what do you think is the better conversion?

they're both nice engines.

 

I say 20B, sure it's pricey, but it's a rotary powered car so keep it rotary. V8 swaps are a good alternative though, but V8s are too common. And when looking at both of those pics the 20B just looks right compared to the other

 

20b

 

20b

 

LS-1 better gas mileage on a light weight engine block with loads of torque, better reliability (meaning less maintenance) vs. another light weight engine with smooth power delivery (if NA'ed also) and with poor gas mileage. Did I mention high RPM rev's?

 

I think your answers are going to be slightly biased.

 

20B. You'll make a **** load more power, just as reliable with a good tuner and it will be worth twice the LS1 junk if you ever sell.

 

20B, but it comes at a high price if you want the same hp/displacement as a well sorted 2 rotor single turbo.

 

From what I've read, assuming the average RX-7 owner, an LS1 would probably suit their needs much better than a 20B.
Due to the fact that JDM motors can be iffy with their past histories (probably be much easier to track down an LS1 in nice condition), more expensive to buy and get running, harder to tune (or find a good tuner for) and perhaps make more power, etc.
The majority of us being American RX-7 owners, our current state/position does not welcome a 20B swap as it would an LS1.

 

Agreed

 

LS1 hands down.
half the reason is the nice and beefy sixspeed T56 transmissioon that comes with it.
plus the LS1 is so easily serviced.

the FD is unique enough in its own right that an LS1 swap wont make the car any less unique or less attractive or less fun to own or drive. either motor will make the car even better but the 20b will cost you twice as much for the same power and driveability with no real world gain over the LS1.
its not like a 20b weighs less than an LS1.

 

You forgot the part about the 20B making 600rwhp on pump gas all day long and easily fetching a $30k price tag when the car is sold. 20B has it all day over the LS1. Yes the initial cost is more, but it will not depreciate nearly as much with any other motor.

 

Well in all fairness that advantage still goes to the LS1. It can be built to do the same with lower compression pistons and a turbo charger and make that power at an even lower boost. Know one can deny the fact that the LS1 has a major displacement advantage 5.7 vs 4.0L's (and please lets not get into this displacement debate again). We all know that rotaries breath twice their advertised displacement.



Very true plus the LS1 can't duplicate a Ferrari's exhaust note like the 20b does.
me being a serious rotary nut, I couldn't even dream of installing anything but a rotary in an Rx7.

 

A 20B isn't going to just make 600whp easily, your going to need a decent turbo, standalone, FMIC, regulator bolt ons(exhaust, intake etc..)... plus tuning. If power is the goal, I think it would be much easier to make that power with an LS1, hell, bolt ons and a cam with a pretty big shot of nitrous would get you there....plus with a lot more torque and less weight.

I think because of availibity of parts and ease of working on and relieability the LS1 wins for the average guy, but the 20B has the cool factor and is more unique. If I had lots of money I would probably perfer taking a 20b and rebuilding it with high compression rotors and porting it and sticking some ITBs on it and leaving it n/a and make 300whp with it, but since I don't have that much money, a simple ls1 swap will make 300whp n/a completely stock for half the money...so for me, an LS1 is the obvious choice.

 

Just so you know, 20b is capable of a lot more than 300rwhp NA with ITB's. And it's not as expensive as you may think. I full bridge 20b (which could easily be done by a DIY porter) would make close to 400rwhp for less than installing a single.

 

if you plan on selling the car ever, I'd imagine you would take in a pretty penny more with a 20b than with an ls1 car.

 

If you even have to ask a question like this, go with the V8. A 20B project is something you have to want to do. Search for EvilAviator's posts where he details his trials and tribulations. Most of his posts were made in '02, and it's still not running as far as I know.

You're suffering from Jimlab's disease. I wonder how many victim 20Bs have gone on eBay because of this disease. Well, more for us I suppose.

 

LOL, after spending another 40k to get it running, if it even runs. LS1, but I am biased.

 

Oh God. Where we go again...

 

hmm..for some reason my post was deleted here.

no wonder i went -1 on my post count..i wonder why it was deleted.

 

Not to steal a post but I know someone with a LT1 complete front clip for 2K, should I go that route or rebuild a blown 13b?

 

lol on the 600rwhp comment...
the LS1 is less expensive to build to reach those power levels (and survive them)

lol on the resale value...
are you building a car to sell or to keep and enjoy driving?

dont get me wrong, I love the 20b, its a shame it was never offered here. but for most people a 20b project is way out of their reach or budget to do it right the first time and have it running well and in power levels they are proud of. but the LS1 is almost a drop in solution and there are usually several shops in any town that are capable of dropping in new pistons and hardware to make the LS1 meet 500rwhp N/A, or do some sort of forced induction setup.

 

20b and keep it n/a.

 

Well, considering I made 643rwhp and 520torque with the 2 rotor, Ive yet to be beat by the all mighty LS1, but Im biased....

 

A turbo 20B would hurt the weight balance a great deal more than a LS-1 would, but a N/a 3-rotor would hurt the balance less than a LS-1. The Ls-1 combines the wieght of a n/a 3-rotor with the power of a mild turbo 3-rotor. A high strung turbo 3-rotor wins in the end of power games. If it were up to me, I would build a N/a 3-rotor and maybe beat them at their own game, throw on NOS!!! and go whoop ***.