I’m at the point where I can complete the rest of the engine work while it’s in the frame. It’s easier to install it if the cylinders and pistons are not installed as that lightens the engine and it’s less unwieldy to handle.
Here is short video of getting the engine in the frame.
VIDEO: 1983 BMW R100RS Install The Engine In The Frame
Engine Mounting Hardware
The engine uses two long threaded rods, one in the front and one in the rear that fit through holes in tabs in the frame. There is a spacer the fits between the inside of the frame and the outside of the engine block so securely clamp the engine in the frame. Each rod uses a spacer on each end. Each end of the rod has a wave washer and a nut. I’m using new stainless steel nuts and wave washers.
Protecting The Powder Coat
I use a foam wrapping material to protect the frame tubes so I won’t chip the powder coat when I put the engine in the frame. I take a sheet and fold it over several times and secure it with masking tape.
I had the frame powder coated, by I dialed down the gloss level.
Location of Frame VIN
The VIN number is stamped into the lower right frame rail next to where the rear engine rod goes. It matches the one on the engine, although it’s faint and not easy to read.
Putting Engine In The Frame
The engine is front heavy and will tip over to the front easily. I put the engine on the floor and put a 2×4 under the bottom of the inner timing cover to keep it from falling over. When I’m ready, I pick it up and insert it into the frame from the right side keeping it toward the rear of the frame where there is more room to install it without it bumping into the steering head reinforcing tube on the bottom of the spine tube.
Then I slide the frame back so the engine moves toward the front of the frame so the holes in the block line up with the holes in frame tables. I put the 2×4 under the inner timing cover to stabilize the engine.
I install the rear rod first. There is a gap between the block and the frame. I put one of the spacers in the gap, pull the frame up a bit to align the hole in the frame tab with the hole in the engine block and push the rod through the frame, the spacer and into the hole in the block.
Then I use a plastic mallet to tap the rod through the block until it starts to come out the other side. I install the second spacer between the engine block and the frame, and tap the rod until it passes through the spacer. I have to wiggle the frame a bit to get the hole in the frame to align with then rod and then I tap the rod through the frame. I adjust the rod so the ends are equidistant from the frame.
It’s easier to install the front rod as I can pivot the frame on the rear rod to align the frame holes with the engine block holes. Again, there is a spacer on each side of the engine block between the block and the frame.
Put Engine and Frame On Motorcycle Stand
I have a Harbor Freight motorcycle stand. I collapse it all the way down. Then I bend my knees and pick up the frame with the engine by the spine tube by straightening my knees. I carefully move the frame with the engine over the stand and place the oil pan on top of the plywood. I estimate the frame with the engine weights about 60-70 pounds. The plywood will distribute the weight of the engine uniformly so there won’t be any high stress on the oil pan.
I use two ratchet straps to secure the engine to the stand and elevate it to the highest level which is a comfortable working height when sitting on my stool. I protect the powder coat from the ratchet straps with some of the packing sheets under the straps.
Torque Engine Threaded Rod Nuts
First I adjust the rods so the exposed threads are equal on each side. Then I use a box end 19 mm wrench on one nut while I torque the other with a torque wrench set to 55 FOOT-Lbs to secure the engine in the frame.
I’ll have to remove the left rear nut when I mount the Brown’s side stand, but I won’t do that until I’m ready to install the exhaust because the side stand bracket uses the bolt through the header bracket along with the rear engine threaded rod to secure the side stand bracket.
I always treat getting the engine installed into the frame as a milestone. At this point, things start coming together instead of staying disassembled.