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-   -   What generation do you own, which engine did you swap in, and why? (https://www.rx7club.com/other-engine-conversions-non-v-8-118/what-generation-do-you-own-engine-did-you-swap-why-683813/)

$100T2 08-28-07 07:54 PM

What generation do you own, which engine did you swap in, and why?
 
Maybe this could be a sticky even. :)

I personally got in over my head. I bought 3 RX-7s, with high hopes for all of them. I'm currently working my way back down to one, an 84 GS. The 'vert and the T2 are both leaving, and I'm planning on doing a piston engine swap.

My rationale for this is simple: There is just more aftermarket support for other engines, and with the FB weighing so little, any motor with some low end torque should move it like a bat out of hell. Add to the fact that there is only so much performance potential from a 12A, and going up to a 13B (usually with a turbo) is just as much work, if not more, than any other swap. Add in the fact that a 13BT can be a bit moody, and well, I want a fun car that I don't have to screw with every day.

I've been debating which engine to use, and figured that maybe we could all have a rational discussion to figure out why you guys went with the motor/tranny combo you went with.

The first thing I did was assess my mechanical skills, as well as those of anybody I know who could help me out. Now, I'm fairly smart, pretty fearless, so I figure that even if I have to tackle the swap by myself, I could pull it off. I have several friends who have race cars for over at the speedway, so they know their way around things I don't know how to do... Any specialized stuff, they can help me out with.

Next, I looked around for the most common swaps: Ford 5.0 engines, Chevy V-8s. They are readily available, not too expensive, and have HUGE aftermarket support. Add to the fact that every mechanic in America can work on both of them, and you can understand why they are the top two choices for swap motors.

Here's the problem: Given how hard it is to find wheels for the wonderful 4 x 110 bolt pattern, it's tough to find tires that can hook up that kind of torque. I live in Rhode Island, where the roads always have some sort of shit on them, whether it's rain, snow, sand, whatever. Fishtailing the car all over the road every time you drive is not a whole lot of fun.

So, I thought some more... What's common enough to find easily in a junkyard, still has decent aftermarket support, and enough performance to spin the tires when I want?

And it dawned on me: The 4.3L Chevy S-10 motor. I did a bit of research, and apparently, you can get it up to 275 ft-lbs of torque with a cam and headers, both of which are easily sourced from Summit. Then, more good news: Parts from the good ol' 350 Chevy, like pistons and rods, drop right in. Want to run a turbo or supercharger and need lower compression pistons? If they work on a 5.7, they work on a 4.3.

To top it off, Grannys sells a 4.3 swap kit. The motor leaves plenty of room for mods, A/C, and all that good stuff. Want to add a turbo? All you have to do is swap the headers from one side of the engine to the other, and they will face forward rather than backward so you can mount a turbo. I mean, it's actually pretty straight-forward.

The problem is the transmission, at least for me: I'd love to bolt a T-56 up to it. It would be nice and quick, and if 5.7L guys are getting 30 mpg with a T-56, imagine what kind of mileage you could get with the 4.3L. I'm assuming the 2WD truck 5 speed would work ok, but I'm concerned about how tall the gearing would be... I need to research it more.

I figure I can find a wrecked S-10 with a 5 speed in the local paper for $500 or so. I'll pull the motor, tranny, harness, ECU, radiator, etc, etc, and anything else I can for the swap, and that should do it. Will it be as fast as the Mustang or Camaro motors? No. Will it be fast enough? Probably not. ;) But, man, it should handle great, run great, and be an enjoyable car that when my son turns 16, he can drive.

So, that's what I'm doing and why. What did you pick?

driftking777 08-28-07 11:43 PM

I picked a ka24de motor when my 12A popped because i had one sitting around for rebuild anyways. knowing the my friends own a shop that does fab work, i went there and got free labor on the install of it. My other motor just popped also (due to a broken wrist pin) and so i had all the turbo stuff already for the motor...

so in turn i had damn near a free motor swap capable of over 400whp...you cant really beat that...

however with all the other upgrades i now have been doing im in alittle over 5k into the car (including the price of the car) which i suppose for a fully adjustable suspension (front AND rear) and 5 lug all around, you really cant beat it with that kind of power.

but thats me

~Nick

aussiesmg 08-29-07 07:07 AM

You've crossed over into the darkside now bro.....

I have 2 projects going on now

1. Ford 5.0 T5 Grannys kit, aluminum heads, roller rockers, Holley Systemax, 75mm TB 80 mm MAF, 30lb injectors, 94/95 fuel rail, double row timing chain, hi torque starter, light flywheel and so on, everything done right this car should weigh less than it did with the 12a. Main issues with the 5.0 is the clutch due to the hydraulic Mazda but cable Ford, I'm looking at using CNC units including a push slave, otherwise the Granny's kit is a bolt in affair, support by company leaves something to be desired.

