Replacing cam follower bores (and followers).

Replacing cam follower bores (and followers).

I really do not know how this type of damage occurs!

Looks as if it was squeezed in a vice or something. 

In any case, new follower bores and followers will be required...

A new follower bore is cut on the lathe from bronze bushing material.

The case is heated to over 250'F and the chilled bushing is inserted.

The bushing is honed to the final dimensions. Here I am using a fixed hone, however the final hone may be done with an adjustable hone and/or a brake hone.

Final fitment is done using the new followers.

Cylinder Boring and Honing Services

Scottie's Workshop has a full service motorcycle Machine Shop specializing in vintage BMWs.

One does not remove engine cylinders everyday; normally it is part of a major engine overhaul. So we don't just bore and hone cylinders; we refurbish them.

First, push rod tubes are removed and the cylinders bead blasted to remove all rust and old paint.

The cylinders are then bored and honed cylinders in the time tested way: on a boring machine or engine lathe based on the measurements of the new pistons.  Honing is done using Sonnen style parallel stone hones and cylinders will be cross hatched with a ball hone.

Pistons are weight matched and we can lighten your wrist pins about 14 grams for an additional $75.

Piston skirt clearance is determined by the piston manufacturer. When possible we prefer to use new KS pistons (many of which we have in stock).

The cylinders are then taped up and painted with high temp semi-gloss black and baked in the oven to cure.

Pushrod tubes can be cleaned and reused if desired, or we can install new ones made from stainless steel.

Machine Shop time to bore and refurbish a pair of cylinders is about 2.5 hours. We can provide services individually if you like.

When shipping cylinders to us, DOUBLE BOX each cylinder and insure them for damage.  They are quite delicate!!
 

We will only bore cylinders if you ship us the pistons to be used. 

We hone based on the measurement of the piston.

Even pistons from the same manufacturer vary; we do not recommend boring/honing "on spec".

We can bore your cylinders with the push rod tubes installed, if you wish.

Your cylinders and pistons will be shipped back to you cleaned, oiled and ready to install.

Shop made tools: castellated nut socket

Special tools are very helpful in certain situations. The challenge with most castellated nut sockets is that they typically four points. The sockets slip off the nut, or the points become rounded or break off. I wanted to build a socket that encapsulates the nut, can't slip off, and has replaceable points in case of wear or breakage.  The socket has a standard 1/2" square drive.

If you would like one of our sockets, they are $249.95 plus shipping.  Please call us to place an order.

Holes are located and drilled on the Bridgeport using the DRO. The holes are slightly smaller than the pins chosen to fit into them.

The ID and OD of the socket is shaped on the lathe.

The pins are inserted.

This socket is designed for an M14 castle nut.  

The nut is held securely by the socket which can't slip off.

Repairing engine block crash damage

Scottie's Workshop can repair some damaged BMW engine blocks. If you have a damaged block you'd like to save, please call us to discuss.

Here are some photos of a recent repair we did to a damaged R67 block.

The stud hole is cracked.

The engine case is bent nearly a millimeter.

The case is cleaned and bead blasted.

The cracks are stop drilled and cylinder face is tig welded and peened.  

The new face is flycut.

The cylinder studs are located using DRO and steel timesert threads are installed.

The repair is complete.

Repairing worn tongue and groove slot in front brake backing plate

The tongue and groove slot which holds the front brake backing plate on many vintage models of BMWs often becomes worn. This results in annoying click or clunk whenever the brakes are engaged, or when the bike rolls to a stop.  Scottie's can machine these new parts to "like new" condition to repair this problem. Machine shop time is about 2 hours. Call us for details.

Once new metal is added by TIG welding, the part is machined.

The result is a precise "like new" part and a precise fit.

Drilling RHS oil galley in early twins blocks

Early blocks did not have RHS piston skirt oiling galley. This often leads to overheated RHS pistons and piston/cylinder scoring, and sometimes engine seizure. Scottie's can machine your block to include the oil galley, exactly like the later engine blocks. Machine shop time is about 3/4 hour. Call us for details.