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Discussion Starter · #1 ·
I heard two things: I heard that it can be done with a normal shop press, the second thing I heard was that you need to heat either the pin or connecting rod before pressing the pin in. Can someone clear this up for me. How do the machine shops do it. Also do they use gauge blocks to ensure the pin is in the center when pressing it through the rod?
 

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They heat the small end I use gage blocks and just slide them in quickly. You can use a pressure but you might want to heat the rod end some first. Mostly a press is used to take them out.
 

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never done it myself but have seen them do it. They heated the rod in an oven and then used a jig to get right in the center.
 

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I use an old propane camp stove. I just put the small end of the rods on the burner and let 'em sit until they start to smoke (the iron usually has some oils impregnated and it will smoke when they're hot enough), flip them over and let 'em bake a while longer...then set the rod down in the piston and push the pin through by hand. Its really easy and you really don't have to pay the machine shop to do it for you. I had a machine shop heat the tip of the rod until it was white with a torch once and push the pin through. The rod was WAY too hot. All you need is about 900-1200 degrees MAX. I have also used a natural gas stove top...though my GF wasn't too happy about it.

To take them off, you have to press them. Sometimes the piston breaks. I've pressed thousands of pistons and I think I've broken 3 pistons....and all 3 were my own fault. They have to be cold to the touch (piston and rods) not warm, not hot, and you have to have them supported correctly.

_________________
"it is better to appear ignorant than to open your mouth and remove all doubt"--Mark Twain

<font size=-1>[ This Message was edited by: mavman on 6/3/06 7:05am ]</font>
 

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Discussion Starter · #6 ·
How do you get them perfectly in the center? Do you guys use a jig or anything what thickness jig would it have tobe? Also, so it will literally slide in after heating.....this cool.
 

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no jigs. Just heat the rods, set it down inside the upside down piston, and push the pin through. You have a few seconds to work with and you can center the rod inside the piston before they "lock" together. Just make sure of a few things. Make sure the pin and piston are PERFECTLY clean (no oil, residue, nothing). I like to clean them with starting fluid or rubbing alcohol to get ALL the crap off. Same for the rod's small end...but make sure the rod is dry before heating it (duh). Secondly, make sure you put them on the RIGHT way. Put 'em on backwards and you'll have to press them all back off...and the chance is there that a piston or two might break in the process, so save yourself the headache and make sure they're on the right way. Like I mentioned, gas stove, propane stove work great to heat rods. Just heat the small end only, not the whole thing. You'll want to be able to grab the big end without burning yourself. Once you do a couple, you'll find out that it's gravy...and that machine shops charge too much to do it. BTW, electric stove won't work...not nearly hot enough. Best bet is to get a few junk rods and pistons and try it on those first. Again, be sure to put them on the right way. Even though they're "junk" pistons and rods, you'll want to get yourself in the habit of doing it RIGHT. The rods don't have to be perfectly centered. Close will work just fine. Yes, they will slide in after heating the rod, but you have to be careful...like I said, you only have a few seconds between the time you pull it off the stove and the time it takes to push the pin through (by hand). Once the rod cools and the pin heats, they can't be moved any more without use of a press. AND, if by chance you do get one on backwards (lets hope you don't) let it sit for a day or so to completely cool off before you try to press it. Try it with a hot rod and piston/pin and you'll be rewarded with a exploding piston, especially if it's a cast piston (including hyperutectics...they explode nicely because they are very brittle).

I wish I had a vid capture card to take a vid...I have about a thousand or so extra rods and pistons laying around and the camp stove is still ready to go...that way I could post a vid on how easy it really is.
 

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Discussion Starter · #9 ·
Thanks guys!!!!!!! You are so right the cost up this end for machine work is WAY to high!!!!!! I had a friend almost get burned (no pun intended) at a machine shop for block prep work, he told him it would cost 1300 for (clean, bore and hone, cam and freeze plugs) hmmmm whats wrong with that picture, the minute you mention you just want the basic stuff done that you can't do in your own shop they jack up the price!!! PISSES ME OFF
 

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Discussion Starter · #10 ·
I knwo the front and back of the piston and also the top and bottom of the rings, I didn't relize you could put a connecting rod on backwards though. What is the right way? Is it marked, am I missin something? Just want to make sure I do it right.

Thanks,
Chris
 

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And the numbers on the rod/cap will be towards the outside of the block.
 

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Returning to the old post, I have new pistons - speed pro brand from summit.

Speed Pro Z8KH273CP40 - Speed-Pro Piston and Ring Kits - summitracing.com
(TRW-8KH273CP40)

Does it matter how tight the pins roll in the piston? I got them from machine shop where they installed connecting rods. Half of them rolls pretty loose (in the piston, I can make the piston rolling by breathe) while the other half rolls pretty tight. Same if adding some oil to it. Furthermore, the pins are shorter about 0.020" than is the distance between clips in the piston, so whole connecting rods moves with the wrist pin (front to rear movement). Does this make future problems and how to fix it?
 
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