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flyboat Samba Member
Joined: April 21, 2010 Posts: 2752 Location: Bath NC
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Posted: Sat Nov 10, 2012 2:46 pm Post subject: a rattle I can't figure out. |
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I have had a valve train type noise for some time. I have torn the heads down. All looked good. Reinstalled with new rockers and push rods (chromoly). Rattle still exists. So today I decided to tear the engine completely down. I expected to find a bad lifter bore or maybe even a bad bearing. Nope, all looked like a new build.
I am left thinking that maybe I have a piston slap issue. The pistons and cylinders look good. The clearance is a bit more than I like. But other than that, I can't find anything that would create this rattle/knock. What are your thoughts.
2276
10 to 1 cr
1.4 ratio rockers
welded and ported heads
Erson cam .327 lift, 233 duration, 106 lobe centers.
Weber twin 44 idf _________________ 79 super Vert
62 Ragtop Bug
66 tintop Westy
Porsche 914
09 Z06 Vette track car |
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vwracerdave Samba Member
Joined: November 11, 2004 Posts: 15280 Location: Deep in the 405
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Posted: Sat Nov 10, 2012 3:16 pm Post subject: |
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Engines with dual valve springs and chromoly P/R are noisier then single springs with aluminum P/R. Steel transmits noise while aluminum dampens noise. You need to carefully check the side clearances of your rockers. _________________ 2017 Street Comp Champion - Thunder Valley Raceway Park - Noble, OK
2010 Sportsman ET Champion - Mid-America Dragway - Arkansas City, KS
1997 Sportsman ET Champion - Thunder Valley Raceway Park - Noble ,OK
Featured in Dec. 2001 HOT VW's Magazine page 63
Watch my racing video's http://www.youtube.com/user/okvwracer/videos |
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flyboat Samba Member
Joined: April 21, 2010 Posts: 2752 Location: Bath NC
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Posted: Sat Nov 10, 2012 3:39 pm Post subject: |
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I have set the side clearance of the rockers to .003-.004"
I am aware of the extra noise from the set up. My concern stems from the fact that the noise seems to be coming from the left side of the engine no matter how I adjust the valve lash, which is set to "O". This makes me think there is something wrong in the set up on the left. But it all looks good.
Does piston slap sound like valve train noise? Would there be any visible evidence? _________________ 79 super Vert
62 Ragtop Bug
66 tintop Westy
Porsche 914
09 Z06 Vette track car |
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modok Samba Member
Joined: October 30, 2009 Posts: 26743 Location: Colorado Springs
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Posted: Sat Nov 10, 2012 5:08 pm Post subject: |
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Some cams make more rattle than others, if all the other parts look normal but you still have a lot of lash noise then suspect the cam!
The ends of the pushrods take time to wear into the lifters and rockers, until they do wear in there will be more noise. Changing them around may delay the process |
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flyboat Samba Member
Joined: April 21, 2010 Posts: 2752 Location: Bath NC
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Posted: Sat Nov 10, 2012 5:26 pm Post subject: |
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I Gotcha _________________ 79 super Vert
62 Ragtop Bug
66 tintop Westy
Porsche 914
09 Z06 Vette track car |
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Itisa1835 Samba Member
Joined: September 02, 2011 Posts: 123 Location: Norco
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Posted: Sat Nov 10, 2012 5:33 pm Post subject: |
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First switch the rocker arm assemblies from one side to the other and see if the noise moves to the other side, and then move the push rods to see...understand? if you end up with the noise still on one side you know what to check... one on my tricks is to use an old push rod with no tips and put one end up after the metal such as cylinders and head when jacked up and running and listen... |
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mightymouse Samba Member
Joined: May 26, 2004 Posts: 4220 Location: las vegas
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Posted: Sat Nov 10, 2012 11:28 pm Post subject: |
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check for the valve guides loose. Took me a while to find it, but that was my crazy tapping noise. Valve guide literally sliding back and forth and hitting the retainer. madness. _________________ Nothing can stop the man with the right mental attitude from achieving his goal; nothing on earth can help the man with the wrong mental attitude.
Thomas Jefferson
Note to EVERYONE.
