V8 motor swap
 

The rotory engines do make power and all it takes some serious money and they a unreliable. The car I have is a 1980 rx7 and the engine no longer works. Plus it has about 150k miles on the old clock. I would like to do the v8 swap because I'm more familiar with them. I was just wondering what all I would have to do in order to do this swap. Maybe take an older trans am motor. Sure its only a 305 at is rated at 200+hp but compared to the monster torque and power this rx7 puts out now. The 305 would probably feel very much more like a sports car. The rx7 has around 100 hp? Thats what I heard anyway. put a shortend rear maybe just a cheaper 10 bolt chevy rear with posi. A good drive shaft and a 5 speed out of a a GM car. What all has to be done to do this swap. Motor mounts trans mounts. How about the rear. how many problems here? Hooking the brakes up correctly? Do they sell any kits that this can be a bolt in project?

Thanks
Brett

You are evil!! Putting a v8 in an rx-7!! bad, just bad.

If you are going to do it, do it right. get an aluminum block 283 and a 4 spd corvette tranny... sorry, can't remember which year. it was old, though. Using these will keep you as close to the orriginal weight as possible, but you will still have more weight on the front end and you will be throwing off the weight balance.

When you do the exhaust, have the drivers side wrap around to the passenger side and hook up there.

use an electric fan and don't put any more accesories on it than you need.

I knew a guy who did this.. it was a LOT of work. You are better off getting a 13b and dropping it in there. For the money you will end up spending, you can get an awesome 13b setup.

Better yet, if you want a boinger, GET A 280z!!!

Didn't we just have this discussion???

I tried to already have this topic opened but people went way off the subject and almost had to call the U.S. military to help calm down everybody. I was just wondering how much money is invloved. i don't have any 13b motors around here anyway. More weight infront. Naw. Fiberglass fenders bumpers hood etc. That should help.

spendy spendy spedny
i had my swap all mapped out would cost me around 7k to get it done my way completely,,,,,,,but thats just me i soon gave up on it, and went all rotary.....little cheaper (but still not cheap) but worth the fun level that a little 1.3 liter can cook up. to each his own but im sure youll regret droppin one into an Sa.....if i was gonna chose one i would either chose a third gen with an lt-1 swap,,,,,(only if the TT was gone) or a 84-85 gsl-se....no suspenison conversion necesarry, but u still have to upgrade the springs......and the only fiberglass fenders that are availible are for a widebody kit and dont help much

i only read the first sentence of the orignal post, and rotary's are quite reliable if you know what your doing. v8's don't go in rx'7's they go in Trans Am's.

Nothing bad to say about V8 Swaps, except I am tired of hearing about them.

MODS:

Could you PLEASE make another Section for V8 Engine swaps?

This is getting OLD.

yea i agree with DF. While this is a rotary forum (it says so on the home page) there seems to be enought interest in V8 swaps, and while i don't like the idea a whole lot thats not to say its wrong. A v8 forum should be put in.

i agree with the other section as well.. we just had a post floating around about this, and ive seen them in the second and third gen forums as well.

as for me? if anything, i would go 2.3t like Eville140 did. they come with a t03 (99% sure) and you can run INSANE amounts of boost on stock internals, and it likes it. i know the merkur xr4ti's boost gauge goes up to 30psi, and the red doenst start till 25. that motor, t5 tranny, 3" downpipe and exhaust, intake, fmic, boost controller :drool: and i hear those parts are cheap as hell. i think eville140 said he put $800 in the car, and it ran low 8's in the 1/8 mile. thast just badass.

Just send people to http://www.torquecentral.com/forumdi...?s=&forumid=11
It's a whole forum dedicated to the V8 swap. When I have car questions, I come here. When I have motor questions, go there. Both great sets of guys. The guys at V8RX7 are pretty damn anti-rotory, while the guys here are pretty damn anti-pistons. Can't we all just get a long :-)

Yep, I do the exact same thing. Both places are very helpful.

Heck don;t even make another section, save the bandwidth and just make a forum that links to http://www.torquecentral.com/forumdi...?s=&forumid=11 :)


Later
Randy

Don't go with a 305, waste of time. Go Ford 302. its alot lighter than a 350. A when using a ford 5-speed the mazda driveshaft can actually be inseted into the Stang shaft and welded. Saving some cash as well.

Also, I would not go with the electric fan, I tried one but if you are going to use headers instead of manifolds, the thing won't keep the car cool enough.

