Let's see what those numbers are, possibly I gave incorrect info for the cam you have?
Glen
ps- what are you using for "checking tappets"???
--Previous Message--
: I took the aspirin before going home from
: work so I would be prepared for the
: task at hand.
:
: After I took care of things at home I
: headed to the garage. First I moved
: the indicators to valves 1 & 2 from
: 7 & 8. I repeated all my checks
: (intake LCA and overlap angle). Just
: like my previous tests, I found the LCA
: was still at 109 ATDC and the overlap
: was still at 4 BTDC. That reassured me
: that nothing had moved and that my
: method was consistent.
:
: Then I removed the new sprockets and
: chain and refitted the paint marked old
: parts. I did this two ways. First I
: just tightened the cam bolts with no
: chain tension, then I repeated my tests
: with the timing chain tensioned by
: turning the crank in the normal
: direction of rotation (to take out all
: the slop in the sprocket mounting
: holes). My findings are below.
:
: Old timing parts with no chain tension
: when bolts tightened:
: Intake LCA = 107 ATDC
: Intake/Exhaust overlap = 6 BTDC
:
: Old timing parts with chain under
: tension when bolts tightened:
: Intake LCA = 108.5 ATDC
: Intake/Exhaust overlap = 4 BTDC
:
: Yesterday's readings...
: New timing parts with no chain tension
: when bolts tightened:
: Intake LCA = 109 ATDC
: Intake/Exhaust overlap = 4 BTDC
:
: So... I still cannot explain why the
: overlap is not occurring at TDC.
: However, I can say that if I fit the
: new timing components and set the
: timing by intake LCA, the overlap will
: occur at the same point it did/does
: with the old timing parts. Since the
: engine ran well with this timing before
: the rebuild I am comfortable taking
: this approach. I could retard the
: timing a degree or two so the overlap
: occurs closer to TDC and the LCA falls
: right at 110 degrees. However, then it
: will become more retarded as the chain
: stretches.
:
: I'm still thinking about this but I am
: more comfortable now having measured
: the timing with the old parts.
:
: Doug L.
:
:
:
:
: --Previous Message--
: No it would be @ .040 tappet rise, in
: the
: case of this cam.
: "Assuming I do have a stock cam
: and that its real duration is about 256
: degrees, then the duration would have
: to have been checked/measured somewhere
: between the 0.010" and 0.015"
: of lift you mentioned."
:
: I do both event points and centerline,
: sometimes on more than 1 lobe.
: Some grinds are set by setting the
: crank angle at a specific point in
: lift. Some just split the overlap. The
: results should all be the same or very
: close.
: I can't add anything to what is in the
: Crane article, the applications are
: different but methods the same. I don't
: have any online references, all of my
: stuff is paper!
: Take 2 aspirin and post more in the
: morning!
: g.
:
:
Responses