Fuel Pump Eccentric on a Roller Cam Engine

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Fuel Pump Eccentric on a Roller Cam Engine

Jake Papageorge

The situation:  A 96 351W (TFI IV) engine, that had less than 100 miles on it.  It was pulled into and out of a building for over 20 years and almost NEVER really warmed up (please don't ask, it is a long story)!

Catalysts were completely bricked, and this engine had about 30-to-45%-cylinder leakage.  The cylinders are completely glazed.  I took it apart, sent the block out to be touch-honed and got a new set of Hastings Plasma Molly rings and some Clevitte P rods and mains along with a new Melling select std. volume oil pump.  I have an 85 that has a flat tappet 4V engine that is absolutely anemic (all be it only having 45K on it).  The 85 is getting this shiny new roller set up with a new Comp Cams camshaft that is better suited to a carbureted application along with a set of new 180cc aluminum heads with adjustable valvetrain.  Now that you have the background, I am running into two problems:

I am using the TFI IV factory double row roller chain (which is not a roller chain at all) which, as you can see, has the appropriate stand-off cast into the cam sprocket it to accommodate a two-piece fuel pump eccentric.  Of course, I had to enlarge the ID of the thick washer and eccentric and go get a hardened 7/16 bolt because the Comp Cam stick had a 7/16 20 thread as opposed to the 3/8 that was in the OEM camshaft and hone out the ID of the cam sprocket to get it onto the snout of the comp cam with the same slight interference fit the OEM cam had.  

I opted for the 2 piece eccentric because the camshaft has the right dowel for a 2 piece and getting this dowel out of this cam is inevitably end up destroying the cam!  That thing is IN THERE!  Nevertheless, a 2 piece is MORE than good enough, EXCEPT, this thing is really sloppy!  Maybe I am just over-thinking, but this thing easily has a sixteenth inch of radial movement.  That does not SOUND like a lot, but when you actually start moving this thing around, it seems like a lot!  It IS an aftermarket eccentric (Pioneer) but an old OEM eccentric behaves exactly the same way.  

Problem number two is the center main bearing that has the thrust bearings.  The new Clevitte P bearing set has a fully grooved configuration on this center main bearing as opposed to the partially grooved main bearings that are for the rest of the mains.  I HATE FULLY GROOVED BEARINGS!  I called Clevitte, they could give me absolutely NO good reason why they did this, other than that's what THEY determined worked the best for thrust bearing oiling, but at the expense of rod bearing oiling on those two crankpins ajacent to the center main, not to mention the loss of valuable bearing material!  

That is not even the BIGGEST problem with that center main/thrust bearing. The bigger problem is that the center main bearings simply drop into the block with virtually no resistance whatsoever to seat them into the saddles of the block and main cap.  I checked the oil clearance, and ALL the bearings have .0015 to .002 and appear to have appropriate crush, but those mains fitting all loose like that has me a little freaked out!  Anyone else ever run into this?  

I just do not like the composition of stock replacement King engine bearings and Clevitte "H"/ King "X" bearings are just not an option for a truck engine with a soft cast crank.  I suppose I could go get a set of Speed Pro main bearings, but I have never run into this on a Clevitte!  The center main bearing saddle, just like the rest of them measure perfect with appropriate size and no OOR.  I just figured I would see if anyone else has had something like this occur.  

Again, sorry for the long post, I try to get all the details as best I can!