DriftingRX7FC

Hello,

I bought '87 rx7 with engine that had broken apex seal. Seller gave me another engine to go in. Once I took the engine out and started to compare them side by side i figure out that there are few minor differences. Later I found out that the engine he gave me was actually out of '88.

Engine out of '87
1. Had flywheel attached by 1 nut (if someone knows the size of socket I need to remove this please tell me) I measured it and it is about 2' 1/8
2. hole where transmission fits in was smaller than '88. I bought clutch alignment tool and it fit snugly into the engine I pulled out but has too much room in the other engine.

Engine out of '88
1. had counter weight

So my question is, how can I get new engine to fit in? Do I need to get transmission out of '88 to go with it? Also what do I do about the flywheel and counter weight? Do I need a different fly wheel that attaches by bolts to counter weight or do I just remove the counter weight and put flywheel from '87

Also I noticed that some hoses on '87 were replaced by plastic tubes on '88. Is there any other difference?

If someone can tell me what I need to get this to work I would be very grateful.

P.S. this is my first rotary's, i'm not an expert mechanic nor do i claim to be one. If you know how to help me finish this work please describe it as simple as possible and if you have pictures or diagrams please post it.

RotaryRocket88

iTrader: (7)

'86-'88 are S4 engines, and will be essentially identical if from the same type of car (ie non-turbo or turbo).

A 2 1/8" or 54mm socket is needed to take the flywheel nut off. It'll be torqued to somewhere around 300 ft. lbs., so a very long breaker bar or a very good impact gun is needed to break it loose.

The '88 sounds like it was mated to an automatic transmission, which used a separate counter weight that attached to the flex plate. A manual flywheel has the counterweight integrated. If the car has a manual transmission, you just need to swap the counterweight for the flywheel off of the '87 engine.

The S4 auto rear counterweight can also be used with aftermarket flywheels, so it has some value to a person doing that kind of modification. S4 counterweights are balanced for any S4 rotors, regardless of compression ratio.

2.

DriftingRX7FC

@RotaryRocket88 do you know where I can find puller to take off the flywheel? And is there a trick to take off the counterweight?

I'm planning to reuse the engine with blown Apex Seal, I was told there is shop in my area that can rebuild that engine so i can turbo charge it. and as far as I understand I will need that counterwieght on the engine with turbo

Aaron Cake

iTrader: (1)

You don't need a puller to take off the flywheel. Just unscrew the nut then place a pry bar between the flywheel and rear iron. Pry out, then tap the flywheel (on the non-friction surface) with a big hammer. It should pop right off.

The counterweight may come off the same way, or because it is so small you may need a puller. I've honestly never had to remove one.

Oh, the front counterweight just slides right off.

DriftingRX7FC

Thank you so much I will give it a try, unfortunately I would be able to work on it until this weekend. I will let you know if that works.

So just to make sure that I understood it right you mean to do something like this? And pardon me my horrible diagramming skills.

Engine in picture is not from RX-7 I just found one online to try to demonstrate. long bar on the right side is the pry bar and bar with square on bottom is hammer placement

Aaron Cake

iTrader: (1)

Have a view of this video:

http://www.youtube.com/watch?v=W1MXfs_Srs4

Flywheel removal is at about 3 minutes.

DriftingRX7FC

Thanks a lot, this guy makes the whole process looks easy. Now all that left is for me to buy engine stand and cordless impact wrench

DriftingRX7FC

One more questions!
Can someone point me to the right place? I want to rebuilt the '88 NA motor that has blown Apex Seal to take a turbo.

What do I need to know and if this even a good way of going about this?
What kind of rebuilt kit do I need?
Do I need to port? (I may be new but I understand already that different port achieve extra torque at different RPM range, I want to have more toque from mid to high range , i want to build this car for track and drifting)

If there is already thread on this just point me to right direction and you can close this one because I already got my questions answered.

Aaron Cake

iTrader: (1)

A cordless impact wrench isn't going to do it most likely. The wrench in the video is a 500 FT-LBs impact. You may be able to put the nut on with the typical 250 FT-LBs cordless impact but not take it off. An alternative is to place the engine on the floor with the oil pan and pickup removed to it sits flat. Use a small bit of chain to lock the engine from rotating by chaining from one of the clutch bolts to the transmission mount bolts on the rear iron. Get a 6 foot piece of pipe on a breaker bar with the flywheel socket, brace the engine from turning (2 x 4 between it and the ceiling) and then bounce a few times on the pipe...Works every time.

As for the rebuild, the FSM has inspection procedures for all the internal parts. If the engine threw an apex seal, then you are probably going to have one bad housing and one bad rotor.

