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RIP (12/27/60-7/18/15)
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767 Posts
Discussion Starter #1 (Edited)
I started assembling my block. Got the mains done and all the caps platigage good. (neat stuff).
The rods are new as are the pistons. Problem is I can't get the caps off by hand.:crazy:
Managed to get one off by beating the rod nuts with a rubber mallet, then prying tit off with a flat blade., but there's no way in hell I would be able to remove the caps to pg them once in the block.:banghead:
(they had to mill the crank journals and may have bored out the new rods)
Pretty sure I shouldn't have to pound or pry them off :(
Is there some trick to this?
Now what?
thanks as always
Tk
 

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64-67 Expert
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8,569 Posts
This is normal. The fit is so precise, that they bind up. Very carefully use a brass drift and tap either side of the cap, on the edges where the bolts are, to 'walk' them back off of the bolts. If you are VERY CAREFUL, you can turn the crank a hair (so as not to disturb the plastigage) so it drops down a bit while holding onto the rod cap, and sometimes it will break loose. BE CERTAIN that the bearings are in the right way: the tang lines up with the rod cap, and that the chamfered edges of the bearings face the crank counter-weights. If you have the non-chamfered edges of the bearings facing the crank counterweights, it can cause the rod cap to bind up on the crank journal radius.
 

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RIP (12/27/60-7/18/15)
Joined
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767 Posts
Discussion Starter #4 (Edited)
I was all set to return all the pistons to the machine shop..........maybe they could/would drill the holes out a few 10 thousants. (looks down as you shake your head)
So Uncle G......this is something im stuck with............ I sure dont like the idea of beating on my motor with all the new main bearings in just to do plastigage.
can I forgo the plastigage in lieu of saving me from me as it were?
thanks Sir
 

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64-67 Expert
Joined
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8,569 Posts
NO. You CAN beg/borrow/steal a micrometer and an inside micrometer and measure the rod journals and the inside of the big end of the rods with the caps bolted on but not on the crank. (on the bench) This is the 'real' way of doing it, and is done without the engine being assembled/dissassembled. Here's the thing: it's hard to do if you've never done it before. (Google it on line for more info.) You are reading in ten-thousanths of an inch....mistakes in your measurements mean disaster. If you are having to actually pound on your rods that hard, something is WRONG. IF you install the rods without measuring them, you will likely end up with the same results you had last time. Me, I like to button up a bottom end and run it for a few decades before I lay eyes on it again. Your call.
 
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