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Author Topic: both Exhaust Valve guides busted!! >>  (Read 2985 times)

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ghost183

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Re: both Exhaust Valve guides busted!! >>
« Reply #15 on: June 08, 2019, 07:18:40 PM »

thanks for all your insight fellas..


i spent the better part of this week on this issue..  talking to people, harley svc techs, google, and measuring clearances, checking timing, you name it.. i probably did it. 

the mechanic at the dealer made a note in my svc history of the compression readings after the install which sparked me to talk to other dealers..  and do some diagnosing and figured 2 things out for sure....

1) that i made a good decision and dont go to the dealer anymore..


2) initial compression readings were 226 rear, 218 front, which is extremely high for a stage 3 kit, 10.5 compression..


as of wednesday that just passed, the initial mechanic doesnt work there anymore, but the current mechanic still stated its normal till after breaking.. so ok..


but heres the kicker, after the initial install, and for 1200 or so miles i use to have an abrupt and violent compression kickback, no metal to metal noise.. but it was bad enough that i did want to start the motor in fear of breaking the starter clutch(gear) apart or burning out the starter.. i mean really bad blow out thru the intake too.. and dealer still stated its nrmal till after breakin..

at that 1000-1200 mile point, i had learned my way around the tuner well, so i went into the tuner and reduced starting fuel pulse and it became normal.. 

but...

somewhere along during that initial 1200 miles or so one of those kickbacks happened at just the right time, causing just enough slack on the timing chain and i had piston/valve contact


i didnt catch it till i rolled the valves on glass and they ever so slightly kinda favored rolling to one side..  so ok,, im blind as sh*t so i clamped them individually in my lathe and spun the valves at 1000 rpm. and man o man did the bend show up at that rpm

btw..
  that clear line on the pistons valve pocket, isnt clean metal.. camera picked up the flashlight,  flash or something, who knows.. its not there normally..



on another note..
  the guide installation..

the heads have been checked and pasted with flying colors, no issues except for VERY slight indication of out of round contact on the valve seats that have already been lapped out using another valve

based on some statements from you guys about this..

the busted guides have been measured for location (micrometer) and pressed out and the sleeves are spotless, clean, no scars, so im thinking giving them a polish hone, re-install another set of OEM valve guides by heating the head, freezing the guide, and pressing in to match the original location, is this not a good idea?
« Last Edit: June 08, 2019, 07:30:37 PM by ghost183 »
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2008 CVO FXSTSSE2, Stage 1 port, milled .030 + 030 MLS, 11cc domed pistons, W-777's, Fueling 7060 HP+, TMAX, Barnett Clutch, SE Comp, V&H Big Radius 2-2 with smartpartz baffles and DK torque discs, Shotgun Air Ride, Vulcan 4.5* rake,, Chromed front legs

trippy

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Re: both Exhaust Valve guides busted!! >>
« Reply #16 on: June 09, 2019, 07:40:44 AM »

Just thought you might be interested in reading this,

http://cylinderheadshop.com/valves-guides-for-harleys/

Just a thought,

Good luck getting it sorted, as said earlier, lucky its the Exhaust and not the inlet!!
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prodrag1320

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Re: both Exhaust Valve guides busted!! >>
« Reply #17 on: June 09, 2019, 08:43:15 AM »

thanks for all your insight fellas..


i spent the better part of this week on this issue..  talking to people, harley svc techs, google, and measuring clearances, checking timing, you name it.. i probably did it. 

the mechanic at the dealer made a note in my svc history of the compression readings after the install which sparked me to talk to other dealers..  and do some diagnosing and figured 2 things out for sure....

1) that i made a good decision and dont go to the dealer anymore..


2) initial compression readings were 226 rear, 218 front, which is extremely high for a stage 3 kit, 10.5 compression..


as of wednesday that just passed, the initial mechanic doesnt work there anymore, but the current mechanic still stated its normal till after breaking.. so ok..


but heres the kicker, after the initial install, and for 1200 or so miles i use to have an abrupt and violent compression kickback, no metal to metal noise.. but it was bad enough that i did want to start the motor in fear of breaking the starter clutch(gear) apart or burning out the starter.. i mean really bad blow out thru the intake too.. and dealer still stated its nrmal till after breakin..

at that 1000-1200 mile point, i had learned my way around the tuner well, so i went into the tuner and reduced starting fuel pulse and it became normal.. 

but...

somewhere along during that initial 1200 miles or so one of those kickbacks happened at just the right time, causing just enough slack on the timing chain and i had piston/valve contact


i didnt catch it till i rolled the valves on glass and they ever so slightly kinda favored rolling to one side..  so ok,, im blind as sh*t so i clamped them individually in my lathe and spun the valves at 1000 rpm. and man o man did the bend show up at that rpm

btw..
  that clear line on the pistons valve pocket, isnt clean metal.. camera picked up the flashlight,  flash or something, who knows.. its not there normally..



on another note..
  the guide installation..

the heads have been checked and pasted with flying colors, no issues except for VERY slight indication of out of round contact on the valve seats that have already been lapped out using another valve

based on some statements from you guys about this..

the busted guides have been measured for location (micrometer) and pressed out and the sleeves are spotless, clean, no scars, so im thinking giving them a polish hone, re-install another set of OEM valve guides by heating the head, freezing the guide, and pressing in to match the original location, is this not a good idea?




you do know you have to use a oversize guide,.001 at least.as far as heating the head & cooling the guide,this is the method to press guides in but you`ll never get it in the exact location so seat work isnt needed.also if your clearances were so tight that "slack" in the cam chains cuase contact,it would have happened anyway

HD Street Performance

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Re: both Exhaust Valve guides busted!! >>
« Reply #18 on: June 09, 2019, 10:47:19 AM »

Again no way of knowing the real root cause, we have a small bit of data.
220+ cranking compression is not normal on any harley stage twin cam build unless it was sampled with collapsed lifters before the first start. The only OEM or Screaming Eagle build I can recall that will crank that with compression releases disconnected is the SE CVO 110 stock. The rings are the only "break in" item and with the hone pattern HD uses it happens fast or not at all when the fuel and timing are not reasonably close on first start or if the tech takes the bike for a ride it like you stole it shake down run. Compression goes up after the rings seat.

The forensics are not important at this point. You need to get this fixed and the internet isn't going to aid you unless you want to use the talking points to argue with the dealer. I recommend you pull the plug and get to an independant shop that has a good reputation for quality and can take a build such as this, turn key, including and especially important the tune.
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MCE

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Re: both Exhaust Valve guides busted!! >>
« Reply #19 on: June 12, 2019, 07:03:58 PM »

You'll need a valve job on the EX after putting guides in it. They're never exactly the same for whatever reason.
I would look at the piston reliefs very closely too. If the valves are oversize, the reliefs may not be large enough.
It's usually the intakes for that though.

Just food for thought.
« Last Edit: June 12, 2019, 07:37:43 PM by MCE Performance »
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