The 13B Rebuild Chronicles :: Chapter 11 :: Leak Correction

Early in the week I called Mazdaspeed Motorsports and ordered two oil pan gaskets (one for between the oil pan and the baffle and another for between the baffle and the engine block).  While I was at it I decided to get new motor mounts as the threads on mine were pretty much trashed.  The stock mounts were $20 for one side and $30 for the other, but for $40 each they had the competition mounts which are 40% stiffer. Guess which ones I ordered?

I also took my alternator up to a local starter & alternator shop and had them rebuild it. For $90 I got a new rotor, brushes, bearing, and pulley. A little cheaper than buying a whole new reman, but these guys stand behind their work and they got it done quick. None of our local auto parts shops had the alternator in stock and they were all about $150 anyway.

So, Saturday arrived and Doug and I hit the ground running at around 8:30 AM.  Well, not so much running as worming around on our backs. We literally spent most of the day on our backs under the car amidst oil, grease and cat litter. It was a long, dirty, and tiring day to be honest.

First, we moved the jack stands to the rear of the front wheel wheels so that we had free access to the front of the car. Then we removed the front wheels to create more elbow room, and removed the skid plate from underneath.  Next we jacked up the engine from underneath the transmission, about 4 inches up.  It was not enough to be able to remove the oil pan around the steering linkage though.

So, we then unbolted the steering linkage on each side. The driver’s side was easy (a 19mm nut) while the passenger side needed the cotter pin removed which was no easy task. We had to make a run to AutoZone to buy a ball joint removal fork (not sure of the technical term) and then popped the joints out and dropped the linkage down to provide easy access to the oil pan. While doing the AutoZone run we had also grabbed Doug’s air ratchet from his house so removing the oil pan bolts was quick work.

After we had pried the oil pan off, we spent a good hour or so removing the dried RTV from the pan and baffle. I worked the baffle over with a chisel to get the bulk of the RTV off and then a wire brush air tool to buff it back to pristine shape.  Doug did a similar action on the oil pan but also spent some time straightening out the pan and grinding some rough spots down. When he was done the darn thing looked almost new.

Then, after another Autozone run (forgot to get more RTV on the last trip), we built ourselves a gasket sandwich with lots of black RTV. Oil pan, RTV, gasket, RTV, baffle, RTV, gasket, RTV. Used an entire tube of the stuff!

We then got back on the floor (again) and installed the oil pan (again) and gently bolted it down all the way around. It looks good, and I am confident that we will not have any leaks this time around.

Before we dropped the engine back down onto the motor mounts we removed the existing mounts and installed the new Mazdaspeed competition mounts. We reused the underneath nuts but had to use new nuts for above (10 x 1.25 if anyone needs to know).  After that we bolted the skid plate back into place and were basically back to where we were a week ago.

I am certainly no expert, but if anyone else is doing their first rebuild my advice is this: use an oil pan gasket no matter what the guy on  the rebuild DVD says!  By the time we got done I was covered in grime, had oily cat litter in my hair, and muscle aches from lying on a cold concrete floor all day. Thankless work.

Next step: buy new or rebuild the existing rear brake caliper…or maybe not. We put the front wheels back on, removed the jackstands, jacked up the rear driver’s side, removed the wheel, and pulled the caliper.  Upon inspection we found that the caliper was not ceased. It was dry and greaseless but still operational. We pulled it apart, regreased all of the seals and plungers, and made sure everything was moving smoothly.  Later this week I will grab some new brake pads and reinstall the caliper with pads. I will also check all the calipers all the way around, grease them as needed, and install new pads.

Then we’ll pop her on the trailer and be ready for the Thursday night shakedown run at Desoto Speedway.

The 13B Rebuild Chronicles :: Chapter 10 :: The Moment of Truth

Well, it is Saturday, March 21st, and rather than boring you with an essay on today’s adventure I am going to let you see it – albeit an abridged version – for yourself…

As you can see and hear above we got her running quite well today. The initial starter trouble that I had encountered last week was easily fixed when we realized that the sending cable (from the starter button) was not attached to the starter-mounted solenoid. Doug figured this out within about 10 minutes using his trusty test light.

When we first fired her up she sounded quite rough and was stalling consistently while also producing tons of smoke. The engine was flooding continually. I had to turn the engine over with the fuel pump off and then flip it on the moment the engine caught. The timing was obviously off but she wouldn’t idle long enough for us to use the timing light effectively. We messed around for a while trying to adjust the idle but it would not smooth out. After almost an hour I suddenly realized that we had not hooked up the Mass Airflow Sensor. Doh! That explains the flooding!  The poor ECU…trying desperately to meter air & fuel ratios without knowing how much air was flowing.

