fc_newb

so im very new to the 7 realm of things, how ever being a prevous honda junky and nissan junky and having swaped cars. im wondering besides the turbo 2 swap for a n/a fc what other swaps are out there for the rx7's besided the v8 swaps, can you drop like the miata engine and boost it? or what not...

my sencond question is it safe to boost a n/a rotor engine?

Aaron Cake

iTrader: (1)

You can swap any engine into any vehicle with know-how and a welder. What you can do is simply limited by the knowledge you have, the tools which are available and how much time/money you want to throw into the project.

As far as turbocharging the NA engine, see the FAQ sticky at the top of this forum.

fc_newb

i know the thing about any engine can go in to anything... but im talking about simple kinda stuff... like other factory engine that are a direct drop in like the b series engines in a civic/del sol/ integra chassis.. or even just having to buy mounts, like the h,k, and f swaps for civics etc..


edit:
i did take the time to read what i coul find on the topic of boosting a na 13b. but i didnt find something that now ponders my mind.. is the compression and timing differnt on a n/a than a tII applicant? sense being differnt amount of compression, difernt amount of fuel, and such. and how long will it last? (even taking care of them like a hawk), would i have to buy new gaskets?

goose415

what would i have to cchange to drop an s5 TII into a N/A s4? i found an engine and it has the harness and ecu and it comes with a tranny and clutch w/ flywheel... are the engine mounts the same...ish

sadrmmr04

iTrader: (1)

physically the motors are basically identical so mounting is not a problem, the problem comes from wiring differences. for an S4 you are better off with an S4 motor and vice versa for the S5. read up in the FAQ for more info. rotary resurrection has a good tech section for this question as well

goose415

how hard is it

Aaron Cake

iTrader: (1)

These cars are not economy cars like many Hondas which have many shared parts to save money. Each series RX-7 has a different mounting arrangement for the engine and transmission. While they are not direct bolt in, it is usually simple to adapt one to another. As long as you stay within your series, then all engines swap directly in. For example, you can bolt the TII engine into the NA, or the 13B from a 1st gen into a 12A 1st gen. There are differences in flywheel and clutch, so generally you need to match the flywheel and clutch assembly to the transmission.

Note that I am only talking about physically bolting the engine into the chassis. Making it run means using the appropriate harness and ECU that goes with that engine. Or a full standalone.

There aren't any other engines that direct swap into the RX-7.

I'm sorry, but what do you mean by gaskets? Buying new gaskets is a fundamental part of working on cars. Anytime something sealed with a gasket is removed, the gasket should be replaced to avoid leaks.

Yes, the compression is different NA vs. turbo. NAs are either 9.4 or 9.7 depending on year, and TIIs are all 8.4. Realistically, the NA vs. TII engines are two totally different engines and share only a few common parts.

Not knowing what apex seals were (from one of your replies to another thread), I don't suggest you take on a turbo-NA project.

All the mounts are the same. But the electronics on S5 are totally different then S4. Install an S4 TII engine and you will be much better off.

fc_newb

First, No Honda i have own has ever been an "economy" car for me.. all of them have got some where under 20 mpg... ive had a descent amount.. from fully built GSR(b18c1) in a 92 civic si hatchback, 1997 Honda prelude with j spec engine with fully built head, 93 h22a civic hatch. m2 lsd tranny, i/h/e, hondata s200, and a 93 del sol with a h22a as well i/h/e, fully chipped/socket-ed and tuned, brembo brakes, arp studs, arp wheel studs and more. even the 240 i had was ca18det swapped with a Silvia k front end on it. ive built over 85 % of these cars.. im sorry i dont know every end and out about a rotary engine... ive never had one, thats why i got on this forum to expand my knowledge and so i can tastefully mod, and take care of such a beautiful car. this is a WHOLE NEW world for me. so dont ridicule me, and say i should do something because i didnt know what an apex seal was. you should never underestimate some one because they dont know every end and out. i built a full gsr car, ran 12.6 on street radial all motor. n i bearly new what a compression ring and didnt even know to stagger the rings them self. sorry if this come off extremely defensive but i dont like being told what i cant do.


When i talk about gasket, im talking about what i guess would normally be called a head gasket, but from my understanding there 4(?) on a s4 engine. if you where just to boost a N/A engine, making a 9.4/9.7 compression with we'll say 10 psi, would you have to change them to a turboII gasket or if there where to be any aftermarket metal gasket.

