The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: John M on March 07, 2011, 08:33:30 PM
-
I am considering using copper head gaskets when buttoning up my rebuilt top end for the boost in compression ( supposedly a 1/2 point which would put the bike around 9.2 to 1. Any experience or cautionary notes would be appreciated. Best regards John
-
This is all I found on Boxerworks. There was quite a discussion about them a year or two ago, but that history is lost for the time being.
[size=14]by John Falconer » Sat Oct 30, 2010 5:25 pm
I haven't used theirs [San Jose BMW] but wouldn't be surprised to learn that they source them from the same place I did purchase a set from. I had a particular need for a specific thickness at the time and used them until I could finish matching up a preferred set of parts and machining.
They work ... but they also leave the motor with less oil-tightness - they don't dribble, but they ooze; and this after carefully anealing and using the Copper-Kote like recommended sealing goop.
So ... my personal opinion - stick with the stock head gaskets and get the clearances you really need/want by proper machining.[/size]
http://www.boxerworks.com/forum2/viewtopic.php?f=1&t=823&p=9864&hilit=copper+head+gaskets#p9864
I don't know where you plan to get yours. It doesn't look like SJ even sells them for the R65.
http://www.sjbmw.com/parts.asp#src=copper
-
Thanks Rob , anyone else with personal experience ?
-
Thanks Rob , anyone else with personal experience ?
Only that I need 98 RON fuel at 9.2:1. 95 RON will ping some unless I retard the ignition by 2 deg and even then it's borderline.
I don't know how the increase in compression will impact on your later engine as cam timing may be different and that has a big impact on the "effective compression ratio"
-
I installed them on my '81 about 13 years ago .
You need to put some sort of head gasket sealant on them before installation, or they will leak/seep oil, especially around the push rod openings .
Also you need to anneal the gaskets every time you remove the heads .
I haven't noticed any change in engine performance and I still use regular grade fuel during the cooler months, which is 87 octane here in the US, but I need to use mid-grade fuel (89 octane) during the 'hot season'.
-
Many moons ago i put some on my old Beezer C15 didnt improve performance but did increase my oil consumption .....which was pretty high to start with.
Lou
-
Easy choice, no copper head gaskets. Thanks to everyone for their input.
-
Just a note to remember that octane is often quoted using different measurement systems in different parts of the world.
For example, “petrol” in the UK/Europe is sold using a RON (Research Octane Number) measure of octane that Barry uses above, while “gasoline” in the US/Canada is sold using an average of the RON and the MON (Motor Octane Number). Bob Roller above is using (RON+MON)/2. RON is a typically 8 to 10 numerical points higher than MON, therefore the average (RON+MON)/2 is 4 to 5 numerical points higher than MON.
There’s lots of reasons why one system of measurement might be preferred over another, but the difference between the typical UK/Europe and US/Canada methods of presentation means that the typical US/Canada 87 octane “regular” gasoline is equivalent to between 91 and 92-octane in the UK/Europe. In much of the UK/Europe, “regular” petrol is 95-octane, which is about the same as “mid-grade” 90ish-octane gasoline in the US/Canada.
Mark
-
Check this site out for fuel that will stop pinging. Of course this information is for discussion only and not endorsed for on road usage...
http://www.gnttype.org/techarea/misc/octanebooster.html