Tech Tips: Fall 1985

PROP PROBLEMS

Many owners of MGB roadsters from 1971 on have trunk lids that are bent or creased. This is caused by the telescopic trunk lid prop fitted to these cars which replace the ‘rod type’ props fitted to earlier models. The trunk lids on these cars are very heavy and require more support than the original BL design allows.

One can correct this problem by adding a second prop to the right side of the trunk lid. This addition allows the lid’s weight to be evenly distributed and keeps the lid from bending.

First purchase a second trunk lid prop (Moss part #457-465). Then, using scrap sheet metal, fashion two brackets to hold the new prop in place. These new brackets must be attached carefully to insure that they are the correct distance from the edges of the trunk opening. If this distance is not the same as on the original prop, only one of the props will latch causing us to be again using only one prop. These brackets can be attached using bolts, pop-rivets, or (for the well-equipped enthusiast) welded on. After attaching the new prop be sure to grease its track and oil the latches, not only to ease operation but also to prevent rust.

Although the addition of a second prop does make it a little more difficult to close the trunk, it does go a long way to extend the life of your MGB’s trunk lid

David R. Farlow
Cambridge City. IN

OIL CLEAN-UP

To demonstrate the integrity of his Hispano-Suiza cars, Marc Birkigt would drive a production model from Paris to Cannes and back and then park on a white linen sheet with nothing else showing but tire marks. Your Triumph was never built to the exacting standards of M Birkigt, but it can be maintained or rebuilt so that it will never commit an indiscretion on your or a friend’s driveway.

The valve cover is the most likely spot to spring a leak and often requires no more than a bit of tightening or renewal of the fiber washers underneath the locknuts. If you do a fair amount of work on your car, the valve cover will be on and off several times a summer. The standard valve cover gasket is OK for a new engine. For a more mature vehicle, you will have to straighten a few warps & bows before installing a new gasket.

Oil leaking from the bottom of the engine is probably due to loose oil pan screws or an oil pan gasket that has reached retirement age. Put the car on axle stands and try tightening the bolts holding the pan to the bottom of the block. If this doesn’t stop the flow of oil then there’s no way around the problem except to put the car back up on stands, drain the oil, drop the pan and clean off the old gasket. This is an afternoon’s job since the TR chassis has no cross-members to make removal of the pan interesting. Clean the pan of sludge while it’s off and check small end and main bearing clearances if oil pressure has been low. The gasket should be assembled between the pan and block with Permatex or other sealant remembering that the number of holes is different on the front and back of the block.

Another place oil leaks from the engine is the the timing chain cover, either around the gasket or at the front oil seal. In any case the fan has to come off to remove the cover which also means that the radiator must be removed.

Because the crankcase and valve cover gaskets are the biggest ones on the engine often they will spring an oil leak through no fault of their own. Ifthe PCV valve (top and rear of engine on the carburetor side) is blocked or the hoses in or out are kinked, then pressure from combustion products leaking past piston rings (engine blow-by) can build up inside the engine and force oil out. Since these two gaskets show the longest face to the interior of the engine, then they are most likely to leak. Cleaning the PCV valve and ensuring the hoses are open is an essential part of eliminating oil leaks. Earlier TR engines vented blow-by directly to the air through an oil filler cap filled with metal mesh. While this efficiently removed the crankcase gases, it also took a fair amount of oil with it, depositing them on the engine and other places in the engine compartment. There’s no hope for an engine in this state except to go for a ring job.

Keith Dannacker
Alberta, Canada