From: Dave Baker
Subject: Re: Checking valve timing.
Date: 15 Jan 1999
To check the cam timing you need to put a dial guage on the inlet valve on no 1
cylinder and a degree wheel on the crank pulley. Rotate the engine until the
valve is at full lift and read off the number of degrees after TDC on the
degree wheel. It can be hard to tell exactly where full lift is so do this:
Rotate engine to 1 thou before the full lift position. Read the degree wheel.
Rotate past full lift and back to 1 thou less - read the wheel again. True
full position is midway between the two readings. Check the manufacturer's
recommended full lift setting and correct with offset dowels or an adjustable
cam pulley if more than 2 or 3 degrees out. Easier to describe than do until
you have had a bit of practice at setting up engines.
Don't be surprised if the cam you bought is a long way out - many of them are
badly ground and not properly referenced to the woodruff keyway to ensure they
install at the correct timing on the standard sprockets. Probably just a good
ruse to get people to buy an adjustable sprocket too.
I have all my own cams properly ground so that they time in correctly on the
standard sprockets in the same way as the OE cams do. Maybe thats why I don't
make any damn money in this line of work :)
Dave Baker at Puma Race Engines (London - England) - specialist flow
development and engine work. .