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Engine Specific Info and Questions => IDI Engine => Topic started by: myvolkswagen on January 29, 2011, 11:02:53 am
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Do I really have to take my rods and arp bolts to the machine shop again to have them resize and press in? Btw is there a special way to take out stock ones or can you just bang them out?
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I'm curious about this myself, but for taking the old bolts out, just give em a whack!
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Yes someone knowledgable please reply
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I took mine to a machinist. He whacked the old bolts out with a ball peen hammer and used the same hammer to put them in. He then torqued them to spec 45lbs IIRC and checked to see if they needed resized and they did not.
In summary you could put the bolts in yourself and then check to see if they need it. I was handling the con rods like glass and my machinist said that if it was a 23:1 comp engine and I needed to handle like glass then they would never make it. I still wrapped them in my towels and took them home.
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It says right in the arp instructions NOT to hit them sigh a hdmmer. No way I could get them in without one. Maybe a rubber mallet? I don't want to take them to a shop to have them smashed with a hammer cuz I cdn do that myself
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they are supposed to be put in with a press, hitting them with a hammer "could" deform them and weaken the rod/bolt
whatever you do, you need to check and see if the big end is still round after the install.
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i took mine to the machine shop, got the bolts pressed in, resized, polished, and new bushings. was under a 100 dollars for all that, honestly tho it doesn't look like they did anything special to polish them, just ground them down and balanced them, not mirror finished or anything
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Indeed the new bolts need to be pressed in by some means... Some creative use of a deep socket and a good c-clamp will accomplish this though..
I finally sucked it up and pressed mine in today.. I checked with my crappy gauges, then stopped by the machine shop and had them check too.. They were fine.. I'm guessing that ARP puts that in there to cover their butt, but it can't hurt to have them checked out at any rate..
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i took mine to the machine shop, got the bolts pressed in, resized, polished, and new bushings. was under a 100 dollars for all that, honestly tho it doesn't look like they did anything special to polish them, just ground them down and balanced them, not mirror finished or anything
Polishing is probably not the right term (but one alot of people use) de-burring would be more accurate.
Anywhere you have have a change in direction in a casting, or a sharp edge, you have a chance of a "stress riser"-which might give a crack a place to start. If you grind down that little ridge on the beam of the rod to make it smooth with no edge, in theroy its "stronger". The accepted way would be down the beam length-wise.
There would be nothing more to gain by have it polished to a mirror finish. Its dark inside your motor-noone will see them. ;)
What we do at our shop is tap them in with a brass hammer or with a brass drift.
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So should I be worried about re sizing the rods when I put arp's in?
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So should I be worried about re sizing the rods when I put arp's in?
you should check them or have someone else check them for you
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I think the checking of roundness is the most important part. Those suckers go in HARD and could make it egg shaped by a thou or more. Mine didn't and everyone I talk to hasn't, but I would get them checked anyway. I bet you could press them in with a c clamp and a deep socket
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What the hell. I'll just take them in
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That is what I did...he only charged 10 dollars and it was in/out as I waited.
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OK, then... my engine's rods have been checked/re-sized/polished/etc, but... I didn't get ARP or any replacement bolts!!! Should I?
J.R.
SoCal
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Technically the rod bolts are supposed to be replaced as they are stretch bolts.. BUT I as well as others have reused them without issue.. If you're building some variety of fire breathing monster, new bolts are good insurance.. In my latest venture I have no idea how many times the engine had been monkied with (several at best) and opted to replace them.. I found the arp bolts (which are reuseable) were roughly the cost of stock replacement rod bolts so it was a no brainer...
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I did the same. Arp was $20 more for me. Smokey eddy would tell you not to reuse those bolts
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IMO, replace the bolts, but ARP is not required unless you're going absolutely nuts. High rpm's put the most stress on rod bolts and it's the same bolt as an ABA that people rev to 8000rpm before going ARP.
Diesel rods/pistons are a bit heavier, but I still wouln't worry at all until over 6000rpm
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IMO, replace the bolts, but ARP is not required unless you're going absolutely nuts. High rpm's put the most stress on rod bolts and it's the same bolt as an ABA that people rev to 8000rpm before going ARP.
Diesel rods/pistons are a bit heavier, but I still wouln't worry at all until over 6000rpm
I agree it's not needed but if it's $20 more for arp and they are reusable then why not. Stockers are stupid expensive where I'm at anyway
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Yes-have the bores checked after new bolts are installed. But given how much heft there is on these, I'd be suprised if things changed.
If you aren't able to check your ARP bolts with a strech gauge, (and even if you can) cycle the bolts with the suppiled moly on the threads AND under the nut 3 or 4 times-torque-undo-torque-undo. (we probably do 1000 arp rod bolts a year-never once do they stretch 1st shot) You are basiclly burnishing the new threads of the nuts to the new thread of the bolts. Remember-bolt stretch is what provides the clamping force-NOT how hard you have to turn the wrench.
Rod bolts never fail in compression-so 23 to 1 isnt an issue-rpm is what makes them fail. Its the sudden decel at TDC-and pulling the piston back down. I went with ARP cuz we're a dealer-and I'm used to having good bolts.
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arp bolts were actually cheaper than oem for me, i got them off amazon.com
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arp bolts were actually cheaper than oem for me, i got them off amazon.com
X2, but the 10.00 for hammering and checking made it even...probably should do that with oem too I guess.
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This was very informative thanks a ton
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I had ARP bolts put in my last set of rods.
They did need resized,.. i'm not sure if that was because of the ARP.
You'll probably need to take them to a machine shop anyway, to have the bushings in the small end pressed-out and replaced, then reamed to fit the piston pins.
Then they need rebalanced too.