The OVS on the Alfa has been a well discussed topic on the ALFA Bulletin Board. Apparently it is a component that is subject to failure, although in fairness, I don’t expect that Alfa engineers ever expected this part to last over thirty years! The part is susceptible to corrosion – often suffering pin hole leaks, rotted out internals and clogged lines.
Richard Lesniewicz aka “divotandtralee” a contributor to the Bulletin Board, studied the problem and designed and partially manufactured a replacement for the original unit. The new OVS is entirely brass and Richard machined the individual components of the assembly and sold them as a kit to be assembled by the purchaser. “Assembly” in this case is primarily soldering. The new OVS is almost identical in size to the original and once painted black will be almost indistinguishable once mounted in the engine bay.
Richard sketched the OVS to first demonstrate how it functions and then to show what happens to it after extended use:
This is a link to his instructions for assembly and use:OVS Construction Instructions
It is important to align the tubes off of the primary canister in the same fashion as the original OVS. Since that is still on the car, I will wait until I remove it to complete the “construction” of the brass OVS. The following image shows my progress to date:
This image shows the location of the original OVS mounted to the RH engine bay valance. After disconnecting its hoses and pulling it out of the car I was able to put it on the bench and use it to determine the proper location of the ports on the new brass OVS. I followed the directions and installed the port fixtures.
After final assembly of the kit, I decided to apply some Bondo body filler to the canister to even out some of my solder joints and create a better appearance once painted. This took a little more time but the final product was worth it.
I then made my own mounting bracket that permits the bracket to be fixed to the car separately from the canister itself. I used some brass plate and a piece of 1/2″ x 1/16″ x 9.5″ steel bent into shape. I was pleased with the result.
I then primed and painted the assembly:
I then connected the various canister hoses and mounted the assembly to the car:
The button in the center off the OVS top is a rivet that is pushed into a rubber grommet. the rivet and grommet can be pulled out to permit inspection of the inside of the canister. Next step will be to get some new hoses.