FC~N~Flyin

Hey everyone I just registered on here, this place is pretty awesome can't believe how many RX7 owners are here. Anyways my problem is simple. I had recently bought a 1989 Mazda RX7 (convertable) that has absoutly no engine in it. Im about to turn 18 (this Saturday actually) so yeah I am still young and ignorant when it comes to certain things, except for when it comes to a wankel engine. I know everything about them, even the history of them (I wrote an essay on Felix once in the 10th grade) thanks to my brother Carl, who happens also to be a member on here (articj57) but anyways yeah were both pretty much rotorheads, all together him myself, and his girlfriend all have 2nd gen RX7's its pretty great lol. Anyways I can talk about that some other time back to my topic Im only 18 and are low on funds so I was thinking of instead putting a 13b back inside Id go with something more unique and inexpensive, such as a V8. Now I know it seems kinda harsh for my first car (even though its not I have previously owned a Mitsubishi Starion Turbo and an Oldsmobile Caprice Classic haha) but Ive been reading up on this stuff and it looks pretty awesome. As much as I would like to put a turbo charged wankel under the hood theres no way I could afford such a thing right now. I see V8's in the paper here all the time, mainly the Chevy 350 which is what I would most likely do for since there pretty cheap and they do run(cheap as in 400-500 dollars) and would be easier to get since its local rather than trying to get a turbo II engine off ebay and would have to worry about finding a way to ship the motor (which wouldnt be cheap...). Anyways Ive typed a shitload of nonesence, I apolligise so anyways what do you fellow 2nd Gen RX7 owners suggest? Just want to get some ideas before I stick with one path. Thanks for your time and have a good evening.

-FC~N~Flyin

604Ryder

most people on this site would tell u to stay away from V8's and i would have to agree .... u can buy used engines now for as low as a few hundred ... i heard verts arent the best to mod though

digitalsolo

iTrader: (2)

http://www.torquecentral.com

Come check us out there. We're not welcome here, even if it is an innocent question like this. It'll be moved to "Other Engine Conversions"

If you have questions, feel free to hit me up on AIM (digitalsolo), PM, or email (webmonger@terminalfear.com).

chris_stampe

What do you want the car to do?

TurboIIRyan

go straight - Chevy LS1 V8
Turn - Chevy LS1 V8
Sound nice - Chevy LS1 V8
Have torque - Chevy LS1 V8

see a trend here

Impreza2RX7

Nope, I dont see a trend, turbo rotaries seem to do it better.

TurboIIRyan

In your opinion yes, in mine not so.

Impreza2RX7

I havent raced a V8 7 yet, but every V8 powered car I've raced, I've killed except a V8 914. I was on its bumper after he launched, and I didnt launch and I overrevved 2nd.. V8s are overrated..

RotaryResurrection

iTrader: (8)

correct...



You gotta be kidding me. I've driven converted cars. Side by side with equivalent suspension/tires, the rotary engined car will eat the v8 car in the turn. IT will still turn, and probably still better than most cars...but it is not as confidence inspring with the big v8 under the hood.

And for you BS'ers sitting here chomping at the bit to tell us that the v8 conversion only adds 50-100lb or less to the car, you're full of ****. You can strip other parts out of the car to make up the difference and end up with a car that weighs about the same, but it won't handle or feel the same.

Stock for stock, the v8 with it's transmission will outweigh the rotary with it's transmission by 100+lb. Most guys use iron block and not all use aluminum heads, and those suckers are heavy. I can pick up a rotary block with my bare hands, walk 20 feet across the shop and sit it into the bed of my truck if I need to. Bet you cant do that with a v8.


Subjective. There are some sweet sounding SBC's out there, but it just seems odd to hear the note from the *** end of an import car. There are enough s-10s, camaros, silverados, and monte carlos in the world to overcome the need to make imports sound the same way.


Valid point, but torque is often overrated. Set up a race between a car with 500hp and 250ftlb torque, and a car with 250hp and 500ftlb torque, and see what happens

Crash Test Joey

iTrader: (1)

He specifically referred to an LS1. The block and heads are aluminum, not iron. To my knowledge, nobody has upgraded to the iron 6.0L block in an RX7 yet. You're arguing an invalid point. Sure, my all iron 4 bolt Chevy weighs more than a rotary. Absolutely. But it's been proven (more than once) with 4-corner scales that an LS1/T56 swap does not add 100 lbs to the car. If you don't relocate the battery, the weight distribution is about 53/47. If you put it in the rear, you're at 51/49. And saying a rotary powered car can move the battery isn't a valid argument either, because then you'd move your weight bias to the rear by 2 points. You wouldn't want to do anything crazy like now, right? That'd be like... oh, I don't know.. filling the gas tank?

