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#1
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Hydraulic Roller lash and noisy running
I just finished my engine build and had my local hot rod mechanic help get it running. There's still quite a bit of valvetrain noise and I'm wondering if you can help me diagnose it. He said it needs break-in time but Johnson's tech said lifters don't need break-in.
The mechanic set it with zero lash plus 1/4 turn. The Johnson lifters 2112OPR need .035" +/-.010" lash. That's just over a half turn. I gave them the extra quarter but it didn't solve the issue. Should I re-do the lash entirely? Can I ever expect the valvetrain to be silent? Anyone know a Pontiac engine expert in LA? Here's a video of how it sounds with .035" lash, as Johnson spec'ed: https://photos.app.goo.gl/qzuBS32QeZBdZu8s9 Does it sound like it's still loose? Should I fully remove the rockers and be sure or is this somewhat normal? |
#2
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What roller rockers are you using? i am not an expert, but it migth be mostly the rocker arms you are hearing. just did a topend rebuild with the same lifters as you and i can also hear my rockers. but for now did just a 1/4 of a turn.
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Murphy's law - "Anything that can go wrong will go wrong". -469 ,Butler 310+ Eheads, Hurricane intake portmatched by butler, Butler roller 230/236 @0.50 112 LSA, Johnson lifters, pypes 2 1/2" exhaust, 3.42 yukon duragrip lsd, holley sniper efi, hyperfuel efi tank +++ |
#3
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Oh interesting.
1.5p CompCams roller rockers-- though they look more orange than these pictures. Maybe an older model, I got them from another user on here a while ago. |
#4
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What is your motor and what heads are you running. And also what cam?
Do you have the rockers installed right on the studs? There is a half round side and a flat side to the shaft of each rocker and you want the flat side facing up . Also roller lifters as you where told do not need to break in, so I would not be looking for any more advice/ help from that local hot rodder if I could avoid it!
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I do stuff for reasons. Last edited by 25stevem; 05-25-2022 at 05:25 PM. |
#5
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Quote:
Speedmaster heads Comp Cams XR288HR Thanks-- I'll check on the flat vs round side of the rockers. I had installed the rocker studs without lock-tite, just torqued down. That was a big mistake, the studs rattled themselves loose while I was trying to start the motor. He found that, reinstalled them with lock-tite but I can verify they were installed flat side up. Last edited by ignaro; 05-25-2022 at 05:33 PM. |
#6
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Does it sound fine when cold?
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#7
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That rocker type will create a characteristic "sewing machine" type sound which would be normal. If what you are hearing is more of a clatter or ticking, that is likely the lifters.
I have a comp roller and while it performs great the ramps, specifically the closing ramps are pretty aggressive and may contribute to valvetrain noise. mine clack pretty bad, but I'm running the Lunati lifters which are kind of known for that.
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-Jason 1969 Pontiac Firebird |
#8
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What length push rods was the motor built with and was the rocker geometry checked?
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I do stuff for reasons. |
#9
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It does not sound any different cold vs hot.
I would definitely call it a sewing machine noise. The 1/4 turn I gave it might've decreased the "clacking" that sounded like a typewriter-- the video above does a pretty good job of representing the sound. It's worth my double-checking that the rockers were installed flat-side-up but this may just be something I have to get used to. Thanks a ton, I'll report back...! |
#10
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PM sent!Tom
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#11
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Those cams are known to be noisy.Tom
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#12
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I completely missed the video. I wouldn't call that clatter. I would call that probably pretty normal considering the cam and rocker type. If you drive it down the road at about 2500 rpm or so I would bet it makes a fast fluttering type sound like a sewing machine at full song.
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-Jason 1969 Pontiac Firebird |
#13
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Sounds normal to me. Those XR cams are loud in my experience. If the "clack" goes away with some RPM, I'd say you're golden.
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'71 Holden HQ Monaro - 3850lbs race weight, 400c/i - 11.4 @ 120 '66 Pontiac GTO - 389, 4 speed street cruiser |
#14
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As already asked did anyone check the valve train geometry to verify correct length pushrods?
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Tim Corcoran |
The Following User Says Thank You to Tim Corcoran For This Useful Post: | ||
#15
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Just for ****'s & giggles I would confirm that when the valves are closed that the belly of the rocker is not touching the spring nor the retainer.
This relates to the question of push rod lenght/ geometry.
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I do stuff for reasons. |
The Following User Says Thank You to 25stevem For This Useful Post: | ||
#16
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What rocker studs are you running? I'll assume 7/16 which is 20 threads per inch, that's a BBC rocker commonly used in Pontiac builds.
If so, your 1/2 turn of preload is still not enough for the Johnson lifters you are using. 1/2 turn on those studs will only give you .025" preload. 1 full turn is .050" preload. If Johnson is calling for .035" + or - .010" then you would need about 3/4 turn of preload on the 7/16-20 stud to get you in that "range". I would adjust them properly first and go from there. |
#17
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Quote:
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#18
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Yep. Been there, done that.
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#19
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Yep, good point as the lash will open up when warm with aluminum heads. Adding a pinch more preload certainly won't hurt.
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#20
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Yup, go 3/4 turn.
What's your idle RPM out of curiosity? Your alt belts needs tightening... .
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. 1970 GTO Judge Tribute Pro-Tour Project 535 IA2 http://forums.maxperformanceinc.com/...d.php?t=760624 1971 Trans Am 463, 315cfm E-head Sniper XFlow EFI, TKO600 extreme, 9", GW suspension, Baer brakes, pro tour car https://forums.maxperformanceinc.com...ght=procharger Theme Song: http://www.youtube.com/watch?v=7zKAS...ature=youtu.be |
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