mike tkach

iTrader: (3)

aahh,hoses hooked to flame arrester,totally different than to a vacuum source.

bck

Basic na build. Here's a pic as he installed them. I actually thought this was common practice when he told me about it. I figured for sure others would be doing this and that's why I wanted to point it out.

f_inscreenname

Does the hose from the gutted PCV go to the flame arrestor or to the carb base?

SB

iTrader: (1)

See #10
http://www.mercruiserparts.com/Show_...FLAME+ARRESTOR

It's an internally open fitting that could be mistaken as a PCV valve

bck

You guy are quick. I see you figured it all out while I was finding the pic to post. I wasn't aware hooking them up to the arrestor was much different other than it would be a weaker source of vacuum. These weren't hollow initially, they were full functioning pcvs that had the bottom removed and the insides taken out. Anyway, be aware of this extra piece pressed into the top if you ever gut a standard pcv valve.

SB

iTrader: (1)

See #9 and #10 post

SB

iTrader: (1)

bck - always good to post this stuff because you never know who knows what or not.

I'm glad for you that you found that piece on the rocker arm . Lucky !

BUP

iTrader: (9)

Some merc apps use both one breather valve and one PCV valve for OEM stock apps.

http://www.mercruiserparts.com/Show_...d+Rocker+Cover

BUP

iTrader: (9)

The guy who is making & using a knocked out internal PVC valve instead of using a real breather valve really is clueless. Why because the hole opening is 3 times bigger in size for the breather valve compared to a PVC valve. Crankcase pressure needs enough sizing to escape / vent.

In the link above post # 18 the breather valve is part # 6 or the same exact type is in SB parts diagram post part # 10 - you can buy them all day long from merc for real cheap. Cost 3.80 full retail and do not have to punch anything out of them.

35fountain

Putting a PCV valve in the valve cover and attaching a hose to the flame arrestor is not going to do anything. A PCV valve needs a vacuum source, either from the base of the carb,, manifold like some of the HP 500's. Those fittings look like PCV's in post #18 but are not. They are plastic fittings allowing free flow crankcase ventilation to the flame arrestor. When your engine is idling or at low rpm's the vacuum in the manifold is at its highest which causes the pcv to open. Being in the open position it is now sucking unburned fumes, moisture etc out of the crankcase dumping it back into the intake to be re-burned. The machine shop that flowed my carbs told me NEVER install a PCV valve in high performance engine unless you want to blow it up. As someone previously said ...A Detonation Monster