Once that was connected things got better quickly. The engine turned over and caught without having to turn the fuel pump on and off, but it would not run for more than a second or two.  Okay, now we’re getting somewhere though.

Next we pulled out the crank angle sensor (the thing on which the distributor is mounted) and reinserted it with the rotor pointing at the 1st spark plug in the firing order (front leading plug) and the engine at what we figured to be 15 degrees before TDC (top dead center). My pulley has numerous notches in it (rather than the normal two) and we had been using the first (TDC) notch up until now. But from my research I knew that we should ideally be somewhere around 16-26 degrees ahead of TDC. So we decided to use the furtherest (clockwise) notch which looked to be 15 degrees before top dead center (BTDC).

So, using a wrench we turned the engine over until the timing mark on the front housing was lined up to the 15 BTDC notch on the pulley, and then re-inserted the crank angle sensor back into the front housing so it meshed back in with the gear (ensuring that the distributor rotor was still pointed squarely at the 1st Leading plug), put the distributor cap back on, and fired her up again. She fired up with one short push of the starter, no gas pedal needed, and idled beautifully at around 2,000 RPM. Doug tuned the idle down to around 1,200 RPM and she sounded GOOD. The last two video clips above are after we made this change. In the last video you will hear us revving her up to around 5K and she sounds smooth and sweet…like a gigantic mosquito right?

Next we decided to reinforce the radiator and the front airbox. We did this with some sheet aluminum, rivets, and self-tapping screws. Here’s a couple pics of that work:

Now for the bad news. While doing this we had the car jacked up on the front to work on the radiator reinforcements and noticed oil on the floor. Actually two puddles. One was from the oil temp sensor. Some thread tape took care of that quickly. But the second puddle was significantly more ominous. Turns out that the oil pan is not holding the seal. I almost screamed out loud when we discovered this.  I do NOT want to take the engine out and put it back in again.  What we’ll do is remove the steering linkage from below the oilpan, and hopefully that will give us enough access to remove the oil pan and reinstall it with new gaskets from below. Keep your fingers crossed on that one for us please.

Also found that we have a warped alternator pulley and/or shaft. It is wobbling slightly and creating metal shavings on the pulley bolt when the engine runs. No big deal. We removed the alternator before shutting down for the day. $55 and a quick trip to AutoZone will handle that. *(Correction: discovered later that this was a misquote, actual price is around $15o but none in stock).

I will call Mazda Motorsports on Monday to order the oilpan gaskets and hopefully next weekend we’ll get the oilpan sorted.  Then we’ll do an all around brake job, check suspension, bushings etc. and hopefully take her out to Desoto Speedway test & tune night the following Thursday evening for a shakedown run.

Can’t wait!  And my best friend, Kimbo, will be back from Australia next week too, so I’ll get to share the fun with him.  Like Xmas in March it is!

The 13B Rebuild Chronicles :: Chapter 9 :: Engine Install, Part 3

This Saturday was a short day due to commitments in the afternoon, so I planned on starting early but didn’t get going until after 9AM. Both Matt and Doug had commitments also, so I was alone.  My plan was to fabricate a brace for the radiator, but being that I have absolutely no metal working experience I was a bit lost without help.  So instead I just decided to find my original skid plate. I started at the back wall, next to the tire stack, and what do you know…hiding behind my spare quarter panel was a piece of aluminum in a very specific shape that suspiciously resembled the cavity below the engine bay.  Wow, sometimes things just happen the way they’re supposed to.

So, I bolted it up to the frame, then dropped the radiator in and bolted that onto the skid plate. Perfect fit!  It needs some additional reinforcement as the aluminum seems a bit weak to really hold the radiator safely, but for the moment it is in. Here’s a picture of it from below (not very exciting, but for the purposes of a complete photographic record).

Then I hooked up the radiator hoses, screwed in the water temperature sensor and tightened down all clamps. Finally, I bolted up the air intake to the manifold. So, except for bolting up the airbox and inserting the air filter, we’re done! Well, for the moment at least.

Next, I drained the fuel cell by disconnecting the fuel line and pumping the fuel over the edge of the engine bay into a fuel can.  As you can probably tell from the photo below it took me a couple of attempts to disconnect the correct fuel line. Between the time it took me to get from the engine bay to the cockpit to flip the fuel pump on and off I ended up with a nice pool of gas under the car. Never fear, we’ll be cleaning that up before shooting any flaming arrows around the shop.

