[font size="1" color="#FF0000"]LAST EDITED ON 28-Jan-01 AT 01:32 PM (EST)[/font][p][font size="3" color="#191979"]

Bill,

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>If you don't want to send
>him on a wild goose
>chase then don't tell him
>to start drilling out oil
>passages because that's exactly what
>that is.
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Please re-read the previous posts BEFORE putting words in my mouth - I'm not the one who suggested enlarging/drilling. I suggested to "beratte" exactly what I did to my 400 which is running happliy along without any oil pressure problems whatsoever. It builds oil pressure immediately, even when I start it at 0°F! However, I defend the drilling suggestion from "bubbaf250" as it won't hurt to enlarge oil passages on a stock engine that are too restrictive (think about a FE for example), as long as it does not affect the oil distribution within the engine. However, to enlarge the correct holes on a 335 series engine - it is not easy. Of course, one can't just drill every passage to .750" and then expect their stocker 400 to be able to spin 10,000 RPM. Many times the holes are too small because the factory was trying to save $$$ on machining time or cast iron weight. Other times it is just simply a mistake. Your external oil line suggestion is to compensate for the restrictive convoluted oil supply path, but it will not fix worn out main, rod, or cam bearings.

This isn't a place for "this guy told me this", and "that book told me that", rather I know because I have DONE the work myself. I have rebuilt several Ford and Chrysler engines, countless transmissions, and many many rear axles (including at least 6 Dana 60s) and none have failed because of some mistake or modification that I made.

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>However the forces
>acting on them from the
>cranks throws which convert vertical
>motion to rotary motion are
>significantly more stressful than the
>forces acting on the camshaft
>hence the tendency of the
>main & rod bearings to
>wear more.
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Stressful is not the correct word. Because the main bearing loads are higher than what those that the cam bearings carry, they are designed larger in both width and diameter, to spread the load out over a larger area (Force/Area=Stress). Babbit can only handle so much compressive stress before it fatigues and fails. The reason that the mains and rods generally wear faster than cam bearings is twofold - oil supply(tribology) and rubbing velocity(v=wr). Cam bearings still wear, and I have replaced many worn ones. I'm a degreed mechanical engineer, and I can correctly explain this stuff to anybody who wants to know more about why these things happen.

I know we are getting way off track here, and I can see this is developing into an argument which isn't helping out "beratte" with his original question. So with that said, I will stop replying to this post.

Art

 

>
>Bill,
>
>Please re-read the previous posts BEFORE
>putting words in my mouth
>- I'm not the one
>who suggested enlarging/drilling.

You're right you weren't the one who advocated drilling out the oil passages so I guess I don't inderstand why you replied to my post in the first place.

>I suggested to "beratte" exactly what
>I did to my 400
>which is running happliy along
>without any oil pressure problems
>whatsoever. It builds oil
>pressure immediately, even when I
>start it at 0°F!

Good for you. It sounds like you gave him some sound advice.

>However, I defend the drilling
>suggestion from "bubbaf250" as it
>won't hurt to enlarge oil
>passages on a stock engine
>that are too restrictive (think
>about a FE for example),
>as long as it does
>not affect the oil distribution
>within the engine. However,
>to enlarge the correct holes
>on a 335 series engine
>- it is not easy.
> Of course, one can't
>just drill every passage to
>.750" and then expect their
>stocker 400 to be able
>to spin 10,000 RPM.
>Many times the holes are
>too small because the factory
>was trying to save $$$
>on machining time or cast
>iron weight. Other times
>it is just simply a
>mistake.

Then why do experts like Jack Roush, etc advocate restricting the oil passages? And BTW it wasn't bubba who advocated drilling it was frankensteins4X4.

>Your external oil
>line suggestion is to compensate
>for the restrictive convoluted oil
>supply path, but it will
>not fix worn out main,
>rod, or cam bearings.

I never said it would nor would I do it on a worn engine. I advocate doing it on any M block after it's been rebuilt.

>This isn't a place for "this
>guy told me this", and
>"that book told me that",
>rather I know because I
>have DONE the work myself.
> I have rebuilt several
>Ford and Chrysler engines, countless
>transmissions, and many many rear
>axles (including at least 6
>Dana 60s) and none have
>failed because of some mistake
>or modification that I made.

I've rebuilt a few engines myself...what's your point? There's a huge difference in rebuilding engines vs. trannies and rear ends. Rear ends rarely fail anyway compared to engines & transmissions.


>Stressful is not the correct word.
> Because the main bearing
>loads are higher than what
>those that the cam bearings
>carry, they are designed larger
>in both width and diameter,
>to spread the load out
>over a larger area (Force/Area=Stress).
> Babbit can only handle
>so much compressive stress before
>it fatigues and fails.
>The reason that the mains
>and rods generally wear faster
>than cam bearings is twofold
>- oil supply(tribology) and rubbing
>velocity(v=wr). Cam bearings still
>wear, and I have replaced
>many worn ones. I'm
>a degreed mechanical engineer, and
>I can correctly explain this
>stuff to anybody who wants
>to know more about why
>these things happen.

I'm not saying cam bearings don't wear, all bearing surfaces wear. I simply said that cam bearings were not the most likely cause for low oil pressure in a 335 series motor. Let's not forget it was "engineers" who designed the poor oiling system in the first place.

>I know we are getting way
>off track here, and I
>can see this is developing
>into an argument which isn't
>helping out "beratte" with his
>original question. So with
>that said, I will stop
>replying to this post.

Suit yourself.