Stock 13B Rebuild w/Sequential Twins
 

:icon_tup:
This journal is a collection of lessons learned during the August to November 2007 successful R/R & rebuild of my 1993 R-1, 13B, with OEM Twin-Sequential turbos. Anyone planning the same type “DIY” project will soon discover, as I did, that every step of the process isn’t thoroughly explained in the MAZDA Workshop Manual. Perhaps Mazda did this intentionally, assuming that anyone using their manual for such a project is likely a professional mechanic or specialty shop. I don’t know. What I do know is that in order to get a successful result and, one that doesn’t break the bank, requires an engineers mind-set with the patience of a Samurai thoroughly versed in Budo and Bushito. :dark:

Be prepared for the typical “sticker-$hock” you’ll experience when your research for an OEM water-pump fan-belt, for example, prices out at $65.00 dollars or more. :wtf: That one caught my attention and prompted a quick call. The parts guy confirmed the correctness of the bill and apologized for the price with a, “…sorry, I forgot to mention that” response.

Numerically, 3rd gen’s, are an uncommon sight in the US and, reasonably stock ones, rarer still. The only thing scarcer is a professional mechanic, MAZDA or otherwise, who REALLY knows how to properly work on these cars. Of course, it also depends on where you live. Not everyone is lucky enough to have a Gotham Racing or Rotary Performance shop down the street or the next town over. So, the average owner is pretty much forced into becoming their own pit crew/mechanic etc., if they plan to get any sustained driving pleasure outa the car. And, after all, these cars are a blast to drive.

Now, there’s plenty of information out there on how to MOD your REX, go non-sequential and single turbo installs. But IMO, not nearly enough on an OEM rebuild. So, for who want to go the OEM route, I hope you find this post helpful.

The how-to tech- information I plan to post will include build photos, useful URLs found and gotchas to avoid. I hope you find em useful.

This thread's gonna be a work in progress, in my spare time, so check back frequently.

awesome. i should have done this as well. i did keep a photo log of our work but it is far from "step-by-step"

looking forward to progress of the thread!

Here's a link to the tread on my original coolant problem that prompted the rebuild project. https://www.rx7club.com/3rd-generation-specific-1993-2002-16/results-not-flushing-your-coolant-686776/

History
 

History:

Death by coolant is a pretty funky way to loose an engine. :Wconfused It’s a first for me. :confused: So, to help others avoid the expensive lesson I learned, I’ll research my records (if I can find em) for dates on the age of my coolant at time of engine failure. Based on a rough mileage estimate, the coolant had approximately 32,000 highway miles on it since its' last change. https://www.rx7club.com/showthread.php?t=686776
So, it’s hard to believe that so much damage occurred so quickly. :suspect:

My first indication of a possible coolant system problem was in October, 2006.:squint: It was after work, I’d had one of those days, and was focused on getting home. :cylonA: I got in the car, started it up and was waiting for the gauges to normalize before pulling off. That’s when my low-coolant warning-light/buzzer came on and didn’t go off. I immediately shut the engine down, got out, popped the engine coolant cap, topped off the fluid and continued on my way.

At the time, I didn’t really think much of it. I just figured the coolant level was off because of a failing radiator cap, the vented kind, and It was time to purchase a new one from NAPA. This fact was reinforced the morning before when I noticed that my cold-engines lower radiator hose wasn’t collapsed as usual, indicating a breach of the cooling system. I concluded the AST's radiator cap must be bad, or so I thought. :scratch:

In hind-sight though, that was probably the very first indication that something was wrong with my cooling system. I just failed to recognize the symptoms. :dunno:

As the low-coolant event began to replay itself with increased frequency over time, I next thought I must have a hose leak somewhere. By December, 2006 the problem was chronic and annoying. My son, GoodfellaFD3S recommended I check the engine for indications of a failed coolant seal. So, I borrowed a pressure gauge tester and preformed an over night leak-down test. The test was negative. The system held 12PSI overnight. This wasn’t making any sense.

Several days later, I did the Champagne Bubble test GoodfellaFD3S had recommended. With engine cold and the engine fill cap off, I started the engine, went to front of the car and stared at the filler neck. The thermostat typically takes 5 to 6 minutes to open as the engines reaches normal operating temperature. However, small occasional bubbles began rising in the fill-neck almost right away. NOT GOOD ! It was 3 January 2007 and my car had kicked the bucket. :sad: :sad: It would sit in the garage for the next 4 months. L

The good news was I’d found my problem. The bad news was the engine coolant seals had failed and had to be replaced. That meant the engine had to come out !! $$$$

Next step: .

