Re: 440 valve clearance issue
[Re: moparpaul66]
#2495274
05/12/18 09:21 PM
05/12/18 09:21 PM
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Joined: Oct 2007
Posts: 736 New York
R/T1968R/T
super stock
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super stock
Joined: Oct 2007
Posts: 736
New York
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How thick is your current head gasket?If its a .020 steel shim already a switch to closed chambered heads will help
Last edited by R/T1968R/T; 05/12/18 09:23 PM.
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Re: 440 valve clearance issue
[Re: moparpaul66]
#2495354
05/13/18 12:53 AM
05/13/18 12:53 AM
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Joined: Nov 2003
Posts: 36,041 Lincoln Nebraska
RapidRobert
Circle Track
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Circle Track
Joined: Nov 2003
Posts: 36,041
Lincoln Nebraska
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I would for sure put it back to where it was for now (& how much clearance did you have then?). Yes I would call several cam mfrs to see what they say. "Dwayne" -68plymouth (sp) on here is the best. I'm in the same boat ex I am in the mockup stage & I might cut notches in the pistons/keeping track of the gram reduction & sub in heavier pins if it comes down to it.
live every 24 hour block of time like it's your last day on earth
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Re: 440 valve clearance issue
[Re: moparpaul66]
#2495498
05/13/18 01:30 PM
05/13/18 01:30 PM
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Joined: Jan 2003
Posts: 14,506 So. Burlington, Vt.
fast68plymouth
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 14,506
So. Burlington, Vt.
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That combo and 125psi don't really add up in my mind.
First thing I'd do is borrow another compression tester and redo the test. All plugs removed, battery charger on, carb wide open. Test all cyls at 4 pumps and 8 pumps.
If you haven't, degree the cam so you know where it really is. I'd shoot for 106-108.
With the info you posted, at .030 over...... Even if the heads were 90cc, it would still be almost 9.4:1.
Plugging the numbers into the Wallace calculator shows about 150psi, which is plenty for that cam....... And no quench.
If the heads were 84cc instead, the CR would be 9.85, which would add about 10psi to the gauge.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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Re: 440 valve clearance issue
[Re: moparpaul66]
#2495546
05/13/18 02:47 PM
05/13/18 02:47 PM
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Joined: Oct 2015
Posts: 570 UK
rb446
mopar
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mopar
Joined: Oct 2015
Posts: 570
UK
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I thought I might have to cut the piston reliefs when installing the CC .650/.650 solid cam in my stock rebuilt/balanced 1968 6-pak bottom end, quite surprised when we found we had adequate VTP clearance w/039 fel pro's with the 2.14/1.81 906 heads, 1 thing that sticks in the mind from all those years ago.....only .020 with that cam, what was it straight up?
Last edited by rb446; 05/13/18 02:57 PM.
1969 'Cuda 446ci, best 9.96@133.9 in 1990 1971 340 'Cuda, best 11.01@122.8 in 1987
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Re: 440 valve clearance issue
[Re: moparpaul66]
#2495713
05/13/18 10:48 PM
05/13/18 10:48 PM
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Joined: Nov 2003
Posts: 36,041 Lincoln Nebraska
RapidRobert
Circle Track
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Circle Track
Joined: Nov 2003
Posts: 36,041
Lincoln Nebraska
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solid "cup seat height" is way lower (shorter) than a hyd lifter, not sure why tho, more than preload I would think.
live every 24 hour block of time like it's your last day on earth
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Re: 440 valve clearance issue
[Re: moparpaul66]
#2495730
05/13/18 11:22 PM
05/13/18 11:22 PM
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Joined: Jun 2008
Posts: 3,916 usa
lewtot184
master
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master
Joined: Jun 2008
Posts: 3,916
usa
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Thanks guys for all the help. Think I found my problem.... Is seat height different on a solid vs hydraulic lifter to compensate for preload? I've been using a hydraulic lifter full of washers to make it solid... why?
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Re: 440 valve clearance issue
[Re: moparpaul66]
#2495944
05/14/18 01:31 PM
05/14/18 01:31 PM
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Joined: Jan 2003
Posts: 14,506 So. Burlington, Vt.
fast68plymouth
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 14,506
So. Burlington, Vt.
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Use an actual solid lifter and an adjustable length checking pushrod, along with checking springs on the head. Adjust to just zero lash with the cam on the base circle....... Then do your checks.
With that cam at the correct c/l......... There should be plenty of clearance, unless the heads have been milled a bunch.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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