V-8 engine swap???
My wife bought me 2 RX-7s
Joined: Aug 2001
Posts: 2,328
Likes: 3
From: Saskatoon, Saskatchewan, Canada
Originally posted by enigma32
:: stands and claps for fatboy7 ::
The funny part is that kuuldigs (the poster of this thread) hasn't even shown up to watch the havoc he created.... =P
:: stands and claps for fatboy7 ::
The funny part is that kuuldigs (the poster of this thread) hasn't even shown up to watch the havoc he created.... =P
Hunting Skylines
Joined: Apr 2001
Posts: 3,431
Likes: 4
From: Brisbane, Queensland, Australia.
Originally posted by '85 GSL 302
That puts me at $3830 for the whole car give or take. My swap was actually a bit more because I used a motor that was torn down so I had to go out and find a lot of stupid things like new timing chain covers and oil pans. However I didn't have to pay for the engine itself. Had I just gotten a donner motor for like $700 and rebuild it it would have been cheaper. So after calculating my swap let's say anyone could duplicate my exact car for $4000. That gives you a 300hp car with a brand new motor, tranny, and driveshaft including the price of the car. I'm sorry but I find it hard to believe you can buy an RX-7 and make 300hp and have it be a great daily driver with minumal upkeep. I'm not saying it isn't possible, but it's unlikely. As for mods, sure, you can spend just as much on a V8 as you can a rotory motor. It's just that the V8 with mods will put out 2-3 times the power. As for future power, a cam ($150) and a set of shorty headers ($225) will remove the remaining bottle necks in my car and probably give me another 30-40hp. I'll post dyno results when they come in.
And here's a picture of the engine bay. There's actually quite a bit of room in it.
That puts me at $3830 for the whole car give or take. My swap was actually a bit more because I used a motor that was torn down so I had to go out and find a lot of stupid things like new timing chain covers and oil pans. However I didn't have to pay for the engine itself. Had I just gotten a donner motor for like $700 and rebuild it it would have been cheaper. So after calculating my swap let's say anyone could duplicate my exact car for $4000. That gives you a 300hp car with a brand new motor, tranny, and driveshaft including the price of the car. I'm sorry but I find it hard to believe you can buy an RX-7 and make 300hp and have it be a great daily driver with minumal upkeep. I'm not saying it isn't possible, but it's unlikely. As for mods, sure, you can spend just as much on a V8 as you can a rotory motor. It's just that the V8 with mods will put out 2-3 times the power. As for future power, a cam ($150) and a set of shorty headers ($225) will remove the remaining bottle necks in my car and probably give me another 30-40hp. I'll post dyno results when they come in.
And here's a picture of the engine bay. There's actually quite a bit of room in it.
I still don't agree with you're prices though. For $4000 US I can get a 10sec engine package that will make a hell of a lot more than 300hp I assure you. If you only want 300hp that's easily attainable with a 13B turbo and bolt mods. Taken from www.mazfix.com.au Note price is in AUD.
10sec Engine Package
The ten sec Package has been added to the Mazfix range to cater for the serious racer. The combination in this package will boost your RX into Tens. In choosing our 10sec Package you not only receive a quick engine package, but you also receive many years of development and experienced at no extra charge. Always at the race track, we readily lend support to our valued customers when they are racing.
13B Import Engine Tested, checked bearings, oil pressure, compression Engine is Mazfix modified. Series 4 or 5 depending on availability.
TO 4 Turbo Mazfix specs. Brand new big front cover with 4 inch inlet.
All turbo, oil and water lines custom made.
600 HP EFI Fuel pump
Surge Tank
Two pre pumps.
45mm Waste Gate.
Custom Exhaust Manifold.
Custom front engine mount.
MicroTech LTX 8 includes 4 coils (laptop programmable).
Using your sump.
Engine mods.
K & N air filter.
Hi flow secondary injectors. Serviced and flow tested primary injectors.
Adjustable fuel pressure regulator.
PRICE: $7,995
The ten sec Package has been added to the Mazfix range to cater for the serious racer. The combination in this package will boost your RX into Tens. In choosing our 10sec Package you not only receive a quick engine package, but you also receive many years of development and experienced at no extra charge. Always at the race track, we readily lend support to our valued customers when they are racing.
