rod bearing clearances
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From: Colorado
rod bearing clearances
is it more benificial to have your bearing clearances tight or loose, while staying within spec? what is your reasoning behind it? or does it not really make a difference if they are within spec. also, after installing new rod bearings, its it normal that the crank would be more difficult to turn?
Joined: Nov 2003
Posts: 335
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From: ca, USA
Re: rod bearing clearances (96dxB16)
I like them tight. I think it helps reliability. It definetly seems smoother, and it should make better oil pressure. I would be more concerned with consistency more than if they're tight or loose. I would just want them all one way or the other.
If the engine is already together and you just change a bearing. It shouldnt be much harder to turn, there should be some lube on it. The rings are what give you the most resistance when you try to crank it.
If the engine is already together and you just change a bearing. It shouldnt be much harder to turn, there should be some lube on it. The rings are what give you the most resistance when you try to crank it.
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Joined: Nov 2003
Posts: 5,167
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From: baxter, tn, usa
for all motor you need to run tight now for high out all motor may want to run a little loose.
when i build all motors i run .0010 to .0017 on mains and rods.
turbo i run .0020 to .0023-25.
i use 10w40 mobile 1 when i am putting a motor together,and it has always worked for me,also when im on the bottom half i go ahead and prime the oil pump so that the engine does not get a dry start.you can also shim it for more pressure but the same volume,meaning keeping oil on the bearings almost constantly so to speak.
if you want to use the same color on mains and rods you will probably need to machine the crank a little to get the clearances you need like the pro's do,we are talking thousandths here so nothing big.
the tighter the clearance the more parasidic drag you have meaning it won't rev quick and accelerate quick.now run loose and you'll see the diff.
hope this has helped you.
also when i said same color for mains and rods like green mains and yellow rods,if i'm not mistaken all the honda rod bearings diff in thickness by 3 tenths of a thousandths
when i build all motors i run .0010 to .0017 on mains and rods.
turbo i run .0020 to .0023-25.
i use 10w40 mobile 1 when i am putting a motor together,and it has always worked for me,also when im on the bottom half i go ahead and prime the oil pump so that the engine does not get a dry start.you can also shim it for more pressure but the same volume,meaning keeping oil on the bearings almost constantly so to speak.
if you want to use the same color on mains and rods you will probably need to machine the crank a little to get the clearances you need like the pro's do,we are talking thousandths here so nothing big.
the tighter the clearance the more parasidic drag you have meaning it won't rev quick and accelerate quick.now run loose and you'll see the diff.
hope this has helped you.
also when i said same color for mains and rods like green mains and yellow rods,if i'm not mistaken all the honda rod bearings diff in thickness by 3 tenths of a thousandths
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Joined: Oct 2002
Posts: 4,768
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From: Flowery Branch, Ga
Simply put:
Slightly tight to mid spec - good reliable stock rebuild
Loose specs on bearings - less parasitic friction, more oil flow for higher RPM's, but shorter lifespan of internal parts.
Slightly tight to mid spec - good reliable stock rebuild
Loose specs on bearings - less parasitic friction, more oil flow for higher RPM's, but shorter lifespan of internal parts.
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pkolaboy
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