Go with what you want man. I'm running a 350 with headers using an electric fan and have no cooling problems. If you want some real answers pm me or email me I'm more than happy to show people "the way".

Oh, I handles great, and what's even better, after I get threw the corners I have power to get to the next corner befor the other rx-7's

Re: V8 motor swap
 

My Rx-7 has more than 100hp ;) And it's pushing 180k, I thought you said these things were unreliable??

Re: Re: V8 motor swap
 

Oh you did!!

stay away from gm shit. 305's are the biggest pos engine unless you dump a ton of money into. If you must have a v8 in your FB go Ford or MOPAR.

Brett, filter out the useless crap and listen to the guys that have done the V8 swaps. The other guys only tell you things they think they heard from someone else's friend who's brother dated a girl who's dad wanted to swap a Corvette motor in his 4X4!

Winnipeg85GSL and 85 GSL 302 are not steering you wrong. Neither is rotor vs piston but the Chevy swap might be a little more expensive (couple hundred $) and a small block Chevy is physicaly bigger than a small block Ford.

Is you RX7 a standard or an auto?

By far the easiest swap is a Ford 302/AOD automatic. The auto shifter is cable opperated so you can put it where it's most comfortable. The T5 stick usualy doesn't center exactly where the stock one comes out so you gotta be a little creative. You can buy the motor mounts or make them yourself if you have a welder and the tranny Xmember is even easier to make. Although a Fox body donor car (Mustang, Lincoln LSC or Mark VII) is the preference, any Ford that came with a 5.0 will do. The advantage of the Fox body cars is that they already have the proper double sump oil pan that will clear the front crossmember and steering. (saves you $60 at Summit) You will also use the wiring harness and computer from the donor car especialy if it has EFI.

I don't know how strict your emissions laws are in your neck of the woods but usualy to be legal you need to use a motor that is the same year or newer than the car. Also, the motor has to retain all of its emissions equipment. The catalytic converter is considered a chassis piece therefore the stock RX7 one can be retained if it is functionning. Usualy they are really not adequate because the rotary is notoriously hard on them. The RX7 has two cats in-line with each other. The main cat is an oxidizing type but you can sub in a higher flowing aftermarket TWC (three way cat) that will not affect performance. Because TWCs are better than Oxidizing cats, smog refs will actually give you a pat on the back.

The stock rear end can be used as it is much stronger than most people think, but the stock gearing is a little high. This is why I suggested the AOD Ford tranny. OD has a ratio of 0.67 and will give you an approximate RPM of about 2500 @ 60mph. Lower gears are available but IMHO they are not worth it. A stock 8.8 inch rear end from a Mustang is about 1.5 inches wider than the Mazda rear and can come with gears as low as 2.73:1 if you like. Also, a 7.5 inch axle from a 4 banger Mustang can be swapped in as it is comparable and maybe a little stronger than the Mazda unit which is 7" ring gear BTW. The Ford 7.5 can also be found under Ranger pickups and Bronco IIs. You will need to have your driveshaft modified if you use the stock Mazda rear to accept the proper yoke to mate to the Ford tranny. If you go with all Ford components you may need to shorten the driveshaft depending on what Ford it came from.

If you have more questions, just PM me and we can talk. I can direct you to sources that WILL help you if you are absolutely set on a Chevy motor.

Toughguy :)

Here, so no one can say that I didn't help

www.grannysspeedshop.com

Ryan

Here's a few pics of my Ford 302/T-5 swap. It has a sotck rearend which uses a Ford front half of the driveshaft and the mazda rear yoke.

http://images.cardomain.com/member_i...506_9_full.jpg

Now has some different valve covers and is a little cleaner.

http://images.cardomain.com/member_i...506_8_full.jpg

Shifter worked out perfectly!

http://images.cardomain.com/member_i...506_2_full.jpg

Re: V8 motor swap
 

From one Brett to another: It's your car, and you can do whatever you want to it, even if it is equivalent to blasphemy.
However, if you switch to a V8, it's probably adviseable to switch the body as well---- to say, a mid-'80's 300ZX or something. Why rape the soul of the legendary RX7 by ripping its heart out rather than selling it to someone who will give it a good home? Just my $0.02 worth...

