Alright guys I did my 2nd cam swap on my vette this past weekend

First off, Screw ARP balancer bolts, never using one again. Im not sure if there is something with the early ls1's but that bolt was definitely too long and almost ruined the threads in my crank.

Basically what happened is I was in the process of torquing the ARP bolt and it just seem to keep spinning/cross threading and never getting tight so before it did damage I decided to pull it out and inspect. Well that bolt was a total bitch to try and get back out. Sure enough, the end of the bolt looked like a mushroom and the threads on the bolt were pretty messed up. I was able to stick a pen magnet in there and get all the metal shavings out and I threaded my old balancer bolt in and out with some bolt blaster on there to clean it as best I could. I probably threaded it in and out 50 times. cleaning off the bolt with a rag every time until the threads came clean. I also use compressed air in the snout. Once I had done all this, the bolt would thread in and out by hand with ease and didnt seem to get hung up or anything.

So I ended up using a new GM bolt but Im worried about 2 things

1. Im worried about the small amount of bolt blaster that may still be in the hole when I was cleaning up the threads.

2. When I installed the new bolt I didnt have access to the torque specs/procedure for installing a new bolt. So I seated the balancer completely and then torqued it to 160ft lbs. This sucker was tight. It would have taken a gorilla with a 5ft pole to be able to get it any tigher and I was NOT about to break a bolt off in my crank and try and go further.

Unfortunately on a vette the crank bolt isnt easily accessed because the steering rack is in the way.


Do you guys think ill be ok? Do you think its tight enough?

Any opinions are welcome

 

So what if people say it will be OK, it's tight enough, then it backs out. A lot of good those opinions will be, right? The tq specs are tighten to 250 ft lbs with the old bolt to seat the pulley, remove old bolt, then with new bolt, tighten to 37 ft lbs then turn an additional 140 degrees. Would only be a wild *** guess how close to that 160 ft lbs is.

 

you sure you had the correct bolt? sounds like you had a ls7 bolt

 

I just used what they sent me so im not sure but its ridiculous if they sent the wrong one. The reason i went to 160 is because that's the highest my torque wrench would go. I mean i could try and go further i guess. I guess i was wondering if anyone had sucess with a standard tq spec on a stock bolt

 

There is no standard tq spec on a stock bolt.

 

This is the correct procedure posted by 2xLS1. The GM procedure is below for reference and shows exactly this method for the Corvette. If I were a betting person, I would say it will loosen up. Best to install it correctly before driving too much because if it backs out the rack could be damaged. As you noted, it is right behind the rack.

I don't think you had the correct ARP bolt either.

 

Rather than hope it doesnt come off Im just going to order another new bolt and reinstall the balancer. I noticed that my timing cover is leaking a little, probably didnt put enough rtv on the bottom so I guess its coming off.. But id be willing to bet that the 160ft lbs I put on that bolt is more than enough. Guess its coming off anyway

 

If i remember correctly the part number is 234-2503

 

Bottom line is you bottomed out the crank bolt you somehow got an LS7 crank bolt. That's it. There's no other way that would have happened.

You need part # 234-2503, and I'm willing to bet you RECEIVED 234-2504

 

160ft/lb is a LOT of torque. I HIGHLY doubt you have to worry about that backing out, regular old SBC balancers were torqued to 60ft/lb and never had one back out.

 

There's a reason the spec calls for like 250 ft-lbs. HINT: There's no crank key.

Get a new bolt and do it right or don't do it. I also recommend the correct length ARP bolt.

 

The first cam swap I did in my car I had the correct tools to reinstall the balancer but I didn't have the proper tools to tighten the balancer. I was sure I cranked that bitch down good enough though. After about 2 years or 1000 miles and a hand full of passes at the track, my wife and I were cruising down the highway one night and out of no where, clank clunk ping, I was like, WTF was that? Thought we ran something over and it flew up at the bottom of the car. Well last fall I was pulling my car back apart for another winter surgery and that's when I saw it. I couldn't believe it, the crank bolt was missing! Immediately I thought of that night we heard the noise on the highway. I was lucky that the balancer was still in place, but the morel of the story is FOLLOW THE CORRECT TORQUE PROCEDURE! Don't assume that it's good enough.

 

To properly torque a stock bolt its going to take more then 150ish foot pounds. To get to the degree that they want you to it takes a heck of a cheater pipe and you still gotta pull like hell. I recently did a diesel and the figure was around 250 for the crank bolt and it was very similar to doing an fbody stretch bolt so im guessing its in that neighborhood of 250.

 

Its 250 to reinstall the balancer. The ARP bolt requires 180ft lbs if I remember correctly. So basically there is no way the stock one requires 250.

 

I just hate that though. Im so scared now of stripping out the threads in the crank. This next time ill try and degree it but Most guys say they cant get it much more than 100 degrees. not 140 like factory says. The last thing I need is to break a bolt off in my crank.

 

the stock bolt is torque to yield. It requires tq then rotation. There is no tq only spec for that type of bolt. Everyone here has told you the correct way to do it. How bout you just do it however you want and live with the consequences.

 

Fully aware of the correct way to do it. and yes ill live with the consequences of not going clear to 140 degrees. ill get close but if it requires a breaker bar and a floor jack handle to get me there than ill take the chance so that I dont break a bolt and have to pull my motor to replace the crank.

 

This is exactly the way that I had to do it and I had the same fear, but it all worked out ok. Hope it goes as well for you as it did for me.

 

You WON'T break the bolt... it's DESIGNED to stretch, hence being torque to yield.

Also, it shouldn't take you a cheater bar to hit 250 ft/lbs. Get a 300 ft/lb torque wrench, the handle is plenty long to get the leverage.

 

ARP is 235 on the instructions.

I have a good snapon wrench that goes 250 I dont need a cheater bar on that.

Do it right the first time.

Tim