engine crankcase ventalation, breathers..... valve covers

[regalman4925]

i have to buy new valve covers for my motor because my scorpion roller rockers did not clear them, this has brought up a few questions that i have been thinking about for some time. i am use to doing car motors and you run a pcv valve from the carb to the valve cover and a breather on the opposite side. most of the valve covers i have looked at do not have a spot for a breather or any type of ventalation for that matter, some do not even have a oil fill. the original motor from what i can figure out in the pile of parts had a spot go the the valve cover and connected to the flame arrestor as does my 20' bow rider i have also. one of my buddies that has a 32' cat with some serious power, from what i recall on his motor he has a breather on each side and no hoses to such vapor through.... i am confused on this one

[niceguy]

I just bought these and had them powder coated to match the boat. Really nice pieces for the price and has one hole with threaded cap for oil fill and then one additional hole on each cover for breathers.

http://www.cpperformance.com/detail.aspx?ID=5387

[Griff]

Stock valve covers should clear roller rockers. You have to grind off the drip tabs inside the valve covers and maybe grind off the corners on 2 rocker arms. You can also get an extra thick steel cored valve cover gasket to use in conjunction with the O ring gasket.

[regalman4925]

i used a thick rubber gasket and something is still catching. the poly locks are too tall on these rockers and left at least 3/16ths of a gap from them seating without the rubber gasket. i have a clicking noise i can hear when i turn the motor over with a wrench. i might chaeck again tonight and see if i can figure it out. also there were no drip tabs and the rockers are trimmed some already.

[FlyinZX14]

I had to use Moroso tall steel valve covers to clear my rockers, poly locks and manifolds. If you have stock mercruiser manifolds, tall valve covers will clear the rockers, but not the exhaust...I messed with this for a while earlier this year...

[picklenjim]

Rex sells a set like the Hardin set above a little bit cheaper.No breather holes though.They sell the breather stacks seperately.That way you can mount them where ever you want on the valve cover to clear anything that might be in the way.Eliminates the hoses going to the flame arrestor along with any oil leaks.Also you can pull the valve covers without removing the exhaust manifolds.Stock valve cover with roller rockers-No way Jose.

[Ghostrider]

Originally Posted by picklenjim

Rex sells a set like the Hardin set above a little bit cheaper.No breather holes though.They sell the breather stacks seperately.That way you can mount them where ever you want on the valve cover to clear anything that might be in the way.Eliminates the hoses going to the flame arrestor along with any oil leaks.Also you can pull the valve covers without removing the exhaust manifolds.Stock valve cover with roller rockers-No way Jose.

That's what I've just bought. I'm just trying to decide what kind of breather to run, an open K&N style filter, a covered filter, the tall cap style breather or plumbed to a remote puke tank with a breather cap style.

Anyone have any input on the best way to do it?
Of, and Roller Rockers wont clear the Gen VI cast alloy covers, they're way too shallow! (Lesson Learned!)

[picklenjim]

[QUOTE=Ghostrider;2936904]That's what I've just bought. I'm just trying to decide what kind of breather to run, an open K&N style filter, a covered filter, the tall cap style breather or plumbed to a remote puke tank with a breather cap style.

Personally I would run the tall cap style breather.Their leak free and maintenance free and they look good too.Wouldn't even consider plumbing in a puke tank unless you had a motor that needs it.http://teaguecustommarine.com//store...products_id=28

Here's a picture of a Teague motor with those valve covers and the tall breather stacks.He uses that setup on all his engines.

[Ghostrider]

Brilliant, Thanks!