Ford Racing 427W ate cam gear

[Rick Parker]

Thank you Wbulk

"We have all seen SB pump rods twisting off for various reasons. So a lot of guys put on the ARP better pump rod, which is a good idea. But consider, with a HV pump if you have stock oil clearances that pump is going to put a greater strain on that distributor gear and reasonably cause greater wear. I just don't put in the HV pumps in the SB for that reason. It's not worth ruining the engine for."

I personally have used 3 variations of HV pumps on my 289 for 23 years with no issues. Keep this in mind... the PUMPS dont create the resistance imparted upn the gears, it is the resistance to flow (ie pressure) that does. The clearances built into the mains & rod bearings AND rod side clearance is what will permit the oil an "escape route". If you put an HV pump on an engine with clearances that are tight and on the low side, as in a standard non hipo build you're asking for trouble. IMO the reason for a HV pump is if the clearances are set on the high side for less drag, then with a little thought resrictors can be place to redirect the additional volume of oil. They have their place if used for the right application. Fluid dynamics 101

PS: When istalling any fresh cam always check the leading edge of the teeth on the gear. Many time they will have a very sharp edge that need to be burnished or "knocked down" so it will not be the initial contact point with the distributor gear. This is a small but important detail for all builds.

[Luce]

She's back together and screaming like a banshee again, but with a slightly more stable idle. Now I can get back to pulling excess fuel and adding timing to the light load parts of the map. I put about 50 miles on it yesterday, now I want to change the oil and filter again to be sure I have all of the old cam gear out.

The pump has a pressure relief bypass valve to keep the resistance in check. The added swept area / volume does add a little more load on the gear, but only 30% or so. The gear shouldn't be so marginally designed to fail over an additional 30% load. Going from cast iron to steel should easily regain that margin. And yes, I have an ARP drive shaft.

The HV pump is cheap insurance. It ensures you have plenty of pressure on a well aged motor that's pushed hard, even when the oil gets a little too hot. All you sacrifice is a little fuel economy.

Wbulk, you're post scared me for a second when you said there should be a minimum .005" clearance between the distributor gear and the block. Just to make sure I'm right, the gear DOES ride on the block, but you want to see end play in the distributor of .005" when installed. That is what I have. Saying it needs .005" minimum clearance sound like it shouldn't ever touch the block.

With the dizzy out, I have about .025" of shaft endplay, but when installed and the gear is seated in the block, instead of the top of the shaft, under the advance mechanism hitting the upper bearing, I have .005".