Lash cap damaged valve tips
#2254522
02/16/17 12:54 PM
02/16/17 12:54 PM
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Joined: Oct 2012
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the Netherlands
dutchrunner
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Always thought lash caps protect your valve tips?
Found 5 (No 1-2-3-4-5) intake valve tips damaged under lash caps.
Tops of all caps are fine and also all rockers.
Looks like the valve tip was too soft and now there is like a pin on the same place as the small hole that's in the lash cap.
Engine is about 7000 miles street driven. Gen 2 hemi with StageV heads and solid roller efi cam. Wide pad rockers and "street springs".
What the xxx happened?
No 6-7-8 are fine.
1969 Roadrunner Sox&Martin tribute with 572Hemi and F&B performance Six-Pack XFI2.0 injection.
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Re: Lash cap damaged valve tips
[Re: dutchrunner]
#2254545
02/16/17 01:29 PM
02/16/17 01:29 PM
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the Netherlands
dutchrunner
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Lash is as per cam instructions.
As are the other 3 which are not damaged.
1969 Roadrunner Sox&Martin tribute with 572Hemi and F&B performance Six-Pack XFI2.0 injection.
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Re: Lash cap damaged valve tips
[Re: dutchrunner]
#2254597
02/16/17 02:56 PM
02/16/17 02:56 PM
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the Netherlands
dutchrunner
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Not sure where the valves came from. Are StageV custom heads Cam specs are known D-1749-13-11/20/13. .659/.631 lift and matching springs. Just trying to find out wat could have caused this. Want to prevent repeat with new valves.
1969 Roadrunner Sox&Martin tribute with 572Hemi and F&B performance Six-Pack XFI2.0 injection.
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Re: Lash cap damaged valve tips
[Re: dutchrunner]
#2254720
02/16/17 07:52 PM
02/16/17 07:52 PM
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Joined: Sep 2014
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Washington
madscientist
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I have seen this when the valve train has an issue. It could be not enough spring pressure, too much spring pressure, not enough spring rate, valves too heavy or the big one, push rods that flex, or flex too much.
That will hammer stuff that would not normally ever see damage.
Just because you think it won't make it true. Horsepower is KING. To dispute this is stupid. C. Alston
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Re: Lash cap damaged valve tips
[Re: dutchrunner]
#2254894
02/17/17 02:43 AM
02/17/17 02:43 AM
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Joined: Oct 2012
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the Netherlands
dutchrunner
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My speedshop called the valve supplier where they bought the valves from when we rebuild the engine. He says it's turning the lascaps and this causes them to eat-up the tips. Changing all intake and installing locking lashcaps.
@ Cab_Burge . It's a street engine. average rpm 4000 and max 6000.
@ Madscientist . There all checked for spring pressure and installed height.
1969 Roadrunner Sox&Martin tribute with 572Hemi and F&B performance Six-Pack XFI2.0 injection.
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Re: Lash cap damaged valve tips
[Re: BSB67]
#2254969
02/17/17 12:15 PM
02/17/17 12:15 PM
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Joined: Nov 2004
Posts: 4,330
Lynchburg, VA
Leon441
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Ive seen this before.
Cam profile are typically more radical on intake side. The valve spring is not keeping the valve under control. Most of us don't have a spintron to test the valvetrain.
You have an unhappy intake valve train. Talk with your cam grinder about your intake lobe profile.
Some things they may tell you may surprise you. Seat pressure and weak springs kill parts. You are getting an early warning. I suspect you have too much valvespring for the lift. Meaning the valvespring is not being cycled properly. If you do not open the valve to .050" from coil bind the spring will dance around. For years we set spring height based on a psi for seat pressure or the manufacturer reccomendation for installed height. PAC has me setting spring height based on full open spring height. Amazing the difference it has made in valvespring life.
I regularly turn 9,000 and get incredible life.
Last edited by Leon441; 02/17/17 12:16 PM.
Career best 8.02 @ 169 at 3050# and 10" tires small block power.
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Re: Lash cap damaged valve tips
[Re: dutchrunner]
#2255043
02/17/17 03:00 PM
02/17/17 03:00 PM
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Joined: Apr 2005
Posts: 1,505
TN
SCATPACK 1
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That is good info Leon. i never new thought of that before. Always just set them for seat pressure and mad sure max lift was not coil bind. I am going to give your set up a try on my next set.
