OIL Indexing

Kansas Bad Man

Well Known and Active Forum User
Non-VOC Member
Installing the big end crank pin in the fly wheels and the cam spindles in the crank cases is critical in there indexing to provide for best lubrication of parts and the oil cooling of parts by conduction. There has been much discussion covering this subject with polar solutions as to the best location of the indexing. One school of thought is that the oil path should be directed to the lowest pressure point of the part in operation, and the other is that it should be directed to the opposite side of the highest pressure point during operation.

The reason that it has been brought to my attention recently was the viewing of the ( TP ) connecting rods shown in the ongoing racer build . It only verifies to me that the polar view extends to the manufactures as well.
The little end of the connecting rod on the ( TP ) units have the "mist oil hole" favoring the area closest to the piston crowns bottom side , that would be the opposite pressure side during the compression and power stroke. My connecting rods in my liner are Correlo, they have there , ( oil slinger holes, notice I said slinger ) at about 4 o'clock and 8 o'clock , oil is provided to the little end by splash during the pressure points created during compression and power strokes and during the non pressure points during(maybe a little bit of pressure) exhaust and the intake strokes.

When it is the preferred method to lube at the non pressure side, oil has to wick to the pleasure side during the intake and exhaust strokes.

All of the above theories apply to the big end with one overlooked law of physique's . The oil supply to the crank is of a low pressure and pulsating due to the plunger design of the pump ( notice I said crank not big end ) the rotating crank creates a centrifuge with a diameter of 1 3/4 inches . the centrifuged action creates a increase of oil pressure due to the centrifugal force applied to mass. In addition the siphon principle is also in play. The oil pressure of the Vincent oiling system is at its highest point when leaving the crank pin oiling holes. Most crank pins have different sizes of oil holes to help the evening out of lubrication oil to the rods on a twin. The oil comes off the crank through the sides of the rods at a high velocity, carrying heat from the pin and its bearings. The next job of the oil is three foul when Correlo rods are used . splash lube the non thrust side of the cylinder walls, lube the little end of the rod and provide cooling oil to the piston crown. Additional oiling of the thrust side of the piston cylinder is due to its shrouded splash trough .

The cam spindles oiling is effected in the same way as described as above. There are a few points I would like to make when it comes to cam spindles but I'm tired.
 

Bill Thomas

Well Known and Active Forum User
VOC Member
Hello Max, Just looked at my "short " Carrillo Rod, And it has the oil hole at the top !! Is that OK ? I got it for a project 560cc Comet, Not sure if it will ever get done, But live in hope !! All The Best, Bill.
 

vibrac

Well Known and Active Forum User
VOC Member
Hello Max, Just looked at my "short " Carrillo Rod, And it has the oil hole at the top !! Is that OK ? I got it for a project 560cc Comet, Not sure if it will ever get done, But live in hope !! All The Best, Bill.
Not sure it will ever get done now where have I heard that song before ... I have just made a realistic estimate of my workshop load. Projected end date on the critical path is 22 Jan 2019 with the Egli Comet due start on May 2017 :(on the plus side I am 5 days ahead of schedule:D. (oh and the schedule excludes maintenance:oops:) So why am I still looking at Acutions and e-bay for more bikes? thats what I need to fathom
 

Kansas Bad Man

Well Known and Active Forum User
Non-VOC Member
Hello Max, Just looked at my "short " Carrillo Rod, And it has the oil hole at the top !! Is that OK ? I got it for a project 560cc Comet, Not sure if it will ever get done, But live in hope !! All The Best, Bill.


Shure it will work, a lot of the car Carrillo rods have the oil hole in the top. My rods "H" beam faces for and aft.

Good luck on the Comet----Max
 

Kansas Bad Man

Well Known and Active Forum User
Non-VOC Member
If you go to Vincent.com, you will find an article I wrote called "Oiling your Vincent"

Here are a couple of things I would like to touch on. When ordering custom made pistons, most of the manufactures offer , custom drilling of oil holes that always are located to lube at the pressure side of the wrist pin. There was a discussion some time ago between Trev and I, about the indexing of the oil holes on the cam spindles, up or down, pressure side or non pressure side, he mentioned that he had a twin under his work bench that had never been apart and he would inspect to find out what the indexing was when they left the factory. He never posted his find, so how about it Trev?
 

Bill Thomas

Well Known and Active Forum User
VOC Member
Hello Max, I have never been keen on the Vin small end, When I was racing , every time I took the top off the Pin was Blued !! I never ran a tight bush, Did someone try a needle roller small end once ?. Cheers Bill.
 

vibrac

Well Known and Active Forum User
VOC Member
Ron Kemp used a floating small end bush in his racer a few judicious oil groves on outside stopped the blueing
 
Top