Thread: Rod Bolts

Tweet

So here's another one.

I was getting ready to start putting my pistons in and when I went to take the rod caps off the guy that did my machining put them on so tight I can't get them undone. Am I missing something here like a backwards thread. I was stunned so I quit for the night before I wreck something. Feels like he used an impact wrench to put them on. I even wrapped one in a towel and lightly put it in my vice and I couldn't get it to budge . Any suggestions or ideas.

It's not just one I tried a few, I'm gonna call him tomorrow.

Sean

put it in a vice and use a 3/8 impact gun to get the nut loose.

That's scary!!

If he used an impact gun you may have two problems:

1. Twisted rods if the big end wasn't properly supported, like in a vise
2. Overly stretched/stressed rod bolts

Then I'll throw in the third - if he didn't protect the rod surface and the rods have digs and gouges - stress risers - to cause failures.

If he used a torque wrench to "set" the two pieces together and in a vise for machine work, not a problem -- but you have to know!!!!
You also need to disassemble, also, with the big end in a protected jaw vise

A little history here - I had some machine done at a very good machine shop, but the engine was disassembled by their new guy. He, and thankfully while I was standing there, started to use a big ol' mill bastard file to mark a rod with notches to mate the rod and cap. I literally screamed. That was rod #1, by the time he would have gotten to #8, there would have been 8 gouges, on the rod and 8 on the cap. They replaced that rod. They also paid for 3 stock car engines which he had done the same thing and had broken rods and he went looking for a new job.

Also important to know if he assembled the rods for resizing did he use a torque wrench or a bolt stretch gauge???? Should use the same method when installing the pistons/rods in the engine... Rods should always be worked in a vise with aluminum jaws. As Dave said, doesn't take much to get a stress riser in your rods...........Also, when you take the rod cap off a reworked rod, don't use a hammer!!!!! There's a tool made to do it correctly and prevent doing damage to the rod and cap......

I got him to press in the pistons and balance everything as well as do all my machine work, he even threw in ARP main and head studs all for $1000. Less than half of the machine work alone anywhere else. He's been around for years building engines, very well known and even runs a dragster. His garage is the size of my house equiped with everything a guy could want. This being said I doubt he would do anything stupid, I just didn't know why they would be so tight. I'll try again today.

Thanks,
Sean

Originally Posted by sgo70

I got him to press in the pistons and balance everything as well as do all my machine work, he even threw in ARP main and head studs all for $1000. Less than half of the machine work alone anywhere else. He's been around for years building engines, very well known and even runs a dragster. His garage is the size of my house equiped with everything a guy could want. This being said I doubt he would do anything stupid, I just didn't know why they would be so tight. I'll try again today.

Thanks,
Sean

then use a 1/2" drive, w/6 point socket, put the assemblies in a padded vise and take apart if you are satisfied with his reputation and work

well a rod vise is what you need ARP rod bolts are TQ to 50 with moly if you do not have a rod vise then have him back them off .i do rods all the time and if i am not building the engine i will back the rod bolts off .less you piss me off then i just may not this would fall in to cruel and unusual punishment .that and not hand fitting the caps so you can get them apart you could try some 1/4 alum plate and clamp the rods in a bench vise by the big end and use the alum for soft jaws