To chamfer or not to chamfer...that's the question!

[81_El_Homewrecker]

What are your ideas about chambering the oil passages on new crankshafts. Helping a buddy build a 355 and I told him the new crank won't come chamfered. If it's worth chambering I said to get a crank that's not balanced and then when he takes it to get balanced they can chamfer them then. That's what I did with mine. Just wondering if you guys think it's worth it and what not.

 

[Injectedcutty]

Personally, i think he would see better results by chamfering the oil passages on the block. I have heard of doing the crank but havent seen numbers on the results. I do know that chamfering the block does help though.

 

[81_El_Homewrecker]

Personally, i think he would see better results by chamfering the oil passages on the block. I have heard of doing the crank but havent seen numbers on the results. I do know that chamfering the block does help though.

How? There's main bearings there...the idea behind the chamfer on the crank was for better oil spread for the rod bearings.

 

[Injectedcutty]

How? There's main bearings there...the idea behind the chamfer on the crank was for better oil spread for the rod bearings.

Sounds like a good idea, i just have always seen chamfers being put on the oil drainback holes in the intake valley to get the oil back down quicker...your idea seems like a good one.

 

[theoldsone]

The oil can't get there is there is no pressure... Just remember that.

 

[81_El_Homewrecker]

The oil can't get there is there is no pressure... Just remember that.

Explain?

 

[theoldsone]

Chamfering oil passages aid in the ease of oil distribution. While a crank (or any rotating Assembly) rotates at high rpm's oil is most needed in those critical areas such as the bottom end rod and main journal bearings. Instead of oil having work it's way over a hard edge it can easily flow through a soft edge. Oil pressure is not created by the oil pump. It's created by clearance between the hard parts and bearings. So in other terms it helps oil distribution in critical moments(high rpms) thus maintaining adequate oil pressure.

 

[81_El_Homewrecker]

Chamfering oil passages aid in the ease of oil distribution. While a crank (or any rotating Assembly) rotates at high rpm's oil is most needed in those critical areas such as the bottom end rod and main journal bearings. Instead of oil having work it's way over a hard edge it can easily flow through a soft edge. Oil pressure is not created by the oil pump. It's created by clearance between the hard parts and bearings. So in other terms it helps oil distribution in critical moments(high rpms) thus maintaining adequate oil pressure.

Got it...so you agree that it is worth the extra cost?

 

[theoldsone]

Depends. If your building anything from mild to wild, it would give you an assurance at mind when ripping down the road @ 5000rpms punching through the gears your crankshaft is happy lol.