I drained it fully and then walked across the street to the brand new 7/11 to get some fresh fuel. I got 5.5 gallons of 93 octane and mixed about 7 ounces of Valvoline two cycle oil in with it. This is about a 100:1 ratio, which is what seems to be the more prevalent ratio recommendation that I could find online AND the one listed on the back of my Valvoline bottle. To be safe though I called Pineapple Racing to find out their recommendation. Rob at Pineapple said to use only 4oz of oil per 5 gallons of gas, which is a 160:1 ration. Just because I am super paranoid I also called Dan at Atkins Rotary and asked him the same question. His answer was: “read the bottle”.  He said that because each brand of oil is slightly different he recommends following the oil manufacturer’s mixture ratio as listed on the bottle. That did seem to make sense – and validated my supreme intelligence at the same time – hence it has been adjudicated as the official “right answer”.

Not my best side I know, but I took the bloody photo with one hand while pouring gas with the other, so I don’t want to hear any wisecracks.

So, everything is now done as far as the engine goes except for starting the darn thing. Again I turned everything on but when pushing the started button nothing happened. Just a soft click and that’s all.  I climbed under the car and scoped out the starter. Everything looked fine. Ground and main attached properly. I wanted to test to see if power was getting to the starter by using a screwdriver to jump the terminals but, even after adding the floor jack in addition to the jack stands under the car, I just could not sum up the courage to turn then engine over while lying underneath 2500 lbs of steel without anyone else around. Safety first, right?

So, that wrapped it up. Another weekend down without hearing her purr   It will definitely happen next weekend though, so be prepared to hear it. I plan to take a video clip on my iPhone and post it next week so that you can all enjoy the sound! Strange the pleasures we find in life.

Until then,

Grant Boshoff
Thrust Motorsports

The 13B Rebuild Chronicles :: Chapter 8 :: Engine Install, Part 2

Sunday came and I could not stay away. After brunch with the family I spent some time online researching the oil injector issue, then snuck out to the man-cave with my son (got to get him initiated sometime).

What I found is that the stock 13B’s have an oil metering pump (OMP) mounted to the front cover, just beneath the water pump, which feeds oil directly into the rotor housings via the oil injectors. This is for the purpose of lubricating the metal on metal contact between the seals and the housing. The oil injectors have been known to clog up from time to time, so some enthusiasts jettison the OMP in favor of running premix (two stroke oil mixed in with the gasoline). This made sense to me for a race application as it removes the possibility of engine damage due to a faulty OMP or clogged oil injectors.

So, upon my arrival at the cave I inspected the engine to see what the story was. If you recall, the oil lines to the injectors were missing. I compared pictures I had found online to my oil injectors and found that the harnesses of the oil lines were intact on the injectors but the lines had actually been cut…very strange. Then I inspected the OMP…oh, hold on, I don’t have an OMP. The OMP mounting area on the front cover had been covered up with a cover plate (standard issue when doing the OMP removal modification).

Now, some of you (who have read this blog from the first chapter) might be smelling a rat at this point…I certainly was. The guy who sold me the car had removed the OMP. Which means that he was running premix. Which means that I should have been running premix. Uh, information I could REALLY have used BEFORE I ran my car at Daytona with straight gasoline! $3.99 worth of Valvoline two-cycle oil could have saved me over a thousand dollars worth of rebuild parts, and 18 months of no racing. But then I would never have started this blog, so I suppose everything works out.

Truthfully, this experience has been worth it to me, as I have learned so much about my car by doing this rebuild that it is worth it. By the time I get her back on the track I will know the car and engine inside & out…literally.

Anyway, so the other thing this dork of a previous owner did was to just snip off the oil injector lines without capping them. Not sure how much of an effect this vacuum leak would actually have on the engine, but it would certainly not help.

So, to business. I removed the oil injectors from both the rotor housings and the lower intake manifold, and plugged all four holes with 10mm bolts. Sorry, forgot to take pics of this.

Then I climbed underneath and installed the new exhaust manifold gasket and bolted up the exhaust headers. Below photo taken from underneath the engine. That was all for Sunday.

Then Tuesday afternoon Doug and I ditched work a little early and met up at the cave to try and finish things up.  We installed the distributor, spark plugs and wires. Luckily Mazda had the good sense to mark the top of the distributor cap with the spark plug positions. What a simple yet profound concept…how come all auto makers don’t afford us this simple convenience?

Then the new oil filter went in, the fuel rail and fuel injectors, the alternator & belt, and finally the upper intake manifold. Not much to tell about all that…pretty straightforward. I had all my nuts & bolts in clearly marked zip lock baggies from disassembly so it was just a matter of bolting parts on.

