Rod to Rod Clearance how much is too much ?

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Twisted-72

Twisted-72

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So I bought a parts car a while back for the drivetrain. Engine and trans has had a bit done to them. So the other day I pulled the oil pan to check out what I really had. I see the eagle rods, JE pistons and it's been balanced. Looking at the rods I noticed the rod to rod clearance seemed alot. I measured .035 between the rods. Is this too much? The engine made no strange sounds and had good oil pressure.
 
I've never heard of issues with too much side clearance. Too little seems to usually be the killer with lower ends. Only so much oil can get past the main bearing itself. I'd run it as I don't think there would be any gain in welding up & re-grinding the crank.
 
No problem with that side clearance.
 
I never worry about it unless it's so tight I can't assemble or it's so loose it's gonna fall apart.
 
When I assembled mine I forget what I measured but I was told that by my grandpa that if you can move them side to side and can hear them click slightly/move you are good, and if they don't move or were hard to install they are too tight. This is only for a quick check of course, but it gives you an idea.
 
DartVadar said:
When I assembled mine I forget what I measured but I was told that by my grandpa that if you can move them side to side and can hear them click slightly/move you are good, and if they don't move or were hard to install they are too tight. This is only for a quick check of course, but it gives you an idea.
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Oh I can move them side to side and hear them click.
 
There is a spec in the engine section of the service manual. I don't have one handy at this time, but you can download one for free and look.
 
Twisted-72 said:
Oh I can move them side to side and hear them click.
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That's good, that just tells you that they are not binding or too tight, but seeing how close you are to the factory spec is probably a good idea. I'm still figuring this stuff out myself so i'd listen to some more knowledgeable people on here. But I think you should be good, too much wouldn't seem like it would cause problems.
 
DartVadar said:
That's good, that just tells you that they are not binding or too tight, but seeing how close you are to the factory spec is probably a good idea. I'm still figuring this stuff out myself so i'd listen to some more knowledgeable people on here. But I think you should be good, too much wouldn't seem like it would cause problems.
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My Mopar race manual calls for .009 - .017 and I'm at .035
 
You are about .020" wider than the factory specification......don't sweat it. I've seen .120" (yes, 1/8") side clearance with spacers over the pin between the sides of the piston and rod to hold the rod in place under the piston. I've got a 451 with .035 side clearance making 787 HP @ 7200 rpm. I'm telling you, .035" is okay.
 
Twisted-72 said:
My Mopar race manual calls for .009 - .017 and I'm at .035
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Should be fine, I don't think I've ever heard of an engine failure because the rode side clearance was a bit too big. If it ran good before with good oil pressure and didn't make any weird noises I say run it.
 
You can't be too loose on rod side clearance with in reason. Like the others are telling you. It is nothing to worry about. You will be fine.
 
The factory 69 service manual calls for .009" - .017" side clearance (two rods).
 
I was told years ago, that too much side clearance would flood the cylinder walls with oil, and cause excessive oil consumption.
 
66/6 said:
I was told years ago, that too much side clearance would flood the cylinder walls with oil, and cause excessive oil consumption.
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I've also read that Elvis is alive.
 
Subscribed, I'm curious to see what kind of oil pressure you'll have. Do you have a high volume pump?
 
Dana said:
Subscribed, I'm curious to see what kind of oil pressure you'll have. Do you have a high volume pump?
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Not sure of what pump is on it now, but I will be installing a new high volume pump.
 
Twisted-72 said:
Not sure of what pump is on it now, but I will be installing a new high volume pump.
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excessive rod side clearance will let more oil thru the rods-coming out of the crank passages, but will probably not hurt if you still have good oil pressure, other than more oil slinging around in there.
 
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