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diesel rx7 ?

Old 04-12-12, 11:31 AM
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diesel rx7 ?

so my vert blew up time to rebuild stick it on the shelf and move on !
im thinking of putting a small diesel in it has anyone done this ?
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Old 04-12-12, 12:23 PM
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i was talking about this with a friend the other day, problem is that the only thing that would fit would be like a vw tdi, and you can barely squeeze 300hp from one. you would get sick mileage, it would be reliable, and it would be different, but unless you got alot of extra time and money i cant see it being worth it.
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Old 04-12-12, 12:34 PM
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it has been done. i never took the time to read through it thoroughly. there is a posted video near the end.

these arent super high powered engines but can put out 150hp / 250ft lb of torque easily and still get 50 mpg. I assume you could get 60mpg plus in an rx7 since its smaller, lighter and more aerodynamic.

from the looks of it, the hard part is getting it mounted at an angle, and getting the drivetrain to work. the injection pump and all of that is electronic so a pedal swap or a mechanical injection pump would be required.
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Old 04-13-12, 12:07 AM
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I have thought about putting a Diesel in my first gen FB, and had numerous discussions with knowledgeable people, including my fabricator who helps me with my various projects. This can certainly be done, but it is not going to be as simple as some of the other popular swaps. The most desirable engines are in front wheel drive cars, so the transmission adapter is difficult. We even considered the possibility of putting a front wheel drive unit in and driving the front wheels. Some of the Audi units sit fore-and-aft and might be good candidates. It seems the most desirable units are not sold in the US, and dealing with sources in Europe is outside my experience, but I think pricewise, the Europeans are much more proud of their used engines than the Japanese.

The JDM import engines are a great way to go, and reasonably priced, but they are pretty much all gasoline engines. If you are an experienced fabricator you might consider a Nissan SR20 or RB20 turbo engine, capable of giving you about 200 horsepower and close to 30 mpg fuel economy. I recently did a RB20 installation in my 84, and I think it is the perfect engine for this car for street use.

Of course, your 2nd gen convertible is several hundred pounds heavier. That is something to consider when thinking about a small diesel. Be sure to compare your weight with the weight of the donor car when judging the potential performance.
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Old 01-10-14, 03:33 AM
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How about converting a rotary to run on diesel. I bet if you filled in the combustion chambers on the rotors some, to up the compression, you could adapt a cummins or a volvo 6 cyl bosche VE pump pretty easily. convert one spark plug hole to fit an injector, and the other to house a glowplug (or just use an intake air heater like some trucks do for cold starting), and away you go. Pretty sure I read somewhere that either Mazda or NSU had some running diesel wankels at some point.

May not be the most efficient diesel (due to injector location), but you could get lucky. Maybe it'd be awesome! Certainly, whether really good or not, if it ran well enough to drive the car comfortably, it would be unique and quite an achievement.

With all the rotary turbo parts out there, it'd be nothing to make it a TurboWankiesel!

Thinking further, you could maybe convert one spark plug hole per rotor to house a precombustion chamber (look it up) AND a glowplug like the older VW's had. That already has the right swirl characteristics to support good diesel combustion, and you could angle it's outlet in the direction of rotor travel. Might be onto something here...

Last edited by wreckerx7; 01-10-14 at 03:41 AM.
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Old 01-13-14, 08:08 PM
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Because a diesel practically runs on detonation, I doubt the apex seals would last.

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Old 01-14-14, 06:41 PM
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That's actually a common misconception. But its essence is that the pressure rise during diesel combustion is much more rapid than gas. That's why you see much stronger ring lands on diesel pistons.
Rolls Royce made a diesel rotary, and used steel apex seals, I believe.
Check out these two links I've found:
Starting Low Compression Ratio Rotary Wankel Diesel Engine
Weird: Rolls Royce Diesel Wankel - TheDieselGarage.com
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Old 01-14-14, 06:49 PM
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Someone put a Perkins 2.2L diesel in his first gen. That's the little 4 Cylinder engine that came in some of the old B2200's I believe.

Perkins Diesel Swap
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