Racingjunk Forums

Racingjunk Forums (https://www.racingjunk.com/forums/index.php)
-   Engine Tech (https://www.racingjunk.com/forums/forumdisplay.php?f=9)
-   -   Motor burns oil (https://www.racingjunk.com/forums/showthread.php?t=28584)

davelee 08-07-2010 06:19 AM

Motor burns oil
 
Hi,
I just built a new big BBC 622, and it is in a street car. The block was cross hatched honed with 400 grit. The motor is a 4 3/4 stroke with 6.700 inch rod. I am running total seal gapless top ring. The rings are 1/16, 1/16, 3/16. After I broke the engine in I put in valvoline racing oil 20/50 . I have a couple 100 miles on the motor and it seems like it burns maybe 1/2 qt per 30 to 40 gallons of gas. This is my first big inch motor. Is this normal for a motor this size? or did I over look something?
Thanks

kwkracing 08-07-2010 06:45 AM

probably not. If it was built as a race engine it has a few extra thousands on some things and probably has no exhaust valve seals. Which is not a bad thing.

davelee 08-07-2010 10:53 AM

It has New teflon valve seals on the intake and exhaust valves
thanks

chevy582r10 08-07-2010 05:41 PM

Re: Motor burns oil
 

Originally Posted by davelee
Hi,
I just built a new big BBC 622, and it is in a street car. The block was cross hatched honed with 400 grit. The motor is a 4 3/4 stroke with 6.700 inch rod. I am running total seal gapless top ring. The rings are 1/16, 1/16, 3/16. After I broke the engine in I put in valvoline racing oil 20/50 . I have a couple 100 miles on the motor and it seems like it burns maybe 1/2 qt per 30 to 40 gallons of gas. This is my first big inch motor. Is this normal for a motor this size? or did I over look something?
Thanks

I built a 400 with 6 inch rods once. The wrist pin was way up in the oil ring. That thing burned oil big time with 20w50 in it. Maybe a quart every 150 miles or so. Changed the oil to 10w30 racing oil and could get about 2K miles to a quart. I figure the rings just couldn't control the heavier oil as easily. I never got to find out exactly why. I've built a bunch of other engines similar to this with no problem since then.

oldandtired 08-10-2010 11:05 AM

Do you have the low tension oil ring package?

TheRabbit 08-10-2010 12:50 PM


Originally Posted by oldandtired
Do you have the low tension oil ring package?

X2.
And I wouldn't run 20/50. The thicker oil with low tension rings will make it burn oil worse. I used 10/30.


All times are GMT -8. The time now is 10:03 AM.