Serpentine belt question

I don't know if any of you have installed a serpentine belt system in your car, but I have a couple of question for those of you with any experience with such a system. I put one in a while back and I love the way it looks and how easy it is to adjust. However, I have a couple of bits of odd behavior that I think started around the time I put it in. Because of this, I am considering going back to the stock belt and pulleys.

1. When cold, the engine shakes and the shroud sounds like it's about to come off. It feels a bit loose, but I can't find and missing or loose fasteners.

2. I sometimes hear an odd swishing sound from the engine. It does rise and fall with engine speed.

I don't know for sure that the serpentine system causes these symptoms, and #1 is the only potentially serious one. I had to remove part of the tins to get a puller in there to swap the lower pulley, and I don't want to go through that hassle again without a reasonable expectation that the serpentine system is in fact the issue.

Lots of discussion on the serpentine belt system in the high performance sections of TheSamba and ShopTalk forums.

EVERYONE stresses that they only be used for track purposes and never for extended street use. I guess that they provide zero slippage at high speeds and can result in the fans detonating over time. The only welded fan that's strong enough AND balanced correctly to work with the system are from Berg and cost $$.

Ever notice on an engine with a stock belt, that when revved, the belt expands/distorts through centrifugal forces? This is sort of what you want. A little slippage, you don't get this with the serpentine set-up.

Just mentioning it, what I've read . . .

You probably wanna remove that serpentine belt assembly this weekend and sell it to me on Monday. Been looking for a good used one for the drag engine for a while now.

Oooooppsss . . . did I just "say" that out loud ?

Didn't hear a thing, TC ;-)

I DID find a missing shroud bolt, and I have tightened all of that down so it doesn't rattle. I am still thinking of removing the serpentine system. If I do, you'll be the first to know, TC. What're you thinking for $?

I have run serpentine belts on 2 street engines for more than 10,000 miles with no issues. If you look over part parts catalogs you may notice a lot of parts say "not for street use" or "off road only" or "racing only". I am using welded and balanced fans, but the current engine also cranks upward of 7200rpm when pushed. I am running the so called "power pulley", with sand sealing, on the serpentine belt, so that reduces top end fan RPM a bit, and delivers a bit more power to the wheels....and no, it doesn't overheat....and a full out 1-2 powershift no longer tosses off the belt like it did with the stock approach...

Lane

I installed a Serpentine Belt from CB a couple of years ago:
a. The crank bolt has come loose several times resulting in a loosening of the crank pulley. This causes intermittant rattling which seems to go away at higher rpms. Luckily I caught it each time and temporarily tightened.
b. I replaced the alternator because of worn bearings. This resulted in a swishing sound because the fan was not rotating straight - caused it to wobble inside the shroud and scrape. The correct tension and perfect alignment are critical.
c. Conclusion - I am still running it but Glenn had to put a 5' pipe on the wrench to tighten the crank pully while it is in the car. It caused no problem coming and going to Carlisle and Ocean City, MD last year.

In conclusion, maybe it would be worth not worrying about it by changing back.

The reason I installed it in the first place was I threw a belt on the drag strip and didn't know it until I got back to the pits and several people came running over with fire extinguishers. We made it about a third of the way home, threw a rod and then had to go get the trailer and explain to my wife why I was rebuilding the engine again.:-(

And yes I have to remove both of my Dells because the engine compartment sheet metal was adapted from a Type 2. Now I have tight sheet metal around the engine and all stock rubber seals.

Paul

Thanks for the info, Paul. I have the BMD system which was recommended to me by several folks who run them on the street. I will probably remove the alternator tomorrow and inspect bearings and fan. I have heard the swishing sound for well over a year, and it may have been there since the beginning - just took a while to notice. I have always chalked it up to being the belt itself. When I tinker with the alternator, I will put a straight edge across both pulleys to verify alignment again.

This may be much ado about nothing, as I was looking for something to tinker on (can only watch so much TV), but I'm glad I tightened down the shroud.

Lane, leave the Speedster alone, and find another hobby(in addition to Speedsters)! You just can't help yourself, can you?

Nope. When I get bored I have the irresistible urge to tinker.

Got a spare week . . .

http://www.thesamba.com/vw/forum/search.php?search_keywords=serpentine+belt&search_terms=all&search_author=&search_forum=-1&search_time=0&search_fields=all&search_cat=1&sort_by=0&sort_dir=DESC&show_results=topics&return_chars=200

Removed belt and inspected fan and alternator bearings - all good. Reinstalled and made sure to set alignment of pulleys properly. No more nasty noises.

Hmmm... What to tinker on next...?

Lane, head on over to my garage! Ill be sure and put you to work.

I have a feeling that the hydraulic clutch conversion that I've been putting off since the spring will be the next big project. Got all the parts, but haven't wanted to take the car off the road. Now that it's getting a bit cool for top down driving, I can do without it for a weekend or two.

Also, I just cashed in 4 days worth of vacation. Now I'll have some toy money for this year. WOOHOO!!!!!

Besides....When he's out in the garage "tinkering", he's out of his wife's hair.