13B Import Engine Tested, checked bearings, oil pressure, compression Engine is Mazfix modified. Series 4 or 5 depending on availability.
TO 4 Turbo Mazfix specs. Brand new big front cover with 4 inch inlet.
All turbo, oil and water lines custom made.
600 HP EFI Fuel pump
Surge Tank
Two pre pumps.
45mm Waste Gate.
Custom Exhaust Manifold.
Custom front engine mount.
MicroTech LTX 8 includes 4 coils (laptop programmable).
Using your sump.
Engine mods.
K & N air filter.
Hi flow secondary injectors. Serviced and flow tested primary injectors.
Adjustable fuel pressure regulator.
PRICE: $7,995
Last edited by REVHED; Jul 29, 2003 at 05:00 PM.
U sUx0rz @ THe IntaRwEB!
Joined: Feb 2001
Posts: 327
Likes: 0
From: Claysburg, PA, USA
I've weighed in on this before, and have been labeled a heretic (what's new?), but I do support the V8 swap into a 7. The whole point of that swap is to get added displacement. I don't doubt that a 300hp turbo rotary isn't hard. In fact, that seems pretty darn easy. However, how long will it last before grenading? Can it swallow 87 octane and not complain? Sure it makes 300hp, but what kind of torque does it develop from say 1500 rpm and up? You could build a 500 hp SBC for well under $2500... can ya do that with a rotary and get it to last for 30k miles? I can understand why people do this swap and I've got no beef for either side. I like import motors that you've gotta keep up in the powerband. It makes the car much more challenging to drive fast, when you're constantly up and downshifting. I like challenges. On the other hand, I also love the stupidly excessive torque and pull a domestic V8 generates.
--Danny
--Danny
Senior Member
Joined: Apr 2003
Posts: 479
Likes: 0
From: SC
Originally posted by Makwana
Don't you got too make custom mounts too fif that v8 in there woulden't that be pricey? So i'm guessing that u spent more then that.
Don't you got too make custom mounts too fif that v8 in there woulden't that be pricey? So i'm guessing that u spent more then that.
Originally posted by REVHED
For $4000 US I can get a 10sec engine package that will make a hell of a lot more than 300hp I assure you.
For $4000 US I can get a 10sec engine package that will make a hell of a lot more than 300hp I assure you.
$7995 AU is 5,319.07 USD and that still doesn't get you a new tranny nor will it pay for the price of the car. Now a 150 shot of nitrous and I garentee my V8 would put out the same power, with more torque and still less price. Not to mention it would be streetable, use cheaper gas, and last over 100k miles. Of course you still wouldn't be able to put that power down with a stock car, and you'd probably have to switch to a Ford rear end same as me in the end. Keep 'em coming though!
Full Member
Joined: Apr 2003
Posts: 74
Likes: 0
From: Lubbock
85 302,
That is some Bling Bling Pinky Ring on the engine compartment..... Kudo's.
My RX7-306 weight is 2600lbs... 55/45, and make 375 crank hp. I have tracked the car and it is no rx7, but it is something special, that is for sure.
A father will love his child even if they need a heart transplant.... you love your rx, I'll love mine.
That is some Bling Bling Pinky Ring on the engine compartment..... Kudo's.
My RX7-306 weight is 2600lbs... 55/45, and make 375 crank hp. I have tracked the car and it is no rx7, but it is something special, that is for sure.
A father will love his child even if they need a heart transplant.... you love your rx, I'll love mine.
Senior Member
Joined: Sep 2002
Posts: 686
Likes: 0
From: Central New York
I love rotaries.
I'm a student.
Rotary sounds great to me.
And quite reliable with ok gas mileage.
*sigh* I wish everyone would stop saying rotaries are not as reliable.
The only thing I'll grant the V8 fans in this argument is that it's cheaper to get more horsepower.
[/enigma's posts in this thread]
I'm a student.
Rotary sounds great to me.
And quite reliable with ok gas mileage.
*sigh* I wish everyone would stop saying rotaries are not as reliable.
The only thing I'll grant the V8 fans in this argument is that it's cheaper to get more horsepower.
[/enigma's posts in this thread]
U sUx0rz @ THe IntaRwEB!
