KinetikRX

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 ***** who will take pleasure in leaving heavy old mustangs behind with one of their own weapons



Rather evil, dont you think

Turbo III

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

13BAce

It would probably be really weird to hear an RX-7 that sounded like a mustang. I'd definitely do a double take.

dac

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.







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

KinetikRX

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





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-

dac

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.

Twin89Stangs

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.

dac

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.... $$$$$

Twin89Stangs

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



Any weight saved is a help!

loyalrx7nut

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