Since acquiring the tooling and fixtures of “Nortec” we now offer the Anti-wet sump valve upgrade for Norton twins, 500 thru 850!
This involves the installation of a check ball in the timing cover at the point at which the oil pump feed bush contacts the cover.
This essentially prevents oil from passing through the gears of the pump and draining the oil tank into the engine sump while the bike is parked, a common problem on all Norton twins.
Additionally, two o-ring seals are installed inside the pump to prevent oil from passing between the feed and return sides which also can contribute to wetsumping.
The charge for this service is $80 plus shipping.
This includes machine work, check ball and spring and a special oil pump feed bush seal, as well as the internal pump seals.
Nortec Pressure Relief Valve Modification
This modification applies to the Norton Commando models through 1974 that from the factory, had the discharge point of the pressure relief valve relocated from directly into the sump, as was the case with the previous Atlas and Dominator models and the later MK3’s, to the feed line from the oil tank. This allowed in many cases, oil to pass through the pressure relief valve in the timing cover, into the sump when the engine was not running, thereby adding to the wet-sumping problem. Our modification places the discharge point back to its original point, directly into the sump, and requires that the oilway from the feed line in the engine case be plugged with a set-screw that we can supply. It is recommended that the threads in the case be cleaned with a degreasing agent such as carburetor or brake cleaner, and then a quality thread-locking compound such as “Loctite” be applied to the screw. The screw should be threaded in to below flush with the gasket surface, so as not to interfere with the sealing of the timing cover.
The cost of this service is $20, and can be done at the same time that the Nortec anti-wetsump valve modification is done. As stated above, we will supply the set-screw along with a sketch and instructions for its installation. Please indicate in the note with your timing cover and oil pump shipment whether or not you would like us to perform this additional service.
What we will need is your timing cover, and oil pump, in reasonably clean condition. The pump will be disassembled, inspected for excessive wear or damage, machined for the o-ring seals and reassembled. The cover will be machined for the check-ball installation. On Mk III models, please include the existing check valve spring, unless you want to by a new one.
Turn around time is two weeks. This does NOT include shipping time.
Method of payment is PayPal. The total will be determined after work is completed and return shipping calculated. Please include your phone number, email address and shipping address.
*We also recommend that the timing cover crankshaft and camshaft seals be replaced at the same time, along with a new pump gasket. We also offer all related gaskets and seals for sale. If the timing cover seals are purchased through AMR the seals will be installed at no additonal cost. Please include your list of added parts with your shipment, or by email.