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Old 05-05-2011, 09:54:40 PM   #1
Damon
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Lash caps with solid lifter cam?

Guys- I got a weird one here I wanted to run past you all. SBC with aftermarket heads. The valve stem tips are very low relative to the top of the retainer. I have no idea why- it was just born that way, I guess. I don't want to take the heads off, nor spring for a new set of valves.

To get reasonable rocker geometry the rocker needs to be "leaned back" more than it is now (shorter sticks would fix the problem). However, when I do that the underside of the rocker arms touch the tops of the retainers (1.45" springs).

If I put some lash caps on top of the valves that will almost certainly give me the retainer clearance I need to install shorter sticks and lean the rockers back a little more.

SO...... is this an OK way to proceed? Any problem running them with a solid lifter cam which, of course, will have some amount of lash clearance in the valve-closed position?
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Old 05-05-2011, 10:04:01 PM   #2
mrdragster1970
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.

A crutch is never a good idea compared to doing it properly.
That being said, will the cap be seated on the valve or the locks??
If there's not much stem showing, be careful you aren't making a time bomb.
I've used caps on TIT valves to save the Jesels, never as a spacer,
but if they seat properly, I don't see a difference??
Watch the lash close and they should stay in place hopefully??

Good luck.

.
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Old 05-05-2011, 10:14:46 PM   #3
Damon
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I think they will clear the locks- I thought of that possible problem. Since they are big retainers that use 10* locks they have that "recess" in the locks close to the valve stem. Probably not a very good description, but I think you know what I'm saying- typical 10* aftermarket locks. It is my hope that the recess in the top edge of the locks is there specifically to accomodate lash caps. I hope.

Normally I wouldn't crutch a solution but you know..... money's tight, lash caps are cheap and it would save a whole lotta work I don't have the time to do. It's not like I'm getting paid for this. I'm getting called into the breech for a friend who needs something fixed right away and for no money.
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1990 454SS pickup. Original "tow truck motor" 454 upgraded to something a little more "aggressive." Seems pretty stout but the fuel bill is nuts.

78 Malibu. Inherited with only 35K on the odo! Mild 383 with Weiand 142 blower on top. Mid 12s appears to be the best it's gonna do on street rubber. Runs so good I may never drive it again.

"Last remaining QJet tuner on planet Earth!"
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Old 05-06-2011, 01:51:00 AM   #4
rustbucket79
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Easy check that caps aren't hitting the locks, use a paint pen on the bottom edge of the lash cap, install and rotate while pressing down. If there is paint transfer, you'll need to trim the edge of the cap, no transfer and you're good to go. Use this method if you don't want to pull off a couple of retainers.

If you're willing to pull retainers, just put 1 lock on the valve, pull to top of stem, and install a lash cap and visually inspect for adequate clearance. This is the more reliable method as the first method could have .005" clearance that could eventually change and a dropped valve would result.
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Old 05-06-2011, 03:11:23 PM   #5
Fbird
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Should work fine IF.......caps actually seat on the valve stem....I would measure the inside hieght of the caps (should all be the same within +/- .002 then take the "longest" ie deepest one and use it to check ALL the valves to make sure it seats.....if not then "shorten" the cap....till it does...then shorten ALL the caps.....that way you won't (prick) yourself accidently mixxing them up.
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Old 05-06-2011, 10:16:00 PM   #6
Damon
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Got it. Thanks, guys.
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1990 454SS pickup. Original "tow truck motor" 454 upgraded to something a little more "aggressive." Seems pretty stout but the fuel bill is nuts.

78 Malibu. Inherited with only 35K on the odo! Mild 383 with Weiand 142 blower on top. Mid 12s appears to be the best it's gonna do on street rubber. Runs so good I may never drive it again.

"Last remaining QJet tuner on planet Earth!"
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