Slant Six Forum :: Doc - Struck Oil, But Another Problem

: 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.

Author:	XMAN [ Fri Dec 21, 2001 6:31 pm ]
Post subject:	Doc - Struck Oil, But Another Problem
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. usclstaffingnet@sprintmail.com

Author:	dschumers [ Fri Dec 21, 2001 7:40 pm ]
Post subject:	Re: Doc - Struck Oil, But Another Problem
Quote: : 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. My Racer Brown runs at .016" and .018". I think lash settings are governed by the profile of the lobe. As for the pushrod thing, you didn't happen to have a valve sieze in the guide did you? slantzilla@excite.com

Author:	Doctor Dodge (Doug Dutra) [ Sat Dec 22, 2001 10:47 am ]
Post subject:	Re: Jumping Pushrods PIC
Quote: : 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

Author:	XMAN [ Sat Dec 22, 2001 11:59 am ]
Post subject:	Re: Jumping Pushrods II
Quote: : 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 Doc, Put the push rod back in this AM, double checked the lash settings, started up and ran 30mins, then reset the lash (.017 Intake/.019 Exhaust). took it on maiden seems okay. Question: I can't get it to idle smooth at less than 1,000 rpm - is that about right for a built up /6 ??? 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. usclstaffingnet@sprintmail.com

Author:	Doctor Dodge (Doug Dutra) [ Sat Dec 22, 2001 11:39 pm ]
Post subject:	Re: Too Much Advance
Quote: : 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. What cam and how is it installed? (centerline) 18-20 is a lot of initial and 40-42 total is too much. Why no vacuum advance? A blown "pod" or no signal from the carb? Sounds like you have some distributor work to do. As a reference, most race SL6 run 28 to 32Âº total advance. (initial + mechanical) DD

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