Narrow grooves in Some upper main bearings?

[jdperform]

I used to use Vanderville style main bearings in SB Mopar because of the very narrow groove in the Clevite H bearings. The Vanderville style is no longer available. Forcing me to widen the groove similar in dimension to SBC design. What would be the difference between SBC and SB Mopar in main and rod oiling requirements ? It seems the sq in is about 1/3 in the SB Mopar vs the Chevy . I'd rather have 2 gallons per minute more oil feeding the crank that 1 teaspoon not enough. Dry sump only. Circle Track. Help me figure this thought please.

[wyrmrider]

you only have to widen from the hole to parting line in direction of rotation
but chucking two into a fixture on the lathe makes quick work of them
how's the oil trough at the parting line on the rotation side to spread it out a little
we used to that a lot even by had with a ball burr
do you feed both ends or do the old cross over thing in the valley
do you find if you sleeve the lifter bores you cut down on your flow?
too bad they are not side oilers

[RW TECH]

I used to use Vanderville style main bearings in SB Mopar because of the very narrow groove in the Clevite H bearings. The Vanderville style is no longer available. Forcing me to widen the groove similar in dimension to SBC design. What would be the difference between SBC and SB Mopar in main and rod oiling requirements ? It seems the sq in is about 1/3 in the SB Mopar vs the Chevy . I'd rather have 2 gallons per minute more oil feeding the crank that 1 teaspoon not enough. Dry sump only. Circle Track. Help me figure this thought please.

Take a look at upper main bearings for GM LS in the 2, 4, and 5 positions. Higher-end racing is taking a similar approach to the LS arrangement, sometimes with practically no groove at all.

Believe it or not, the rod bearings will look better than if there's all kinds of groove that ultimately bleeds of a ton of oil at the parting line area.

[wyrmrider]

groove the block- feed from the side
no oil hemorrhage from the top

[Warp Speed]

groove the block- feed from the side
no oil hemorrhage from the top

Huh?!?

[wyrmrider]

half grove the main from the oil feed to the main bolt

open the hole in the bearing at the parting line
puts the oil where it needs to be to make a hydronamic wedge- well almost- but much better than at point of max clearance at the top

[RW TECH]

half grove the main from the oil feed to the main bolt

open the hole in the bearing at the parting line
puts the oil where it needs to be to make a hydronamic wedge- well almost- but much better than at point of max clearance at the top

The current "racy stuff" has oil hole at the top with grooves that terminate before the eccentricity area of the bearing. Some folks make home-made brass bearings that have a hole and no groove.

[Warp Speed]

half grove the main from the oil feed to the main bolt

open the hole in the bearing at the parting line
puts the oil where it needs to be to make a hydronamic wedge- well almost- but much better than at point of max clearance at the top

Max clearance is at the parting lines.........

[wyrmrider]

true but you are trying to feed half way down the bottom shell
we used to grove heavy oil 392 blocks
where do you want the oil wedge- put the oil in as close to before that as possible

[Warp Speed]

true but you are trying to feed half way down the bottom shell
we used to grove heavy oil 392 blocks
where do you want the oil wedge- put the oil in as close to before that as possible

Why?!?
The grooves in the upper bearings are to feed the rods. If the are no rods being fed by the main, it takes very little to no groove to properly feed the main bearing itself.

[wyrmrider]

True on the rod feed but with 70 wt torco we thought feeding closer to where the wedge was formed would be better- we were not getting oil spread all the way across the journal also tried putting in a diagonal grove or an X
At the parting line the bearings had a trough (wider at the top tapering down about a 1/2 inch) with sides which we felt would be a good place to pool up some oil

[Warp Speed]

True on the rod feed but with 70 wt torco we thought feeding closer to where the wedge was formed would be better- we were not getting oil spread all the way across the journal also tried putting in a diagonal grove or an X
At the parting line the bearings had a trough (wider at the top tapering down about a 1/2 inch) with sides which we felt would be a good place to pool up some oil

How did you know you were not getting "oil spread across the journal"?

[wyrmrider]

we had distress on the outer side of the mains progressing from the feed hole
may have been running too much clearance
not scientific but for 1960 side oiling seemed to help
now to go box some rods

[Warp Speed]

we had distress on the outer side of the mains progressing from the feed hole
may have been running too much clearance
not scientific but for 1960 side oiling seemed to help
now to go box some rods

Sounds like classic edge loading, not necessarily an oiling problem. Often, covering up one problem instead of fixing the root cause, can lead to a whole nother set of problems. In this case, very poor oil control.

[pamotorman]

groove the block- feed from the side
no oil hemorrhage from the top

Huh?!?

like this and drill extra holes in the insert to match the block groove. I did this for years and never had bearing problems. I grooved the block by milling a slot in a old insert and used that as I guide to cut the block with a mounted grinding stone in a die grinder. https://www.grainger.com/product/DREMEL ... 1?$smthumb$