11 BMW 1983 R100RS Install Engine in Frame

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.

Video

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.

Engine Mount Studs and Hardware

Engine Threaded Rods and Hardware

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.

Frame Rails Protected with Packing Wrap

Frame Rails Protected with Packing Sheets Folded Over

Foam Packing Sheet I Use To Protect The Frame

Foam Packing Sheet I Use To Protect The Frame

I had the frame powder coated, by I dialed down the gloss level.

Frame Back From Powder Coating

Frame Back From Powder Coating

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.

Location of Frame Serial Number on Lower Right Bottom Rail

Location of Frame Serial Number on Lower Right Bottom Rail

VIN Is Faint But Visible

VIN Is Faint But Visible

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.

Engine Ready To Pickup And Install In The Frame

Engine Ready To Pickup And Install In The Frame

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.

Engine Installed To The Rear Of Frame Inside Frame Rails

Engine Installed To The Rear Of Frame Inside Frame Rails

2x4 Under Inner Timing Cover Prevents Engine Tipping Forward

2×4 Under Inner Timing Cover Prevents Engine Tipping Forward

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.

Rear Frame Hole For Engine Stud

Rear Frame Hole For Engine Rod

Gap Between Engine Block and Frame Tab

Gap Between Engine Block and Frame Tab

Spacer Goes Here

Spacer Goes Here

Right Rear Engine Stud Spacer Installed

Right Rear Engine Rod Spacer Installed

Sliding Rear Engine Stud Through Holes In Frame and Engine Block

Sliding Rear Engine Rod Through Holes In Frame and Engine 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.

Rear Engine Stud Installed

Rear Engine Rod Installed

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.

Spacer Between Frame and Engine Block

Right Front Spacer Between Frame and Engine Block

Front Engine Stud Installed

Front Engine Rod Installed

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.

Harbor Freight Motorcycle Stand with Plywood To Protect Oil Pan

Harbor Freight Motorcycle Stand with Plywood To Protect Oil Pan

Engine & Frame On Sitting On Plywood on the Motorcycle Stand Arms

Engine Sitting On Plywood on the Motorcycle Stand Arms

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.

Engine & Frame Strapped to Motorcycle Stand

Engine & Frame Strapped to Motorcycle Stand

Protecting The Powder Coat From The Ratchet Straps

Protecting The Powder Coat From The Ratchet Straps

Protecting The Powder Coat From The Ratchet Straps

Protecting The Powder Coat From The Ratchet 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.

Torque Engine Mount Nuts To 55 FOOT-Lbs

Torque Engine Threaded Rod Nuts To 55 FOOT-Lbs

Torque Engine Mounting Stud Nuts

Torque Engine Threaded Rod Nuts

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.

4 thoughts on “11 BMW 1983 R100RS Install Engine in Frame

  1. Thanks for your magnificent site, of tremendous practical value, that I refer to constantly. Your educational skills are outstanding and the clarity of your instructions in unheard of. I have a question. I have cleaned and lubricated the clutch on a R100R year 1995, only 40000 km, the clutch disk and other items did not exhibit any significant wear. I had removed the studs supporting the engine, in order to move it slightly to the front I had carefully (it seemed) noted what the front and rear stud were, the right and left side and associated washers spacers (a combination, not a single washer spacer per side on my bike) And now I have my doubts, wondering if I possibly made a labelling mistake while cleaning the parts. Is there any way to check the proper centering of the engine-gearbox assembly in the frame ? In other words, should the spacers between the engine and the frame have the same combined thickness on either side (right and left) as suggested in your post, for both front and rear studs ? Also, could it be any possible difference of combined thickness of the spacers between the front and rear studs, as this seems likely to me in the original assembly ? Rgds from France, from a Denver and Colorado lover as well…

    • Good Morning Yves,

      Thank you for your kind words.

      Unfortunately, I have not worked on any of the later mono-shock bikes so I’m not knowledgeable about the details. I do know that the foot pegs and engine mounting hardware changed.

      I’m sorry I can’t be of assistance to you.

      Best.
      Brook.

  2. Hello Brook, What size are the engine mounting rods? Does EME carry these parts? Thank you
    I really enjoy you tutorials on this build because I’m in the process of rebuilding
    my R75/6 but with only 19K on the bike but not ridden since ’07

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