Engine Removal !! But first the shopping list. What to replace and what to keep.

Engine tear-down.

Port-Mortem and analysis. :bigeyes:

Subscribed. this should be helpful to me as im getting an FD as soon as i finish college.

a bit of advice. blog-style buildup threads often have a lot of momentum at first in terms of the number and quality of the posts and then they die down as posting starts to become a chore. be mindful of that and don't feel obligated to post a lot in the beginning or you may get sick of it.

Not to worry
 

:) Reliving the experience is one of the side benefits of doing the rebuild. You get to review all your steps and chronicle the project in the sequence events occurred. Pretty valuable knowledge in the long run.

Once the engine was back in the car, the real fun began. Anxiety over what may have been overlooked is never too far off as you turn the key for the first time.

Frustration over the vacuum hose connections was but one of the many bugs I had to work out. The sequential system isn't well documented by Mazda but I did find one link/URL http://www.autosportracetech.com/RX-7/TurboTroubleshooting.htm that especially helped explain the whole thing. But, before you go and get wrapped around the axel about the sequential’s complexity, I highly recommend the purchase of a "Mityvac" http://www.mityvac.com/ tester. It'll save you hours of guessing and quickly help you trouble shoot and locate any vacuum or pressure related problem. One of the vacuum connections I mixed up on re-assembly, :wallbash: as an example was the connections to the vacuum tank and pressure tank, from the "Rats-Nest (or AKA the HAPPY-TRAY). This little jewel helped sort this out in minutes. Purchase Price was $115.00 dollars plus tax. Well worth the price if you plan to retain your sequential setup. Plus, you can use this unit to bleed your break and clutch systems too. Very cool!!

No, Chronicling my project will help me put it all in order for later reference. But, your right about finding time to do it….

Vacuum Hose Mixup Pressure versus Vacuum Tank Connections
 

:confused: Notice the steel rats-nest pipe closet to the Alternator rear housing... this routes to the pressure tank, the triangle shapped black plastic tank that sits between the Upper Intake Manifold and the Alternator.

The Vacuum tank is the large black rectangular tank that is bolted to the front engine cover and sits to the right of the alternator and behind the A/Cs idler pulley and power steering "L" bracket.

I had these two connections reversed.

Pull Engine and Trans or just Engine??
 

:Wconfused Now, if you've decided to pull your own engine, remember that it has to go back in. Everbody has opinions on which method is best and that's fine. Me? Having done it both ways, I prefer the trans/engine combo removal method.

For one thing the entire unit is balanced and sits or balances well on the cherry picker chain during removal and re-installation. :biggrin:

Second, clearing the cross-member frame at the motor-mount frame junction is easier if the trans is mated to the engine. That'll give the trans tailshaft that little bit of extra wiggle room in the trasmission tunnel to help you clear and seat the motor mounts in their frame seats. A key point is no matter how high off the ground the chassis is, make sure it's either dead level or slightly nose down. Otherwise you'll find yourself fighting the path of motor mounts all the way. :wallbash: That is, the 14mm threaded shaft on the bottom of the motor mounts barely clears the cross-member motor-mount seating points and tends to hang up. The clearance is critically close, so expect it to make your life unpleasant. Also, be careful not to smash the TPS (throttle position sensor) into the fire-wall in the process. Better to remove it than damage it.

The only downside to this method is having to disconnect the PPF (Power Plant Frame) from the trans and rear, especially if you're working on the garage floor. Having a "Lift" of course, would make this part of the operation go much much easier. But, that's for later and is one of the items I do intend to cover.

Parts Replaced Pictures
 

Most of the OEM parts shown are from Malloy Mazda http://mazda.malloyautomall.com/Department-Parts.aspx , 888-533-3400, ask for Mazda Parts Dept. Ray Crowe is the parts manager and is, IMO the BEST Parts guy ever. If I order a part on Monday I usually have it by Tuesday or Wednesday.

He knows the REX and ususally gets the right part the first time out. I've occassionally had to be specific if the part was some obscure trim fastener or internal transmission peice or the like. But, for the most part, he's the man for anything MAZDA OEM.

