New longblock, how much blowby?

[UpperUpsilon]

So, in contrast to all the bad news that usually crops up here at iboats, we've got our new longblock installed. First start in the driveway today, and it runs great. Timed it and all that jazz. Engine idled (we varied the rpms) and came up to temp. We saw a faint haze/steam coming from the crankcase vents... I'm guessing this is normal since it hasn't been broken in/rings seated yet. These fumes/steam/haze is blowby, right?

So, is that haze normal before break in?

And, any tips on break in besides the normal "go boating"?

 

[Bondo]

Re: New longblock, how much blowby?

So, is that haze normal before break in?

Ayuh,... I wouldn't be concerned at this point...

And, any tips on break in besides the normal "go boating"?

Ayuh,... Run it like ya just Stole it....

 

[gadget73]

Re: New longblock, how much blowby?

All motors have some blowby. No PCV system on a boat, so it just wafts out of the vents. Sounds normal to me. If you see heavy oil slime forming in the tubes or around the rubber grommets in the valve covers, then you may have a problem.


Vaguely related, has anyone ever considered adding a proper PCV to a marine engine so that it would evacuate those fumes and keep fresh air in the crankcase? I have the ports on my intake to add one in, but I haven't done so because I wasn't sure if it was a bad idea or not.

 

[UpperUpsilon]

Re: New longblock, how much blowby?

I think that some marine engines do have PCV, so I'm sure you could add it with the valve and a new arestor... But I think it's just an emissions thing, so not absolutely necessary.

 

[Rat Capri]

Re: New longblock, how much blowby?

PCV system is a good thing.. cleaner oil, positive oil pressure control and better ring sealing.If you have the ability I would recommend it...that's my .02