Thanks for sharing
Old Geezer Racing
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Re: Lash cap damaged valve tips
[Re: Leon441]
#2255068
02/17/17 03:55 PM
02/17/17 03:55 PM
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Joined: Jul 2006
Posts: 4,319
Puyallup, WA
StealthWedge67
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Ive seen this before.
Cam profile are typically more radical on intake side. The valve spring is not keeping the valve under control. Most of us don't have a spintron to test the valvetrain.
You have an unhappy intake valve train. Talk with your cam grinder about your intake lobe profile.
Some things they may tell you may surprise you. Seat pressure and weak springs kill parts. You are getting an early warning. I suspect you have too much valvespring for the lift. Meaning the valvespring is not being cycled properly. If you do not open the valve to .050" from coil bind the spring will dance around. For years we set spring height based on a psi for seat pressure or the manufacturer reccomendation for installed height. PAC has me setting spring height based on full open spring height. Amazing the difference it has made in valvespring life.
I regularly turn 9,000 and get incredible life. enlightening info, Leon. Now we're learning!! glad I checked in on this thread.
LemonWedge - Street heavy / Strip ready - 11.07 @ 120
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Re: Lash cap damaged valve tips
[Re: dutchrunner]
#2255388
02/18/17 06:16 AM
02/18/17 06:16 AM
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Joined: Oct 2012
Posts: 48
the Netherlands
dutchrunner
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Thanks for this input. Will forward to speedshop. Cam is based on EFI can in Mr. Nedbal's book. Should be right.
1969 Roadrunner Sox&Martin tribute with 572Hemi and F&B performance Six-Pack XFI2.0 injection.
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Re: Lash cap damaged valve tips
[Re: dutchrunner]
#2257971
02/22/17 11:47 PM
02/22/17 11:47 PM
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Joined: May 2013
Posts: 80
new york
68HEMIRR
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Dutch.....are you setting your lash at operating temperature?.....did this with mine when it was on the dyno......when i got home and was cooled off i checked it cold.....mine grew .019.....something to look into
BORN TO BE WILD
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Re: Lash cap damaged valve tips
[Re: 68HEMIRR]
#2257995
02/23/17 12:36 AM
02/23/17 12:36 AM
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Joined: Aug 2003
Posts: 43,099
Bend,OR USA
Cab_Burge
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I Win
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Bend,OR USA
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Dutch.....are you setting your lash at operating temperature?.....did this with mine when it was on the dyno......when i got home and was cooled off i checked it cold.....mine grew .019.....something to look into Did it grow and got wider or did it tighten up when cooled off 
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: Lash cap damaged valve tips
[Re: dutchrunner]
#2258119
02/23/17 11:06 AM
02/23/17 11:06 AM
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Joined: May 2013
Posts: 80
new york
68HEMIRR
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stage v aluminum heads....keith black aluminum block.....hot lash....22 intake...24 exhaust.....cold lash.....003 intake....005 exhaust.....tightened up by .019
BORN TO BE WILD
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Re: Lash cap damaged valve tips
[Re: dutchrunner]
#2258330
02/23/17 09:13 PM
02/23/17 09:13 PM
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Joined: Nov 2004
Posts: 6,890
North Alabama
Monte_Smith
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Leon has it right. There is nothing wrong with the valves or the lash caps. What IS wrong is something in the valvetrain.
Now while it could be too much spring pressure, it could also be too little for how aggressive the intake lobe is and could actually be trying to "throw" the lifter off the cam......OR it falls out from under the lifter on the backside. This beats the hell out of valvetrain parts. How MUCH lift is of little consequence, it's how aggressive the lobe is.
We have guys on Drag Week with cams over an inch of lift and they live just fine. I just have to slow the lobes down and set the parts up right.
HEMI valvetrain is inherently bad already. Mismatched parts make it horrible
Last edited by Monte_Smith; 02/23/17 09:19 PM.
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) those Stage V heads are Hemiriod heads, correct? If so how high are you revving that rascal? Who set those heads up? Do you know if all the open valve springs pressure are close to the same (+ or- 15 lbs) of each other? 
I'm thinking those lash caps (only) are floating off of the tips at the higher RPMs and then hammering them back onto the valve tips to make that impression on them 