Also would it be to much of a nightmare to convert the s4 harness for the s5 turboII engine. or would it be easier just to get the s5 engine harness?

goose415

well the enginei found comes with an ECU, harness, tranny, clutch and flywheel

Aaron Cake

iTrader: (1)

All of that is "blah blah blah" to me. I know little of Hondas outside of my 2000 Insight but what I do know is that many Hondas share common parts and mounts, making all of these swaps very easy.


You are not getting ridicule from me, you are getting very valuable advice that comes from over 10 years of playing rotary.

What you will get from me is gentle ribbing and sarcasm when you ask a question that is well covered in the FAQs, which you have.

At the moment, you can't turbocharge an NA rotary. When you read up, do some basic research (I mean, you couldn't just Google "mazda rotary compression ratio"?) you will be far better equipped to ask questions and take on the project.

There is no head gasket, and nothing in the rotary that is an equivalent. If you combined the apex and side seals with the water jacket o-rings, you would have what is functionally a head gasket.

Basic rotary: http://auto.howstuffworks.com/rotary-engine.htm
Here's a really nice animation and breakdown: http://www.youtube.com/watch?v=6BCgl2uumlI
Here is a page showing one of my turbo-NA engine builds. It covers the basics of building any rotary and will make how the engine is assembled and sealed very clear so that you don't ask questions like the one I quoted below:
http://www.aaroncake.net/rx-7/projec...aug42004-1.htm

I don't know how to answer this, because it doesn't make any sense.

Mazda changed all the wiring harnesses from S4 to S5. The S4 body harness won't plug into the S5 harnesses and vice versa. The plugs would have to be rewired, which just is not worth the trouble.


See above.

aka_rocket

i just want to say it once....do a search. there, i said it. that being said, aaron cake is almost a god here in terms of the wealth of knowledge and experience he has with the rotary. heed his words. they will make life with a rotary a lot easier. have fun. its nothing compared to a honda.

fc_newb

im not going to heed anyones word. i dont even heed my mother or fathers words of wisdom. ive come out just fine to this point.. maybe a little short fused, but pretty unaverage guy whos happy with whats hes got..


and aaron, when i was talking about "head gaskets" i had in mind that there are atually casket( layed out like a head gasket) that goes around the rotor houseing. to seperate the collent jackets from each other and from the compustion/intake/exhaust areas.

When boosting a/ well any piston style engine that is NA or is factory boosted, and upinthe pressure you would replace the factory paper/cork gasket with metal. again not knowing that there is orings instead.

and you could of just said you cant boost a n/a engine.. due to complications of differnt intereal parts.

im not 5 and i have many years of schooling behind my belt, im not a complete idiot when it comes to cars, and trucks.

and before i posted this post i did try searching, i even searched threw this forum. via the search section.

and when you say rewired, if there is plugs couldnt they just be repin'd to fit the right harness, with out changing or splicing the harness.

Aaron Cake

iTrader: (1)

I'm not going to dwell on this, but in your profile under "Occupation" it says "milking the goverment for now". Tomorrow I'm officially old at 30, so I can now rib the kids a little. Don't ignore all of your parents advice, because later in life you will learn how valuable it really is. The key is knowing when to take their advice and when to say "Screw off, I need to make my own mistakes, you did!".

Not true though. The NA engine can be turbocharged, it is just not recommended that someone who doesn't know what an apex seal is attempt the process.

The internal parts of the NA engine are almost exactly the same as the TII engine, with only compression ratio being different. The rotor seals, coolant o-rings and all related springs and bearings, e-shaft, etc. are all the same.

But look at the NA engine compared to the TII engine:

NA:


TII:


They are, for all intends and purposes, completely different.

How odd, because turbocharging the NA is the most commonly asked question on this forum and there are literally tens of thousands of posts referring to it.

In the FAQ, you will also see this section:

How do I add a turbo to my NA 13B?
What Turbo kits can I add onto my non turbo RX-7?
There are no longer kits formally made at the time of this post, however there are companies from time to time that do make available non turbo to Turbo Kits. Because most of these companies stop building the kits, or go out of business in short time, it is impossible to keep active links for them.

