Best choice of engines
 

I had thrown this out once before on the "other rotary"forum and had one reply. I am new to the rotary scene and have limited mechanical skills so I am looking more for reliability than large amounts of hp. A local shop will be putting a rotary into my 67 Datsun roadster and I'd like some opinions on which motor to use. I've read up on carb'd 12a and 13b motors and it seems as though the hp figures are pretty close to the stock output of a 2nd gen TII(I think the sp 13b's were a little more?). For my application, would it make more sense to go with the TII set up? Would a carb set up(Dellorto. Mikuni, Weber dcoe) be easier/less expensive to maintain? For what it's worth, I would like to see about 150-180hp at the flywheel at the most. The little car is scary enough to drive on the freeway with all the SUVs out there! Thanks in advance!

If it where me I would go with a 4 port high compression 13b. Either an old school REPU motor or a GSL-SE motor using 12a side plates.Street Port it and run a Webber or Holley and good exhaust and your goal should be easy to reach.

You could also use a later 88-90 6 port 13b to accomplish this, but I think the 4 port would breathe better and could potentially make more power.

Good luck,
Mike

If you have NO mechanical skill I can tell you now don't get a carbed car. Adjusting them is a bitch.

A 13b 6port out of a 85-91 would be a easy motor to work with.

Thanks! I'll sell the Dellorto that I just picked up! I can bolt things on but when it come to fine tuning(or tuning in general) I'll leave it up to the pros. I picked up a n/a S5 intake(upper, middle, lower manifolds w/tb $75 ebay) off a GTU awhile back and was thinking of possibly using that and some 89-91 rotors on a 6 port motor and just have the shop do a mild port job on the motor. Would this get me close to the numbers I'm after? Also, if I took this route, could I run a tranny off an n/a car as opposed to a TII?

If you're planning to exceed 200 WHP, or do drag launches, get a TII tranny. There's a thread somewhere with a photo of what happens to the NA tranny, but they reliably break under >200 HP use or really anything more than stock with drag racing.

-=Russ=-

Do a stock turboII conversion it will give you the power and reliability you are looking for. You can find them pretty cheap complete motor and tranny with the computer and wiring harness. I had this setup in a 1973 RX3 totally stock the only thing I added was a fuel cut defencer and that thing screamed. I had it for 3 years and drove it around as my daily driver and drag raced it almost every weekend. Never had any problems with it and I finally sold it to a friend and it finally blew 2 years later but it was due to something getting sucked in the motor. Reliability and a little power is what you want go with this setup. And put a good exhaust system on it and it will sound nice. The turbo muffles a lot of the noise my car was pretty loud cause I had 3 inch piping from the turbo back to a staight flow muffler.

12a's can take more abuse than the 13b . . .

Thanks for the replies. I really like the idea of using the stock FI and not having to fiddle with a carb but I sure do like the look of the engine bay with without all the vacuum lines and wiring. Let me ask you this, if the shop doing the swap were to dial in a Dellorto or Mikuni(they have a great carb guy and a dyno), would it basically stay in adjustment until parts wear out? Altitude and climate changes are not a much of a concern to me because the car does not see much usage other than occasional weekends drives and other than a couple of winter morning start ups, the SUs on it now have performed very well. Again, I am not looking for a bunch of hp. The numbers I quoted that I was after would be on the extreme side considering the car now makes at most 92hp at the flywheel. Stock port 12a with a side draft and an RB header kit???