[Healeys] Engine start procedure

Bob Spidell bspidell at comcast.net
Thu Sep 9 07:32:04 MDT 2010


Hmmm ... this should be an interesting topic.

I haven't built enough engines to offer definitive advice, but it seems 
the contemporary recommendation--for rebuilt older engines with flat 
tappets, anyway--is to start the engine and run it at 1,500-2,000 rpm 
for 15-20 minutes to bed in the cam (tune mixture, timing, etc. for rpms 
and smoothness while it's running).   The idea is to provide plentiful 
oil flow to the cam and tappets during initial bedding-in.  Would this 
not apply to a Healey engine?

Some say 'break it in like you're going to drive it,' like my father who 
has rebuilt numerous auto and other engines (corollary: 'break it in 
slow, get a slow car').  He doesn't worry about the cam.

I know for aircraft (piston) engines break-in is critical--it's 
universally recommended to run the engine at high power settings, full 
rich at lower altitudes and no short hops for the first 50 hours or so.  
To not do so is to almost guarantee that the rings won't seat.

I would recommend adding some sort of ZDDP additive to the oil--at the 
least, it can't hurt and it may help protect the cam during break-in.  
Before you start the engine, spin it over with the plugs out until you 
get an oil pressure reading on the gauge (hopefully, you used copious 
amounts of assembly lube).  Also, it's recommended to run at varying 
speeds and loads for at least the first few hundred miles so you don't 
build a low ridge on the cylinder walls.

I don't think most new cars even state a breakin procedure--the 
machining and clearances are so much more precise it isn't necessary.


bs

*******************************************************************
Bob Spidell           San Jose, CA            bspidell at comcast.net

*******************************************************************


More information about the Healeys mailing list