The BSA A7-A10 Forum

Technical => A7 & A10 Engine => Topic started by: 1KCBC on 14.10. 2006 15:28

Title: Valve clearances
Post by: 1KCBC on 14.10. 2006 15:28
My A10 plunger now the valve clearance is inlet .010 in., exhaust .012 in.
and I would like to know that if I want to change the setting to .008 in. both valve.Is it reduce the noise of the engine and any occurence after.

Title: Re: Valve clearances
Post by: a10gf on 14.10. 2006 23:34
Hi, in "BSA twins & triples" Roy Bacon writes 0.010 in & out for A10 51-54, which is what I have been using (plunger, iron top). There is a mention for 0.015 in & out for 1950 A10, early production valves, top or what?? 0.010 in & 0.016 out is listed for A10 from 55.

I would not try going under 0.010, but it could work fine, who knows? A way of checking whats going on is to measure the result clearance when the engine is (very) hot, to be sure you still have some clearance on all four, and it's interesting to get a readout of how much the clearance have decreased from whatever you choosed to start with (edit: from cold engine, of course). BTW I have a clear conception that a little noise from the top is a good safety measure!

Hope this helps
Title: Re: Valve clearances
Post by: Beezageezauk on 15.10. 2006 12:18
I particularly agree with the final comment from A10GF.  Better having your valve clearances a little slack than a little tight.  The engine might sound a bit "Tappety" but you won't burn your exhaust valve out.  I tend to set mine by the book but have the feeler gauge slightly loose.  Beezageezauk.
Title: Re: Valve clearances
Post by: BrianDallasTX on 22.10. 2006 16:45
I agree about the noise and having the valves looser than tight, but they should be set when cold.  Or that was how I learned to do it.