Oh boohoohoo. Whinning cry baby!:gayboy:


Toughguy :pity:

Man, some of you guys really need to stop reading Harlequinn romance novels... you're starting to sound like actors from early Shakespearean sonnets.. :puke:

It's a freaking car, it doesn't have feelings, it's not going to know the difference. The only person that'll know is the owner, and the people he kills in straight line races in stock RX-7s...

http://images.cardomain.com/member_i...506_9_full.jpg
http://images.cardomain.com/member_i...506_8_full.jpg
http://images.cardomain.com/member_i...506_2_full.jpg

Damn. That does look good in there..
It look OEM practically. You have more space in there than I do.:(

Look guys, I'm not gonna get involved in just another V8 swap discussion, cause I'm f**kin' tired of that.
But what I do know is that this topic gets here every so many days, and that's real BS. There's no use in going through the same discussion over and over again.
And IF you need to discus this topic, then at least use facts, not "things you heared from someone you know that knows someone that..."
ROTARIES ARE NOT UNRELIABLE! Anybody who says that is stupid. So I don't give a shit what you put under that bonnet, but don't tell me lies about the reason you did that. If your 12A is not reliable you're just too stupid to keep it going (or the previous owner was). That's all.
Any engine that was maintained wrongly (or not at all) will become unreliable, and unfortunatly too many rotaries have been/are in the hands of people who "think" they know how to deal with them.
There's nothing more to say about that.
So if you still believe you need a V8, go ahead. But I just don't get it why you don't buy a V8 powered car to start with then. Probably even cheaper in the end...

My original 12A is pushing twenty years and running strong. Why would anyone want to put pistons in an RX-7?

see, now if I was going to put a piston engine in an Rx-7, I'd see about getting a 3000GT VR4 engine or something like that with a whole lot more hp than 200. Make it have an un-godly amount of power with lots of torque. Make it worth the time and effort.

Thats my other .02 if you want it.

I say go with the v8 dude! I have a mint condition 2nd gen gtu model that i am putting a 400 hp lt1 v8 with a 150 shot of nos in it!!!! GO WITH YOUR FEELINGS!!!

I've got a soon to be 393 with a T-5 tranny....but right now it's a 351w with a AOD and turbo II rear end in a '79 7. Runs real strong...pulls mustangs and camaros pretty well (stock that is). I hope to be getting about 450-550hp on all motor and then possible throwing a 150 shot to it...just going to make it very fast but still streetable for now ;)

I didn't realize this thread was sooo old lol

Before you get the BS flag, not for the pistons, explain how you have a TII rear end, that is irs, in your originally solid axle 79.

Lots of guys put V8's in everything. Why not try a 6 Cylinder? For example: Those 300cui Straight 6's out of the F-150's has a tremendus powerband.

Im All for motor swaps. I'd just like to see someone do something different. I've seen a V8 in just about anything to the point that It really does nothing for me, no matter the power.


The most amazing car I seen last year was a 5.0L Mustang Chassis with a 2.3L Turbo Engine in it with an Automatic. Ran low 13's far above Sea Level. THAT was impressive. Had it had a V8 in it? I wouldn't have given it another thought.

Few years ago I seen an FC come out with a 350 in it. I didnt even give it a second thought. Was it fast? Well, 300 HP at the wheels smokes any tires. But when a sub 200WHP RX-7 spanks it, thats when my imagry of V8 + RX-7 went out the window.

Thats just my thoughts anyhow. If you do the swap, make it count for something different.

Pics would be good too.

I say he's a troll.

Ok first step is reversing your crossmember for oil pan clearance.

Then depending on how much money you want to spend and how fast you need it done, you can either buy engine mount & trans mounts from grannysspeedshop.com or get the designs from torquecentral.com and build them in an afternoon.

As it's been said the easiest swap is a 5.0L 302 HO with an AOD, this also a light V8 motor, but whatever motor you choose put the heads as close to the firewall as possible.

Examples of light motors are Caddy 4.9 (aluminum) and the Gen3 GM (LS series)

Some people say the weight distribution will be thrown off, but someone swapped an LS1 in his FD and it is lighter now, then when it had the 13b in there!

well everything under the car has been changed over to the tII setup...I didn't do the work though. I weighed the car a few weeks ago and with a stock truck engine and AOD it weighed in at 2500 with me in it.

That's just what I was told about the rear end...I didn't own it when it was installed. Aparently it's got LSD though.

If the car still has a solid axle, it does not have a TII rear end, period. If you got sold that line by the installer, I would be checking the rest of the car for misrepresentation.

