Beck TD, Part 40 - Blocking the Heater

Now that I got my throttle linkage sorted in Part 39, I am continuing to work on tasks I want to accomplish before and during an engine swap. Yesterday, I visited Joe Lazenby to check out the Volvo B18 engine I'm buying to "temporarily" replace my current one, which recent posts proved needs major work. As we stood evaluating the running engine, I asked about the plumbing for the heater.

The Volvo water pump is different from any other I've seen. It uses o-rings to seal to the cylinder head, and to two pipes that exit the side. One goes to the radiator, and the other goes the entire length of the block to attach to the heater core. I previously saved this Internet photo that shows it clearly (circled in yellow here), but I failed to document the source. If you know where it came from, I would love to credit the owner.

It's worth noting that this particular engine has the pipe extended to terminate behind the engine. I presume that was that particular builder's solution to exactly what I was trying to accomplish - to omit the heater. Beck TD has an incredibly ugly installation of a tiny heater that couldn't have helped much, and I have been using a section of rubber hose to bypass it and connect to the return at the back of the block. Now would be a perfect time to clean that up. While the engine is out, I hope to remove that heater and weld up the hole also.

Joe was of the opinion that the plumbing can be omitted and the outlets blocked. I asked how to do that, and he said, "You'll have to make something." Oh boy! My favorite thing - making odd parts.

I did a bit more research, and found a photo (at this link) of a racing engine on a dyno. On that engine, it appears that the hole was blocked with weld or epoxy and painted. That settles it - if a racing engine can block it, I'm sure my street engine can. However, I wanted mine to be reversible. Who knows - maybe this engine will be returned to a Volvo someday, and will need a heater to be hooked up.

Here's what I needed to duplicate - the end of the pipe that goes into the water pump, sealed by a rubber gasket, and held in place under one of the bolts that secures the water pump. It is upside down in this photo:

I measured, and it was a reminder that dimensions were simpler back in the day when calculations were done with a pencil. The pipe is 5/8", the sealing ring is 3/4", and the pipe stub is 1/2" long. It was easy to use the lathe to make a matching plug and check its fit in the water pump:

After that, I marked the spot where the plug exited the pump, and used the milling machine to create a flat for attaching a bracket. That was a cut and try operation, but after several tries I had the depth right.

I made a simple bracket that would marry the flat spot on the plug to the face where the mounting bolt would seat:

I did a test assembly, and marked the spots where the holes should be on the plug. It took just a few minutes to drill and tap them for 6-32 socket head cap screws.

I removed the piece from the collet in the milling machine, cut it off on the band saw and trued it up on the lathe, and then assembled everything.

Matching the original photo of the pipe, the water pump is upside down here. That plug is a tight fit in the seal, and I have high hopes that it will not leak. I still have to plug the end at the block also, but that should be a standard pipe plug that can be threaded into the block.

We won't know whether this works until I have a running engine again. When I do I'll update this post and tell the results!  UPDATE  Works great! No leaks! END UPDATE

Continue on to Part 41...