: Finally got the cam back from Hughes after they
: drilled the omitted oil hole in rear
: journal. What a bunch of jerks they didn't
: even want to pay the shipping after
: admitting it was their fault. A lot of time,
: expense and 2 week delay in pulling out the
: engine,disassemble, reassemble, touch up and
: reinstall. Anyhow, reassembled engine today
: and put it back in car. Started up to run
: for 20mins at 1750rpm. Getting good flow at
: rockers. After running for 18mins I heard a
: miss and looked down to see the #2 Intake
: rocker jump off the push rod. Didn't bend
: the push rod and lifter and lobe appear
: perfect. All lifters were rotating. Ran fine
: until that point. Now the Hughes specs call
: for a setting of .018 on Intake and .020
: Exhaust. All valves were set carefully to
: Hughes specs and double checked. Can't
: figure out why this happened. Is it common
: on a performance cam to run the intake at
: 8thds over stock specs but have exhaust
: right on stock specs?? Any and all comments
: greatly appreciated.

: Finally got the cam back from Hughes after they
: drilled the omitted oil hole in rear
: journal. What a bunch of jerks they didn't
: even want to pay the shipping after
: admitting it was their fault. A lot of time,
: expense and 2 week delay in pulling out the
: engine,disassemble, reassemble, touch up and
: reinstall. Anyhow, reassembled engine today
: and put it back in car. Started up to run
: for 20mins at 1750rpm. Getting good flow at
: rockers. After running for 18mins I heard a
: miss and looked down to see the #2 Intake
: rocker jump off the push rod. Didn't bend
: the push rod and lifter and lobe appear
: perfect. All lifters were rotating. Ran fine
: until that point. Now the Hughes specs call
: for a setting of .018 on Intake and .020
: Exhaust. All valves were set carefully to
: Hughes specs and double checked. Can't
: figure out why this happened. Is it common
: on a performance cam to run the intake at
: 8thds over stock specs but have exhaust
: right on stock specs?? Any and all comments
: greatly appreciated.

: I would check the guides, an easy way to do a
: quick check is to to use a "lever"
: or just strike the tip of the rocker arm,
: you can feel or hear when the guides are
: free and working right. If you tap on them,
: the "ding" sound made is different
: between the intakes and exhausts so listen
: to all the intakes then all the exhausts as
: groups, a stuck guide will sound different.
: (dull thud)
:
: You should try some different valve lash
: clearence settings, this measurement is not
: "set in stone" but shoot for the
: best noise control and idle quality, .016 on
: the intakes or even .014 should not degrade
: the idle much. See how it works, let us know
: what you combo likes best.
:
: The other thing to review is the rocker arm
: geometery. The angle of the pushrod to
: rocker arm's adjustment ball can get steep
: if you do a lot of block and / or head
: milling.
:
: Here is a PIC showing pretty good rocker arm
: geometery. See how the roller tip is well
: centered over the valve stem and the push
: rod is in-line with the adjuster screw's
: centerline at near full lift. I used a .060
: rocker shaft shim to get to this point, the
: set-up shown could use a little more shim to
: get the system a tad past centerline at full
: lift, that would take some of the at rest
: angle out of this combo. Watch-out when
: using a lot of shim, grind back the upper
: edges of any shim you use. The reason you
: see a hose clamp around the head's rocker
: shaft tower is because that tower has a
: crack in it, a thick shim can act like a
: wedge and "split" the towers.
: Sounds like you are making good progress.
: DD

: Also the engine goes and
: comes somewhat and get fair amount of
: popping when it is reved up and let off.
: Have played around with the carb (Carter
: 650cfm) and timing to get best performance.
: Have MP Electronic ignition. Runs best at
: about 18-20 degrees BTC and about 40-42
: degrees total. Is this about right?? I'm
: only getting mechanical advance - no vacuum
: advance. Get the same max advance with or
: without the vac hose connected to the carb.