4.1 oiling modifications

[dank GN]

Just wanted to share some of the oiling mods I have performed on my production 4.1 block . First with the block I enlarged the feed passage to 1/2” . After doing this you will have to enlarge the turbo feed outlet to a 3/8” npt . After opening that up I went in and radiussed all the corners so they would be somewhat smooth instead of the 90* sharp turns they are stock . After that I went to the timing cover and enlarged the oil supply passage to 1/2” aswell as knocked Down those 90* turns . After all these mods it should help with the volume of oil going to my mains aswell as the actual flow . Here are some pictures

 

[earlbrown]

While you're there, don't forget to cut a groove in the front cam bearing bore to connect the DS lifter galley without a special bearing.


And the ''earlbrown booster hole'' in the TC

 

[dank GN]

While you're there, don't forget to cut a groove in the front cam bearing bore to connect the DS lifter galley without a special bearing.


And the ''earlbrown booster hole'' in the TC

Copy that I will do that aswell. Now do I cut the trench up and around or does the cut go down and around to the DS lifter inlet?

 

[dank GN]

How does this look? Is it deep enough? Wide enough?

 

[earlbrown]

From the picture it looks like the entrance of your slot is the skinniest part of the channel.

I usually go a little wider than that. (most likely because the stone I have is wider. ) I think it's about 1/8'' or so.

Keep in mine all that trench does is supply the DS lifters with oil to feed the rockers, and oil to hemorrhage out of 12 circular leaks.

Since the leakage is a fixed amount, too skinny will starve the area, too wide won't hurt a thing.


Also: If your REALLY good with micro drills, now would be a good time to think about a thrust oiler for the camshaft flange. There's two ways to tackle it..... One is the obvious ''chuck up a mini-drill and DON'T screw up''.... two is to drill a real hole then tap it for a Mikuni idle jet out of an ATV carb.

 

[dank GN]

Copy I have a good feeling as I’m at a pretty good depth .

 

[earlbrown]

Honestly I'm sure it's fine. The DS really doesn't need that much oil. ESP with roller rockers.

Just make sure to chuck up a wire wheel and give that trench a good cleaning/deburring. Bonus points if you go both directions.

 

[dank GN]

Honestly I'm sure it's fine. The DS really doesn't need that much oil. ESP with roller rockers.

Just make sure to chuck up a wire wheel and give that trench a good cleaning/deburring. Bonus points if you go both directions.

Do I really want to go both directions if the point is to gives the lifters just enough oil and have the majority going to the mains ?

 

[earlbrown]

I'm talking about with the wire wheel. Deburring that groove in both directions will give you the best odds of removing any small shards of metal before they have a chance to come loose under actual use.

 

[Mr.Spool]

Just wanted to share some of the oiling mods I have performed on my production 4.1 block .

and what kind of oil pressure are you seeing from this?

 

[dank GN]

and what kind of oil pressure are you seeing from this?

Don’t know as the motor isn’t running yet . And it won’t show on the pressure it will benefit the volume of oil getting to the main bearings. .

 

[Mr.Spool]

Don’t know as the motor isn’t running yet . And it won’t show on the pressure

When it's running let us know.

 

[dank GN]

All these mods are well documented mods . They are written down in the power source, aswell as abunch of buick sources FYI

 

[earlbrown]

Flow mods won't show a pressure change on the gauge. That's set by the spring and cup on the filter adapter.


The flow mods are to let that pressure at the sending unit actually get to the bearing journals easier so the oil an do it's job. (and have less parasitic drag doing it)

 

[dank GN]

Flow mods won't show a pressure change on the gauge. That's set by the spring and cup on the filter adapter.


The flow mods are to let that pressure at the sending unit actually get to the bearing journals easier so the oil an do it's job. (and have less parasitic drag doing it)

I thought I said something similar lol I guess you said it better

 

[earlbrown]

It took everything I had not to use the term ''hydrodynamic wedge'' and ''vicious friction'' in a sentence.

 

[dank GN]

It took everything I had not to use the term ''hydrodynamic wedge'' and ''vicious friction'' in a sentence.

Lol those are some mighty big words you are throwing around there bud . Try and keep it dumbed down for us buick folk lol jk

 

[~JM~]

It took everything I had not to use the term ''hydrodynamic wedge'' and ''vicious friction'' in a sentence.

I experienced that while Water Skiing once before.

 

[TexasT]

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Some stickies from way back. Last one is the world famous earlbrown oiling mods.

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[liquidh8]

Are all the old thread missing pictures?,,Dang