The fuel pulsation dampener is a "Fire-Starter" item/part that I replaced along with the Main engine Wiring harness, the Turbos and the primary and secondary injectors.

All soft parts were also replaced.... cooper-crush washers, rubber "O-Rings" etc...

More OEM Parts
 

:shocking:

Injectors New OEM
 

:shocking:

Damaged Water Pump housing
 

Here's a few shots of my old water pump housing.... notice the severe pitting and errosion to the impeller area.... :scared:

I plan to install a Zinc insert into the radiators drain cock.... This should provide and additional layer of protection from future destruction due to cavitation at the water pumps impeller site.

NEW OEM Turbos
 

During the engine tear-down, I got another surprise. My stock turbos were shot. Aside from pushing oil, the Turbine side (Exhaust) blades of the secondary turbo had sustained foreign object damage in the past. Thing is, they looked fine when still installed in the cast-iron housing. But when I separated the turbo cartridge from the cast-iron housing I was able to see the entire blade surface. The blades are hidden otherwise and, it was obvious they’d received some damage. Near as I can figure it most likely happened when I blew my last motor a few years before. Anyway, now I was faced with another unforeseen expense.

I had two choices. I could either go single turbo or try to get a good set of low mileage OEM twins. The second option wasn’t looking too good though. The scarcity of good used, low mileage sequential twins that were reasonable priced seemed unlikely. Purchasing a new OEM set of Sequential Twins from Mazda would have been around the $3,000 Dollar price range. So going Single Turbo was looking like the obvious choice.

GoodfellaFD3S across an e-bay listing for NEW OEM Stock twins one day. It was risk but I opted to buy em and take my chances. When they arrived, sure enough they were BRAND-NEW, never installed. I’ve included pictures. Check it out.

So, e-bay can be a good source for parts if your willing to take a chance. Sometimes is works out well.

I also replaced my main engine wire harness via Malloy Mazda. My old harness was serviceable but the insulation had become pretty brittle. So, to avoid any electrical problems the new harness seemed like a good idea. Best estimate on the old harness, it had at least 110,000 of wear. Quality of the replacement harness is high and includes an update on the number of plug coming into the cockpit area. There’s a White (female I think) 25 pin or so, plug. The male it plugs into is located near the firewall and up by the heater core. It’s a pain in the ass to get at. But, If you locate this plug prior to installing the new harness through the firewall, it fairly easy to get at and pull down.

you bought NEW injectors and NEW turbos... wow.

how much did you pay for the new twins off ebay, if you dont mind me asking?

First, excellent thread. I'm in a place devoid of rotory knowledge and I'm having to diagnose and repair myself...not that I mind but it would be nice to have some "hands on" help for some things...so threads like this are a great help.

Please, if you can, post some part costs with the major items. It would help the blow of sticker shock if we know what to expect to spend on some of these things when our time comes.

I do have one question. I too am a fan of the sequential set up and wondered if you considered upgrading your turbos to BNR's? It is my understanding from this site that you can install these and still use the stock ECU with no problem.

Turbo Selection OEM or BNRs
 

:scratch: :cool: Ummm.... I actually considered the the BNR route in leu of stock sequentials. But, I didn't get very far down this road because the stock OEMs came available early on. The rest of it became a moot point. Also, New Jersey has recurrent Motor Vehicle Inspection requirements. So... I didn't really want to hassel with those folks.... So... to answer your question. No, I didn't get to seriously consider the BNRs. :scratch:

New Turbos
 

:icon_tup: :icon_tup: Hey Jacobcarmill.... no, I don't mind ya asking.... ans = $800 + S/H so... the total was just over $900 something... I asked the seller to insure them for full Mazda-Replacement price.... just in case... He did and that kinda pushed the price up .... still well worth it though.:icon_tup:

:patriot: So,,, thanks to GoodfellaFD3S I got the ultimate hook-up :patriot:

Being that he's still running an oem intercooler, oem main cat, and (new) stock fuel injectors, BNRs and a single setup were never seriously considered, although 99 spec twins were :)

Ceramicoated U/I and L/I manifolds
 

:icon_tup: :icon_tup: Along the way GoodfellaFD3S suggested I get My upper and lower intakes ceramicoated as much for the heat-management qualities as for the Blink effect. Here's a couple of photos of IRPs work.... :icon_tup:

Ceramicoated Water/Pump - housing...
 