The turbo question is a can of worms, so I'll skip that with just a message to read the 2nd gen FAQ in the turbo section. Technically you wouldn't need to do anything to the engine during the build to turbocharge it, but there are just so many options and possibilities that I'd need an understanding of what your power goals are first. Plus if you are rebuilding the NA engine, why not just get a blown TII engine and build that instead?

I tend to use Atkins rebuild kits because they are convenient. Most builds will require kit "C":
http://www.atkinsrotary.com/index.php?pag=5

I would recommend using stock corner seals, and you don't need to cryo your side seals or any other seals.

Here's a full 13B rebuild. Though it is an older 13B, the procedure is the same for any rotary.

http://www.youtube.com/watch?v=ijJeUk_GqiI

As for porting, that depends. Porting on the 6 port engine has to be chosen wisely as anything more than a mild street port will drastically reduce low end and midrange torque. It depends on what you want out of the engine. Normally I say to only do the most mild porting on the 6 port, concentrating mainly on the primary port and exhaust ports with only cleanup work done on the secondary and aux.

DriftingRX7FC

I was planning to go to about 300hp range or more as long as I can have reliable engine and not overdo the turbo that I have to constantly worry about blowing engine or having to rebuild it every couple month.

The reason why I decided to go with '88 NA is because I already have a spare engine and I don't have to find TII. I guess my biggest factor is money. I want to go cheaper route.

I have watched the all 20 videos, also I have downloaded detailed instructions from ALLDATAdiy.com for engine rebuilt with exact specs on all parts. So I feel pretty confident and very excited about doing this project.

As far as what I want from the engine with port is to get more mid to high range torque. The main reason for porting is to prep for turbo.

DriftingRX7FC

One more questions that someone got lost,

Is Eccentric Shaft on '88 has same inside diameter as eccentric shaft on '87.

The clutch alignment tool I bought fits perfectly into eccentric shaft on my '87 engine but when I put it inside '88 it has plenty of wiggle room.

Does this mean that main shaft on '88 transmission 5 sp has bigger diameter than main shaft on '87 transmission 5sp? What about diameter of main shaft on '88 auto transmission vs '88 5 speed?

Aaron Cake

iTrader: (1)

Stock ports then.

And use the TII lower intake manifold modified to match the 6 port block, which will allow you to bolt on all TII parts. Then use the BNR stage 2 hybrid stock turbo.

http://www.aaroncake.net/RX-7/4PortLIMTo6Port.htm

Prepping for the turbo requires no porting, and since the NA engine already has such massive port area, I wouldn't suggest it for your power level.

However, remove the exhaust diffuser wings in the exhaust port. They just grind right out with a grinding stone.

All 13B eccentrics are the same dimensionally.

Sounds like the pilot bearing is missing on the '88.

Oh, automatic. Yeah, that shaft wouldn't have pilot bearing installed from the factory. You just need to install one.

DriftingRX7FC

You were exactly right, the pilot bearing was missing. My dad finally figured it out after we got transmission out of '88.

I tried to use pulley from one auto store and I just ended up messing up the bearing. Then I went to O'Reilly and they got me pulley number 67033 by EverTough with sliding hammer 67031 that got the job done. Unfortunatly I already messed up the bearing to the point it can not be used.

I found parts store that going to overnight it from their warehouse and I should be able to install it and start putting engine back into the car.

Here is the bearing I pulled out. I wish I knew last weekend what I know now, this would have saved me a lot of headache and whole lot of driving that I had to do. I spend more money on gas than I did to buy new pilot bearing.

Also was able to remove flywheel following your instructions in the video, came out very easy.

DriftingRX7FC

I think I ran into last issue, when i was getting ready to put engine back in I figure out that rubber piece broke on the engine mount, another special order part, I put the engine with transmission in anyways and will just replace mounts once I get it. Hoping to have it done with only 1 more day of work as long as nothing else breaks.

I have learned that I need to buy following things to make this job goes smooth.

Pilot Bearing,
Engine Mounts,
Spark Plugs (strangely enough I had to go to three different auto parts store before I found it)
54mm socket,
Belts,
Extra hoses (instead of rubber hoses, on '88 it were plastic tubes, many of them snapped).

To make the job easier it is best to have car lift so you can drop the engine instead of pulling it up. Also car lift makes it so much easier to work under the car to disconnect hoses and wiring.

Aaron Cake

iTrader: (1)

Dropping the engine would require removing the subframe...It is much easier to remove it from above with an engine crane.

DriftingRX7FC

In that case I'm surprised why official instructions from ALLDATAdiy.com call it for dropping it?

