Author Topic: oil holes in rods  (Read 765 times)

Offline Savo

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oil holes in rods
« on: 19.02. 2014 00:26 »
I've used 2 rods with oil holes both facing flywheel.  Will this starve drive side?

Offline Briz

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Re: oil holes in rods
« Reply #1 on: 19.02. 2014 01:02 »
No.
I dont believe those holes do a damn thing!
Theres plenty of oil sploshing about in there to adequately lube a roller bearing.

Online RichardL

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Re: oil holes in rods
« Reply #2 on: 19.02. 2014 01:42 »
First, my complete respect to Briz, who, unlike myself, is an awesome mechanic.

That said, I believe the reason for the hole in the left rod is to assure venting that allows oil to flow to the left end of the crankshaft. Taking this definition, holes in both rods would be OK. Then, there is a school of thought that it adds a bit of additional oil fling to the left bore. Here, Briz's thinking that there is already enough lubrication "sploshing about" for all the needed purposes comes into play and would render the hole unnecessary. Nevertheless, if you believe the flinging theory, two holes would be a bad thing. I have never heard nor read that the oil hole might be for the roller bearing.

Finally, MAP Cycle did not include the hole in their billet rods, saying they didn't think it was needed. Personally, I chose to go along with BSA and drilled the hole into my billet rod from them

Richard L.
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Online RichardL

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Re: oil holes in rods
« Reply #3 on: 19.02. 2014 02:11 »
But, Richard, the oil flow area around the circumference of a large rod journal is more than four times that of the 3/64" diameter rod hole.

True, Richard, but for a brief moment in time the resistance to flow is very small through the hole versus around the bearing (Richard thinks).

Do you get the feeling Richard might be conflicted?

Richard L. and Richard L.
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Online bikerboy

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Re: oil holes in rods
« Reply #4 on: 19.02. 2014 02:42 »
I personally would block up the hole on the RH rod simply because the LH big end has always been the one to give trouble and I would be scared to death of starving it of oil. :)

Offline kiwipom

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Re: oil holes in rods
« Reply #5 on: 19.02. 2014 07:26 »
hi guys, yes when I purchased `billet rods` from S.R.M. I was told that the oil hole was unnecessary as it was only there to maintain oil flow through the sludge trap,cheers
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Online RichardL

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Re: oil holes in rods
« Reply #6 on: 19.02. 2014 12:08 »
... the oil hole was unnecessary as it was only there to maintain oil flow through the sludge trap,cheers

Huh? Kiwi, are you sure they said UNnecessary? Some people might believe that oil flow through the sludge trap is sort'a important.

Richard L.
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