2. Grassroots Challenger, 400hp 350 Chev out of a junker purchased for $400, turbo 350 and shift kit, doing my own mounts, budget if you aren't aware is $2007 next year $2008 and so on. I hope the bare car will weigh about 2200lb or less and with NOS make 550hp for $2000 bucks, shell cost $10 with GSL-SE suspension.

I am building one with the good stuff and one cheap as chips both are 84 models with GSL-SE suspension, which gies 114.3 lug pattern for one, bigger brakes and wider offset at -38 (more available rims choices).

Now the 4.3 only saves 11% weight over the SBC and although can make power it is expense to do so, from weight point of view Ford 5.0 rules.

SLIDN7 08-29-07 11:13 AM

I own a 88 TII and im swapping into it a 13B RE twin turbo cosmo engine.

88IntegraLS 08-29-07 10:45 PM

I know a guy putting a peripheral port 13b onto the front of an airplane.

85rx-7gsl-se 08-29-07 11:28 PM

Hey $100T2, I actually recently met a guy who has a 1980 SA with a fuel injected 4.3 V6 and a 350 auto. It is an ex-drag car that he now daily drives as a Dominos pizza delivery car. He supossedly is running around 8.3s in the 1/8th mile. Not too shabby. He plans on twin-turbo'ing it soon.

dbragg 08-30-07 10:08 AM

im pondering an idea into my SA, ill keep you posted

digitalsolo 08-30-07 10:24 AM

I've got an '86 RX7 Luxury Coupe with an LSx motor.

I bought the '86 RX7 because it was 700 dollars and I wanted a beater car to keep milage/weather off of my Grand Prix (which is a collector car). The FC was cheap, and appeared it would be somewhat entertaining to drive, especially for a "beater" car.

After a couple months of driving it, I decided it was in good enough shape to merit fixing up some of the "minor annoyance" type issues. I redid the factory harness, fixed the idle issues, fixed all the switches and lights, replaced a rusted fender and put in a nice grey interior (stock was red and rotted out). At this point it was a pretty decent looking as well as driving car.

Later on, a caliper failed, so I upgraded to TII brakes/hubs and rebuilt the rest of the braking system, got GXL wheels, and repainted the car (Maaco quicky job).

At this point, I figured I'd keep the car around, why not TII or 20B swap it? Starting looking into those, and found the www.v8rx7.com site instead. Bought a TPI Camaro donor, and started the swap...

The TPI Camaro motor turned out to be trash, so I bought a high compression, built 355 longblock to put under the TPI setup... completed the swap, and didn't care for the motor particularly, so the TPI was swapped for a carb'd setup to help it breath. Decided the carb sucked, and I hate distributors, sold the entire drivetrain and bought an LS1...

Installed the first LS1, and had crank issues (salvage motor, had slight crank wobble and dripped oil, which drove me nuts). Yanked it, rebuilt it, still had issues. Sold it. Bought 6.0L. 6.0L had assembly issues (assembled by previous owner), spun main bearing. Pulled it to rebuild as 408/L92 motor... still sitting on the shelf with the parts, haven't gotten around to it yet...

Over the winter (after 6.0L) I bare metal stripped the car, repainted it properly, redid the gauges and factory harnesses, added GAB struts, poly bushings, eibach pro-kit, new wheels, etc....

Bought 5.3L for dirt cheap, as I wanted to drive the damned car while I built the 408. Installed it, life's been great. :) I did manage to kill 2 4L60e trannies, so I've got a 6 speed going in next weekend. The 5.3L w/ spray has been entertaining enough, I haven't bothered with the 408 yet. Maybe this winter...

Hmm, I'm sure they'll be more chapters later...

$100T2 08-30-07 10:18 PM

digitalsolo, is that "V8" badge off an Audi?

NOPR 08-31-07 10:18 AM


Originally Posted by digitalsolo (Post 7286701)
I've got an '86 RX7 Luxury Coupe with an LSx motor.

I bought the '86 RX7 because it was 700 dollars and I wanted a beater car to keep milage/weather off of my Grand Prix (which is a collector car). The FC was cheap, and appeared it would be somewhat entertaining to drive, especially for a "beater" car.

After a couple months of driving it, I decided it was in good enough shape to merit fixing up some of the "minor annoyance" type issues. I redid the factory harness, fixed the idle issues, fixed all the switches and lights, replaced a rusted fender and put in a nice grey interior (stock was red and rotted out). At this point it was a pretty decent looking as well as driving car.

