Wednesday, November 12, 2008

Cross Drill Oil Holes on Crankshaft Journal

A lot of people believes a cross drill oil hole on crank journal will increase lubrication passage. But, we believe a crank with cross drill oil hole will reduce lubricating function. The reason is very simple, the oil pick up from the rod journal flow into the main journal. Without cross drill, these lube will pour into one end of this passage to create higher lube oil pressure. With cross drill, the oil may divide to both end. Of course the oil pressure will reduce and minimize the lubrication purpose.

ARP 8740, 2000, & L19 Rod Bolts

Of course, the tensile strength of different material rod bolts are different:

ARP 8740 190,000 PSI
ARP 2000 210,000 PSI
ARP L19 260,000 PSI

The prices of each materail are way different also. As for engine under 900 HP, rod bolts with 8740 material shall be enough to handle such impact and movement. Of course, with higher grade rod bolts make people more comfortable, but it is not necessary just for hear say.

B150 Aluminum Bronze Distributor Gear

The tensile strength between B150 Aluminum bronze and copper bronze is 2:1. The raw material price between B150 aluminum bronze and copper bronze is 3:1. There are some distributor gear made from copper bronze which you can pay less than 50% of gear made from B150 Aluminum bronze. Of course, you got what you paid for. The copper bronze distributor gear may last 6 months in operation if your are lucky. Check what kind material before you buy a new bronze distibutor gear.

Aluminum Rocker

There are too many low price aluminum rocker arms in today's market. Those rocker arms are made from aluminum alloy but without specify how? For racing application to withstand high spring pressure and RPM, extrusion technical of aluminum alloy is must. We have study and analysis to find these low price aluminum rocker arms are made by DIE CAST. This is cost saving process to form aluminum products. This is the reason why the price is so low. As you got what you paid for these Die Cast aluminum rocker arms have about 12,000 PSI tensile strength compare with Extrusion process to have over 60,000 PSI tensile strength. This is reason why the Die Cast rocker arms are such heavy and has thick front arm to avoid breakage during operation. Beware the poor quality rocker arm. Check with supplier their rocker arm is Die Cast or Extrusion before you buy.