oldtuckunder Posted April 15, 2015 Report Share Posted April 15, 2015 (edited) Engine rebuild completed, with just enough time to get a few hundred running in miles before Gurtson this weekend. Scared myself last night whilst priming the oil system before starting, in the past have always with an adaptor shaft driven the oil pump in reverse with an electric drill to fill the system before attempting a start, and always worked on the the theory that when the oil gets to rocker #1 we have oil everywhere. No oil to rocker #1! No oil to any rocker! no oil to rear plug in cylinder head! give up this is serious problem go to bed. Wake up, cold light of dawn brain nearly working, on this rebuild I have removed the external rocker oil feed, given I had a major #5 BE fail which may be an oil feed issue (only may) I have decided that protecting the bottom end is the number 1 criteria, who cares if the rocker assembly runs short of oil and wears out faster, rocker shafts are cheap (ne almost consumable cost) and its dead easy to replace, wip off rocker cover, undo six nuts, remove rocker assembley, strip and rebuild in under an hour and refit! Now compare that with the time and cost of having a BE or Main Faill because it was starved of oil because too much was being pumped up to the head! Anyway back to my no oil to rocker problem, OK youve guessed it, of course without the external feed pipe to the back of the head, There is no supply path/feed to the rocker shaft unless the engine is running or at least the cam is rotating enough to squeeze a bit of oil up there. Yes the oil isn't directly pumped up to the rocker, but only receives oil courtesy of the the small secondary pump flat on the rear cam journal. I had sat there spinning the oil pump drive for at least 10 mins with nothing appearing at the rockers wondering what the hell had I done! NB. The oil feed to the rockers is actually quite tiny, and when I started the engine today, I recon it took a good 2 mins with the engine running before oil got to #1 rocker, glad I had lubed the rocker assembly well when assembling the day before. Not sorry to be rid of the external oil feed to the rockers though. Edited April 15, 2015 by oldtuckunder Quote Link to post Share on other sites
Tim D. Posted April 22, 2015 Report Share Posted April 22, 2015 Also found this on a rebuilt engine. Quite nerve racking while you wait for the flow to start. Cheers Tim Quote Link to post Share on other sites
Guest ntc Posted April 22, 2015 Report Share Posted April 22, 2015 You will not get flow without the cam rotating . Quote Link to post Share on other sites
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