strotter Posted March 2, 2002 Share Posted March 2, 2002 Last weekend I overtorqued the #1 rod bolts on my 327, and thought "just to be safe" I'd replace them both. Pulled them both out, took one down to my excellent local machine shop and asked one of the guys to get a pair for me. Dum dee dee, dropped by today to pick them up, they had them, I got them, all was good in the world. I was getting ready to leave when one of the machinists said to me "You didn't take those both out of the same rod, did you?" "Yeah, I did," I told him. "Oh man," he said, "you probably need a new rod. Taking out both of them at once changes the geometry of the rod - the cap will never fit on there right again. I don't even know why, but it happens." I was flabbergasted. I'd never heard of such a thing. He suggested I assemble and torque it, and then check it for circularity with Plastigage, and also to look at the rod/cap junction for flat contact - I might just get lucky. I won't have time to do it until Sunday, but let me ask now: Has anybody ever heard of this? I've been playing with motors for years, and I've never even come across a suggestion of such a thing! I'm not saying he's wrong, as a matter of fact I'm sure I'll find just what he's saying is true and I'll be buying a new rod soon, but I was just thrown for a loop by something totally unforseen. Any comments? Am I more of an amateur than I thought I was, or what? Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted March 2, 2002 Share Posted March 2, 2002 ARP has a technical assistance phone # 805-278-7223.They can tell you. I never heard of such a thing, which would mean that you can not replace rod bolts at all unless you replace the rods.I have put new bolts (L20 to old rods (1600) a few times and never had a problem What wizard fits these new rods to the new bolts? ARP sells thousands of replacement rod bolts without any disclaimer of replacing rods because of geometry or whatever. Quote Link to comment Share on other sites More sharing options...
pparaska Posted March 2, 2002 Share Posted March 2, 2002 Weird, but the common advice is to have the rod's at least checked for size and shape on the big end when replacing bolts - and usually just have them resized while bolts are being replaced. Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted March 6, 2002 Share Posted March 6, 2002 guys the reason they say that is if you don,t use a rod vise when removeing the rod bolts and you just used a hammer and drift punch to back the bolt out of the rod its extremely common for the rod to be stressed/slightly bent durring the bolt removal process. now if you only removed one bolt from the rod while its still on the crankshaft you have a slightly better chance of not damageing the rod while your backing the bolt out because the crank journal tends to absorb some of the stress as you tap/beat it out of the rod. you can AVOID ALL THIS BY USEING 7/16"CAP SCREW RODS or useing a rod vise.BUT WHAT EVER YOU DO DON,T DO WHAT I SAW ONE GUY DOING.....heating the rods with a torch and then putting the shank of the rod bolt on dry ice so it just pops out of the rod as that DESTROYS THE BOLTS HEAT TREATMENT/WEAKENS THE BOLTS BIG TIME!!! Quote Link to comment Share on other sites More sharing options...
pparaska Posted March 6, 2002 Share Posted March 6, 2002 Thanks, grumpy - I learn again. BTW, how about a regular vise with flat, broad aluminum jaws, if you don't have a rod vise? Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted March 7, 2002 Share Posted March 7, 2002 I really like the suggestion of high tech ingenuity using high heat and a sub zero quench for restoration purposes. The only rod bolts I ever removed were on Datsuns and I never had any trouble removing them. I am pleased that Mr. Grump is taking the time to teach us about these Chebbys because when all else fails I reach for the biggest hammer. I do not go looking for a torch or bother with dry ice!! Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted March 7, 2002 Share Posted March 7, 2002 ljohnson READ IT AGAIN"BUT WHAT EVER YOU DO... DON,T DO WHAT I SAW ONE GUY DOING.....heating the rods with a torch and then putting the shank of the rod bolt on dry ice so it just pops out of the rod as that DESTROYS THE BOLTS HEAT TREATMENT/WEAKENS THE BOLTS BIG TIME!!! pparaska IF you don,t have a rod vise you can get by with that aluminum jaw vise but I would use two 1/8" thick lead sheets to cushion the jaws and to be very sure not to mark the rods as I worked on them changing the rod bolts. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted March 7, 2002 Share Posted March 7, 2002 But Mr Grump, just think of all that squirming metallic activity sizzling on dry ice. The proceedure had to be entertaining to leave such an impression on you. I have been chuckling ever since I read your description. I learned something and got a good laugh. Thank you Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted March 7, 2002 Share Posted March 7, 2002 OK so IM slow to catch on sometimes Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted March 7, 2002 Share Posted March 7, 2002 Gotcha , this was better than my "columbia clutch line" that caught your attention last time . You are a true warrior! Quote Link to comment Share on other sites More sharing options...
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