Later on, a caliper failed, so I upgraded to TII brakes/hubs and rebuilt the rest of the braking system, got GXL wheels, and repainted the car (Maaco quicky job).

At this point, I figured I'd keep the car around, why not TII or 20B swap it? Starting looking into those, and found the www.v8rx7.com site instead. Bought a TPI Camaro donor, and started the swap...

The TPI Camaro motor turned out to be trash, so I bought a high compression, built 355 longblock to put under the TPI setup... completed the swap, and didn't care for the motor particularly, so the TPI was swapped for a carb'd setup to help it breath. Decided the carb sucked, and I hate distributors, sold the entire drivetrain and bought an LS1...

Installed the first LS1, and had crank issues (salvage motor, had slight crank wobble and dripped oil, which drove me nuts). Yanked it, rebuilt it, still had issues. Sold it. Bought 6.0L. 6.0L had assembly issues (assembled by previous owner), spun main bearing. Pulled it to rebuild as 408/L92 motor... still sitting on the shelf with the parts, haven't gotten around to it yet...

Over the winter (after 6.0L) I bare metal stripped the car, repainted it properly, redid the gauges and factory harnesses, added GAB struts, poly bushings, eibach pro-kit, new wheels, etc....

Bought 5.3L for dirt cheap, as I wanted to drive the damned car while I built the 408. Installed it, life's been great. :) I did manage to kill 2 4L60e trannies, so I've got a 6 speed going in next weekend. The 5.3L w/ spray has been entertaining enough, I haven't bothered with the 408 yet. Maybe this winter...

Hmm, I'm sure they'll be more chapters later...

jeesh, that sounds like the type of epic engine swapping saga you'd hear from a rotary owner!

rosey 09-01-07 12:22 AM

I did an ls1 in an FC. Why? because I had an FC sitting around and wanted a fast car. For me, a gen-III gm engine is the logical choice. They are easily available, the swap is well documented with all parts needed easily available or easy to make yourself(hell, the hinson engine/transmission mounts are the only lsx/rx7 specific part I had to buy).

I have a ton of fun playing with the EFI system on my ls1 with EFIlive, I like it much better than the microtech I was using on the rotary, despite the fact that I can't change things in real time unless I shell out for a roadrunner. This is perhaps my favorite part of the gen-III engines, the huge enthusiast base and high technological state of the engine make it very interesting too me...lets not forget the power/torque it can effortlessly crank out.

The LSx swaps are not done very often on 1st gens, and I'm sure there is a reason for that(might have something to do with the steering rack? I forget.) but it has been done. Tire size only plays a small roll in traction, I run a 245 street tire with 400whp going to the ground and I can use almost all of it from 2nd gear on. Sure I can pretty much spin the tires on command in 1st and 2nd, but that is why throttle pedals aren't an on/off switch, its certainly not out of control or difficult to drive in the rain. I'm sure with the right gearing and some decent street tires you won't have any traction problems, especially if you throwing in a near stock engine.

I'd go for a iron block genIII engine if your feeling up to the task, a t56 would easily bolt to it, and it would make nice power, without being ridiculous, and leaving you plenty of room to grow. I would imagine its not much heavier than a 4.3 v6 anyway.

Otherwise, I would go with a 5.0/T5 setup...I think this would be a very easy nearly bolt in solution, and the 302 is as light as an ls1. It can also make quite a bit of power with after market help, kinda weak in stock form, but still plenty to have fun with. I would still take a genIII engine hands down, but if your looking for a drivers car on the cheap, the 5.0 would do it wonderfully.

dbragg 09-01-07 12:47 PM

best DD/fun car IMO, LSX FD

1Seven4Me 09-02-07 01:00 AM

LS1 in an 88 FC.
why? after my brother got screwed over on his RX7 by a local shop, ($2k deposit, no motor, and they're bankrupt... he was screwed) I started studying the swap and decided to do my own. his still is yet to start his swap(other reasons) but he as a LT1 sitting that he's $0 into.
I picked the car up at a towing auction & found the wrecked camaro donor on craiglsist. the bad was it had higher miles, and needed the trans replaced, so I upgraded to a built 4L60E w/ stall.
after wheeling & dealing some, I got the T2 diff for free(plus the work).

had 3 other FC parts cars in the process too.....

DanielBlakley 09-02-07 01:21 AM

I don't know why everyone thinks that piston engines are so much easier to swap.

