Loose Rod Bolts

[440sixpack]

I'm doing a light rebuild on a low mile 428 mainly to stop oil leaks.  since it's out I'm putting in now rings and bearings .

My question is all of my rod bolts are loose, they'll fall out.  other than being a pain when I go  to put the pistons back in I don't suppose it matters but is this normal ?   should I be doing something about it ?

[cjshaker]

No it's not normal, and I would definitely look into what the issue is. Just a guess, but I wonder if they used the smaller 3/8 bolts typically used on standard 390/428 rods, instead of the 13/32 that was used on CJ/Low Riser rods? Is it a CJ engine, or are they CJ/Low Riser rods? Either way, I wouldn't feel comfortable at all unless the bolts were properly sized, installed (they should be press fit), and then the big ends resized.

[e philpott]

Getting the cap alignment correct would be a crap shoot with loose bolts , you need new bolts and Rods reconditioned

[gt350hr]

No it's not normal, and I would definitely look into what the issue is. Just a guess, but I wonder if they used the smaller 3/8 bolts typically used on standard 390/428 rods, instead of the 13/32 that was used on CJ/Low Riser rods? Is it a CJ engine, or are they CJ/Low Riser rods? Either way, I wouldn't feel comfortable at all unless the bolts were properly sized, installed (they should be press fit), and then the big ends resized.

   +1 I've seen this happen!

[Falcon67]

Some of the above or possible bolt stretch.  Either way, replace.  Rod bolts have the hardest job in the motor, last place to skimp.  Also buy a rod bolt stretch gauge to ensure proper bolt torque on re-assembly.  Worth the $ to add to your toolbox.

[440sixpack]

By loose I mean they push out easy.  if I implied they're sloppy I didn't mean to.

Sounds like whatever I do I need new bolts so I'll get a set and see if they're loose as well then go from there.

[440sixpack]

ARP lists 2 sets.   a 155-60001  for the cobra jet and a 155-6002 for a 352-428  .    I don't have CJ heads but I don't know if I have CJ rods or not.  how can I tell ?

[RJP]

The quick & dirty way to tell is a 9/16" socket will not fit the 13/32" rod nut. The CJ nut takes a 19/32" socket. Bolt shank is .406" and std 390/428 bolts are .375"

[440sixpack]

My rod bolts and the holes in the rod both measure .373.  so they're standard bolts.  I'll order some.

[rcodecj]

My bet is you are going to have to recondition the rods.
I would measure for diameter and roundness for sure.

[440sixpack]

Very possible.   though all the bearings looked normal after 66,000 miles. 

I notice the ARP bolts are serrated while mine are smooth.  this might tighten things up.  though other problems could still exist.

[gt350hr]

  Yes and they will distort the rods a bit too. At the least have them checked for roundness.
      Randy

[440sixpack]

Well the ARP's fit plenty tight.   

So is it best to carefully  pound  them in or pull them in with the nuts ?

[cjshaker]

Neither. Nothing should be pounded on or in, and using the nuts will damage the threads. They need to be pressed in. If a proper supporting piece or jig is used, a regular press, or even a vise will work. Still, they should be checked for roundness afterwards.

[440sixpack]

I put a few in and it took 40 lbs of torque to seat them. ARP says to torque them to 50 for the stretch set.  but I can press them in if it's better.


I'll probably get them checked but I really think it's a waste.   I measured each of them before and after on the thin side and I had 1 that distorted .001 the rest were zero.   that's with a professional quality mic so I'm confident it can't bee too bad. my crank has a little wear too.


I suppose the caps could be a little misaligned though with new bolts.

[cjshaker]

To add to my last post.....
...or you could just ignore all the advice, draw them up with the nuts, throw them together and hope for the best

[RustyCrankshaft]

I've always pressed them in, then torqued or stretched (depending on if a stock or aftermarket bolt) with the caps on in a rod vise or at least softjaws. Back off, re-torque/stretch and check the big ends again.

If I changed the rod bolts after machining I ALWAYS check them again before install. Some times they're ok, many times they aren't. And on a stock-ish engine even if they aren't ok they might be good enough to live, but I always figured it wasn't worth risking the engine for a half hour worth of work measuring them.

[blykins]

Forgive me for being blunt and crass.......

But I'm not sure why you ask for help when you head 180° from any advice given. 

*Rod bolts need to be pressed in and the rods need to be resized.  Anything that is off .001" is not good enough.

*Don't add head gasket thickness to correct a compression ratio issue. 

*Don't use Cometics on a block/head that don't have the proper surface finish. 

A correctly chosen camshaft would have given you the powerband you wanted and can be chosen to work with a higher compression ratio.  Buying a random camshaft, then retarding it to crutch compression ratio issues can quickly get you an engine that's not in the least bit optimal.

You may quickly end up with an engine that leaks from the head gaskets, has detonation issues because of high compression/large quench, and wears bearings because rod bores are out of round. 

We are trying to help steer you in the correct direction.

BTW, from your other thread, the keyways on a crankshaft gear have their own corresponding dots on the crank gear. 

[440sixpack]

 I never did get a good explanation of what to expect from the cam I was interested in so I decided to go with it.  had I known it was that easy to get a custom one I wouldn't have ordered it. at this point I'm about over it but if I'm going to have to wait for a month to check my rods if you think it's possible to get a cam in something close to that time frame I'd be very interested in  having you order me one.

The rods I will probably have checked though I doubt it's necessary.   my situation isn't like everyone's,  there is one machine shop within 150 miles of me and they pick up and deliver every 2-3 weeks.  meaning checking my rods will be a 2-6week adventure.  shipping would be a PITA since I'm not set up to press the pistons off or on.   I'd like to get this project out of my way I have other things I want to get on.  being overly cautious is inconvenient in this next of the woods.       but if I must I must,  I get it and thank you.   


If the Cometics are a bad idea then I won't.  advice taken.

I did not see the other dots on the cam gear I will look again.  that makes sense.

[Heo]

Do you have pressed pistonpins? i thought all FE had
floating pistonpins

[440sixpack]

They do.  but you have to press the pin out of the rod.   don't you ?  now I have to look.


Brent,  I sent an email to your website about the custom cam.

[440sixpack]

You're right.   I'm going to stamp them pull them apart and ship them off today.

[440sixpack]

Interesting follow up on the rods.  the big ends all checked out fine but the small ends could use new bushings.

[My427stang]

Good thing you had them checked.