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 Post subject: Knocks at speed....
PostPosted: Fri Jul 02, 2010 9:02 am 
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Hello all.... New here and looking for some answers to a curious problem. I have a 2332cc bernie bergmann motor that I purchased for my buggy. It has performed flawlessly for a year now, but all of the sudden last week it started knocking. It is a higher pitch knock. Sounds alot like a loose rocker arm, but it is only really noticeable from 2000- 3000 rpm and only when you are cruising. The noise is there regardless of oil pressure (90 psi dead cold- 25 psi idle at 190 degrees) with no odd flickering or anything. If you are accelerating under a load, decelerating, or free revving the engine you can hardly hear it if at all. Cruise 45 mph down the road nice and easy and it sounds like it is gonna fly apart. Also the engine still runs great. Pulls fine, no sputters or coughs???? All 4 plugs look good. Barely ever hits 190 degrees unless i am running 70 mph. I have taken it to several "experts" in my area and they tell me to adjust my valves and give me bewildered looks when I tell them I did before I came (.004-.006 cold). Engine was built to be a stump puller for my buggy. It has 042 heads, 110 cam, 1 1/2" exhaust, Dual 44 webers, and a porsche fan. I run 15/50 Mobil 1 and I broke it in on non synthetic oil. I have been very nice to this engine by the standards of most buggy owners. Almost all street miles(3000 or so), 3 off road trips, and its been to 5200 rpm once. I have heard everything from "run thicker oil" to "check the head studs" to "rebuild it". HELP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!


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 Post subject: Re: Knocks at speed....
PostPosted: Fri Jul 02, 2010 6:52 pm 
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Kind of a clattery sound?

I'd bet the flywheel has come loose.
You have an aluminum crankshaft pulley?
If so, take it off.
If the keyway is wallowed out, that's it.

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 Post subject: Re: Knocks at speed....
PostPosted: Sat Jul 03, 2010 9:08 am 
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My vote also flywheel. Thanks Dave T

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 Post subject: Re: Knocks at speed....
PostPosted: Sat Jul 03, 2010 9:37 am 
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When I ordered that engine I ended up waiting months for it because he just came out with the new serpentine version of his porsche fan (buy something nice and this is what you get). The pulley is aluminum. Also that is the most logical suggestion so far. Should I just check the pulley first or pull the engine and check flywheel as well?? I know engines... Still learning to speak VW though. Thanks for the replies.


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 Post subject: Re: Knocks at speed....
PostPosted: Mon Jul 05, 2010 10:03 am 
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Yank the pulley off.
If it's wallowed out you will know it's the flywheel.

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 Post subject: Re: Knocks at speed....
PostPosted: Mon Jul 05, 2010 3:44 pm 
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Location: Atlanta GA
wristpin??

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 Post subject: Re: Knocks at speed....
PostPosted: Mon Sep 06, 2010 11:37 am 
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Been REALLY busy. Not the Pulley. Everything looked fine there. :x So my next question is any body need a nice Porsche Fan kit with 110 amp GM alternator and ceramic coat on everything? Also considering fair offers on the rest of the engine as well. Thanks to being busy I have an Outfront Suby on the way. Need to re-coop a little $$$


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 Post subject: Re: Knocks at speed....
PostPosted: Mon Sep 06, 2010 12:32 pm 
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How much for the porche stuff???

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 Post subject: Re: Knocks at speed....
PostPosted: Mon Sep 06, 2010 1:13 pm 
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I just posted it in the stuff for sale side. I am gonna try to move the whole thing first. If I don't get reasonable offers that way. It will get parted. Happy Labor Day :D


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 Post subject: Re: Knocks at speed....
PostPosted: Mon Sep 06, 2010 5:40 pm 
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if it has mofoco heads i bet on a valve guide. I had a brand new set do that same thing. It was quite while cold but after a little heat it started tapping and thats what it was, a bad valve guide.


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 Post subject: Re: Knocks at speed....
PostPosted: Tue Sep 07, 2010 8:51 am 
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Yeah...It could be 10 things. It shouldn't be ANYTHING on a 6 month old motor that I wasn't even mean to. That is why I am going to let someone who likes these motors fix it. If VW is a religion.....I have lost the faith! :lol:


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 Post subject: Re: Knocks at speed....
PostPosted: Tue Sep 07, 2010 9:03 am 
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Pull the belt ofrun it. I have seen perfectly good looking belts make a knocking noise that you would sear a rod was ready to come flying out of the case.Quick easy check. Could save you lots of searching and time.

