3/5/7 angle valve jobs?
Discussion
Inline__engine said:
stevesingo said:
For referance, here is the workshop repair manual for the BMW s14 engine valves and seats...
V= In 36.6mm Ex 31.4mm +0.1mm tolerance
B= In 1.2mm Ex 1.4mm +0.1mm tolerance
Interesting that the valves are bigger than the seats..
Steve
some of the issues i am mentioning are briefly raised hereV= In 36.6mm Ex 31.4mm +0.1mm tolerance
B= In 1.2mm Ex 1.4mm +0.1mm tolerance
Interesting that the valves are bigger than the seats..
Steve
i.e. T is bigger than V by a smidge. but what is the 45 width on the valve ?
This may seem daft (but every little helps)...
The valve head being bigger than the seat will mean the head is protruding into the combustion chamber by maybe 1cc. This will very slightly reduce the combustion chamber volume, hence increase the compression ratio.
I see it as a fortunate unintended consequence, rather than a reason for doing it.
I suspect that it is more to do with sealing than anything else.
The valve head being bigger than the seat will mean the head is protruding into the combustion chamber by maybe 1cc. This will very slightly reduce the combustion chamber volume, hence increase the compression ratio.
I see it as a fortunate unintended consequence, rather than a reason for doing it.
I suspect that it is more to do with sealing than anything else.
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