SQ(ueek) 4 !

Singles, twins and fours.
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berniejones
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Re: SQ(ueek) 4 !

Postby berniejones » Wed Jun 13, 2018 2:18 pm

Well, it wasn't an air leak at all. Current suspicion is a dry LHS exhaust rocker. Running the engine with the rocker covers off I'm getting healthy dripos from both RHS rockers but less from the LHS inlet and hardly anything from the exhaust.

It could be a restriction in the feed via the 'U' pipe from inlet to exhaust but my suspicion is the rear portion of the external feed pipe has a restriction.
When I received it from Drags it had more than a restriction - it was completely blocked with solder (!) and I've had to take it apart, clean it out and re-solder. Maybe I've got a bit in the rear part of the 'T' that is restricting the flow to the LHS of the head. Time to take tank and carb off again to investigate so might as well deal with that thread while I'm at it!

Cheers,
Bernie
'56 SQ4 project
'52 BSA M21
'61 Dommie 99
'62 BSA A65
'81 T140
'54 Sunbeam S8
AOMCC# 4631

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paul.jameson
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Re: SQ(ueek) 4 !

Postby paul.jameson » Wed Jun 13, 2018 8:25 pm

Check the oil passage up the rocker block. As you know, the oil comes in to one block then goes over to the other block via the 1/8 inch pipe. So at the end of the second rocker block oil path there is a joint between rocker block and cylinder head which has potential to leak oil. A popular trick is to seal the end of the oilway with some silicone. If you have inadvertently changed the rocker blocks about you could have blocked the oilway with someone's old silicone.
Paul Jameson
36 4G, 37 VH, 53 ex ISDT KHA (project), 54 KH(A), 54 4G Mk IV (project), Healey 1000/4 (project)
Former Machine Registrar & Archivist, General Secretary and Single Spares Organiser.


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