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 Post subject: Re: Knocks at speed....
PostPosted: Tue Sep 07, 2010 9:45 am 
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Just a shot in the dark. Is there too much gap between a rocker arm and the post?


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 Post subject: Re: Knocks at speed....
PostPosted: Tue Sep 07, 2010 3:27 pm 
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I'll bet that engine has chromemoly push rods. Your spec is for aluminum ones. The crome moly spec is 0.005 almost 0. So your valve train would be to loose once warm.


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 Post subject: Re: Knocks at speed....
PostPosted: Tue Sep 07, 2010 4:21 pm 
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what Gary and DW said sound good, also kevin,,,,, MOFOCO HEADS = MOF*CKINJUNK as my engine builder told me. he didnt even want to build it with them.... Then plink clunk clank BOOM! valve in my piston! id put money on them being junk heads.


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 Post subject: Re: Knocks at speed....
PostPosted: Tue Sep 07, 2010 5:27 pm 
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Nothing amazing on the valve train. He (Bergmann) told me a stock style valve train would last longer than a double spring, massive rocker ratio setup. The build sheet even says the standard .004. I checked the rockers 3 times after the noise started trying between .004-.006. Plus I got about 2500 street miles out of it that were nice and quiet before it started. I will check the head brand. I don't think it is mofoco though. One more Oktoberfest and we shall see... :)


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 Post subject: Re: Knocks at speed....
PostPosted: Tue Sep 07, 2010 5:54 pm 
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(about a beer later.....) Auto Linea G 01 ????? Sounds like someone gave me the chinese S**t :shock:


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 Post subject: Re: Knocks at speed....
PostPosted: Tue Sep 07, 2010 6:20 pm 
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I might be mistaken but i thought auto linea is the one of the most trusted case manufacturers so id assume they produce a quality head.


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 Post subject: Re: Knocks at speed....
PostPosted: Tue Sep 07, 2010 6:42 pm 
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Never heard of it myself. Couldn't tell you either way. Make me feel better about my money if that is the case. Still no less broken.


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 Post subject: Re: Knocks at speed....
PostPosted: Tue Sep 07, 2010 8:50 pm 
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Like passat said, check the side play on your rocker shafts.
If they are stock type, you might have broken a wavy washer spacer.

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 Post subject: Re: Knocks at speed....
PostPosted: Wed Sep 08, 2010 12:08 am 
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Autolinea is the OEM supplier to VW in Brazil. With the exception of DRD 3.0 case , ARPM, Pauter, Autocraft and Scats 3 piece case they make the cases for everyone including VW, Empi and CB. Finding out what is wrong with it might just get you more cash for it.


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 Post subject: Re: Knocks at speed....
PostPosted: Wed Sep 08, 2010 7:53 am 
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Yeah... I was curious about those wavy washers. Is there supposed to be one of those between every moving part in the rocker assembly??? I have no idea how many are supposed to be on each. I never found any remnants of any broken ones when I took the valve covers off. I would love to FIX it then sell it....My one problem is if I have to go INTO the engine, I am just not set up for it. Everything I have done so far in this hobby has been done in a dilapidated old dairy barn of my families. We have a new shop built with no power, and no workbenches yet. I am not gonna throw money at an engine to have it go bad because I tried to take it apart on a dirty barn floor.


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 Post subject: Re: Knocks at speed....
PostPosted: Wed Sep 08, 2010 12:47 pm 
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Those waved washers break on stock engines. Any performance engine should not have the wavy washers. Normally there is one on each side of the rocker arm. Without a decent place to work I would not take it apart.


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 Post subject: Re: Knocks at speed....
PostPosted: Thu Sep 09, 2010 9:29 pm 
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Okay...I have the rocker assemblies off and there aren't wavy washers between every rocker arm. More like 1 here, 3 here, none here, I don't know. and they aren't wavy either. Should there be any play in the assembly (back and forth on the shaft). Cause there is...About a 16th or so.
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 Post subject: Re: Knocks at speed....
PostPosted: Thu Sep 09, 2010 9:38 pm 
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A sixteenth is way to much. Even about .004 left to right play on the rocker shaft makes noise.


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