Chapter Log

I bought my engine mount from the CozyGirrls. It's a beautiful piece of work. I haven't taken a photo of it yet, but it's exactly what their site shows as a picture, so I just used theirs. Hope they don't mind!

Instructions from the CozyGirrls:

Mazda Rotary Engine Mounting System
Installation Instructions for 13B/Renesis and 20B – preliminary.

This is specifically to mount a CG Products bed mount that extends to the CG Products redrive mounting plate and utilizes a CG Products redrive mounting plate with the starter located on the plugs side of the engine.

Before You Start You Will Need

Tools Required

-inch/lbs torque wrench
-ft/lbs torque wrench
-ratchet
-18mm socket
-18mm combination wrench
-5mm allen wrench
-5mm male hex socket to torque
-7/16” socket
-5/16” combination wrench
-1/4” dia rat tail file
-1/8” dia drill bit
-1/4” dia drill bit
-9/32” transfer punch 
-electric drill
-safety wire pliers

Other Materials required

-grey liquid gasket
-acetone
-Loctite #
-.032” stainless safety wire

In addition we strongly recommend an engine stand and an adapter that bolts to the side of the engine is commercially available or easy to weld your own.

First and foremost make sure the bottom of your engine and your oil pan are spotlessly clean, down to clean metal with a fresh single edge razor blade, then acetone. Run an appropriate size bolt in and out of each threaded hole or better yet a clean tap. The large holes in the engine iron are M10x1.25p metric threads, the pan bolt threads are M6x1p metric threads. The threaded holes in the aluminum adapter plates are AN-4 (1/4-28 UNF-2B) Appropriate fasteners are supplied for all holes.

Due to the “stacked sandwich” nature of the engine construction there will be some variances in hole placement as well as a large variety of front cover holes where it mates to the oil pan. To partially compensate it appears Mazda used holes in the oil pan approximately 50% larger than the fasteners. The holes in the bed mount plate are .250” diameter and a close fit to the 6mm pan bolts. The Message here is that while we managed to get the holes located as closely as possible, with tolerances, gaskets and sealers there is a variance from engine to engine in the hole placement and the further you get from one end to the other the greater the tolerance stack-up so be prepared to do some fitting.

That said, the fit at the flywheel end is the sacred and critical portion of the installation.

First you want to rotate the engine on the engine stand with the flywheel end straight up. Fit the redrive plate (without the redrive is easiest) to your engine placing the spacers and bolts as shown in figure 1.0. Do not use Loctite at this time. Make sure all fasteners are at least two turn loose. Insert the reduction drive shaft through the seal into the flywheel pilot hole; make sure the shaft is seated all the way up against the redrive mounting plate. Make sure there are two flat washers under the head of the lower left 10mm bolt per figure 1, this is a blind hole and the bolt would otherwise bottom out. Install the starter with the bolts two turns loose.

Begin to fit the bed mounting plate. It goes on with the cavity side down towards the oil pan. Again you will want all screws to be two turns loose. You should be able to fit most of the screws as far forward to at least the middle iron. Before adjusting any of the holes remember the objective is to end up with the redrive plate on the end of the engine with absolutely centered on the driveshaft per Real World Solutions installation directions then with no stresses on it induced by the bed mounting plate. This can only be done through careful fitting and adherence to procedure.

With installing the pan, and dry fitting the bed plate with the majority of the pan bolts in place beginning on the flywheel end of the bed plate, gently tighten up the socket head cap screws then back off a half turn. You will need a thick washer under each one to prevent it from bottoming out in the blind holes.

With the drive shaft in the pilot of the eccentric shaft, adjust the redrive plate so that it is approximately parallel with the bottom of the bed mount plate. It may be slightly above or below the bottom edge of the bed mount plate. Slowly tighten each of the large M10 x 1.25 reduction drive plate mounting bolts. When they are all snug, temporarily tighten each one in an alternating cross wise pattern.