The tricky part was connecting up the electrical harness, as I had marked those with magic marker on duct tape (stuck to each plug/connector etc.) and many had worn off or faded so as to be ineligible.  After quite a while of trial and error and assessing wire and vacuum line shape, length etc. we finally got everything hooked up correctly (we hope).

We flipped on the power, ignition lights came on, fuel pump fired up, everything seemed to work fine.  Even though we had not put in fluids yet we just wanted to hear her turn over once or twice, so I hit the started button…and…nothing happened!  Oh bugger!  We’ll have to check the starter wiring and do a little troubleshooting on that but I doubt it will present a problem to our enormous brain power.

Next we went to install the radiator but found that I have apparently lost a vital piece from below the engine. There is nothing down there for the radiator to rest on or bolt on to.  I vaguely recall removing a skid plate type setup from below, but we scoured the shop and it is nowhere to be found. I’ll have to go back to the old house and hope that it is leaning up against the wall in a dark corner of the garage or fabricate something new to secure the radiator. Luckily we have all the tools available in the shop to cut, shape and weld metal.

So, the final punchlist grows shorter:

1. Install radiator.
2. Install airbox and hoses.
3. Troubleshoot starter.
4. Flush fuel cell and replace with fresh (premixed) gas.
5. Top off all fluids.
6. Fire her up!

We should be able to easily take care of all those items this Saturday.  After that we’ll turn our attention to an all-around brake job, suspension & alignment check (camber/caster), replacing a dented quarterpanel, and of course the very important new paint job (blue & white Mazda colors)!

So, until Saturday then,

Grant Boshoff
Thrust Motorsports

The 13B Rebuild Chronicles :: Chapter 7 :: Engine Install, Part 1

Well, the time has finally come!  All week I had been wanting to ditch work and just head to the man cave to work on my car. So, finally Saturday arrived and I got up early in order to get in a full day’s wrenching.  We had tickets to see Robin Williams this evening but he ended up getting sick and postponed the show, so I would not have to end off early. A bittersweet turn of events.

After some breakfast and a little web surfing to try and familiarize myself with the general install procedure, I headed to the shop.  First order of business was to put the car into the shop (it has been sitting on the trailer in our gated compound this whole time). I backed up the truck and got the ball centered perfectly under the tow hitch after only two tries (not too shabby), then dragged the trailer over and backed it up to the shop entrance.

I was alone, so didn’t even try and get the car off the trailer by myself.  Instead I assembled the cherry picker and chained the engine up to it, unbolted it from the engine stand, and hoisted her up.  Then i dropped it on the ground and, using a heavy duty pry bar to lock the flywheel, I torqued down the flywheel nut to 350 ft/lbs. Honestly, I can’t say whether I actually got it to exactly 350, but I used my air wrench which goes to 260 ft/lbs and then hand tightened it further with a cheater bar.

When Matt arrived around noon we unstrapped the car and rolled it off the trailer into the shop. This was quite a task as it would not roll smoothly. Felt like the rear end was seized up or brake calipers locked closed or something.  After some serious pushing & grunting we got her into the shop.  We jacked her up and checked each wheel and found that the driver’s side rear brake caliper was seized up.  I removed the brake pads from the caliper for the time being (so we could roll the car around the shop as needed). We’ll do a full brake job all the way around before she goes onto the track.

We took a lunch break, and did a shift change (Matt headed to the gym while Doug tagged in). Then the fun began. Doug and I hoisted the engine up, installed the clutch, and dropped the engine in.

The way we did this was to jack up the transmission so that we could mate it up to the engine before dropping it down fully onto the engine mounts. Once we got it wiggled in and a couple of bell housing bolts started, we then slowly dropped the jack under the tranny and the hoist at the same time, and seated the engine nicely onto the engine mounts. That done, we removed the chains from the hoist. Doug then bent down under the car to remove the floor jack and came back up with a small metal shim which looked suspiciously like those found inside the clutch pressure plate (doh!!).

So, we then took the engine back out, removed the clutch bolts, pulled the pressure plate out far enough out to be able to insert the shim back into its position, torqued it back down (20 ft/lbs), and reinstalled the engine AGAIN. Not actually that hard.

The next step was to install the fuel rail & fuel injectors, then the upper intake manifold, connect all oil, air & vacuum lines, electrical harnesses, and then fire her up.  Sounds pretty simple, right? Well, not neccessarily so.  The first thing that was seriously bugging me was the oil injectors (the two things sticking up out of the rotor housings – at the bottom of the white areas in the photo above). They had no lines running to them from anywhere that we could see, and I do not recall having disconnected any lines from them during disassembly.  This was of great concern because the purpose of these injectors is to lubricate the inside of the rotor housings. Without lubrication one would have dry metal (apex seals) on metal (rotor housing) unless you used a premix (two stroke oil mixed in with the fuel).

