Crankshaft Oiling

I am currently running a KB/Indy Wedge motor with a billet crank 4.0 stroke and Big block chevy mains. The oiling hole for each rod is extremely close to the radius of the crank on each crank pin. The oil hole location has created problems with oil pressure when the motor warms up. The way I have dealt with the problem is to chamfer cut the rod bearings to maintain a minimum side clearance allowed by the rod manufacturer (Bill Miller Aluminum rods). This allows the rod bearing to cover the oiling hole and maintain pressure.

The problem I have is that I can see marks on the side of the bearing that the bearing contacted the radius of the crank. I feel that because the bearing is pinned for the aluminum rod it has not spun the bearing. I have reduced the rod bearing width so no contact is made (max side clearence) with radius of the crank but then I do not have adequate oil pressure when the motor warms up.

Has anyone had a similar problem before? Is the only way to properly fix the problem is to relocate the oiling holes to the center of each rod bearing? Or is the fact that the bearings are pinned they will not be at risk of spinning? Is the welding work needed to relocate the oiling holes going to possibly weaken the crank and it would be better to scrap the crank and start over?

Do not know horsepower of motor but the car is 2000lbs and the car runs 7.0-7.20ET 1/4 mile. I would like to push the combination to run 6.6-6.8ET.

Thanks,
Dave

 

Has this shaft been off-set ground for a stroke change? This will move the oil holes.

 

Yes, I think so... I purchased it used along with several other parts. The crank is not cracked so I would like to use it, but not if it is going to create other problems. Unsure if I have just been lucky up to this point or if there is a way to work around the oiling hole location.
Dave

 

If the shaft is standard, you could Tig a little of the outside edge of the hole, do some work with a small burr, and have it ground .010"

 

Thanks, I will check into someone who can grind the crankshaft. Do you have to use a special filler rod when welding crankshafts?

Dave

 

For this job, just a rod suitable for 4340