If you can pick up a rotary engine, the turbo, the piping and the intercooler (and anything else that gets removed to do an LS1 swap) and carry them 20 feet across your shop all at once and put them in the bed of your truck I will give you my FD. Better yet, since about 85% of the LS1 swaps are into FD's, pick up BOTH turbos and their associated equipment along with that rotary.


I do agree with your comments on the exhaust note, to an extent. I don't think LS1's are the best sounding engines. They sound a bit 'raspy' or 'tinny' or something, can't really put the right word to it. But honestly, think about how many 'ricers' are driving down the street in the import of their choice with 6" mufflers, no mufflers or unnecessary dual exhaust - all of which sound like total ****. I'd much rather have the exhaust note of a V8 of any type than anything that sounds like an unmuffled 1.3 liter lawn mower.

My personal favorite will always be the FI Ford 302 with 3 chamber Flowmasters. There's a reason it's so popular. 2nd I would have to say the TPI Chevy 350 cars, with Flowmaster or Dynomax muffler. 3rd, a carbed Chevy 350 with dual 2 chamber Flowmasters with headers and an h-pipe. I've owned all 3 of these combinations and they were sweet. None of them will be as fuel efficient as the LS1 though, so that's what's going in my FD

Crash Test Joey

iTrader: (1)

If you're referring to drag racing, you don't need to race one. Just compare timeslips. My untuned, all-iron 'test-fit' motor in my car runs 12.51 @ 107 mph with a 1.7 60' time. Most of the V8 cars of any type that I have driven or raced are well into the 10-11 second range. What does your car run?

When I was at the track Friday night, I saw three 2nd gen RX7's. Two of them were able to run in the 14 second range, and the one with the primer paint job and the really big wing ran a few astounding 17 second passes.

For once I wish the people arguing against using piston powered engines would present a VALID argument.

onikageka

I'm not trying to add fuel to this fire, but I do want to make a point about the cornering potential of a V8 RX7 vs a rotary RX7 with the same power. The addtional weight from the swap is academic, a properly setup suspension can easly make a 2900lb car handle as well as a 2800lb car. And from all the research I've done on my project, 100lbs is the most that is added to the car and can easiely be removed from other areas of the car.

The chief advantage of the V8 in cornering is the broad powerband the V8 offers. Here's an example..

RX7 approaches a corner, brakes late, and downshifts...
Just after corner entry and car is off the brakes and now on the gas...
<<<The V8 RX7 has more availible power at lower engine speeds, and therefore can accelerate easier when cornering. The rotaty engine, if it falls below whatever RPM is required to spool the turbochargers, will not have as much ability to accelerate out of the corner. >>>

If you look at the dyno charts of 13B-REW engines (stock) vs LS1 engines (stock) it's clear to see that the rotary only makes it's power at the very end of the powerband. The LS1 has a much broader curve. These characteristics are amplified when you increase the power. The rotary engine becomes even more peaky and the dyno curve starts to look more like a spike. The LS1 retains it's broad power and torque lines.

Stock for stock, the V8 will have better cornering attributes by virtue of it's powerband. As power increases, the rotary engine really does start to suffer from it's lack of low end power. In the example, the V8 RX7 will start to accelerate at the apex of the corner, like the rotary. The difference is when the power is communicated to the ground. The V8 has instant tractable power. The rotary will either have a quick spike of power at it's peak, or suffer from turbo lag and have to wait until it can get power.

And on a side note about torque...

Torque is horsepower. Do a search and lookup the formula. Horsepower = (Torque x RPM) / 5252. A 180hp 140torque car will be faster than a 140hp 180torque car. But a 180hp 180torque car will be faster than both. Assuming all 3 cars are the same drivetrain and weight.

Whizbang

The LT1 is an affordable alternative w/ a T56. Gotta have a 6spd!

Whizbang

oh i have an idea! Lets do this.


get a dead t2 --> say 700-------------------------get a running t2 w/ hi miles -->2000
get a LT1 w/ a T56 (40k) --> 2900--------------have to get a rebuild motor-->1000+
the swap kit (easiest) -->1800--------------------mods everywhere --->2000+

done with around 325HP and 330ft/lb------------done with 230Hp or more (pending $)
52/48 weight ratio--------------------------------50/50 weight ratio

N/A!!!!!!--------------------------------------------Turbo to get power!!!!!!!


