New to the club and looking for some help.

[bigd765]

Hello everybody! My name is Dave and I'm in Arizona. I have been a big fan of the FB since '88. My dad was going to buy me one back then and decided not to. Ever since I've wanted one. Well I finally bought my '83 a couple of years ago. I found it a few hundred miles from home, but for $300 it was worth the trip. The seller spent a year and a half trying to get it running and never figured it out. Turned over strong, just never fired. Body is in perfect shape except one dent in the back corner. Interior not bad for the age. Arizona is terrible on dashboards. I towed it home and spend maybe two hours on it checking the ignition system until I realized the car was out of gas. Add gas, car fired up immediately. Only problem was I would have to get the RPM's to 2000 before letting out the clutch or it would stall. Could never get the carb dialed in right. So I replaced the intake with a Racing Beat and a Weber side draft carb. Stalling problem was solved and huge power gain. Love driving it, drifting is not a problem. But now I need this to be a commuter car and the 15 mpg is not working for me. I know the 12a was never intended to be an economy motor. So I am thinking of doing a 4.3L V6 swap. I have not been able to find an adapter for the transmission. If anybody can help I would greatly appreciate it.

[ian65]

Hi Dave,
welcome to the forum

is a 4.3L V6 much more economical to run than a rotary? I run a 4.0 V8 as a daily and the gas mileage is about the same as the RX7 for me.
A decent 12a with the standard Nikki carb in a good state of tune should return around 23 mpg if you drive it normally...obviously much less if you floor it everywhere!
Maybe it would be a lot easier and cheaper just to drop a good nikki carb back on the car and get it tuned up rather than go to the trouble of doing an engine conversion.
I don't know what the values of cars converted to piston engines are in the States but in the UK, a 1st gen converted to a piston engine is pretty much worthless.... no problem if you love your car and want to keep it but perhaps a consideration if you ever intend to sell it on.
Good luck whatever you decide to do though... if you get a chance, please start a thread in the 'rides and projects' section.... we'd love to read about you car and your conversion if you go down that route.

cheers,
Ian

[codge]

X 2 for the above.

And welcome from me as well.

Codge

[Lucky]

15mpg seems quite heroic for a 12A, that Weber must be sucking down the gas at an alarming rate! My little 12A with the regular Niki carb gets 20s all day long. I'd recommend getting an FD as a second car and suddenly the gas mileage on the FB will seem perfectly acceptable

[TOOL]

A Nikki just cruising on the primaries should be pretty good......but then what's the point?

[megarock15]

welcome and good score on the fb. There are a few sb chevy 350 swapped fbs on craigs list here in michigan. but none of which are finished.

[RamoNZ]

Just picked up on this - when talking mpg across the Atlantic you need to factor the different gallon sizes.

USA = 3.76
UK = 4.5

Therefore a correction factor of +33% or -25% so using the figures above

15mpg USA = 20mpg UK
23mpg UK = 17.25 USA

In saying that, whilst I'm not a massive fan of swaps, I understand that there are many considerations when someone takes the decision to replace the rotary engine.

If fuel economy is the biggest driving factor behind this particular case then I have a couple questions:

Would the cost of the conversion remove the cost saving justification?
Would it not be better to purchase a fuel sipping daily instead?
Have you considered putting the money toward fuel injection to improve the economy but retain the power?
If you still must swap - would a smaller capacity all alloy engine not be a better bet than a larger iron engine?