OKI92FD

Thread title space is lacking. My motor is fine, but my secondary turbo is going (bearings). Used (great shape) turbos were $145, the whole motor was $400. Decided to go with the later. I don't know what year or how many miles is on the motor, but it ran well before I got it. No comp test either sadly.

I'm going to swap the turbos from this motor to my current one, and prep the new motor for single turbo while it's out of the car. What mods/repairs/maintenance should I do on the new motor while it's sitting in front of me that will be a pain once it's in the car?

I already have some ideas, just trying to get more or better ones. Sorry if this is the wrong section.

adam c

iTrader: (2)

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/things-you-would-recomend-while-building-motor-966595/

OKI92FD

DOH! Wasn't quite sure how to search that.

Ok I'll be honest, I didn't search. Thanks for the link.

Narfle

iTrader: (16)

You should disassemble and inspect it. Or, at least stick a bore scope into it.

OKI92FD

This is my rifle...

Is dagobah near a military base by chance? Or are you being serious? Disassembly would cost dollars or yen or both. Not an option. Bore scope might actually show results if I pulled the lim, which I don't really want to do, but can with little cost.

limepro

iTrader: (2)

You are going.to spend the money going single on a motor.that you have no.clue the condition? save the money going single and make sure the engine is healthy or.you will spend.more in the long run.

OKI92FD

Limepro, I get it man. The thing is, I have spent almost a year sourcing the parts I need to go single. Japan is an awesome place for building Japanese cars, plain and simple, as long as you're patient. Being patient, I've been able to collect the parts I need, including a spare motor, for very low cost. I want this car to last, but...

If this project failed today, I would part out the car and have a new one within a week. Call me hopeful, but longevity isn't a necessary attribute for a car to have in Japan. I can swap a motor in a day or two for less than $100. Dime a dozen is just a slight underestimation.

Edit: now I feel retarded (and may actually be a lil). I'm a mechanic and a marksman, so my first thought when borescope was mentioned was rifle bore. My apologies. Flame on the newb!

Narfle

iTrader: (16)

You dont have enough patience to open the motor?
Opening it takes zero dollars.
If you get in there and find out you have to buy something...then you did yourself a favor.

OKI92FD

I haven't started yet, so I can't be doing anything wrong. That's why I posted. Sorry, I'm not trying to be difficult.

What do you mean when you say open it up? I don't want to rebuild a running motor if that's what you're getting at.

Mahjik

iTrader: (1)

What everyone is getting at is a "running" motor isn't necessarily a "good" motor. If you don't mind the thought that you could put this motor in, and then it dies within a few weeks then don't worry about it. Most people would rather make sure the motor is good before installing. It's not wrong to not be in that camp. You just need to figure out what's more important to you: having a running car quickly, or having a running car that will run for a while.

You asked people what they think you should do, they told you. If you don't want to do it, then that's your decision. In the least, replace the rear main seal and re-seal the oil pan on it. Those are two tasks which are pain while the motor is installed in the car.

OKI92FD

That's the thing though. I have a healthy motor in my car currently. If the one I build dies, I'll just swap again. A day or two of downtime, that's it.

This thread has turned debatable as it applies to my personal situation. I can take adam's advice and find info elsewhere. The site and people are awesome (including the ones in this post). Thanks for the knowledge. Hopefully this thread can help the next guy who has a new used motor without a healthy backup. Thanks for the contributions. I know they were meant well.

zeroG

iTrader: (28)

It really doesn't make any sense at all to not open up the motor and make sure everything is good.

Why spend a day or two of downtime, when you can spend 0 downtime by taking 2 hours of your time to open the motor that doesn't take any money to open up?

Another thing, if you know your current motor is healthy, why would you replace it with a motor that you don't know if it's going to be in good conditions? Why don't you just put the single turbo in your current motor?

mannykiller

iTrader: (93)

Do yourself a favor and get the motor checked. He'd you get it from? compression checks are cheap and easy enough....

shetlen

iTrader: (2)

Manny is right compression check should be one of the first at least, then full rebuild/partial rebuild, then streetport to help the single turbo breath (why single turbo w/o porting?). Longevity might not be important but you still dont want to blow your motor and spit busted seals into your single turbo. If they have an decent auto hobby shop on base you should have everything you need. I tried to get over there to Okinawa with my buddies, but that didn't happen like I planned. either that or find a 99+ engine and turbos. Just my 2 cents.

DaleClark

iTrader: (55)

I disagree with "opening the motor costs nothing". You will have to give everything a thorough cleaning which takes a lot of time. You will probably need new apex seals as uses ones are a bitch to install. New water seals are a must too as they rip apart in disassembly. Other small parts like orings have to be replaced too

Hard to justify cracking open a good motor too.

Dale

Narfle

iTrader: (16)

Any used motor from JDM land is suspect and should be treated as such.
I don't care if you got if from your neighbor.

RotaryEvolution

iTrader: (30)

if it's original, your coolant seals will be on their last legs.

cptpain

iTrader: (1)

youre risking another ailing motor if you do no inspect the internal condition.

you're using the newly bought motors' turbos to replace your bad set..... fine.

but you're wanting to go single on the unknown motor..... not fine. regardless if the motor is a known "good" motor, you still have NO IDEA of the actual condition of the motor. compression tests can be misleading.

and you dont NEED to port the motor when going single. plenty of people making great power on stock ports

Why are you hesitating opening the motor after quite a few people have already chimed in telling you to open it?


if you dont have money to open up the motor then you're already going down a path that ends only in frustration, stress, and inevitably selling the car and parts.

do things the right way the first time through.

OKI92FD

Dale, thanks. At least one person sees my point of view.

I broke the motor down to shortblock today, or almost. I still need to pull the turbos, lim and injectors. I'll go to Mazda next weekend to order some parts. Here's my list, please add recommendations if I missed anything.

Injector o-rings
Gaskets for lim,uim, tb
Gaskets for ex manifold, turbo flanges
New t-stat and o-ring
Oil pan gasket and lip seal

I'm sure I'll think of some other stuff if noone mentions it sooner. Now that the block is visible I'm feeling a little more comfortable with "opening it up", especially since I have to place an order through Mazda anyway. Can anyone give me a ballpark figure on a refresh, apex and water seals, o-rings and any other should-do items if I decide to break it open?

I've been skeptical on the cost of tearing into the motor. If it's cheap I might bite the bullet. If not I'll take my chances.

Mahjik

iTrader: (1)

Take a look here: http://rotaryaviation.com/overhaul_kits.htm

So the basics would be around $600 USD which is not bad to ensure a 'good' fresh motor (provided everything else is within spec).

rx7rcer09

for 145$ motor i say rip it apart and go all out, rebuild while you know the rotors and housings/plates are good port it upgrade the seals and build it to be a top notch motor!!!

Uwan

iTrader: (4)

What part of Okinawa are you? I'm on Kadena

OKI92FD

Live on shields work on Hansen. Which FD are you driving?

OKI92FD

Got her down to shortblock. LIM gasket was bad and there was some soot coming out of the rear port. Other than that everything looks relatively good on the outside.


Ordering gaskets next weekend to put her back together. I'm still struggling with the thought of tearing this thing open though. $600 for a rebuild kit seems absurd to me when the running motor was $400. I understand what you all are recommending and you really got me stuck. I've asked the local community for some advice too. Depending on the results I might break her open.

I don't know now.

OKI92FD

Oops double posted sorry