:bling:Photos of the water/thermostat housing.... The old one was so extreme I had to replace it and decided to get coated as well :bling:

I love your term..."Blink effect".
Solid. Piece out brother.

Blink Effect ?? !! ??
 

:uhh: Uh.... yeah... that was a slip of the fingers..... I meant Bling !! But, when I started to think about it..... BLINK is a more accurate term.... With all the stock sequential hardware, its' pretty hard to see much BLING, as you can see by the photos......:suspect:

Engine removal
 

:scratch: :scratch:
So, now I'm at the engine removal stage and have to make a few decisions. GoodfellaFD3s does 3rd Gen R/Rs on a regular basis and his advice was to only remove the engine. Leave the trans in place.

I must admit that the thought of removing the PPF (Power Plant Frame .... Again ) didn't really have me straining at the bit.... So I decided to try it his way.

Lessons learned ......

1. I had the car tilted at a pretty steep angle with the ass sitting on the garage floor. That was a BIG mistake... yeah, you can get the engine out. But, having the car 2 feet off the floor and level to slightly nose down would've made the entire experience much easier. I discovered this when we tried to reinstall the motor. With the motor-mounts on, ( I'm using stock motor-mounts ) it was near impossible to get the engine back on the transmission imput shaft and the motor-mounts clear of the cross-member mount towers... all in one go. It was one of those end-of-the-day efforts when we were both tired, determined to get the motor in, and pressed for time, a recipe for disaster.

2. When in doubt, stop the procedure and come at it when you're fresh and rested. So, even though I had the motor entered onto the imput shaft, no amount of tweaking was going to get the 14mm studs of the motor-mounts clear of the cross-member and positioned into their mount wells.

3. If ya break parts during the removal process, chances are you're going about it all wrong. My wedge collar for the throw-out bearing was destroyed when it got hung up on the trans imput shaft. I tugged on the hoist and heard the PING..... as the snap ring shot across the garage. So, that was another unplanned part replacement that I had to factor in. All things considered, not a show-stopper, just inconvenient.

4. Watch out for your TPS sensor (Throttle Positioning Sensor) on the back side of the Upper Intake Manifold.... It's real easy to jam it up against the firewall when pulling the engine. Once damaged, it'll generate a "Check-Engine" code and be a pain to trouble-shoot. Most folks will tell you that they don't typically fail.... but they will if exposed to enough shock. If it's in the way.... unplug and remove it. It's held in place by 2 ( I think) 8mm bolts. And, they can be kinda pricey if ya have to buy a new one from Mazda.

5. If ya have a digital camera, take lots of pictures. It'll help you when it comes time to re-assemble. In my case, it was about 3 to 4 weeks to get to the engine assembly stage. In some instances, it was just long enough that I was forgetting where somethings were or how somethings where supposed to go. Like I said in the beginning, Mazda isn't clear on all the assembly steps of the engine. So pictures REALLY help, especially those involving the HAPPY-TRAY, AKA the Rats nest.

6. Seperating the trans from the engine involves releasing the throw-out bearing from the wedge-collar. It's pretty easy (the throw-out bearing pulls, rather than pushes on the pressure-plate-fingers/springs) to disengage. You just need a flat-bladed screw driver, medium size, to slip in between the outer ring and the throw-out bearing. Just press this outer ring toward the pressure-plate with the screw driver blade until you can only see the edge of the ring (it like looking a coin from the side where you can only see its' edge) and give the screw driver a slight twist and the throw-out-bearing will seperate or release from the wedge collar and pop & slide toward the transmission. If you find yourself muscling it, then your screw-driver blade is in the wrong spot.

Now you can rRemove the six (6) bell-housing bolts, clutch slave-cylinder, starter and the engine should be free of the transmission. Disconnect the wire harness from the ECU, pull it through the firewall and lay it on top of the engine, disconnect your hoses, throttle cable etc. and the engines ready to pull. It's that easy. :bigthumb:

Decisions What parts Do I need to replace?
 

:wallbash: Dont make yourself nuts here. If you're doing your engine you know it's gonna be pricey. So, sticker-shock aside, what should you re-use and what to replace. The fuel pulsation dampener is a known FIRE-STARTER :devil: :devil: and I replaced mine. The old one looked to be in pretty good shape however, take a look at where the freaking thing is located....I wouldn't want to come back in to replace this thing... so I ponied up with the $125.00 dollars and got a new one.... :hf: