As a relatively new member of this much valued forum, this is my very first post. I am on a very steep learing curve and I would very much appreciate any help and advice.
Shortly after buying a 1948 MkIV 2.5 saloon (barn find) I discovered the Jag-lovers forum and have become a frequent reader of the interesting articles in the Pre-XK section.
I eventually made a start on the project early this year and decided to first strip and rebuild the engine that hadnt run since 1975.
I was very pleased to discover that, under the circumstances it was in surprisingly good condition. The engine number was not the original but it appeared to be a low mileage fully reconditioned later version engine (relatively little wear / mileage) having, for instance, steel con rods, std size 4 ring pistons and auto mechanical ignition advance.
However, during the strip down I was surprised when I removed the tappet blocks and discover what appeared to be a pressurised oil gallery. to nowhere. At first I though it must feed oil through to the tappets but there were no drillings in the block or tappets.
I have overhauled an air cooled engine that had hydraulic tappets that has corresponding drill holes in the tappet blocks feeding through to the drilled tappets and oil is then fed up through the hollow pushrods to the drilled valve rockers.
Confusingly, 9 of my 12 pushrods are also hollow and drilled (you can blow air through them) but the other 3 are completly sealed but neither the tappets or the rockers are drilled anyway, so whats the point?
I do have a reproduction Service Manual and altough it has an exploded view of the 1.5,2.5 and 3.5 engines, the tappet blocks and tappets are nowhere to be seen…
It also shows the pushrods with (cussion?) springs and drilled rocker arms with wicks but my rockers are completly solid so no provision for any wicks.
I would be very grateful if anyone could shed some light on my findings, especially the pressure fed tappets blocks with the mystery oil galleries.
Thank you. John. Cheshire UK.