Most people that turbo a non turbo make their own kits:
Using the stock TII turbo, exhaust manifold with spacer, NA intakes and NA ECU:
http://www.aaroncake.net/rx-7/naturbo.htm
https://www.rx7club.com/forum/showth...threadid=88540

https://www.rx7club.com/forum/showth...threadid=88758
https://www.rx7club.com/forum/showth...hreadid=124232
http://users2.ev1.net/~ccoutts/turbo..._a_project.htm

Using the stock TII turbo, exhaust manifold, intakes, ECU:
http://forum.teamfc3s.org/showthread.php?t=37694

Turbo-NA Forum:
http://www.aaroncake.net/forum/forum...urbocharged+NA


The aaroncake.net writeup is sort of the prototype installation for my turbo NA project, Project Tina:
http://www.aaroncake.net/rx-7/projecttina

The Project Tina writeup goes to the extreme, but contains an enormous amount of information on one way of turbocharging the NA engine. To be honest, my way is the hard way because I enjoy fabrication and wanted to make my stuff 100% custom. A far easier way is the method shown in the link below, also from the FAQ:
http://forum.teamfc3s.org/showthread.php?t=37694

That method shows the TII lower intake ported to match the 6 port NA block, which then allows all other TII components to be bolted in place making a "6 port TII".

Regardless of the approach taken, for more then about 250HP, you are into standalone EMS territory so don't really bother much with the stock electronics.


The plugs don't match so you would need to swap the physical harness connection. It is generally just not worth the trouble. Stay within your series and you don't have this issue. Another easier way is to just use the S5 block and swap on the S4 manifolds and electronics. Or go to a full standalone.

fc_newb

i did find that but if i recall correctly it doesnt say anything about i cant. this is why im so confused and having trouble asking the right question, in turns make me seem like a jackass/ just some punk, when its not like that.. im trying to build a legit car. and not be some punk kid with a rx7.

i dont have the money for a full stand alone... so would this set up work... if i found a plain s5 turbo 2 engine, put the stock s4 na manifold on it, and found a s4 turbo ecu? while keeping the s5 exhaust housing and turbo.. with standerd front mount intercooler?

rnz520

iTrader: (10)

I am gonna try and make your life a little easier.
If you were to find a bare S5 Turbo 2 block, you would not be able to use the S4 na Intake manifold because it would hit the turbo. On the other hand, you use a S4 Turbo 2 Intake mani, which people here literally almost give away for free, with S4 electronics and injectors and yes you would be able to run that on a T2 computer.
Now word of advice on that is that for going through all the trouble of putting all that S4 stuff on an S5 engine you would not gain any power than if you just put in a S4 Turbo 2 engine, which is cheaper and would save you work.
The simple truth behind that is that the extra 14 hp that come on the S5 engine is due to higher boost and a better ecu, which controls boost, which you wont have.
So if you insist on using a S5 motor go ahead and do that, but if I were you just stick to your series, then when you are ready to make more power, and let me warn you that making power on these is god awful expensive, mainly due to the fuel sytem and huge turbo, buy standalone.
The difference from the stock 1985 Mazda electronics to say a Haltech E6K which you can buy for 600 bucks here ready to go used or not much more new, is unbelievable .
Good luck, if you have any more questions and are afraid to get flamed maybe you can shoot me a pm that way you wont waste bandwith and then people wont waste bandwith flaming you. I'll answer to the best that I can

Aaron Cake

iTrader: (1)

Um, what? I can't make heads or tails of this, because you seem to be very confused. Kill the turbo plans for now and just spend a few weeks reading this forum so that you can acquire the base knowledge necessary.

If I am reading your question right (which I don't know I am), you want to:

1. Get an S5 TII engine (OK)
2. Put an S4 NA intake manifold on it (Why?!)
3. Run it with an S4 turbo ECU (No problem)
4. Use the S5 TII exhaust manifold and turbo (Won't fit with the S4 NA intake)

This plan makes very little sense. You are mixing and matching parts for no good reason, and the parts you have specified don't even fit together. Have you really read the links I provided, because they cover this issue specifically (why the exhaust spacer was used on my original turbo-NA setup).

As the post above this one indicates, there is a simple solution to all this. Buy a complete S4 engine, ECU, emissions (EFI harness), AFM, pressure sensor and all the other parts listed in the TII swap are of the FAQ. Then either use the S4 NA transmission by swapping the NA flywheel onto the TII engine, or use the stronger TII transmission by either using a custom driveshaft to connect to the NA rear end or swap the rest of the drivetrain to TII stuff. Again, this is perfectly documented in the FAQ links with step by step instructions:

2nd gens don't have a front mounted intercooler.

If you are going to run past the capabilities of the stock turbo (about 250HP) then a standalone is the only reasonable option for a car that runs well and will be reliable.