Well I guess can't always trust the manuals!

southsidecox

iTrader: (52)

pm me i you need any oem 86-88 parts reasonably priced ,ive got a ton of them and im 2 and a half hrs away so shipping will be alright,one of the first things you learn about these cars is some of the parts are outrageously priced,you can almost forget about going to your local mazda dealer for anything,i will look today and see if i have a motor mount with good rubber still in it,which one do u need,i know there is the short one on one side and the long alum one

DriftingRX7FC

Mounts are the same on both side, I already found them at local auto parts store with lifetime warranty, i talked to couple other RX-7 owners and was told that factory mounts are known to break. Since I'm going to take it to the track, i want best available mounts to make sure that it can handle the stress.

Aaron Cake

iTrader: (1)

If you are going to track the car, then the best mounts you can get for the car are the ones from AWR Racing.

http://store.awrracing.com/engine-mo...1992-urethane/

No idea why AllData recommends taking the engine out from the bottom, because even the FSM tells you to remove it from the top. A lot of AllData is just generic stuff slightly edited and republished for each car, though, so that may be it.

DriftingRX7FC

well swap is complete but now I have new issues,

First issues I ran into was worn out O-rings on fuel injectors, lucky enough I was able to buy it from O'Reilly,

Now my top issue is the fact that engine dies as soon as it starts. I crank it up, it revs up to about 3.5 rmp and than just dies. All this happens within 2 seconds.

Another issue, after I crank the engine and tries to start once it dies, "Low coolant" light and buzzer comes on.

I believe that I got all the vacuum lines connected correctly and my fuel injectors seem to work not sure what else to check to figure out why engine does not idle.

88WIDEBODY

iTrader: (1)

If you swapped a motor from an 88 into an 87 car, the injectors have a different impedance, the 88 is a high impedance injector while the 86-87 are low impedance, that's why you have the dieing problem. Either swap over your injectors from the original engine or change the ecu to the proper 88 ecu. If you need an ecu I have one that I know works (it came out of my 88 during the swap to an 89 engine). Just let me know and we can arrange payment and shipping thru paypal.

RotaryRocket88

iTrader: (7)

A faulty AFM can allow the car to start, but then kill the fuel pump immediately after. Startup fuel is independent of the AFM's fuel cut switch, but it comes into play under all other conditions. The switch is simple to test with a multimeter. Per the FSM, test the appropriate pin on the connector. If I remember right, it should read 0 when the flap is closed and infinity when it is open at all. You can also jump the yellow 2-wire fuel pump test connector on the passenger strut tower to temporarily bypass the AFM. It should run with this connector jumped.

This is incorrect. Low impedance injectors are found in '86-'87.5 engines. They switched to high impedance mid-year, and the injector color/tab location/PN changed. Colors vary, and can actually change after years of heat, so part numbers and the tab location are the best ways to check.

The ECU has nothing to do with injector impedance. The circuit simply needs to have enough resistance to not burn up the board. Cars with low impedance injectors have a resistor pack (4x 6 ohm resistors) located near the air box.

'86-'87.5: 2-3 ohms per injector + 6 ohm resistor = 8-9 ohms total

'87.5-'91: 12-13 ohms per injector / total

FAQ: https://www.rx7club.com/new-member-rx-7-technical-256/frequently-asked-questions-2nd-generation-rx-7-1986-1992-faq-fc-782402/

LizardFC

iTrader: (1)

Welcome to the local 7's.

+1 on the AFM. You'll run into the same scenario with the AFM unplugged, so I would start there as RotaryRocket88 suggested.

@ Rotaryrocket88 - if his car is an '87 and still has the resistor pack wired up, won't that cause a problem if he is using an '88 engine with high impedance injectors?

DriftingRX7FC

AFM is to blame, or rather me!

Yesterday I dicided to go ahead and swap fuel injectors. When I was swapping I noticed that both had same number and color.

86-87 13B NA, low square center, 460cc, red, 195500-1350

So after that did not work I decided to connect air tube from air filter housing to intake manifold. And what do you know, car runs!

I have no idea why I thought that it should work without it. But now I was able to start the car and take it around the block.

All that is left is to fix couple things.

1. Low coolant light + buzzer

2. Engine temp gauge is not working (maybe it is related to first issue)

LizardFC

iTrader: (1)

Outstanding. Glad it was something simple and not something expensive. Next issue, coolant light - probably just need to bleed the air out of the radiator and fill it up all the way. Bubbles like to gather at the top where the level sensor is and keep the light on. That won't effect the gauge though. Check the temp sensor (driver's side of motor near oil filter) and the wire leading to the gauge. It's very important to have that working before you drive the car as overheating a rotary even once can do serious damage.