block (327 series) V8 into the engine bay. This was very amusing, since the light car/big engine formula works very well, witness the AC Cobra. The 327 is often and inexpensively hot-rodded to well over 500 horsepower, and even the unmodified 327 cars often tore the rear suspension out of the tinfoil body. (The Sunbeam Tiger had the same problem.) They painted the cars black with gold trim and sold something like 2,000 of them before GM corporate decided they wouldn't warranty these things. The few survivors sell for $20K and up.The four cylinder Vega was a complete and total disaster. The bodies and the engines were biodegradable, and engines sometimes crapped out (technical term) at under 40,000 miles. The bodies rusted so quickly you could actually watch them do so. Essentially, the Vega was the spiritual grandparent and inspiration for the Yugo, albeit with better styling. The Yugo factory was (mercifully) destroyed by a cruise missile during the recent unpleasantness in the former Yugoslavia, but the Vega factory never even suffered that good luck, and GM still owns it (probably operating as a homeless shelter in Detroit).The AMC Pacer got an inline four or six instead of a Wankel, and looked like an obese frog. The Vega, however, was an unmitigated toad.

[Charles Wilson]

'N the type of aluminum used in the Vega engine? It's the same aluminum used in the Norton Rotaries! Molybdenum spray anyone?CW

[johnbirchjar]

Hi Mike,what CC/Litres would a 327 Chevy lump be?I don't suppose it would be the same 3ltre one that the Rover Car Company shoehorned into LOTS of their vehicles from the early 1960s and have continued to do so to this very day )J.B.

[FloridaMike]

327 cubic inches is 5.45 liters (60 cubic inches per liter). The same block became the current 350 (5.8 liters) and with some fiddling and a different crank can be opened up to 400 cubic inches or 6.6 liters. The 400 inch version can easily be tweaked to produce well over 500 hp and still be very drivable on the street. They also have some staggering torque figures, and can wind up drive shafts and half shafts like rubber bands. Not too shabby for a cast iron ("Detroit wonder metal") pushrod V-8 with two valves per cylinder (and you can get 4 valve heads if you are really serious) designed in 1954 and originally 265 cubic inches (later 283). These engines are utterly unbreakable, 150,000 miles is nothing for them, the only weak point (and it isn't very weak) is the timing chain and timing gears, improved versions are available aftermarket. What is amazing is that these engines and the parts for them are astonishingly inexpensive and available everywhere, including even on Amazon for a complete short or long block (I don't think the freight is free).This is not considered an especially large or powerful engine. Monday I stumbled on a hot-rod show south of Tampa where I saw a late model Corvette with a 427 inch engine (7.1 liters) with dual turbochargers, and the owner claimed it had been dynoed at just over 1,000 horsepower - which I do consider a bit excessive ;-)Big V-8s are very well suited for US roads and uses - large vehicles like pickup trucks and SUVs with the cargo area full of sheets of plywood (laid flat), a couple of bales of hay, a motorcycle or ATV or two, towing a boat or camper (or just about anything else you can hitch to the rear bumper) at 80 MPH turning 1,500 rpm or so on straight roads with the A/C set to "ice age", gasoline is cheap here again at $2 a gallon (50 cents a liter, +/-), and these things can run forever with just about no maintenance, just keep adding gasoline. Remember that Texas alone takes a full day to drive across.Obviously, they don't work very well in the UK or Euroland. I was in Oxford some years back and had been there a few days, got used to the "scale" of the buildings and streets. Somebody had brought over a full-sized Chevrolet pickup truck and it looked to be as wide as both lanes and as tall as the houses . . . and that is not considered to be an exceptionally large vehicle here. I'd hate to feed it at $8 to $10 a gallon.I think the expression is horses for courses (and I think I'd like to try out that 1,000 hp Corvette sometime.)Best Regards,Mike

[johnbirchjar]

Hi Mike,so looking at your figures the 3 ltre lump Rovers put in their vehicles was a bit of a tiddler .and thinking on I also think the engine was a Chrysler and likewise very simple and allmost bomb proof.Drive across Texas in one day!?Iv'e been led to believe that Texas is bigger than France,( I guess it's got to be about eight hundred miles,?to much for this old biker)I think that we have digresed somewhat from Mazda rotories.ride safe,J.B.

[gripper]

John, the 3.5 litre V8 Rover engine was a development of the Buick engine and was, I believe, an alloy block.

[FloridaMike]

John, the 3.5 litre V8 Rover engine was a development of the Buick engine and was, I believe, an alloy block.

Yes, it was a GM engine destined for Buick, Oldsmobile, Pontiac, originally 215 cubic inches (3.6 liters), in the early 1960s. The three cars were essentially an exercise in badge engineering, but the Pontiac version (Tempest) had a swing axle real suspension which made the handling "interesting", to say the least. I know someone who is driving a lime green Tempest convertible to this day, he bought it new and has kept it wonderfully.You're right, we seem to have digressed a bit from rotary engines . . . gearheads (petrolheads in the UK) tend to be like that.Best,Mike