After all the trouble I have had trying to get this damn thing working, to no avail, I have decided to put in a 5.0 from a donated lincoln into my RX7. The money it would cost to make the rotary viable again versus the money it would take to just drop in a 302 just seemed to make sense. say I spend about $1000nto rebuild the RX I would still be left with, what, a 150HP car. As opposed to spending about 6 or 7 hundred to have an over 300HP beast, with torque I might add. It saddens me in a way though because I really liked the idea of a rotary, but sometimes common sense and practicality have to take over. What I figure i'll end up with is a really fast and fun car that handles well. I just wonder what the rest of the forum thinks about this decision. Will I be an outcast, will I be herealded for my ingenuity? I will however be one fast Mo-Fo who will take pleasure in leaving heavy old mustangs behind with one of their own weapons



Rather evil, dont you think https://www.nopistons.com/forums/pub...IR#>/devil.gif

Yes you'll be an outcast, but you'll be one without spending anywhere near the money it would take to have some real torque although it'll sound really funny https://www.nopistons.com/forums/pub...IR#>/smile.png

It would probably be really weird to hear an RX-7 that sounded like a mustang. I'd definitely do a double take.https://www.nopistons.com/forums/pub...#>/biggrin.png

A stock 5.0 EFI has 225/215 HP. It costs for HP. Your gonna put a couple hundred pounds on your front end. It will never handle as it did with the Rotary motor, besides the Torque from the V8 is a killer. Torque break things... HP moves things.



https://www.nopistons.com/forums/pub...IR#>/smile.png



I think $1000 would be better spent on a Turbo motor, or even a N/A motor and NOS. But why be normal.

Actually Torque is what makes horsepower= look up the formula for calculating HP.

http://www.tpub.com/machines/1.htm123.gif



Simply;







Torque * RPM

Horsepower = ------------

5252





Here's why I say 300+ HP- I will be installing a new performance Cam, crank and forged pistons, larger ported cylinder heads with larger than stock valves, headers, freer flowing exhaust, K&n filter, 650CFM double pumper Holley carb, performer RPM intake manifold- and after a little time Nitrous-

Torque is twist or force... which is what breaks things when abused. Horsepower is what moves things. Kinda like water pressure and flow. Can't have one without the other, but too much pressure is not a good thing.



Don't get me wrong I think it's great to swap motors.



But I don't think you will be happy with this swap.

If he switches to aluminum heads it will drop a fair amount of weight even switching to an aftermarket upper and lower intake will drop weight. Go with a slightly stiffer spring and use aluminum not IRON heads. That will help. Also I would recommend the B303 cam for the Roller 302 motor. I believe that motor is 190-200hp since it is not a Mustang HO 302. But if you got the new aluminum heads and intake with a cam you would be hauling! Also go with 1.7 roller rockers or 1.6 if you want to play it safe for a bit more power. Also switch to a 65mm throttle body and convert to a MASS AIR system instead of the speed density system your car is most likely equipped with unless your going to put a carb on it then forget about all of that stuff! I am thinking in an RX7 you will probably want more top end power out of that V8 and sacrifice a bit of lowe end torque for top end power since the RX7 is a light car. Also it make the car scream up on the topend. So pick a combo that favors mid to high RPM power. I am thinking a stock steup or a setup that favors low end power will make it a pita to get off the line without completely smoking them. I mean I floor it in first in my GT and it is nothing but smoke until 2nd gear then it is nice scratches....

Also the 225hp rating is for the 87-93 H.O engines. In 94-95 ford dropped the rating to 215hp. Saying the new way of checking an engines horsepower is more efficent. Though in dyno tests 87-93 H.O engines turn the same dyno #'s as 94-95 motors.

A 302 is 450 or so pounds, Swapping heads may save 50 lbs. It's still much more weight and torque than any Rotary. Alumnum heads aren't cheap $1000, 1.7 rockers... $250... Cam $130... 65MM TB.... $$$$$

Well yeah.... but if your going to do it do it right from the start!



Any weight saved is a help!

