So I finally got around to getting started and the crank installed in my SBC rebuild. I was planning on reusing the main bolts (probably not my best thought) but then I accidentally had my torque wrench on 87 ft-lbs instead of 77 ft-lbs and one of the bolts broke. It was a good wake up call for me to replace the bolts anyway. Who makes a good, tough main bolt set for the money?

Found these on Jegs...

https://www.jegs.com/i/ARP/070/134-5001/10002/-1

While we are here, any cool tips on getting a broken main bolt out of the threaded bore? It's down in there in the #2 bearing. I was thinking an EZ-out but maybe there are better ideas here....

 

Those are the correct bolts Tootie. You can't do better than ARP.

For the broken bolt - unless the bolt bottomed out, then after snapping there should nothing pulling against the threads in the block.
In other words, IF you could unscrew it, it THEROETICALLY just come right out.
I would make the hole for the EZ OUT with a left-handed drill bit. There is a good chance that as you are drilling, the broken piece will just unthread.
A regular drill bit turning in the CW direction would thread the broken piece in further.

 

I have been lucky in the past by using a sharp ice pick to unscrew a bolt like that if not locked.
Bear in mind drilling will cause shavings, you would then have to remove the crank and all the bearings.

 

Thanks all. Going with the ARP. I'll finesse out the bolt. What a difference 10 ft-lbs makes.

Any benefit going with better rod and head bolts on a stock build?

 

Harbor freight sells a ccw drill bit set that is really nice . Have removed a few broken manifold bolts that snapped off below flush with this set.

 

Yea, they won't snap when your Harbor Freight torque wrench is off by 10-20ft/lb.

I went with new GM bolts but.. go with new bolts regardless.

 

I went with the ARP 12-points for the heads. I am going to leave the rod bolts alone as apparently I need to have the rod lengths reset at the machine shop.

 

Used Pioneer many years ago...better than stock not quite ARP either.
By the time you put rod bolts in resize etc youre right about what a set of Scat I beams would run..maybe.
Never saw the need for a special head bolt on NA unless the springs are so big you need a smaller head than stock.

 

So many people do rebuilds using old bolts and it's scary. 20+ year old head/main bolts should be thrown away. Any bolt that's designed as a torque to yield should be thrown away unless you have some way of measuring the stretch.

ARP stock replacements are good but if they're above your budget, OEM or Pioneer bolts will work just fine.

An extra 10 pounds on the torque wrench should not have broken the bolt unless the bolt was in very poor condition or the calibration of the torque wrench is really off.

 

Yeah. It's a new Craftsman but I think it is questionable quality.

Alky, you didn't mention the rod bolts. I should be fine with the originals?

I just bought a Tekton off Amazon. Lots of good reviews. Gotta ditch the Craftsman sadly.

 

Changing rod bolts distorts the rod, requiring "resizing".

2 problems with that: (1) it shortens the rod, which increases the deck clearance; and (2) it costs almost as much to replace bolts & resize, as it does to just buy new rods.

If you think the rod bolts are questionable in some way for some reason, best to just get new rods.

Never heard of Tekton. No idea whether that's anything good, or just typical chinesium crap, or what. If it's a beam type, probably a much better chance it's OK than if it's a "clicker".

 

I seem to see a lot of your stuff on here tootie, and I really would love to see you succeed with what you are doing now. In the good old days, re-use was the norm, bc stuff wasn't as readily available as it is now. The mentality remains, however, bc too often the up front appears to be big. Once yer all said n dun, however, you find that the costs always balloon that way. NEW RODS and ARP. Lots less expensive in the long run, especially if you want the car for the long run....

 

No you don't have to ditch it. Use the new torque wrench to calibrate the old one.

 

Yep. But this is how the avalanche of draining your wallet begins.
You decide to replace the rods. But now you have to rebalance the crank (unless the rods weigh exactly the same as the old ones).
Now since you have better rods, you decide your pistons need to be forged.
And since you are doing that, you now need a 4340 steel crank.
And so on, and so on, and so on.

You need to be brutally honest with yourself about what your goals and use of your car is really going to be.
DON'T build what you think will impress other people. NEVER!

 

Just got the ARP 12 point head bolts and main cap bolts. Holy moly. Things of beauty but $140 worth of bolts.

 

Yeah, but you're not going to snap those bolts with 10 extra ft/lbs.

 

A bolt is designed to stretch tah hold, think of it as a spiral wedge. Steel has an elastic point/limit that can be stretched over n over(some really big number I forgot) but once the elastic point is passed then it will shortly fail. Weaker bolts really stretch before failure and stronger bolts usually snap.

Your bolt could have failed due to a manufacturing defect, the fiction was significantly reduced, a defective tool like mentioned or it was previously over stretched(even if it was installed at the factory).

A stronger ARP fastener will require more torque to stretch/wedge and therefore distort(out of round) the main/rod caps more and that's why they need re-size/align hone. I would not hesitate to reuse NON-TTY sbc bolts that aren't heavily corroded, damaged or were over-torqued. I would have no problem taking a used main bolt from another junk engine and replacing the one that broke. Unless of course a high HP build but then we are talking a big budget and all good parts with the correct machining.

A new fastener can break in after a few uses and basically have less friction so after some use the same torque applied could result in failure/cap distortion because it takes less force to achieve stretch and now it's over-torqued. This is why so many use a bolt stretch gauge when installing rods. They will figure out the torque on their wrench to achieve stretch spec. Also why some retorque main caps a few times and then measure the bore.

Stronger head bolts are fine, many times when a head gasket fails it's not the bolts it's the head itself compressing. I think the term for alum is it likes to creep or basically squish. Any alum head should use washers on the head bolts to help spread load and also prevent damage from the bolt head to the cylinder head.

For everyone who had a problem using stronger fasteners w/o checking or machining there are those who didn't, I'm just providing info.