Screwdriver

I've gone back on forth on the pulley issue. I guess this answer will do it for me.

Do Tibs have dempening on their stock Crank pulleys? Or would a replacement have no affect whatsoever on dampening?

I've read a few horror stories about people's crank cracking in two and was wondering whether the 2-3 HP was worth the risk. I need new belts anyway, so this would be a good time.

REDZMAN

I bet ya this has been answered.

A search will reveal...

Screwdriver

Redzmang, I must've searched for atleast 30 mins looking for an answer to this question. If it has been answered, I must've missed it.

Lots of opinions on Pulleys. I haven't heard a disaster story on a Tib (which probably due to the exceptional ruggedness of the Beta) but I don't want to be the first.

Anyone?

mr_jeckel

I have read alot about this myself. On the stock pulley, there is rubber that runs on the inside of the pulley. Supposedly this is supposed to dampen the vibrations from the engine. But when I pulled out the pulley, the rubber on the stock pulley was all ripped apart and dry rotted. There is no way this worn out rubber could dampen any type of shock. I think the rubber is only used to reduce the under hood noises associated with making power. As far as balancing, the UR pulley I installed looked very well designed and balanced. The car runs much smoother and feels like it wants to go more. Horsepower wise, I am not sure. I think you only gain 2-3 horsepower from the engine, but in theory, you are freeing up weight on the crank. This creates increases in WHP. I can say that my car is definitely faster with the pulley. Alot faster than 2-3 HP would give, at least. This is just my opinion, though. I have not seen any conclusive facts.

REDZMAN

Let's put it this way.

1. I've got a stock crank pulley sitting right here.

There's no rubber in it at all.

2. There are several members of this site with pulleys installed for over 50K of driving, no issues or problems at all.

3. If you search for "Pulley" or "harmonic", you'll find lots of threads on this. One I looked at really quick had you post in it about harmonic balancers and earlier in the thread it was discussed.

Read around folks. Answers are there. Most of ya just give up to easily.

mr_jeckel

Actually, the stock pulley does have 2 rubber rings approximately 1/2" away from the outside of the pulley. If you look closely, there are 2 black rings (made of rubber). They are definitely made of rubber, too (tap on them with something metal, they do not *ding* but provided a slight recoil). Those rubber rings are the reason why people get worried about harmonic balancing. People say the rubber absorbs vibrations from the crank and create a balancing affect. I have also heard about the weight being balanced too, but I am not sure about this. All in all, I say go with the pulley. I just installed mine with no problems whatsoever. People who ruin their cars are quick to blame anything they can before actually diagnose the problem.

Mad-Machine

Honestly, one of the most inherently unbalanced designs is the flat four as used by aircooled Beetles, early porsches, and Subarus. I do not know about the Subarus, but the air cooled fours used by VW and Porsche had a simple stamped sheet steel pulley. Never hear about those cranks cracking.

I am one of those people with 50,000 miles on the aluminum underdrive pulley. Still running strong with no odd vibrations. My personal feelings on this subject that the Harmonic balancer and the balancing shafts are NOT there to lengthen the lifespan of the engine, but to calm the nerves of drivers who think that an engine that makes ANY noise or vibration is a bad thing.

Yes, I have had people in my cars that when they either hear the CAI or the sucking of the carbs think there is something wrong with them.

JonGTR

I had my crank balanced, or rather just checked. The guy said that the crank was perfectly balanced from the factory so he really didn't work on it. A balancer is not needed.

REDZMAN

Again.

The Crank Pulley I have sitting here, OEM, has no rubber anythings on it.

None.

And I've said what JonGTR has said about a dozen times.

Screwdriver

Just got off the phone with Greg, the owner of Driver's Image.

His words were "we don't do crank pulleys because the motor will usually go within the first year".

Found that interesting. Driver's image is a VERY reputed tuning shop. Unfortunately, they don't do much business anymore because there's not many people left but ricers.