Know your ZDDP levels or you WILL lose a cam and lifters. |
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flyboat Samba Member
Joined: April 21, 2010 Posts: 2752 Location: Bath NC
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Posted: Thu Nov 15, 2012 6:33 am Post subject: |
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Tore down the engine and everything looked really good. I was expecting to find a bad lifter bore. But nope. The valve guides are all tight. The guides do have a small amount of wear. Not what I would think is enough to create the tapping noise.
I suppose this type of valve train is just noisier than I thought. I am going to replace the guides and valves for larger ones and put it back together. Hopefully, that will fix the noise. If not, my next step is to get the aluminum tapered push rods from ACN _________________ 79 super Vert
62 Ragtop Bug
66 tintop Westy
Porsche 914
09 Z06 Vette track car |
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earthquake Samba Member
Joined: January 10, 2008 Posts: 3984 Location: SANDY VALLEY, NEVADA
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Posted: Thu Nov 15, 2012 10:47 am Post subject: |
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I had a motor that made a strange buzz that was a broken rocker stand, it was broke in half. It would go up in pitch when you rev-ed it.
Casey _________________ 74 CLASS 11 LOOK-A-LIKE
69 DUNE BUGGY
79 INTERNATIONAL SCOUT II
05 SCION XB SERIES RELEASE 2[#437]
95 Chevy C3500 dually
98 Ford E150
Link to Kelly J. Nolte 3/20/53 - 11/6/08
https://time-zonelabs.blogspot.com/p/about-kelly.html
DEATH TO CHINGERS!
[From a military recruitment poster in the novel "The Stainless Steel Rat" By Harry Harrison] |
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vwsb74 Samba Member
Joined: July 30, 2009 Posts: 1201 Location: socal
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Posted: Thu Nov 15, 2012 10:50 am Post subject: |
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flyboat wrote: |
Tore down the engine and everything looked really good. I was expecting to find a bad lifter bore. But nope. The valve guides are all tight. The guides do have a small amount of wear. Not what I would think is enough to create the tapping noise.
I suppose this type of valve train is just noisier than I thought. I am going to replace the guides and valves for larger ones and put it back together. Hopefully, that will fix the noise. If not, my next step is to get the aluminum tapered push rods from ACN |
Do you have a straight cut gears? My cb straight cut gears sounds like clak clak... _________________ 74 super beetle
2011 ford explorer traded
2010 mazda 3 hatchback
2014 Honda odyssey
2180cc 48IDA clone
Xr310 cam =171hp@6k rpm sold so as the car😢 |
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flyboat Samba Member
Joined: April 21, 2010 Posts: 2752 Location: Bath NC
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Posted: Thu Nov 15, 2012 11:01 am Post subject: |
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no straight cut gears. _________________ 79 super Vert
62 Ragtop Bug
66 tintop Westy
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mark tucker Samba Member
Joined: April 08, 2009 Posts: 23937 Location: SHALIMAR ,FLORIDA
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Posted: Thu Nov 15, 2012 12:29 pm Post subject: |
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you might try adding the extra oil gally to the lifter gally, and sloting the lifter bores inward about 3/8" and outward about1/4" from each oil gally hole in each lifter bore.my chromoly push rods & 1.33 rocker assy is extreamly quiet.the only one quieter I have heard has a hydro cam in it. |
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flyboat Samba Member
Joined: April 21, 2010 Posts: 2752 Location: Bath NC
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Posted: Thu Nov 15, 2012 12:36 pm Post subject: |
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How did you get in there to slot it, A small file? _________________ 79 super Vert
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mark tucker Samba Member
Joined: April 08, 2009 Posts: 23937 Location: SHALIMAR ,FLORIDA
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Posted: Thu Nov 15, 2012 5:45 pm Post subject: |
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a die grinder with an 1/8" carbide ballend bit.(dremol will do just fine too) about .040" deep.060-.080" wide.
