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Originally posted by captaintobeys:

The top ones look the same wear wise. The are not groved. Is there a set of fully groved ones out there. 3/4 Groved?

I'm a bit concerned by your description of the bearing halves lacking grooves as "the top ones".

I'm sure the bearings were installed properly, but please humor my over-cautiousness, I'd like to clarify what top indicates! Smiler With the engine sitting upright, carburetor on top, oil pan on the bottom, the "top bearing shells", i.e. the ones lodged into the main saddles, should have grooves. The lower bearing shells, i.e. the ones lodged in the main caps, should be the smooth ones. Else there's no way for the oil to flow from the block's oil passage and into the bearing/journal clearance.

In regards to deciding upon half grooved - 3/4 grooved - fully grooved bearings, I'll make these comments:

The purpose of a fully grooved main bearing is to supply oil to the rod bearings throughout 360 degrees of the crankshafts rotation. This at least doubles the amount of oil flowing to the rod bearings. This accomplishes the same thing as a cross-drilled crankshaft or grooved main bearing journals, but it was less expensive and didn't weaken the crankshaft.

Up until the advent of 0W and 5W oil, whenever you purchased a performance (tri-metal) bearing kit for the 351C it came with fully grooved main bearings, including the tri-metal bearings sold over the counter by Ford. It was the introduction of the thin oil viscosities that motivated the bearing manufacturers to stop manufacturing fully grooved bearings. With the thin viscosity oil, the groove in the lower half of the bearing acts like a rain groove in a tire tread, it channels the oil wedge away from the bearing surface. This is not a problem for 20W50, 15W40, 10W40 or 10W30 oil.

So my advice: if the engine is set-up to use oil with viscosity ratings of 10W30, 10W40, 15W40, 20W50 ... I'd use fully grooved bearings. If the engine is set-up to use 0W or 5W type oils, I'd use the 3/4 groove bearings from King Bearing.
Lost in Translation. Yes the halfs were installed properly. Some thing else that confused me in this thread that confused me. Just because some of it is Greek to Me. The bearings is .010 Undersized? I assume this really is that the crank was grounf by .010 and the bearing is .010 thicker. All this has to be made very simple for me.

Just receive the Lfter bore bushing kit. Wish me luck.
I just got around to test fitting a rod bearing set. After applying the torque to 40 ftlbs, the rod would not move on the crank, At all. I want to make sure I am right.

The rod bearings that came out of it are Clevite 77 marked

7 80 010 10 81 010
lower upper
CB 926P CB 962P

The bearings Summit supplied
CB-927 HN-10

What's up. Is it just me and they are real tight new?
all I can imagine is that you have the cap from a different rod & the bore is offset enough that it's binding up

each rod/cap assy is machined to each other, they can't be mixed or flipped in any way, they must be re-assembled exactly the same as they were originally

worst case you may need to get them 'Big Sized' or 'Minor Rebuilt' at the local shop, this can be done with the pistons on the rods
Besides having the bearing "notches" on the same side, the rod and cap are usually marked with a number corresponding to the cylinder that it was installed in. When assembled, the number on the rod cap should be on the same side of the rod as the rod's number, and those numbers should be facing to the outside of the block.

Did you measure your rod journals on the crank?
Just because the main journals were .010 undersized doesn't mean the rods had to be also. The original part numbers you quote (CB 926P CB 962)are standard size for the rod bearings according to a web search.
The bearings you got from Summit CB-927 HN-10 are .010 undersize.
That would definitely keep you from moving the rod once you had torqued down the rod bolts.

trw /clevite catalog lists top and bottom bearing should have same number cb927p w/oversize .010 . my 1972 trw/clevite catalog lists no cb926/cb962 for any app [but these may be oem /ford #'s/application.there are some federal mogul bearings with an oil hole in the upper to oil piston skirt, but not the trw/clevite brg. also on the grooved lower brg, it has @ 30 % of the full width bearing /load carrying capacity.
For choosing a cam, you need an expert in the field, not a bunch of amateurs like us. E-mail Mike or Mark at Bullet Cams- they design them and their company grinds their own in-house. Lots of good testimonials and unbelievable customer service. Bullet bought all the masters from Ultradyne Cams and some of the personnel when they sold out 5-6 years ago. By the time you answer all the questions on their form, you'll be far more knowledgable about your Pantera. Their cam recommendation form is on their web site in Olive Branch, MS. and you may get their first guess back same day.

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