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

24 02 2009

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.rear_end_plate

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




2 responses

15 01 2010

Just wondering what brand of. Rebuild kit u got as well as price if u don’t mind me askin. I checked with a company by the name of Pineapple Racing, very knowledgeable company and great quality work from what i here, but they want $3,500 for a complete rebuild with 5 year warranty. That I cannot afford. Thus I must do it myself and already have the motor sitting on cleen rags and tire on work bench.

15 01 2010

I used the Atkins Rotary Master Rebuild Kit with the solid corner seals. It’s normally around $800 but I got lucky and found a new, unopened one on eBay for $600.

As a side note: although I never actually bought anything from Pineapple Racing I have called them often for help & advice. Rob is very friendly and willing to give advice on rotary engines freely. Very cool guys!

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