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MG MGB Technical - Help a cousin - Bent pushrods

Guys, Hoping your expertice here might help a fellow LBC guy. (It's OK. I have 3 MGB's.) But my next door neighbor has a '73(?) TR6 that he picked up last fall. It had been sitting for about 10 years, but was complete and together. He eased into getting the engine started by oiling everything and slowly working it around to where he was finally ready to hit the ignition. Well, it started right up. After it ran for about 15 minutes, all smoke stopped and it ran as smooth as can be. He needed to do a few things to the car over the winter and started it periodically. No problems. However, a few weeks ago it started running horribly, like a couple of cylinders were dead. Saturday we were messing with it and confirmed that he had 3 dead cylinders. (0 compression) We pulled the valve cover and noticed that the clearance for intake valves #1, 2, and 4 were wide open. We then realized that the pushrods for all three were bent. A lot! We could push the valves in with what seemed like normal force, and even swapped in straight rods and spun the engine with them in (By hand at first). No problem, Valeves dropped all the way and didn't stick, and all 3 showed good compression. Note that he never checked or adjusted valve clearance at all to that piont. So he is going to order a full set of pushrods, and springs as well. Except for maybe floating them when he reved it at some point, we don't see what could have caused this, except maybe soft springs. Any ideas out there as to what could have caused this so we don't get a repeat?
Thanks,
Mark R.
Mark Rotsky

Hi Mark

You could also post this on the TR6 BBS - here is the link.

http://www.british-cars.co.uk/cgi-bin/gen5?runprog=trbbs&access=&mode=tlist&subject=1009

Barry
75 TR6
ex 73 MGB
B.J. Quartermaine

Also check for binding of the rockers on the shaft. Ray
RAY

Likely that the valves were stuck in the guides and bent the pushrods. A bit of running could have resulted in dry guides, followed by rust from humidity, since TR are known for poor feed to the rockers - check that.
FRM
FR Millmore

Several years ago one of my customers got his car going again after 20+ years of sitting idle. Long story short - all the varnish in the tank was being dissolved by the fresh gas. This coated the valve stems making an effective glue. Once the engine was shut down the open valves stayed open. This left the pushrods 'free'. He was lucky and didn't bend any, probably because the engine wouldn't start. Marvel Mystery Oil added each fill up staved off the problem until he replaced the tank, fuel pump and numerous fuel filters.

Tom
Tom Sotomayor

Thanks guys. Some good ideas to check. We'll see what we get on the triumph site also thanks to Barry.
Mark R.
Mark Rotsky

This thread was discussed between 02/04/2007 and 03/04/2007

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