Joined: Feb 2001
Posts: 327
Likes: 0
From: Claysburg, PA, USA
Originally posted by FuLLsMoKe
Use cheaper gas? Rotaries like lower octane gas...
Use cheaper gas? Rotaries like lower octane gas...
--Danny
Senior Member
Joined: Apr 2003
Posts: 479
Likes: 0
From: SC
I should remove the cheaper gas argument. I thought about it and I certainly wouldn't run 87 octain gas on a 150 shot motor. So compairing it to the "10 second Rotory" they would both probably benifit from the highest octain available. So scratch that idea.
But a 300hp V8 easily survives on 87 octain where a 300hp rotory certainly would not. But you're right on the low octain stuff on near stock motors. The 12a's we race run great on 87 and love every minute of it.
As for gas millage I don't know. Right now I'm getting very crappy millage but I'm running extreamly rich on stock Holley jets. But I figure it's possibly to get low 20's city, high 20's highway when it's tuned correctly and it'll make about 300hp. From what I've seen, rotory motors don't put down 300hp without some serious fuel consuption. But neither will get the gas millage as my Honda. That's about the only thing that car had going for it.
But a 300hp V8 easily survives on 87 octain where a 300hp rotory certainly would not. But you're right on the low octain stuff on near stock motors. The 12a's we race run great on 87 and love every minute of it.
As for gas millage I don't know. Right now I'm getting very crappy millage but I'm running extreamly rich on stock Holley jets. But I figure it's possibly to get low 20's city, high 20's highway when it's tuned correctly and it'll make about 300hp. From what I've seen, rotory motors don't put down 300hp without some serious fuel consuption. But neither will get the gas millage as my Honda. That's about the only thing that car had going for it.
Senior Member
Joined: Apr 2003
Posts: 479
Likes: 0
From: SC
I should remove the cheaper gas argument. I thought about it and I certainly wouldn't run 87 octain gas on a 150 shot motor. So compairing it to the "10 second Rotory" they would both probably benifit from the highest octain available. So scratch that idea in the context I previously had presented it. It's not a good argument how I just used it.
But a 300hp V8 can easily survive on 87 octain where a 300hp rotory certainly would not. But you're right on the low octain stuff on near stock motors. The 12a's we race run great on 87 and love every minute of it.
As for gas millage I don't know. Right now I'm getting very crappy millage but I'm running extreamly rich on stock Holley jets. But I figure it's possibly to get low 20's city, high 20's highway when it's tuned correctly and it'll make about 300hp. From what I've seen, rotory motors don't put down 300hp without some serious fuel consuption. But neither will get the gas millage as my Honda. That's about the only thing that car had going for it.
As for handling I can't comment on track usage. Unlike Chris I've never taken my RX-7 out for a lapping day, but I have autoX'd it before and after the motor swap and I noticed only minor differences. It'll still brake oversteer like an SOB, only now it'll power oversteer as well. I have noticed the extra weight a little bit, but it's easily made up for by the increased acceleration. It still feels pretty nice IMO and the V8 definatly hasn't "ruined" the handling at all. I'll let you know how it does at our next race on the 9th now that the motor is all broken in and the car is running at least smooth at WOT.
But a 300hp V8 can easily survive on 87 octain where a 300hp rotory certainly would not. But you're right on the low octain stuff on near stock motors. The 12a's we race run great on 87 and love every minute of it.
As for gas millage I don't know. Right now I'm getting very crappy millage but I'm running extreamly rich on stock Holley jets. But I figure it's possibly to get low 20's city, high 20's highway when it's tuned correctly and it'll make about 300hp. From what I've seen, rotory motors don't put down 300hp without some serious fuel consuption. But neither will get the gas millage as my Honda. That's about the only thing that car had going for it.
As for handling I can't comment on track usage. Unlike Chris I've never taken my RX-7 out for a lapping day, but I have autoX'd it before and after the motor swap and I noticed only minor differences. It'll still brake oversteer like an SOB, only now it'll power oversteer as well. I have noticed the extra weight a little bit, but it's easily made up for by the increased acceleration. It still feels pretty nice IMO and the V8 definatly hasn't "ruined" the handling at all. I'll let you know how it does at our next race on the 9th now that the motor is all broken in and the car is running at least smooth at WOT.
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