Re: Found my valve train noise problem / bad head :(
[Re: 451Mopar]
#680365
04/28/10 10:24 AM
04/28/10 10:24 AM
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Joined: Jul 2009
Posts: 413 Norway (old world)
Oyvind Mopar
mopar
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mopar
Joined: Jul 2009
Posts: 413
Norway (old world)
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So you know the answer. Too short studs, along with heavy springs. I measured my MW victors, and they have 1,13" thread engagement. I would recommend you to switch to bolts with full depth (allow one thread for tightening), you could cut to fit, or adjust them with washers on top. The center pedestal is only 3/4" wide, and in addition the center and two outer are helicoiled, which takes even more away from the X-section. You need to take away the rest of the helicoil, open the hole so it can be welded all way down, and drill/thread again (preferably without helicoil). It is simple to drill/thread using a rocker shaft as fixture, and the same for fitting the pedestal with a round file, after welding. If wrong shims (flat/even thickness) were used the pedestal would split along the rocker shaft centerline, I had an RPM head from a customer with that fault (very thin due to the helicoil). Simply filing the shims sharp, and pressing them in iron heads makes them good, to avoid the cracking. So, with some work and small cost you can redo your head, and switch to full thread bolts on all rocker pedestals will cure the problem. For assembly oil the threads, and release the adjusters fully, turn the engine if needed to avoid bolting down against full lift. Hope it works out for you, wish you good luck!! Best regards Oyvind Mostad / Norway
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Re: Found my valve train noise problem / bad head :(
[Re: 451Mopar]
#680367
05/04/10 04:21 AM
05/04/10 04:21 AM
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Joined: Dec 2006
Posts: 3,667 Arizona
Chris'sBarracuda
master
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master
Joined: Dec 2006
Posts: 3,667
Arizona
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I think I may still have a set of those Max Wedge type stands if you need them.. I'm not using them.. I'll check.. Chris..
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Re: Found my valve train noise problem / bad head :(
[Re: Dodgem]
#680369
06/30/10 12:47 AM
06/30/10 12:47 AM
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Joined: May 2008
Posts: 5,399 Aurora, Colorado
451Mopar
OP
master
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OP
master
Joined: May 2008
Posts: 5,399
Aurora, Colorado
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Quote:
Quote:
I did have 0.020" rocker shaft shims, could that have caused the problem?
I've heard the shims will do that?? seen pictures hear or elsewhere of failours of more than one stand. puts uneven forces to outsides of stands or something like that??? Where they proper shims or just shims??
Ok, on further inspection it looks like it was the shims. I got the shims from Hughes, and I thought they were tapered, but maybe not? Anyhow, it looks like the shims (and me torquing down on the studs) wedged the shim between the stand and rocker shaft splitting the stand in half.
Anyhow, I have the new stands and I'm taking the whole thing to the machine shop tomorrow along with lash caps for the valves. I will have the machine shop set up the rockers for correct alignment with the 0.060" thick lash caps.
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valve train noise problem -Update- Fixed?
[Re: 451Mopar]
#680370
01/13/11 02:27 AM
01/13/11 02:27 AM
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Joined: May 2008
Posts: 5,399 Aurora, Colorado
451Mopar
OP
master
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OP
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Joined: May 2008
Posts: 5,399
Aurora, Colorado
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Ok I think I finally got the rocker gear sorted out (I hope?). I had the stands machined off and used the Billet Racing Parts.com Max Wedge Stands. I asked to have them set about 0.050" higher, but when I got the heads back the rocker stands were about 0.200" higher. With lash caps on the valve tips the sweep pattern looked OK, so I had to get longer pushrods. I got the valve train back together and the engine running, but no oil to the front rocker arms. The machine shop used standard 3/8" Grade 8 bolts, but the T&D shafts are very thick walled (small oiling hole), so I had to grind down the bolt diameter a bit for oil flow through the rocker shafts. Engine was running OK, and allowed to warm up / run for about 20-minutes. I then reved it up, and BANG! it started making bad noises again. Pulled the valve cover and found the pushrod for the center exhaust rocker out of place again (This is where I originally started..) Removed the rocker shaft, and found the Heli-Coil halfway pulled out of the head (only a 1/2" long insert.) This is where the head originally broke, and the machine shop had this milled further down than the rest of the stands and used a spacer to make up the height difference, but did not make the bolt hole deeper and used the original length bolt, so the bolt only caught the first few threads of the heli-coil. After some research, I decided to repair the bolt hole with a "Time-Sert": http://www.timesert.com/index.htmlThis is like a threaded bushing and stronger than the heli-coil type insert. I also chose to use a stainless steel 3/4" long insert for the repair. I then used a longer bolt for plenty of thread engagement. Fired the engine up again, and reved to 6,500+ RPM several times. So far the repair seems to be working good. Now if it just warms up so I can drive the car.... Anyone else use these "Time-Sert" repair kits? They are pricy, but seem really nice of you need to fix a highly loaded bolt hole.
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Re: valve train noise problem -Update- Fixed?
[Re: 451Mopar]
#680375
01/13/11 03:03 PM
01/13/11 03:03 PM
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Joined: Jul 2009
Posts: 413 Norway (old world)
Oyvind Mopar
mopar
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mopar
Joined: Jul 2009
Posts: 413
Norway (old world)
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I have worked on Edelbrock heads that had Hughes shims that were flat and not tapered, they made the support crack but they did not fall off or fail because the longer bolts still keep the parts together. These RPM heads were helicoiled which took even more off the goods making cracking very easy to happen... Check the stands by the exhausts, they are very skinny!! I filed the shims with taper, and bolted together, still works OK. BTW, your solution now is similar to what is used in aircraft parts, I have a huge carburator from an R1820 Wright radial engine , and it has steel inserts in all threaded holes, to prevent pulling alu threads. Hope you have cured the problem with the long bolts. Check that all your bolts or studs engage deep into the head! Good luck!
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Re: valve train noise problem -Update- Fixed?
[Re: Oyvind Mopar]
#680376
01/13/11 04:02 PM
01/13/11 04:02 PM
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Joined: Dec 2009
Posts: 21,066 in a cattle trailer down by th...
Guitar Jones
Paddle faster! I hear banjo music!
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Paddle faster! I hear banjo music!
Joined: Dec 2009
Posts: 21,066
in a cattle trailer down by th...
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I have seen stock Chrysler 3.3/3.8 V6 heads break the rocker stands like that. I'm sure that's not a harmonic or spring pressure issue. These heads are sand cast and casting flaws happen. I'd fix as stated above with the rocker stands and not give it a second thought.
"Come get your wife"
'92 D250 Club Cab CTD, 47RH conversion, pump tweaks, injectors, rear disc and hydroboost conversion. '74 W200 Crew Cab 360, NV4500, D44, D60 and NP205 divorced transfer case. Front and rear disc and hydroboost conversion. 2019 1500 Long Horn Crew Cab 4WD, 5.7 Hemi.
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