Reply to "Oil supply Issue from previous rebuild car 4907"

Hi Matt

So if the engine block doesn't have cam bearing oil passage restrictors, we'll add that to my list. The amended list is thus:

(1) restrictors for all 5 cam bearings (requires two Moroso kits, the Moroso restrictors have 0.060" orifices)
(2) Tappet bore bushings (also with 0.062" restrictions)
(3) Fully grooved main bearings
(4) Proper bearing clearances (Main bearings = 0.0020" - 0.0025". Rod bearings = 0.0025" - 0.0030"). Using either 10W30 or 20W50 oil with this spec.
(5) High capacity racing oil pan with baffles, hinged doors, windage tray, scraper.
(6) Standard oil pump, standard oil pump drive shaft.

The Moroso restrictors have 0.060" orifices, you don't need to drill them. I often quote 0.062 because that's equivalent to 1/16". Everyone has a 1/16" drill bit in their drill bit index. An orifice equivalent to 1.52mm to 1.59mm should be ok. To install the restrictors your machinist will need the appropriate American thread tap. Installation of the restrictor for the #1 cam bearing is a little tricky because it must be installed deeper within the oil passage. The oil passage must be "drilled-out" to clear the tap deep enough until you reach the part where the treads should begin. Install the restriction for the #1 cam bearing deep enough into the passage to clear the horizontal main oil passage, as indicated by the red dot in the picture at the bottom of the page.

The valve train can get by with even smaller orifices, like 0.040". However with hydraulic tappets I would suggest using the larger 0.060" orifice to insure a sufficient amount of oil is supplied to allow the tappets to function properly. The larger orifice is more "universal, it fits into more applications, it restricts the oil sufficient for all applications except perhaps 10,000 rpm drag racing. Plus the larger orifice is less likely to become plugged by debris. Finally, the original Ford tappet bore bushing kit had 0.0060 orifices ... I know because I owned one.

The Moroso restrictor kit only has 4 of the "small" cam bearing restrictors. The original thought was that the #1 cam bearing didn't require a restrictor, however over the years its been determined by grass roots folks that a tremendous amount of oil is diverted by the #1 cam bearing. So I recommend restrictors for all 5 cam bearings, unfortunately it requires 2 Moroso kits to acquire 5 restrictors, one for each cam bearing.

My father in law was a machinist, he used to make my bushings for me, any competent machinist should be able to make them. But Denny Wydendorf will sell them to you if you don't have the option of a machinist to make them for you.