Donald Mitchell | 15/03/2010 17:03:10 |
![]() 90 forum posts 3 photos | Hi engineers, After about 20 years under the bench, my Clayton engine has at last seen the light of day again and I am making an attempt to get it finished and running. I have had the engine running on compressed air today but am not happy at all with the way it is struggling to run. I have checked and better checked the dimensions of all the links in the valve gear and I am convinced I have not made any boo boo's in that department. Is there by any chance anyone out there who has some knowledge of Joy gear as used in the Clayton who would be willing to lend some help? I have all the original M.E. construction notes. I expected (without the knowledge to back it up) that when the engine is in mid-gear the valve travel would be nil - in fact the valve still travels back and forth by some 3/16" when in mid gear, this seems strange to me? Am I right in assuming that when in "full gear" the slideshaft is tilted by 25 degrees from its central "neutral" position ? Regards to all. Donald Mitchell Castle Douglas Bonnie Scotland |
nick feast | 19/03/2010 08:38:03 |
![]() 75 forum posts 7 photos | Hello Donald,
Don't be surprised if the valve gear moves in mid gear, it is meant to. I assume you have built the engine with straight slides as Robin Dyer intended? Then valve timing will be a compromise as this arrangement does not give perfect valve events. however these engines go like the proverbial once under way as the cut off can be shortenend to give good speed.
The valve gear is dimensionally very similiar to what I am describing in the Charlie Q1 series, as Robin Dyer borrowed Don Young's Derby 4F layout as I did. To set the valves in forward gear set the cut off to about one third of full travel and set the valves to just crack open the front and rear port equally on each cylinder. It will take some time for the valves to bed in and the engine might wheeze a bit on starting. Once under way it should fly, infact a lot of people geared them down as they were too fast.
Tilt of the reversing shaft sounds about right.
Good luck,
Nick |
Donald Mitchell | 21/03/2010 13:34:19 |
![]() 90 forum posts 3 photos | Hi Nick, Your reply is much appreciated. Thank you for your confirmation that the valves move in mid gear, I thought I must have made a mistake with some of the links but I am certain that they are all to the correct size. I have been following your series about the Q1 and I had already realised that its valve gear is in fact a variation of the Derby 4F as is the Clayton's. I look forward to your next installment in M.E. and hope that I will learn more about the Joy vale gear. I have sent you a personal message. Donald Mitchell Castle Douglas Bonnie Scotland |
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