GRIZDOG

I am having an odd occurance in my engine.  I think it has something to do with the belt and/or pulleys, but I'm not sure.

 

There is a vibration when the engine rpms go up.  It's not something that happens because of movement, it's definitely tied to engine rpms, because it happens even when I'm sitting still and reving the engine.

 

When I had my wife rev the engine for me I noticed the drive belt would wiggle a bunch at the higher rpms.  I just finished adjusting it, but this was happening before that.  I adjusted it because it is relatively new and I noticed it was starting to get pretty loose.

 

Perhaps I adjusted it imporperly or it's not tight enough?  Too tight?  Honestly, this is the first belt I've put on this engine, so this is the first time I've had to deal with this.

 

Also, this engine is newly rebuilt, so I highly doubt it's anything internal.

 

Has anyone had this kind of vibration problem before?

1972 Super Beetle
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Cobey
How much play is in the belt when you push on it, half way between the pulleys?



[url=http://geeks-at-large.com/ghia](0)(=|=)(0)[/url] 68 Ghia Vert - Gina
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GRIZDOG

Before I adjusted it, the vibration was at lower rpms, like at idle.  It was super sloppy.  After I adjusted it, it's about 1/2" from straight to bent, like the book says.  Now the vibration is at higher rpms, like when you rev the engine.

1972 Super Beetle
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Cobey
It will still wiggle a bit at higher RPMSs.  I would get either a mechanic's stethescope and see if you can use it to pinpoint the the source, or, reach out inside the fan and see if you have gotten something stuck up in there there.  Like aluminum foil.  LOL.
[url=http://geeks-at-large.com/ghia](0)(=|=)(0)[/url] 68 Ghia Vert - Gina
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GRIZDOG

I understand what you're getting at about the tin foil.  This actually started a few days before I did that.

 

How long can I run the engine without the drive belt attached.  I was thinking about trying it out long enough to see if there are any vibrations without the generator and fan turning.  If not, then I would know that one of those items is the source and I could stop having nightmares about another engine rebuild.

1972 Super Beetle
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Cobey


You can run it for a minute or two at a time without risking overheating.

[url=http://geeks-at-large.com/ghia](0)(=|=)(0)[/url] 68 Ghia Vert - Gina
[url=http://geeks-at-large.com/edel/](O\U|U/O)[/url] 72 SB Vert Autostick - Edel
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GRIZDOG

I'll be trying it when I get home today.

1972 Super Beetle
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GRIZDOG

I tried running without the belt.  It ran like crap (even more), but I didn't notice any vibrations.  It runs like crap with the belt on too, but not so much.  This is due to the distributor(?) business in the other thread.

1972 Super Beetle
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Ryan

Stick your hand behind the shroud (engine OFF) and try to wiggle the fan.  If it moves pretty much at all then something is wrong.  Possible problems are a cracked/broken fan hub and/or your rear Alt bearing is toast.  --Ryan

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GRIZDOG

If the fan hub is cracked/broken, can it be replaced, or does it mean replacing the entire fan?  I put it in, but I don't remember the construction of the thing.

 

If the bearing is toast, can it be repaired, or does it mean that I have to buy a new Generator?

 

Would it be a big deal to upgrade to an Alternator?  How much is envolved in doing that?

1972 Super Beetle
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Ryan

If the fan is damaged, then you need to buy a new one.  The bearing in your Gen is pretty iffy.  If it's just the bearing, then if you do your homework you should be able to track down a replacement.  Though you'll probably be searching based on dimensions from a bearing manufacturer.  I don't think anyone lists a straight replacement part.  Now if the hub in the Gen where the bearing is installed got pounded out, then a new Gen/Alt is in order, or you can source parts from a junkyard.  Actually the same would be true for the bearing.  But as you brought up, it would be an ideal time to upgrade to an Alt.  Installing one is a breeze and most places carry Gen to Alt upgrade kits with the stuff you'll need.  Should be under $200, but I'm not sure.  --Ryan

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Cobey
I've been working the alternator angle myself.  you're looking at ~$130 for a 55amp alternator conversion kit.  Cheap bastard me is collecting the parts used for a bit less than that.
[url=http://geeks-at-large.com/ghia](0)(=|=)(0)[/url] 68 Ghia Vert - Gina
[url=http://geeks-at-large.com/edel/](O\U|U/O)[/url] 72 SB Vert Autostick - Edel
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GRIZDOG

California imports has a conversion kit for about $130, plus shipping:

 

http://www2.cip1.com/SearchResults.asp?Search=alternator+conversion+kit

 

Aircooled.net has one for about $170, plus shipping:

 

http://aircooled.net/new-bin/viewproductdetail.php?keyword2=LCH0003&cartid=1103200590879710

 

I wonder if either of those kits includes the new gaskets you'll need when replacing the oil filler stand.  It doesn't look like it, so we'll need that too.

 

A replacement Generator is about $140.  I guess that leaves me little excuse to not upgrade to an Alternator.

1972 Super Beetle
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