M24 gold star rattle

[Dave Halsall]

Good morning  my 1939 km24 has developed  a rattle  that seems tappity l have checked  valve  clearance  and adjusted  to the 3 tho clearance  but  still the rattle  is there.
I wonder if anyone  could  have any  suggestions?  Is is worth  taking  of the timing  cover  off to see if anything  is loose? Or could  it be the small  end ?
Any suggestions would be  most welcome
Dave Halsall

[ducati2242]

My 55 DB500 had a rattle from rebuild . It turned out to be the push rods . wether they were the wrong ones could be anyones guess but I made my own out of bmw r45 / 65 , I think , push rods and the rattle was mysteriously cured done 500 miles now and it never returned . Dont think the ones I had were seating properly . I definitely used at least one end and the tubes from the r45 ones but cant remember if I used both ends .

[ducati2242]

one other thing that not everyone agrees with but i do . The valve clearance on an all alloy engine will increase with heat . I set my gold star valve clearance as tight as i can . as near to zero as i can get . Something to do with thermal expansion between steel and alloy . But mine works perfect .

[Dave Halsall]

Thanks for the  information I assume  the ends  that locate in the tappet fit into the bmw pushrod.
Perhaps  it might  be worth  looking  at the timing  gear  and also  removing  the tin cover from  the cylinder head  and see if anything is loose  or coming  adrift  and  also  setting to zero on clearance  may help  hopefully  its something  simple.
Your  input is very much appreciated

[ducati2242]

I actually used the bmw top end and the bsa bottoms the alloy rod was the same size