Do what you want with the seven, but do not call the rotary unreliable. That is just spreading misinformation. Nothing but lies!

Good God, I am really tired of the whole V8 thing, And let me tell you why,

Its been done TO DEATH if a car has existed odds are someone has dropped a V8 in it. And yes V8's naturally produce more power than a rotary. No a High output V8 will be just as unreliable as a High Output Rotary, and you cant argue that! I owned a Camaro IROC-Z with a fresh 350 GM crate, I had it pushing 500 HP and I tell you what I broke damn near every part on that car! My friends had an assortment of V8 powered vehicles, so did my parents. If you had a V8 you were friends with your mechanic, and thats something alot of the I-6 guys joked about. They werent always as fast as us, but those I-6's lasted forever.

A V8 going fast in a straight line, no longer impresses me. A V8 carving corners, no longer impresses me. Its like going to a gun fight and you already have the biggest gun, everyone knows their screwed. But when a Rotary or a 4 banger or a 6 smacks down a V8, I am impressed. That is like the dorky nerdy kid, beating the hell out of Chuck Norris.

I have no problem with what you do to your car, Its your car, and if you want to treat it like a piece of meat you may do so. I am not flaming, dont take it that way. But what I am telling you is if you can take something, that wasnt impressive before. And had little hope of being that way, and sqeezing crap loads of horsepower from something everyone told you wouldnt work, thats impressive. My FB has close to 140,000 on the odo and pushes 200+ HP as a DD, I love it I wouldnt have it any other way. I am a purist, in everything I drive, I will always be that way. Oh and yes you may be faster than me, but I am getting old, so I dont notice the difference :)

I also own a 240Z with a Chevy 350 and to be honest, my RX7 is more fun to drive. It's a blast to take the Z out and mash down the gas pedal and absorb the g-forces while you hold on for dear life. It's also great fun at the track, but for taking a long drive on country roads or any ride where you'd rather not risk jail time or certain death, I take the RX7. The V8 makes a 240Z feel like a big American car even though it still weighs less than 2500lbs. Definitely less of a sports car feel. All that power and an American gear box take the fun out of shifting as well. And automatic transmissions in a sports car, that shouldn't be legal unless you've had your left foot amputated. What others have said here about reliability is true, you don't need a built up a V8. My engine is pretty much stock and I can't even imagine what you could do with 500HP except drag racing. (and bragging rights).

You should also check out http://www.hybridz.org/

:) mostly bragging rights, the reason everthing broke is it was a DD for sometime. And your right, 500 HP is ridiculous, anyone who has had that power knows that it makes the car undriveable. I hated that IROC, for a DD it sucked ass, and on the track it was a beast, but every other V8 had that much power. 500 HP and a 12 sec car, stupid.... an Rx-7 can do that with FAR less power. Jesus Padilla has about 450 HP right? 10 sec car, that is DAMN impressive.

But yeah after the IROC left the track, by its own power, or by tow truck. It always ended up in the garage....

I think people that swap v8 engines into rx7, are not suppost to be here

There's a section specifically for this, so I'm moving this thread there before people get any more pissed off.

Jon

i thought it was already in the right section? other engine conversions. :shrug:


~Steve

All I have to say to this thread is HHAHAHAHAHAHAHAHAHAHAAAHAHAHAHA!!!! :D

Lets open our minds.....and about the V8 thing being done alot, who the hell cares, its proven its self and thats why people continue to do it.

The 5.0L 302 sounds good. A friend of mine had a 5.0L 302 foxbody stang that he beat the shit out of all the time even with high mileage on it and that engine still ran strong without any probs.

Yes, lets open our minds. No other platform out there is as good as the Rx-7. Thats why people put V-8's in them. ;)

Its about time everyone caught on :ylsuper:

I agree. Lots of RX-7'Purists" have V8 issues but really theres good reason why this is becoming so common! Ive owned many RX-7's and rebuilt many rotaries. Ive also owned many GM's and rebuilt those too. Bottom line for me is cost and availability. I can visit my local junk yard and count a few hundred donor cars with V8's wether I need a alternator or set of heads. There is 1 RX-7 there thats so picked over it isnt funny. Also budget is a major consideration for me. The rotary is unique and with that comes extreme cost to rebuild it. Im a good fabricator and am making almost everything for my conversion. If anyone dosnt like my Rx-7 V8 thats too bad! I say put your money where your moutn is and try beating my track time! Shawn