Now for the fun part.....lets add force induction to V8 option to be more equal!

Chevy 305
Weigand T-81 s/c
Roller setup
turobmatic 400 trans
2 grand stall converter
Ford 8.8 rear end


done at 600+ HP and 700+ torque
revs to 8000

52/48 weight ratio
can be balanced.



Get it?

FC~N~Flyin

Hey guys thanks for the comments Im most likely going to stick with a V8 conversion but only for this one, later on Im planning on purchasing a 91 RX7 TII and trick it out, but not for awhile. Thanks for everyones replies.

oztofrdm

Trust me if you were in NC you would be handing those keys over to me


If you can pick up a rotary engine, the turbo, the piping and the intercooler (and anything else that gets removed to do an LS1 swap) and carry them 20 feet across your shop all at once and put them in the bed of your truck I will give you my FD. Better yet, since about 85% of the LS1 swaps are into FD's, pick up BOTH turbos and their associated equipment along with that rotary.

digitalsolo

iTrader: (2)

****, I've got an old technology FWD pushrod V6 I'll race you anytime. I'm about a 12.7 in street trim, don't know my race trim yet. What's your 7 run?

My 7 should push low 12s before it's sorted, and mid/low 11's once it's done. 1500-2000 above that will put me in the 10s. When the suspension is finished, along with the widebody, I am quite confident higher then 1g skidpads are very possible.

If you wanna argue the merits of the rotary, try actually arguing the MERITS, the engine does have some. Quit making **** up.

Thanks for playing.

edit:

On the same note, Kevin, if you can carry a rotary across the shop, you can likely be pretty close to carrying an LS1 block across it as well.

Crash Test Joey

iTrader: (1)

An assembled LS1 weighs 390 lbs. I'm sorry, how much does a rotary, turbos, intercooler, piping, coils, etc. weigh again? Also need to include all the other miscellaneous crap that gets removed when the rotary comes out. What? About the same? Yea, thought so.

Crash Test Joey

iTrader: (1)

Doubtful. Besides, it's got LS1 parts on order for it, so you wouldn't want it anyway.

oztofrdm

i have never put one on a scale but i know that i could use the one in my bathroom.

1.3L 5.7L give or take
Light, Small, fuel efficent = Heavy, Enormous, Shitty MPG =

GOOD BAD


GO 20B if you really want a Bigger motor.
My 2cents should be everyones 2cents
Naadog, what ever makes you happy, even though its the wrong decision

Whizbang

Too bad your two cents are like Canadian coins....

found everywhere and no one wants them

onikageka

Oztofrdm - I hate to point this out but you're a moron. You whine about the LS1 being heavy then say to "GO 20B if you really want a Bigger motor". The 20B weights a hell of a lot more than a 13B. And the LS1 has been proven over and over to only add 50 lbs of weight at most.

And about MPG... A stock 400hp Z06 can get over 26mpg on the highway. Show me a stock RX7 that can do the same.

Crash Test Joey

iTrader: (1)

Go try that bathroom scale and tell us how it goes.

I don't hate to point out that you're a moron. But I am thankful you won't be doing any V8 swaps. I'd rather not have anything that substantial in common with you. And you can have your two cents back. I don't want to know where it's been.

TurboIIRyan

1.3L fuel efficient eh? since when? Good luck trying to get 28-32mpg out of one. Because thats what teh average LS1 driver gets on teh freeway. Heavy? Nope, approximately the same weight as a 13 with accessories. Enormous? Fits perfectly into a FC engine bay.


I think you are out of arguements. Get your head out of your *** and actually try researching what you are argueing agaisnt.

btw

FC~N~Flyin

Wow I open a poll and all these arguments come up. Well I guess it was inevitable o well.. o and whoever it was talking about carrying a 13b block across whatever feet there full of ****. Me and my brother alone cant even do it and were not all that weak, well I have seen him carry one about 5 feet but he wasnt walking I'll tell you that. Weve rebuilt 4 of those motors in our house and almost everytime we had to slide it on wooden blocks across the floor to get it to the door and then came the stairs going out to the garage, that was a blast Was worth the effort everytime though. Anyways I dont want this topic getting out of hand so any moderators out there who feel the need to close this, go right ahead.