I have heard that even on some of the stock vtec blocks and head (b16 and b18c) some people are running an external oil line (like for ls-vtec) for added oil protection against cam wear.
I was curious if anyone have tried to mod (bore out) the oil orifice for greater oil volume.

 

There is a good thread on the subject of cam/cam follower wear that I just read, I believe it's in the FI section, but as far as know, no one has enlarged the oil passage. That's the first thing I would wonder about too, other than running better oil, like diesel motor oil. (I believe this was a Comp Cams reccomendation too)
What would be the difference between enlarging the orifice and running the external line? Either way, then the volume of oil going through the head is solely dependent on the bearing clearances in the head, right, instead of the size of the orifice?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rorik &raquo;</TD></TR><TR><TD CLASS="quote">There is a good thread on the subject of cam/cam follower wear that I just read, I believe it's in the FI section, but as far as know, no one has enlarged the oil passage. That's the first thing I would wonder about too, other than running better oil, like diesel motor oil. (I believe this was a Comp Cams reccomendation too)
What would be the difference between enlarging the orifice and running the external line? Either way, then the volume of oil going through the head is solely dependent on the bearing clearances in the head, right, instead of the size of the orifice?</TD></TR></TABLE>

if it works* i believe that the difference would be a cleaner/stock look and you wouldnt have to mess with oil adaptors or oil lines.

I was told that it was the orifice that controlled the oil going to the head.
FYI: the head has no bearings.

 

There is a regulated and unregulated oil supply on the P72 head, both serve different functions. The additional line commonly used flows into the unregulated head oil supply.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ToeJam &raquo;</TD></TR><TR><TD CLASS="quote">

if it works* i believe that the difference would be a cleaner/stock look and you wouldnt have to mess with oil adaptors or oil lines.

I was told that it was the orifice that controlled the oil going to the head.
FYI: the head has no bearings.

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I dont think you would want the oil passages to be enlarged since they reach the head by means of pressure. So if there's no additional pressure being produced, then there's no way to push the oil through the enlarged orfice. if anything, enlarging the orfice would only hinder the amount of oil that pushes up in and through it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EnjoyTheRideDC2 &raquo;</TD></TR><TR><TD CLASS="quote">

I dont think you would want the oil passages to be enlarged since they reach the head by means of pressure. So if there's no additional pressure being produced, then there's no way to push the oil through the enlarged orfice. if anything, enlarging the orfice would only hinder the amount of oil that pushes up in and through it.</TD></TR></TABLE>

yup, i already thought about that. I was thinking about shimming an itr oil pump for the extra bump in pressure.

 

Well, I guess in order to contribute much more to this thread, I'd actually have to look at the components and check it out, but basically *if* enlarging the orifice accompishes the same thing as the external line, it'll work. The oil pump moves more volume than the motor needs, which is why shimming the pump increases the pressure. (There is no way enlarging the orifice would hinder the volume though.)