406 Blown

I have just aquired a small block 406 with a 144 blower. I had a concern and spoke to an engine builder about the oil in the cranck case being a little on the black side. I have heard this engine run and watched it perform and it is stout. I know there is the possibility of the exhaust gasses enteing the crank case. My question is does anyone else seem to have this issue and if so how significant is the problem? The engine builder told me that it is common and as long as the engine has no lack of power and is as crisp as I say it is he would probably leave it alone and just keep changing the oil more often. I dont know if blower pistons were installed at the time of the blower install. The engine runs on the rich side until it warms up and then there is no smoke or smell of rich fuel.

Porker if you are out there perhaps you could comment

 

You should do a leak down test to see how bad it is and if it needs rings. You mean blowby , right?

 

Yes blow by. I know at some point it will need to be torn down and inspected. But just wondering as I have never owned a blown motor before. And is this something that everyone experiences with this type of motor.

 

Is the oil black or dirty and smelly? If the oil in the engine is from the original build, the color of the oil could br from assembly lube or cam break in lube. Remove the oil filter, cut it open and see if there is anything wired in there. If not, leak down each cylinder. If ok have fun with it.

 

It was running a K&N filter and I did cut it open and it was clean and no signs of anything. The oil was on the black side but and had no real smell other than what used oil smells like. What PSI and how long should a cylinder hold the commpression?

 

Brad Penn oil looks black -

 

That is wishfull thinking about the brad pennoil I wish. I just changed the oil using Rotella 15-W-40 with Lucas oil stabilizer and zinc additive. I guess I should run it and see what happens. I spoke to the original owner and he told me that after 500 to 1000 miles it gets dark and he just changes it. That is why I was asking if anyone else has been through this

 

One of the handiest tools I own is a dual gage leakdown tester not expensive, easy to use. It will answer a lot of questions. Good luck!