$100T2 09-02-07 09:02 AM


Originally Posted by DanielBlakley (Post 7295214)
I don't know why everyone thinks that piston engines are so much easier to swap.

And I don't understand why people have to come into the Other Engine Conversions section and bitch about piston swaps.

Azar 09-04-07 09:31 AM

LS10AE, because it's the logical choice. :)

And DigitalSolo's V8 badge is off a Jeep Cherokee, I wanna say. I can't remember specifically.

rydestandard666 09-04-07 10:33 AM

I just picked up a 1980 rx7 and I'll be dropping in this 350 I've had laying around for 3 years from my Nova. I'm doing this because it will be cheap and fun.

If I had the time and money to do what I really want to do I would swap in a motor from either a kawasaki zx14 or a suzuki gsxr1300. I happen to like motorcycles way too much and if i really need to drive a car due to weather or w/e I'd prefer it to still rev out to 13k, get awesome gas mileage, and not blow up. Oh yea, the motor would be mounted in the rear too.

digitalsolo 09-08-07 12:37 AM


Originally Posted by Azar (Post 7300148)
LS10AE, because it's the logical choice. :)

And DigitalSolo's V8 badge is off a Jeep Cherokee, I wanna say. I can't remember specifically.

Yup, 01 Grand Cherokee.

Snyper 09-08-07 01:12 AM

93 with an LS6.

james81 09-08-07 07:14 AM


Originally Posted by Snyper (Post 7312943)
93 with an LS6.

Wow, that's a 454ci big block hey?

Snyper 09-08-07 08:46 AM

no 04 Z06 motor.

PSi 09-08-07 06:10 PM

Doing a KA24DET or SR over the winter not sure which though 87 FC3S...Rotoary was shot when i got it, Iove the looks and suspension performance of the car but im a Nissan guy and with that said the easiest swap i could think of for a play / non daily was pobably an SR but i preffer the KA-T (more than likely it will be the KA-T)

-PSi

$100T2 09-09-07 08:44 AM

Well, I got a 4.3L Chevy motor on Ebay for $100. Now, I have to find a tranny. :)

Turbo 3 09-14-07 06:17 PM

Bought my '89 TII out of college as a present to myself for graduating :) It had a blown motor (surprise surprise). I had the place where I bought it install a factory rebuild. Drove it for 1 month, put it away for the winter, next spring - get hit in a parking lot by a drunk who hit and run. Spend most of that summer fighting with the paint shop that I took it to getting a full new paint job (why not?) to get them to paint the car right - only took them three times and wasted most of the summer. Drove it for 2 more months - had it with the total lack of power and started researching.

Everyone says the 20B is the best thing since sliced bread and I took the bait. Bought the engine from a shop in CA, had them port/rebuild it. Spent a year working on it myself. Then took it to a local shop for fabrication/install. We agreed to keep it a side job only for them and to help keep costs down. After a year (it was ok) we went to start it only to find out that water I had used for a leak down test (I had even blew air into it to remove the water) had cracked the motor and wrecked both center irons. Car got put away for the winter and I didn't look at it once I was so disgusted.

Next spring rebuilt the motor with all new parts. Unfortunately - and this was the stupid part for me - I assumed that the shop I used knew the difference between physically building a car and rotary-specific knowledge. After putting in high comp rotors and a special nitride coating the car would start and run great - unfortunately it smoked from oil blow by and oil burning. Drove it like this for 2 years off and on and finally had enough. Sold the whole engine/EMS/turbo/driveline and went with LS2 and T-56 trans, stock TII 4.10 diff (for as long as it lasts).

Finally have the LS2 done now and just got it home recently. The difference between the 20B and the LS2 is staggering. The LS2 is so much more responsive of a package. The 20B would build and make power, sure, but not nearly as much as the stock LS2 does and the LS2 is frighteningly fast in comparison.

Looking back on it back when I had the chance to go 20B/LS2 at the time I really wish I would have looked into, as well as gotten some hands on experience with a V8 car to see the difference. However, since nearly nobody has 20B's, it's not like you can get a test drive to see what they're all about either.

In conclusion... to me the LS2 is a much better choice for what I want the car to do, handle, feel; and it's an absolute blast to drive. Couldn't be happier!!! :)

383Mazda 09-14-07 11:33 PM

'86 GXL model with a 383 small block chevy that was going in a suburban. Why:
Rx7--> $600 off ebay, no motor no trans, but with grannys kit included!
383--> free (could be duplicated for under $3500)
Trans--> ~1,000 200r4 out of an SS monty carlo
odds and ends--> maybe $1000
-----------------------------------------
~$3,000 for corvette performance!!! :)


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