the grove in the vw lifter isant always lined up with the gally so it dosent always have oil pressure to the pushrods with supply oil to the rockers. and adding the extra gally just ensures there is enough volume, you can also deepen&widen the slots in the cam bearing journol in the case halvs to increase the oil flow.a high volume pump should also be used(30mm). |
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flyboat Samba Member
Joined: April 21, 2010 Posts: 2752 Location: Bath NC
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Posted: Thu Nov 15, 2012 6:41 pm Post subject: |
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Ok thanks. I have the 30 mm pump. I will consider this mod. I am also considering the Hoover mods. _________________ 79 super Vert
62 Ragtop Bug
66 tintop Westy
Porsche 914
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the2ndcashboy Samba Member
Joined: March 19, 2007 Posts: 827 Location: Houston
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Posted: Thu Nov 15, 2012 10:00 pm Post subject: |
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That is one of the Hoover mods. Just a little bass-ackwards . Most people slot the lifters, not the case, on the principle that its better to modify the cheaper part. _________________
SRP1 wrote: |
You see....... He talks in code and translation requires a priest, geologist, astronomer, biophysicist, and Indiana Jones. |
modok wrote: |
If anything comes out perfect it just means your measuring tools are substandard. |
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mark tucker Samba Member
Joined: April 08, 2009 Posts: 23937 Location: SHALIMAR ,FLORIDA
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Posted: Thu Nov 15, 2012 10:55 pm Post subject: |
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the cheeper part that will ne redooing when they need changed, or a burr left on 1 and it eats up the lifter bore, or you have a cam that dosent put the grove in the lifter in line with the gally at all times. modify the cheeper part? what a concept.so we should all throw away the webbers and just hog out the solex.& keep filing points instead of using electronics.and weld up junk oe heads instead of using a better casting.and weld up valves so there biger instead of buying good stainless valves.and tighten the loose nut behind the wheel before it causes an axadent.possiably use antiaxodents!!!! use more tire patches on bald tires instead of instaling new ones.I wonder why I never thought of that?hmm how about just welding some counter weights to the pully instead of the crankshaft?they could even be canted so it blows. |
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the2ndcashboy Samba Member
Joined: March 19, 2007 Posts: 827 Location: Houston
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Posted: Fri Nov 16, 2012 2:25 am Post subject: |
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mark tucker wrote: |
the cheeper part that will ne redooing when they need changed, or a burr left on 1 and it eats up the lifter bore, or you have a cam that dosent put the grove in the lifter in line with the gally at all times. modify the cheeper part? what a concept.so we should all throw away the webbers and just hog out the solex.& keep filing points instead of using electronics.and weld up junk oe heads instead of using a better casting.and weld up valves so there biger instead of buying good stainless valves.and tighten the loose nut behind the wheel before it causes an axadent.possiably use antiaxodents!!!! use more tire patches on bald tires instead of instaling new ones.I wonder why I never thought of that?hmm how about just welding some counter weights to the pully instead of the crankshaft?they could even be canted so it blows. |
Lol dude, don't get your panties in a wad. I didn't say grooving the bores was wrong, just that most people do the lifters instead. I don't always mod the cheaper part myself. I moved the main bearing oil holes in my aluminum case instead of moving the holes in the bearing. Thats a little different though, since I was fixing something that was wrong, not adding a mod that some future owner might not want.
And btw: anyone who would install a lifter with a burr on it probably isn't capable of grooving the bores properly either.... _________________
SRP1 wrote: |
You see....... He talks in code and translation requires a priest, geologist, astronomer, biophysicist, and Indiana Jones. |
modok wrote: |
If anything comes out perfect it just means your measuring tools are substandard. |
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Boolean Samba Member
Joined: January 19, 2012 Posts: 1712 Location: Stockholm
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Posted: Fri Nov 16, 2012 10:18 am Post subject: |
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I'm fine with modifying the cheapest part. If that part is wrong. Otherwise, I'll modify the part that needs it most - cheap or not.
The issue with consumables having to be modified every time the engine is torn sounds stupid. JMHO _________________ I strive for perfection. Excellence will not be tolerated!
Build thread here:
http://www.thesamba.com/vw/forum/viewtopic.php?t=529379 |
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modok Samba Member
Joined: October 30, 2009 Posts: 26743 Location: Colorado Springs
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Posted: Fri Nov 16, 2012 5:50 pm Post subject: |
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Groove the side of the bore opposite how the cam rotates. |
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