Wish you could still get the Tierney-Hollen product that's long gone from the marketplace? Well, grab this 253K jpeg image of Art's V4 Oil Kit plans and take it to your friendly neighbourhood aluminum machinist and ask him/her to make one for you.
(Update from February 2004: thanks to Nick Baal for producing this improved rendition of Art's engineering diagram.)Add NPT fittings, braided steel hose, banjo bolts, crush washers, plastic spiral wrap for abrasion protection, and an afternoon of your time, and you too can cure the V4 cam problem once and for all with massively increased flow of freshly filtered oil straight to the cylinder heads.
There are some photos of the finished kit on Art's web page.
Art's kit accomplishes the same thing as the commercial Tierney-Hollen kit, which is no longer available. It is not a direct copy of a T-H kit, but it is the same idea. Art installed his kit on his V65 and reports excellent results. He measured oil pressures before any modifications, and recorded 96 psi at the crank and 5.5 psi at the cylinder haed, both at 5000 rpm (as per shop manual). The specification calls for 77 psi +/- 10 at 176 degrees F at the crank. So you can see that more than sufficient pressure was developed at the crank, yet at the head, there was very little.
After installing his kit, Art measured 91 psi at the crank at 5000 rpm, still easily surpassing minimum requirement. The good news is that at the head, pressure was now up to 30 psi at 3000 rpm (as high as his low-pressure gauge would register).
I won't write up a detailed step-by-step methodology for installation of this kit and the required associated parts. Instead, refer to my review of the Tierney-Hollen kit for a description of how it works, and refer to John Landry's oil system modification articles for descriptions of removal of stock oil lines and replacement with braided steel lines. Note there is one correction made on the diagram. A diameter marked 40mm should actually be 30mm. You can see where I have written in this correction.
As always, if you go ahead with this project, please write back to me and let me know how it went.