Ok, I am going to eat crow here and change my theory on Injector oil for most fuel injected motors and mainly the Polaris CFI 2 motors.
Its no secret that over the last few years that random rod bearing failure has crept its way into the Fuel injected sled market.
I have been a mineral base injector oil guy as long as I can remember.
That being said:
And I have been for 3 main reasons:
1 : its always worked good in the past and pistons looked great>
2 : its compatible with rubber crank seals
3 : it has the best rust protection.
Here is where I am going to switch my position 100% back to synthetic's
In the Polaris motors there has been an alarming change in fuel delivery from 2004 carbureted to 2006 - ( lets leave out the 2005 750/900 ) to keep this simpler.
Once the fuel stopped coming in thru the reed cage from carbs, and injectors started delivering fuel thru 4 injectors or 2, things have started to change in the rod bearing world and you can see the OEM's making them bigger and playing with different bearings and different clearances.
With random results.
AND - Most importantly, oil viscosities..... have been getting lower and lower to a level somewhat like water at room temp ( I.E. The new bagged Arctic Cat oil )
I did not start this thread to have a mass debate, I started it to save my a$$.......Because last spring & all summer I have been assembling motors with a heavy assembly lube in the rod & main bearings ( I believe this was a big mistake ) and hard to get rinsed out with a dry case.
in a CFI 2 motor Mid range and full throttle the fuel pretty much stays in the top of the motor unlike idle & low speed in & out of the throttle there is some fuel build up in the case helping to thin the injector oil and help suspend it so the rod can slice thru it so to speak.
Now here comes a BANK of theory's
#1 - Thought & concern - is the thicker injector oil or assembly lube in the rod bearing can vacuum lock the bearing cage so it cannot easily spin and move at the rate it needs to and can flat spot the rollers.
#2 - I have been using a heavy assembly lube in the center cavity for the drive gear and I am concerned in cold where that it will be hard for the is lube to get out of the center cavity thru the small drain under mag side center bearing that allows for that injector oil to help lube the mag rod bearing after its full enough.
I run 5-40 Extreme blue Valvoline in my Cummins so at cold start it can move oil easily...........I have come to the conclusion that these CFI fuel injectors motors need really thin oil to move thru the case easily since they no longer have fuel to thin the viscosity down to help get the oil to the rods and keep them lubed up and spinning free.
So I am to the point where the dread oil question that may forever live will be answered like this in a CFI 2 or 4 motor...........Run the factory injector oil or something with the same pour point or lower.
As far as exhaust valves go.........what ever works for the rod bearings will have to be tolerated for the exhaust valves no matter what happens on that end. It should be better with synthetic so it is said.
So to all my customers that have received motors that have not run yet, ** ** ( suck the oil tanks dry and fill them with thin viscosity synthetic right away, ) ** and these motors need a lot of low speed running to wash out the assembly lube in the warmest weather possible.
Sub zero weather with the assembly lube I used is almost sure to fail a lower rod bearing if its not rinsed out yet and grabs the roller cage.
I have already started contacting people VIA phone & e-mail but some we have not reached yet.
Thank you !!
Dan
Its no secret that over the last few years that random rod bearing failure has crept its way into the Fuel injected sled market.
I have been a mineral base injector oil guy as long as I can remember.
That being said:
And I have been for 3 main reasons:
1 : its always worked good in the past and pistons looked great>
2 : its compatible with rubber crank seals
3 : it has the best rust protection.
Here is where I am going to switch my position 100% back to synthetic's
In the Polaris motors there has been an alarming change in fuel delivery from 2004 carbureted to 2006 - ( lets leave out the 2005 750/900 ) to keep this simpler.
Once the fuel stopped coming in thru the reed cage from carbs, and injectors started delivering fuel thru 4 injectors or 2, things have started to change in the rod bearing world and you can see the OEM's making them bigger and playing with different bearings and different clearances.
With random results.
AND - Most importantly, oil viscosities..... have been getting lower and lower to a level somewhat like water at room temp ( I.E. The new bagged Arctic Cat oil )
I did not start this thread to have a mass debate, I started it to save my a$$.......Because last spring & all summer I have been assembling motors with a heavy assembly lube in the rod & main bearings ( I believe this was a big mistake ) and hard to get rinsed out with a dry case.
in a CFI 2 motor Mid range and full throttle the fuel pretty much stays in the top of the motor unlike idle & low speed in & out of the throttle there is some fuel build up in the case helping to thin the injector oil and help suspend it so the rod can slice thru it so to speak.
Now here comes a BANK of theory's
#1 - Thought & concern - is the thicker injector oil or assembly lube in the rod bearing can vacuum lock the bearing cage so it cannot easily spin and move at the rate it needs to and can flat spot the rollers.
#2 - I have been using a heavy assembly lube in the center cavity for the drive gear and I am concerned in cold where that it will be hard for the is lube to get out of the center cavity thru the small drain under mag side center bearing that allows for that injector oil to help lube the mag rod bearing after its full enough.
I run 5-40 Extreme blue Valvoline in my Cummins so at cold start it can move oil easily...........I have come to the conclusion that these CFI fuel injectors motors need really thin oil to move thru the case easily since they no longer have fuel to thin the viscosity down to help get the oil to the rods and keep them lubed up and spinning free.
So I am to the point where the dread oil question that may forever live will be answered like this in a CFI 2 or 4 motor...........Run the factory injector oil or something with the same pour point or lower.
As far as exhaust valves go.........what ever works for the rod bearings will have to be tolerated for the exhaust valves no matter what happens on that end. It should be better with synthetic so it is said.
So to all my customers that have received motors that have not run yet, ** ** ( suck the oil tanks dry and fill them with thin viscosity synthetic right away, ) ** and these motors need a lot of low speed running to wash out the assembly lube in the warmest weather possible.
Sub zero weather with the assembly lube I used is almost sure to fail a lower rod bearing if its not rinsed out yet and grabs the roller cage.
I have already started contacting people VIA phone & e-mail but some we have not reached yet.
Thank you !!
Dan
