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Connecting rod resizing appearance-problem or not?

Started by oldcarnut, February 17, 2011, 01:09:51 PM

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oldcarnut

I got my rods and piston assy. back from the machine shop and I'm not sure if what I'm looking at is normal or I got a problem.  Take a look at the pics and see if this is ok.  Where the endcap bolts together, it looks like some of it didn't get machined like it was out of round. Several are like this.  I gave them Arp bolts to install.  Also which side goes to the front of the block?  I can't remember since its been a while when I took them out.  The book mentions the bigger champher but they look about the same sometimes barely a champher on it depending on location.  I see one side on the end cap has the small extra casting.  I don't have a mic to check them out to see how the sizes came out but I'll see if I can find one.

John_Kunkel


Looks like they didn't take enough off of the cap before resizing, I'd take them back.

The squirt hole faces the cam when properly installed.
Pardon me but my karma just ran over your dogma.

TXcharger70

or they could have mixed up one of the caps. I know they should always keep the rod and cap together as a pair once they are machined, if they get mixed they it can throw it off. If you have another cap and rod are doing the same you could try to switch between the two and see if that will fix it. I had a similar problem i mixed my caps and rods up

oldcarnut

I'll take them back in the morning.  The caps are all matched by the stamped numbers and attached as I got them.  Had them for a few weeks and just got around to take a look at them.  You can almost feel a step with the fingernail.  How many times can the rods be resized?  Looks like they heat the wrist pin area fairly hot for pressing on judging by the discoloration. I need to ask them how they keep the wrist pin to bearing journal lengths correct.  If they shave off more on the end caps how/what do they indicate for ref. otherwise it would seem to put the deck clearances off.  Is the red area what your reffering to as a squirt hole?  Man I feel sorta stupid at the moment because I should be remembering this stuff but its been around 14yrs since I messed with building an engine and its not coming back quick enough.  Thanks for the info.

John_Kunkel


The squirt hole is the "V" notch in your first two pics.

Each rod rebuild shortens the pin-to-pin length a little, that's unavoidable unless the small end is bushed. Most regular machine shops don't worry about maintaining equal length in the entire set but they can if they take the time.
Pardon me but my karma just ran over your dogma.

oldkimmer

...........I wouldnt use those rods...they got them way to hot.....just asking for a major problem/catrastrify.......with what u spent on pistons, get a set of new rods........kim........
Back in the good old days 1968 charger rt 440 magnum . 1968  charger 383 magnum. The Beast has been Unleashed!!!!!!!!!!!!!!

oldcarnut

I took the pistons and rods back to the machine shop. He said he would rework any of them if I was not feeling to good about them but really as they were it would not have any affect.  I also had him press all of them off and sent to the balancer to get the rotating assy done.  Just got to order a new harmonic balancer from Summit tonight and get it over to him.  Initially after I had the rods looked at and told they were fine, it didn't seem necessary to buy new ones as money was getting low for other items needed but after paying for 2 press on/offs and the 1 resizing maybe I should have got some new ones but I wouldn't mind hearing from anyone else that had a failure due to any of the forementioned issues speak out. 

Challenger340

I would be more concerned that the Rod bores are actually straight, and decently round, NOT barrelled, or hourglassed ?
Because,
you are probably using "p" eccentricity bearings anyways, which taper in thickness over to the parting lines, usually up around .005" within 1/4"from the parting line  ?
See your part number; cb527 "P" ?? or whatever "P" ??
This is done to account for housing bore stretch @ higher rpm's so the bearings don't "Touch" over at the parting line ?
Anyways,
The lack of stone contact over by the parting line, at the angle, has more to do with the Cap Cutter perpendicularity, or when initially roughed in sized in pairs.
NOT a Big Concern for me.

I'd be more concerned pressing the pistons Off again, to resize AGAIN for non problem ?
I know it don't look pretty, but it is NOT WORTH cutting the Cap and Rod further & further to chase the full contact !

As Far as the discoloration from heating the small ends,
the only result is probably the small end when cooled, will not clamp the Pin "Round", which MAY ? or MayNOT distort the Pin out of round in the Piston Bores, and can result in lack of Piston Pin to Piston Bore clearance ?

PINFITTING the Pins in the Piston Bores @ .001" is a sure fire way to circumvent any potential Pin Galling problems later when using Rod Heaters, to this discolored temp ?
But, if the Rods move freely in there now, I wouldn't worry about it at this point either.


Future Tip;
I usually Pin-Fit the Small end of the Rod FIRST, to EXACTLY .001" Pin Interference, THEN, you only have to heat the Rod end "Straw"Colored, and the pin slides in nicely(after pin-fitting the pistons @ .001"clearance)
Only wimps wear Bowties !

oldcarnut

The pistons actually moved and felt good on the pins.  The brgs. are 2320CP's. After a more closer look there was one I was more concerned about which wasn't in the pictures and one other not quite as much that the line could be felt catching a fingernail.  I asked him to rework the one and check the other and I'd live with the others as they were since they weren't as bad as it looked.  Originally I wanted to get the assy. balanced but he had already pressed them on so I thought about just reusing the balancer and hope for the best..  Sometimes I think I read too much info. but after a fair amount of reading it seemed to be the recommended thing to do getting a new balancer and it all balanced with the new pistons so thought might as well have the others taken off and get it all done and be finished with it. The crank itself has some rough looking rolled edges I want to take off but I reckon it left the factory this way and didn't break off.