Can I Rotate Crank on Crank/Balancer Bolt Only

[Cris]

OK, amateur's question, can I rotate the crank by using a 7/16-20 bolt in the snout of the crank? The balancer is off and I need to rotate the crank. Had a nagging thought on whether the bolt could shear? Also I do see some tools that catch the keyway in the crank for rotating without the balancer.

Thanks, Cris

[jed]

yes you can use the 7/16 x 20 balancer bolt and washer threaded into the crankshaft to rotate the crankshaft.

[Lizardracing]

I welded on a another head from a another bolt, just put the heads together and weld them and grind down the weld on all six flats. That makes the head extra tall and the socket stays on better.
I've also welded on an old 1/2 drive socket to a proper sized bolt and use it for assembly only. A breaker bar makes it easy.
A crank socket that a bunch of people sell work really good too but once the damperr is on not so much.

[rfoll]

I wouldn't do it on an assembled engine. With the bolt torqued to spec, the bolt will rotate and tighten even further. Stripped threads or a broken bolt will ruin your day. The aluminum crank sockets are cheap. Old balancers can be used by honing the ID and putting bolts in for turning with a pry bar.

DSCN1318.JPG

Another old balancer can be used with the bolt holes drilled out and bolted to the face of an installed balancer.

[rebelrouser]

I do it all the time, you just want a washer on the bolt, and do not pick one too long as it may damage threads. Or you can use a simple adjustable wrench, adjusted the diameter of the crank locked against the key on the crank, done that a million times as well.

[dannobee]

I was just going to mention the crescent wrench trick. No special tools needed.

[BillK]

Chris,
Just use some common sense. The torque on the bolt is normally about 60 lbft If for some reason it feels like it is taking more than that then stop and find out why. Like the others said use a high quality bolt and washer and make sure it is long enough to get plenty of threads engaged.

[jacksoni]

from the "similar topics" bottom of the page: viewtopic.php?f=1&t=21947

[77cruiser]

If it takes more than 60 ftlb. something isn't right. With plugs in & some compression maybe a different story.

[steve cowan]

If it takes more than 60 ftlb. something isn't right. With plugs in & some compression maybe a different story.

I think it best when the short block turns over at 6ft/lbs or less

[rfoll]

The OP didn't exactly say what the state of the engine was, or if it was a hypothetical question, "rotate the crank". I have never been able to rotate an engine in the car by the crank bolt, even the anemic 8:1 CR SBC engines all of my cars came with. That is what the home built tools are for. On an engine stand the situation is different and the options are many. I put a flex plate on the crank for a handle when I install it. The flex plate makes rotating the engine easy.

[Cris]

Guys, thanks for the responses. Engine is on a stand, it's an 292 chevy inline six. With the plugs in, it will exceed 50 lb-ft if I rotate it and don't let the compression bleed off. Without the plugs, the breakaway torque will exceed 40 lb-ft, but takes somewhere between 30 and 40 lb-ft after that. This is a GM replacement engine from the 80's ish. I have opened it up and it looks new inside. I am about to run a leakdown test on it, it passed a compression test with flying colors. I got paranoid when I saw there were actual tools to go on the snout of the crank.....and read the horror stories of broken bolts in the crankshaft.

Merry Christmas!