Unfortunately we ran out of daylight. Plus, even though we have power, we do not have internet access at the shop yet (not until I crack a local wifi network), so I would not be able to solve this mystery today.  We tidied up the shop and headed home for a well needed shower. I resolved to spend some time tomorrow figuring out what the deal is with the oil injectors.

Later,

Grant Boshoff
Thrust Motorsports

The 13B Rebuild Chronicles :: Chapter 6 :: Longblock Assembly

We now start our journey into terra incognita. Of the two rebuild DVDs I have, one (Atkins Rotary) ends after the shortblock assembly while the other (Bruce Turrentine) devotes a full three minutes, of a two hour DVD, to the longblock assembly.  So, from here we’re basicsally going by memory of what parts came off where, and the Haynes manually of course. However, because my engine is anything but stock, the Haynes manual is more of a general guide rather than a step by step procedural manual.

So, today we made less progress than last week, made a couple of mistakes along the way, but enjoyed it none the less…a day spent working on my racecar is never a bad day.

I hit the man cave around 10am and started the assembly of the front shaft in order to check the end play.

First I laid out all my parts, and got my laptop setup with Bruce Turrentine running.  Below is a pic of all the parts needed for this step.  I reused all originals except for the bearings, which I used new Mazda factory bearings just to be safe.

I also bought a new oil pump chain from Mazda, but decided to hold onto it for later as my existing chain is in perfect condition and already sized correctly.

First I slid the rear washer onto the shaft, then the spacer (a Y spacer in my case), the rear bearing, and the center plate. Then torqued the bolts down to 17 ft/lbs. By the way, these are the six shorter bolts of the twelve that are used for the stationary gears (the six longer bolts go on the rear stationary gear). I mention this to help anyone else that forgot to mark their bolts during disassembly as I did.

Next, I slid the front bearing onto the shaft (picture above).  Then took the front counterweight and inserted the washer into it (use a bit of petroleum jelly to make it stay in place), and slid it onto the shaft. Following that came the oil chain gear (teeth down), accessory gear (large chamfer facing down), and the front hub. I then inserted the key into the shatf and used a rubber mallet to tap it down into place through all the components on the shaft.  Using a large screwdriver between the counterweight and engine housing to stop the shaft rotating, I inserted the front eccentric shaft bolt and torqued it down to 95 ft/lbs.

Next step is to check the end play. I did not take a single photo of this step for some strange reason. Anyway, all that is done is to simply insert a screwdriver between the bottom of the front counterweight and the center plate, and lever it up. Using feeler gauges make sure that there is between 0.016″ and 0.028″. To round it up and make it simple, use a 0.015″ feeler gauge and ensure that it can slide freely between the counterweight and bearing. Then take a 0.03″ feeler gauge and make sure that it sticks (does not slide freely).

With that done, I then unbolted the front bolt and removed the front hub. I then pre-lubed the oil pump (using our assembly oil mixture), slid the chain around the oil chain gear on the shaft, and bolted the pump down onto the block (forgot to take a pic of that too due to leaving my third arm at home today).

To install the front cover, I painted the machined surface with gasket sealant, laid down the new gasket and dropped the front cover into place. I bolted it down using the original bolts, but found I had only five bolts, while six holes stared back at me. Hmm?  That would require a trip to Autozone later, but no big rush on that. However, when next I went to install the oil pressure regulator I found that I needed a 26mm socket, which I did not have.  So, to Autozone we go!

I picked up a bolt for the front cover (7 x 1.0 metric if anyone’s interested) and a 26mm socket ($7.15 for the socket, yikes!). Upon my return I was happy to note that the new bolt fit perfectly. I then put the front pulley back on and re-torqued the front eccentric shaft bolt.

The problems began, however, with the oil pressure regulator.  The socket and ratchet would not fit between the housings in order to tighten it down. In the pic above you can see the hole into which the oil pressure regulator goes: top right corner of the picture, in the grey metal end plate…see the center plate above it with the cross beam..yeah, not enough space to get the socket over the regulator.

About this time the cavalry arrived in the person of Doug K.  The one thing I love about Doug is that he is always calm and always totally confident that a solution is within reach no matter how hairy the situation. We tried different ratchets, adjustable open wrenches, and so on. Nothing would fit into that tight little space in order to tighten down the regulator. The only thing that MIGHT have a chance of success would be a 26mm closed wrench…but where in the heck would we find one of those?