I know its a sacrileage to v-8 an rx7,but maybe if the circumstances were right,it might be a good idea.It is impossible to beat a rotary for smoothness,ease and lack of maintinence,reliability,no oil leaks(no vavle cover gaskets),light weight,low ctr of gravity,etc.On the other hand,EMMISSIONS is the single thing that bothers me the most.Unless you can afford a stand alone,programmable engine management system(I cant)the emmissions laws are going to slowly shut rotaries out.It happens a little more everyday.I live in a area where there was no testing 15 years ago.Then,our state capital got countywide testing and things changed.5 years ago,ALL counties surrounding that county got testing becuase the air pollution didnt meet specific goals.Last year the standard was met so you think the feds were happy?WRONG!They decided(without any kind of vote I might add)to severely lower the requirements.The testing stations had to buy newer equipment which raised the testing fee,people are trading off older cars(good for the local economy,more taxes,more fees,etc).I thought I would put in my two cents...Doug

Thats news to me I always thought that rotarys are high maintinence, and not as reliable. Oh well. I say if you want to do the swap then do it. It is your car, do what you want. Who gives a **** about what other people think. So what it won't be rotary powered. It'll still be a rx7 body, people will still call your car a rx7, right? I'd go for it! https://www.nopistons.com/forums/pub...#>/BURNOUT.gif

Whoa whoa whoa....

as far as smoothness you need to get into some of these new DOHC engines.... even Ford's 4.6 DOHC cobra V8 is a very quick very smooth revving motor. As far as oil leaks I have seen some spots under my buddys RX7 which he is selling due to too many problems. It was still a fun car but it had its share of problems. granted my GT leaks a bit of oil but it sat for about 2-3 months before I bought it and it only needs a new valve cover gasket. I love Rotary engines... they have their problem but all motors do.

the last 4.6 Cobra I drove was way ahead in refinement compared to the last RX7 I drove and the cobra would smoke the RX7 I last drove but the RX7 was more fun to drive.

Its like my 2.3 Mustang compared to my 5.0 GT mustang.

The 2.3 is loud rough unrefined buzzy but due to the cars better weight balance it is a lot more fun to drive! It will actually out corner my GT and it doesnt even have a rear sway bar compared to the rather hefty and beefy suspension on my GT.

If you can find an all aluminum V8 even if it is under 5.0 liters it may be better. Less weight still have a V8 sound but less weight. I am still thinking this would be a good swap and if I had a motor laying around I would have bought my buddies RX7 it needed a transmisson and a whole new motor... it had dual exhaust and I think it was an 87 Model.....

You might have a good point about an all aluminum v-8 being a good canidate for the swap.I drove desmogged 12A modified carb(NIKKI)engines and have virtually no maintinence except oil and spark plugs.I will admit to being out of the loop concering some of these modern piston engines so feel free to enlighten me.A person who doesnt learn something everyday isnt doing anything(loooke att meee maaaww I ma tiepeen) HAPPY NEW YEAR Doug

Yeah my 2.3 and 5.0 have only needed basic tuneups since I have owned them.... a valve cover gasket is not a big deal about 20min worth of work and it simpley dried out... so no big deal there....

Hi Kinetikrx, Hey it's allright , we don't think you're crazy - not! :p . I haven't heard of a V8 powered Rx7 in Australia, not to say there isn't one, but a craze from a few years back was the V8 swaps into Rx4's. Most were of the 302 variety, but in my part of the world, high horsepower V8's are not cheap to build. I think mainly because most of the good bits come from the US and our shite dollar!! These cars were still quite quick.Hey if it's cheaper/easier go for it. I've done a few radical engine swaps for customers over the years. Dare to be different. https://www.nopistons.com/forums/pub...#>/biggrin.png

Here Wooffinn..........

V8 conversion

Thats too bad- it wont be cheap once I do everything I want to- but it will be cheaper than upgrading a rotary for close to or even more power. No turbo, no weird porting- simple v8 power

For around 1000 dollars or so I could completely rebuild a stock 302 EFI H.O and get it up to around 300+ hp