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Engine Specific Info and Questions => IDI Engine => Topic started by: RustyCaddy on April 22, 2010, 06:03:54 am

Title: Harmonic balancer
Post by: RustyCaddy on April 22, 2010, 06:03:54 am
Has anyone out there added a harmonic balancer to an old IDI.  It sounds like they help reduce deflection in the crankshaft.  i am wondering if it will smooth out the usual vibrations that the older rabbits have when idling?   Any advice is appreciated.
Title: Re: Harmonic balancer
Post by: dh13 on April 22, 2010, 10:02:18 am
I used a 16 valve harmonic balancer. This is a v-belt type harmonic balancer and the bolt pattern matches the crank sprocket for the 1.6L.

Title: Re: Harmonic balancer
Post by: rabbitman on April 22, 2010, 11:43:24 am
I used a 16 valve harmonic balancer. This is a v-belt type harmonic balancer and the bolt pattern matches the crank sprocket for the 1.6L.

Did it idle smoother?
Title: Re: Harmonic balancer
Post by: 8v-of-fury on April 22, 2010, 12:52:47 pm
am I the only one to think the 1.6's idle like a kitten purring?
Title: Re: Harmonic balancer
Post by: rabbitman on April 22, 2010, 01:16:35 pm
am I the only one to think the 1.6's idle like a kitten purring?

They kinda do if you have good engine mounts and they're all aligned good, if somethings not quite right they shake the dash and the mirrors go blurry and stuff.
Title: Re: Harmonic balancer
Post by: rallydiesel on April 22, 2010, 03:46:55 pm
If they are set up right and like you mentioned, have good mounts they idle quite nice. I also found my engine smoothed out a lot with synthetic oil.
Title: Re: Harmonic balancer
Post by: RustyCaddy on April 22, 2010, 07:37:59 pm
Thanks.  Sounds like it might be worth a try...will advance the timing a bit first (old IP) and see how that does and if that still leaves alot of vibration then maybe try the harmonic balancer .

Used a new passenger motor mount and it has less that 3000 miles on it but i might have blown it up already.
Title: Re: Harmonic balancer
Post by: rabbitman on April 22, 2010, 09:17:02 pm
I think the harmonic balancers job is mainly at high rpm/power.
Title: Re: Harmonic balancer
Post by: 8v-of-fury on April 22, 2010, 09:18:28 pm
aren't harmonic balancers mainly found on V engines? to help offset the very rough power transition to the crank?

is that not their intended use? or am i thinking of something else here?
 
Title: Re: Harmonic balancer
Post by: tindias on April 23, 2010, 07:06:16 am
aren't harmonic balancers mainly found on V engines? to help offset the very rough power transition to the crank?

is that not their intended use? or am i thinking of something else here?
 

All VW models with Serp belts have them.  The 16v had them on the V-belts as well. 
Title: Re: Harmonic balancer
Post by: dh13 on April 23, 2010, 09:41:16 am
I used a 16 valve harmonic balancer. This is a v-belt type harmonic balancer and the bolt pattern matches the crank sprocket for the 1.6L.

Did it idle smoother?

I have not run the engine yet. I assume it will be the same as my 1.6na in my jetta. Also I don't think they idle bad. The main issue is in the valve train. If they are all set to factory spec and adjusted well, than these engines purr and have not hickups.
Title: Re: Harmonic balancer
Post by: rabbitman on April 23, 2010, 10:03:05 am
All VW models with Serp belts have them.  The 16v had them on the V-belts as well. 

My brothers 91 jetta 1.8 has one. It's got v belts.
Title: Re: Harmonic balancer
Post by: Rabbit on Roids on April 23, 2010, 10:09:52 am
a 91 8v jetta never came stock with one. none that ive seen atleast. your brothers is the only one ive heard of.
Title: Re: Harmonic balancer
Post by: RustyCaddy on April 23, 2010, 11:24:50 am
i have moved the engine around to minimise stress on the motor mounts as best i can.  The engine idles nice but there is still alot of vibration.  The motor mounts are soft but i used the "G" mount on the passenger side and now wish i had used the "F" style.

The funny thing to watch is the antenna vibrate...sometimes there is like 1/2 in. of motion from side to side in the middle of the antenna...like a pattern on the screen of an electronic ocillator or something  :)
Title: Re: Harmonic balancer
Post by: tindias on April 24, 2010, 07:17:25 am
If you are having that much vibration then you have other problems.  The balancer absorbs vibrations from the crank to prevent stress fractures, mainly at higher rpms.