So, Doug scrounges around the shop and spots a couple large open wrenches hanging off the side of [my shop partner] Ralf’s drill press. Long shot, probably not metric. One is 1 1/4″. The other looks smaller, probably 1 1/8″. Let’s look at it and check anyway.  It is smaller, what…no way…how could it be…what are the chances: 26mm!!  I grab it, use the closed end, it slides perfectly over the oil pressure regulator with room to turn, crank it down, and move on.

Next was to bolt down the oil pick-up, which was a simple two bolts that took us almost three hours to install. I won’t bore you with the gory details but suffice it to say that it involved an inaccurate torque wrench, a snapped bolt, a drill, a broken drill bit, a broken “easy out” bit, a tap set, a couple pounds of aggravation, swearing, sweat & tears thrown in for good measure. That done, we went to install the oil pan gasket and found the one in my Mazda rebuild kit was the wrong size for my “non-stock” engine. So we used a thick layer of grey RTV instead and installed my oil pan splash guard (definitely not a stock item).

Then more RTV and the oil pan went on. This is a totally candid shot…no posing here.

And two dozen bolts later…

Next, after lubricating the rear main seal with some petroleum jelly, we inserted it into the rear stationary gear and used a block of wood (wrapped in a shop towel) and a hammer to press it in until flush with the top of the gear.

The woodruff key was inserted into the groove in the eccentric shaft, and then the flywheel installed.

We let Matty do the honors by handling the flywheel nut.

We tightened down the flywheel nut, but did not torque it fully as this needs to be done when the engine is off the stand (so that the flywheel can be braced against the floor to prevent turning). Once the longblock assembly is complete, and the engine off the stand, we will apply blue locktite to the eccentric shaft threads, some gasket sealer to the flywheel nut, and torque it down to 350 ft/lbs.  For that we need a good size torque wrench with a cheater bar most likely and a big-ass socket (2 1/8″).

Lastly, we bolted on the intake manifold and water pump with pulley. Both of these took new gaskets from the rebuild kit, and gasket sealant of course.

And that pretty much wraps it up for this weekend. Not as much progress as I had hoped due to the hiccups along the way, but she is at least a number of steps closer to being on the track; and that, in the final analysis, is what counts.  Next weekend I hope to get the balance of the longblock finished (dreading having to figure out where all those vacuum lines go) and actually drop the motor into the car.  Maybe, if the racing gods are smiling, we might even be able to hit the ignition switch.

We’ll see you then,

Grant Boshoff
Thrust Motorsports

The 13B Rebuild Chronicles :: Chapter 5 :: Shortblock Assembly

Okay kids, this is it!  We are finally ready to assemble this joker.  Mid-afternnon, Saturday, the fun began. Matt had left to play golf (golf over wrenching on an engine? I know, right?), so that left Doug and I get the job done.

First we bolted up the front end plate to the engine stand and got it positioned in close proximity to the work bench.

Next, we installed all of the water jacket seals in both sides of both rotor housings. This was a tad confusing at first because the rebuild DVDs showed these being installed into the end plates and the center housing, while my engine has flat surfaces on those sections, and the seal grooves in the rotor housings.  Apparently the different series of 13B engines have slightly different configurations. We got that sorted, and proceeded to install the seals. I just squirted Hylomar into the seal grooves on the housings and then inserted the seals and pushed them into place with my fingers.  This got a bit messy as the Hylomar squished outof the grooves, onto fingers, and when dry it turns into sticky rubber which is close to impossible to get off your fingers without the use of something toxic like carb cleaner or mineral spirits.  Next time I will get a small paintbrush and use that to paint the Hylomar into the seal grooves instead.

Then we inserted the metal dowels into the front end plate and dropped the front rotor housing down onto it, first painting the bottom “legs” of the end plate & housing with the brushable gasket sealant. Next came the rotor. This was first lubed up with the assembly oil mixture (on the gear teeth and bearing) and placed inside the housing with the “triangle” pointing to the twelve o’clock position.  Then we simply dropped the eccentric shaft down into the rotor, and carefully slid it inside the rotor bearing.

Next came the installation of the small corner pieces of the apex seals. I forgot to take pics of this but essentially what has to be done is that the apex seal springs need to be pushed down with a small screwdriver and then the corner pieces pushed into the open end of the corner seal. Use a sliding motion from the top (up against the rotor housing, down toward the rotor center) to ensure that the corner piece gets above the apex springs.

Then, remembering to paint the legs with gasket sealer, we slid in the metal dowels and dropped on the intermediate housing. The trick to this is that you need two people. One has to slowly lower the housing down over the eccentric shaft (because the housing is a solid plate with just a hole in the middle) while the other lifts the eccentric shaft up an inch or so. You then tilt the housing so that it pops uver the bulge in the shaft and lower it down into position. Then drop the shaft back down again. Should have taken some pics of that but we didn’t have enough hands (literally).