Rotate the engine on the engine stand to place the bed mount on the top. Using a fine point permanent marker, place a check mark next to each hole that is correctly aligned, you should already have a bolt in it. Use a magnifying glass and a flashlight to first determine a vector (direction) to adjust a hole and with a scale or pair of vernier calipers try to guesstimate an approximate distance. In the case of holes that do not show a matching threaded hole underneath, place an “X” next to them. Remove the bed mounting plate. Filing the holes is best done with the plate clamped flat on a bench with the hole hanging over the edge. Place a piece of wood between the clamp and the aluminum to prevent marring the plate. Use a course ¼” diameter rat tail file. File in the direction of the vector marked, check progress by adding .250” to whatever the guesstimated distance was and measure the slotted hole with calipers.

In the case of holes that are completely mismatched, please make a sketch or picture and mark the image and send it to us. In the future, holes with variable positions from year or model will be left out entirely rather than try to fit the majority. It is easier to mark and drill holes for a particular engine than file to match.

Fill the completely mismatched holes with grey gasket sealer, clean one side and apply tape over the hole, set tape side down till sealer sets through. Double check that you have the correct oil pan for your engine, set it on the hollowed out side of the bed mount plate. Align it with each hole starting at the flywheel end, very carefully checking to see that the side holes are aligned straight. With it aligned and centered to the flywheel end of the pan, use a hot glue gun to secure the flange to the bed mount plate.

Use a transfer punch the same size as the hole in the pan sheet metal to mark the centers of the holes that are misplaced for your engine and front cover. Use a center punch and hammer to enlarge the center marks. Pilot drill the holes with a 1/8” drill, use a drill press if possible. Drill the holes out to .250”, use a drill press if possible.

Repeat the previous procedure test mounting and marking the bed mount plate, always give priority of fit to the flywheel end, adjust the other holes for a free and easy fit.

When satisfied with the fit, loosen the bed mount fasteners and make sure the lower standoffs align and the AN-4 bolts will go in properly, adjust those holes in the base plate if needed as well.

When done with the holes and satisfied with the locations, use a countersink to lightly chamfer the new holes to remove any raised burrs.

NOTE: in the following instructions, pay very close attention to whether you are using INCH pounds or FOOT pounds of torque. All threads in holes and on fasteners must be clean and free of oil or other contaminants.

Tighten the bed mount firmly first to the redrive plate then the pan mounting surface of the engine but do not torque it down. Remove the redrive plate and install the Real World Solutions reduction drive to the plate per the manufacturer’s instructions. Install the redrive plate on the engine using Loctite on the threads of the bolts, torque the M10x1.25 bolts to 37 ft-lbs in an alternating pattern.

Remove the bed mount plate. Wipe the bed mount plate with solvent on both sides. Wipe the gasket surface of the engine with solvent. Apply grey gasket sealer to the engine gasket surface and the underside of the two bottom standoffs, make sure there are no voids and go on both sides of bolt holes.

Place the bed mount plate on the engine and align with a bolt in each corner, tighten down very gently, remove the bolts and install the pan in the same manner to the plate. Use only a screwdriver type of hex driver to very gently drive the pan bolts in place. Clean the excess that squeezes out as you go. Allow the assembly to sit undisturbed for 24 hours.

Using a torque wrench set to 7.13 foot pounds; tighten the pan bolts in an alternating pattern a little at a time on each bolt until you reach the indicating torque. Tighten the four AN-4 bolts to 50 inch pounds. Apply Loctite to the threads and tighten the four AN-4 bolts on the bottom edge facing the prop to 50 inch pounds.

Always remove the engine from the tubular mount should it be necessary to remove the bed mount plate from the engine. Always install the bed mount plate in this manner, do not attempt to place the engine on the bed mount plate with it installed on the tubular mount, oil leaks will result and it will be difficult to properly align the engine and plate without inducing stress.

Install the vibration isolation rubbers up through the four holes in the bed mount plate. Torque the four bolts to 50 foot pounds. The bolts go up through the vibration isolators. Once they are torqued they are wiped with acetone on the nuts and bolt threads then safety striped with thinned red nail polish, a 1/16” wide stripe is sufficient to indicate if the nut has turned on the bolt, inspect frequently!