Fastbasser

I am thinkin about putting in a bigger cam. It appears most of the work is more time consuming than difficult.. One thing seems to be a bear though...

How do you torque the balancer to 350 ft lbs?? My wrench goes to 200..

There has to be a trick to it.. At least I hope so..

Thanks in advance.

MTWallet

I used a digital torque gage on a long breaker bar. Not only is this bolt very important to get torqued correctly, you must also keep the engine from turning while torqueing the bolt. I used a special fixture from GM that bolts in place of the starter and engages the teeth of the flywheel to keep the engine from rotating. Just putting the car in gear is not enough, cause there is too much flexing in the drivetrain.

MTWallet

I used a digital torque gage on a long breaker bar. Not only is this bolt very important to get torqued correctly, you must also rotate it a certain # of degrees after its torqued. Keeping the engine from turning while torqueing the bolt is a real task too. I used a special fixture from GM that bolts in place of the starter and engages the teeth of the flywheel to keep the engine from rotating. Just putting the car in gear is not enough, cause there is too much flexing in the drivetrain.

Fastbasser

Where would I find a digital torque wrench that goes that high?

Thanks in advance.

Patches

I've done several of these. On the M6's, I put it in 5th to torque the bolt. On the A4, I used a screwdriver to keep the flexplate from turning. The initial 240 ft. lb. torque using the old bolt will press the pulley onto the snout a certain distance. The remaining angle torqueing will strtch the balancer bolt to a certain tension to prevent the pulley from backing it out. Below is the distance spec from the manual that should be measure after the initial 240 ft. lb. torqueing and before the 140 degree bolt stretch. I measured this distance after the initial torqueing and the belts lined up nicely.



Notice the marks on my pulley showing the completed 140 degree torque on the bolt head.

C66 Racing

There are several lessons learned about taking this bolt out and putting in a new one. I wish I had read them before doing some pre-runoffs work on the inside of my motor.

Here is my sad story:
http://forums.corvetteforum.com/showthread.php?t=922738

jjcslynn

What do you do about balancing the Harmonic Balancer? I know the book says to scribe and reinstall in the same position or if replacing, add the weights in the same location.
I had my bolt loosen, which I've seen/read about a lot of them doing that, so my HB wasn't in the original location. I just installed it. How do you overcome harmonic vibration if putting on an HB without weights?
I know a lot of you have pulled your engines and built them up, so I'm looking for your experience.

C66 Racing

I'm not really sure of the technically correct answer to that one. None of my balancers has had weights on them. When I bought a new one, it didn't come with any sort of weights, so we just put it on.

jjcslynn

That's what I did, but I seem to have a harmonic vibration at about 2000 rpm. How do you do away with that? Just don't drive at that rpm?

IM QUIKR

Whilest you have it off, do yourself a favor and pin the crank/balancer. This will keep the bolt from backing out.

PS use stainless steel pin x2.

Fastguy

Now I'm wondering if mine is going to fly off. I only have a 150 toque wrench so I basically tightened it until it was in about 3-4mm and then did the 37/140* thing but without loctite.

Patches

Fastguy, that's what I have done on several - torque to .125" and then 37ft. lb. and 140 deg. Never had a new pulley back out yet. The 240 ft'lb. is a torque which yields the correct displacement in the pulley relative to the crank - in other words, the distance pressed on is accomplished via a torque spec.

I have heard of a few re-used pulleys coming out, probably because the press fit on the pulley bore is relaxed after the first install. I got AL shavings from the 2 ASP UD pulleys I have installed indicating a verry tight press fit. I've spooled mine to ~6700 many times with no problem.

C66 Racing

I don't want to over alarm you, but likely for the reason mentioned by Patches, mine came off very quickly. Due to time contraints, I didn't have the ability to take my car for a test drive after rebuilding the motor. We idled it for about 10 minutes a few times to warm up the oil, then ran the rpms up and down several times and everything seemed fine. At the Runoffs, the bolt came out on the third lap. Something like just over 3 minutes at constant 5000+ rpms.

I would suggest you keep a close eye on the bolt for awhile.

As an FYI, my first indication that something was wrong was the smell of burning oil. I believe that as the bolt came out, oil sprayed by the front seal on the crankshaft into the engine bay and some got on the exhaust. The second sign was the power steering getting stiff as the belt slipped, but voltage was still fine as was oil pressure. So, if you smell burning oil, turn the car off asap.

Fastguy

Well, its not a new pulley, its the old one but its the first time being off. Once its back together, its off to the dyno and then 11/19 and 11/20 at Lime Rock so I really will have to keep an eye on it. Nothing like spraying oil on the front tires going 150mph.

C66 Racing

Good luck and have fun at Lime Rock. I took a Skip Barber course there back in 95. Neat track.
I wouldn't worry too much about the oil on the front tires. I went through several corners smelling the smoke before I pulled over to a corner worker stand and didn't notice any loss of traction on the front or rear tires. I think most of the oil blew around in the engine bay and very little if any hit the ground before the rear tires. But, as soon as I smelled the smoke, I did back out of it checking gages, etc.

AMERICANMUSL

Hey Sub!

Thanx for the post...your description and results finally helps me to understand what in part happened to my 382 stroker...almost identical in every respect(occurance and block destruction) too expensive for same stroker short block...went with LPE short block 350...cost effective at this point!

Sorry to hear about your troubles...I'm with you man!

01C5fan

The mechanic that replaced mine said he torqued the bolt by having two guys hang on the end of a big breaker bar. Sounds a little crazy, but that was two years and several track days ago. No problems. Good luck with yours.

C66 Racing

Sorry to hear about that. I know too well what that must have felt like.
Wish I had read all of these posts before taking my motor apart... painful way to live and learn, eh?