Then we added the rear rotor housing. Repeating the same procedure as before we dropped the rotor inside the housing, this time pointing it downwards to the six o’clock position, and installed the corner pieces of the apex seals.

Nearly there. Getting pretty excited! In the picture above you can see clearly what I mean when I say “paint the legs” with gasket sealer (the red areas at the bottom of the housing).  The red tint you see on the rotor is Marvel Mystery Oil which we liberally spread on all end plate and rotor surfaces.

Finally, we set the end plate onto the stack and inserted the rear stationary gear. This was a bit tricky as the gear did not line up at first with the gear teeth on the rear rotor. Doug had to rotate the eccentric shaft a little by hand until the stationary gear dropped into place. Next, we inserted all eighteen of the tension bolts. These bolts run the entire length of the block and hold it all together.

Doug has to take off, which left me to torque down the tension bolts all alone   The tension bolts are supposed to be torqued to 28 ft/lbs, and have to be tightened down in a specific sequence.  I had a diagram drawn (from when I disassembled the engine) but it did not match with the sequence Turrentine appeared to be using in the DVD, so we consulted the Haynes manual and went with that. After hand tightening all the bolts, we cleaned the heads and used a magic marker to number them for future reference.

My torque wrench starts at 25 ft/lbs, so I could not use it to do a logical 10 lbs, 20 lbs, 25lbs, then 28lbs step up procedure. I had to do it by feel ie. tighten each bolt, in sequence, to a snug feel (not tight) then repeat over and over until they were tight enough to register on my torque wrench.  Then I torqued them all to a perfect 28 ft/lbs and called it a day!

Once I stopped working I suddenly realized how sore my feet, back, and various other body parts were! Ouch. I cleaned up the shop, took a few photos of my beautiful engine, and headed home for an extra manly hot bubble bath!

So, here she is. Isn’t she gorgeous?

See you next weekend!

Grant Boshoff
Thrust Motorsports

The 13B Rebuild Chronicles :: Chapter 4 :: Rotor Wet Assembly

Okay, the time had finally come to start the REAL assembly!  After months of procrastinating, ordering parts, cleaning parts, etc. the moment of truth was upon us!

I awoke early today and, after a brief stop at Pangea Cafe (our local coffee spot) for a hot cup of African Nectar (aka Rooibos) tea and some eggs & bacon, I headed to AutoZone for supplies.

Here’s what I got, all of which is needed for the complete longblock assembly (pictured from left to right):

• STP Engine Treatment (to make  an assembly oil mixture with 50/50 STP and regular motor oil).
• Marvel Mystery Oil
• Oiler can (for the assembly oil mixture)
• Spreadable gasket sealant
• Hylomar
• Anti-seize Thread Lubricant
• RTX Silicon Sealant (Permatex Ultra Grey 599)
• Blue LockTite
• Red LockTite
• Paper Towels (not pictured from here in the list)
• Rubber bands
• Scotchbrite pads

First up, I pulled out all my new corner seals and springs (Atkins Rotary solid corner seals), apex seals & springs, side seal springs, oil rings etc.

Cutting open the Fedex box in which my rebuild kit had arrived i used it as a working surface to do the wet assembly.  I knew that there would be a lot of petroleum jelly flying around and did not want to get the carpetted surface of my work bench soaked with it as it would be difficult to get out later.

Following along with Bruce Turrentine’s rebuild DVD I installed the oil seals. Here you can see the rotors with the oil seals installed in the first one:

Shortly thereafter Doug arrived, followed by Matt, which made me happy.  It’s always better to share such experiences, and much valuable male bonding can result from these man-cave adventures.

Matty did one rotor while I did the other. Doug provided quality control and guidance (as he was flipping back and forth between the Bruce Turrrentine and the Atkins Rotary rebuild DVDs).

We installed the corner seal springs & seals, then side seal springs and (previously sized) side seals using copious amounts of KY to keep everything in place.

Then came the install of the apex seal springs and apex seals (except for the small corner inserts). I am using the two-piece Atkins Rotary apex seals (2mm), so the large piece is installed, with the pointed end facing rearwards (toward the flywheel side of the engine), and the corner inserts are added during the longblock assembly, once the rotors are inside the housings.

And finally, we wrap the rotors with rubber bands to hold the apex seals in place until later (just in case the gobs of KY weren’t enough).

