Posted: Sat Mar 27, 2004 4:38 amyou can use a Dwyer 0 to 10 CFH meter
CFH (Cubic Feet Hour)
to check TDC location on engines
use Compression Tester Hose but without valve....
screw into number 1 Cylinder, then hookup other end of hose to Dwyer 0-10 CFH meter
take a crank socket with 1/2" drive breaker bar
and gradually turn crank till you get close to TDC
small steel ball in Meter will be pegging 10 CFH as you turn crank over on compression stroke....as you get nearer to TDC...just tap on end on breaker bar and watch steel ball
when you reach TDC ..steel ball stops
its more difficult to explain this than to actually do this !!
with a little patience and care , you can find TDC to within better than 1/2 degree accuracy , especially if you tilt Dwyer meter on 45 deg angle
i know a real engine builder "should have" located TDC and adjusted pointer when 1st building/assembling engine while heads were off block, but, every once in awhile , some racer tests his engine on my dyno and we find its taking abnormal amount of timing BTDC ...i double check engine's TDC , and many times find this is the problem.
other times we are making a quick camshaft change on the Dyno, and the Dwyer meter makes finding TDC quicker and easier than a TDC Plug Stop or any other methods .
other times its just a quick verification of TDC
CFH (Cubic Feet Hour)
to check TDC location on engines
use Compression Tester Hose but without valve....
screw into number 1 Cylinder, then hookup other end of hose to Dwyer 0-10 CFH meter
take a crank socket with 1/2" drive breaker bar
and gradually turn crank till you get close to TDC
small steel ball in Meter will be pegging 10 CFH as you turn crank over on compression stroke....as you get nearer to TDC...just tap on end on breaker bar and watch steel ball
when you reach TDC ..steel ball stops
its more difficult to explain this than to actually do this !!
with a little patience and care , you can find TDC to within better than 1/2 degree accuracy , especially if you tilt Dwyer meter on 45 deg angle
i know a real engine builder "should have" located TDC and adjusted pointer when 1st building/assembling engine while heads were off block, but, every once in awhile , some racer tests his engine on my dyno and we find its taking abnormal amount of timing BTDC ...i double check engine's TDC , and many times find this is the problem.
other times we are making a quick camshaft change on the Dyno, and the Dwyer meter makes finding TDC quicker and easier than a TDC Plug Stop or any other methods .
other times its just a quick verification of TDC