I know that the Rover V8 push rods ARE the same diameter as they originally were on Buick 215 cid engine, prior to Rover buying rights to it from GM, so I THINK too, that they are the same overall length. DOES ANYONE KNOW FOR SURE IF THEY ARE THE SAME OVERALL LENGTH AS THEY WERE ON THE BUICK?
For your information, I know for certain that the Rover V8, all of them, from the beginning 3.5L, through the 2004 Discovery and others, using the 4.6 L engines, use exactly the same size hydraulic valve lifters (sometimes called tappets) as did the Buick 215, because I have twice used Buick lifters on Rover engines, and drove them for well over 100,000 miles, with not a single problem.

 

I cant tell you for certain, but im pretty sure that they are. The 4.6 is an old Buick block rebuilt by Ford when they decided to increase the size. Pretty dang positive they are the same size.

 

The original Rover engine was a Buick and sleeved down to 3.5 litres and later progressively increased in size 'by whoever' to 3.9, 4.0 and 4.6 litres.

IMO get a Buick push rod from a breakers yard and take it into a 'tame' LR dealer and measure them both.

 

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Yes, I knew all that. However, I grew tired of one guy telling me that the push rod length was such and such, and another guy telling me completely different size, yet a third guy telling me another new size. Hell, I know they are not all different sizes on Rover V8s. So, I have one coming in the mail, a new one, so when it arrives, I will see for myself if the Rover ones are the same length as the original Buick 215 ones, as I have some of them. Bet they are the same!

 

If they are the same, I wonder if you can buy different lengths? So you can get a true adjustment per lifter vs. shimming an entire rocker arm shaft.

 

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No, Rover sold only one valve rocker arm pushrod type, dia. and length, for the entire GM derived all aluminum V8 series, 3.5, 3.9, 4.0, 4.2, 4.6 Litre, and, I THINK it was same size too, as used by GM on Buick 215 cid, 1961-1963. Rover expects us to adjust the lash, by putting shim stock under the pedestals (4 pedestals) for the rocker arm shafts. Since the valve train uses hydraulic lifters, the lash dimension isn't critical enough to need to adjust each pushrod lash, so one just shims pedestals covering lash for the whole bank. The valve train on this engine, is perhaps its weakest link, so converting it to roller rocker arms, with needle bearings in the rocker arms, mounted on a stud plate base, allowing individual rocker arm adjustment, is a huge step in reducing friction-----can you say "no more tap, tap, tap, or worse;" I knew you could. Thus, allowing a much more refining set-up, smoother quieter operation, much more durable, far less wear, in perhaps the most wear vulnerable area of the whole engine. That is the problem I am now working on, and losing sleep over, but, finally, I am starting to make progress on it.