Grant Boshoff
Thrust Motorsports

The 13B Rebuild Chronicles :: Chapter 3 :: Rotor Dry Assembly

Last week I finally settled on which rotors to use. After purchasing numerous set (on eBay) I finally found one (out of six) that was acceptable for use.

The first two I bought were in rough shape. They had heavy carbon deposits and badly worn bearings.

The second set were the wrong year (and hence the wrong weight and compression ratio). The eBay seller had listed them as 86-88 rotors, which is what I needed (even though my car is an 83 GSE-LE body and engine, the rotating assembly is from an 86-88 13B engine). Upon receipt of the rotors I was excited at first. Taking them out of the box they looked great. Clean and shiny, great looking teeth and bearings. But something was wrong…too shiny. Hmmm. I looked closer and found that the shiny appearance was a result of a textured surface reflecting the light ie. CNC mill lines running the length of the rotor faces.

Up until 88 Mazda cast their rotors. From 1989 onwards they started milling them, so you can easily see the difference in the surface texture (see above photo). What the heck? This guy had sold me the wrong rotors! Pissed me off at first. Then I made lemonade. The 89-91 rotors are lighter weight (about 9.5 lbs compared to around 10 lbs) and higher compression (9.7:1 compression ratio compared to 9.4:1 on mine) and are therefore more valuable as they are a popular performance upgrade on 13B engines.  So, I popped them back on eBay and sold them for a $100 profit, and used the dough to order my third set of rotors.

The third set finally arrived and were gorgeous. Both rotors still had their original gold tone on them, and were in overall close to mint condition.

So, today I then began sizing my new side seals.  I pulled out my set of new Atkins Rotary side seals and set to work.  In order to trim the seals down I got two pieces of fine sand paper (from an orbital sander so they had an adhesive backing) and stuck them onto a granite slab. I used 150 grit and 220 grit paper. I found that the seals were much longer than needed and would have taken me way too long to trim on the sandpaper, so I took a grinder with a fine grain wheel and inserted it into my bench-mounted vise. I used that to do the bulk of the trimming and them fine-tuned it using the sandpaper.  I trimmed all side seals to between 0.002″ and 0.006″.

Because each side seals is slightly different size, I used two folders to keep track of each rotor and taped each side seal onto them. Here’s how it looked when done.

Grant Boshoff
Thrust Motorsports

The 13B Rebuild Chronicles :: Chapter 2 :: Engine Painting

Okay, this may not be the most important part of rebuilding the 13B, but I needed it to give me a morale boost.  Here’s what has happened since my last post in November: not much!  I kept putting off starting the rebuild due to never quite having the appropriate funds available for the rebuild kit and replacement rotors that I needed.   Between the two one would normally spend about $1100-$1400. So, I lost myself in the holiday season and only just emerged a couple weekends ago to start the process in earnest.

With the new racing season fast approaching (Feb) I made a commitment to really get cracking and get my car done so that I can race a full season this year.  I jumped on eBay a week ago and, lo and behold, found someone selling a brand new, still shrink wrapped, Atkins Rotary master rebuild kit…for only $600…score!!  I scooped that up and at the same time found a set of decent used rotors for $56.  Hurdle number one jumped.

Then last weekend I went Harbor Freight and picked up their 1,000lb engine stand. I messed around for half a day trying to find a metal shop locally who could build me an engine stand adapter – like the ones that Pineapple Racing sells – only to discover that I really didn’t need it.  Not sure if it is just a myth or if Harbor Freight has changed their engine stands, but my end plate bolts up directly onto the engine stand without need for an adapter!  Another $60 saved!  My Scotch ancestors are smiling down on me

I then drove all the way to New Port Richey to pick up a parts washer from Harbor Freight there. The local Harbor Freight had a run on parts washers (yah, believe it). They sold their entitre inventory of parts washers out in one day, and it caught them so off guard that they couldn’t reorder in time to get a few of the 300 sitting in their warehouse to the store. Strange, but true.

Alright, finally to the good stuff.

This weekend, I hit the shop and with my hands submerged in mineral spirits proceeded to clean of and prep my end plates, rotor housings etc.  I got them all nice and clean and proceeded to paint them. I chose traditional Mazda blue and white color scheme.  I spent a lot of time masking off all contact surfaces where gaskets would need to be mounted as well as bolt holes, etc. etc. Not sure if I needed to be that anal, but I figured I would rather spend the time and do it right than blow my engine out because of a bad seal caused by paint where it doesn’t belong.

Here’s the photo story:

Beautiful, ain’t she?  How is it that a man can feel this way about hunks of metal?  It is a wonderous thing.

Grant Boshoff
Thrust Motorsports