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-   -   Remove baffle on new valve cover? (https://67-72chevytrucks.com/vboard/showthread.php?t=821202)

KyFarm 04-28-2021 02:43 PM

Remove baffle on new valve cover?
 
2 Attachment(s)
Going with these Holley valve covers (241-292) as the ones that came with the HT383 had no provision for a breather, 15/16” hole, for PCV on both sides.

Anyway there is a baffle fairly close to the opening for the PCV but on the other side, breather side and oil fill, is it okay to remove the baffle?

Wouldn’t be able to get funnel in very far and oil would drain in very slowly?

Thanks for any help.
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MySons68C20 04-28-2021 03:17 PM

Re: Remove baffle on new valve cover?
 
in my experience if you remove the baffle oil will be pulled into the pcv valve and it'll smoke like a freight train.

KyFarm 04-28-2021 03:29 PM

Re: Remove baffle on new valve cover?
 
Quote:

Originally Posted by MySons68C20 (Post 8914547)
in my experience if you remove the baffle oil will be pulled into the pcv valve and it'll smoke like a freight train.

Gonna leave it in on the PCV side, I want to know if I can remove it on the Breather/Oil fill side?

MySons68C20 04-28-2021 03:36 PM

Re: Remove baffle on new valve cover?
 
I would leave it as is. There is a lot of oil splash that will wind up soaking your breather etc. They put it there for a reason so I would leave it alone.
I guess you could try it but if you are like me having to pull stuff apart twice bugs me lol!

cadillac_al 04-28-2021 09:01 PM

Re: Remove baffle on new valve cover?
 
I had to think about it a few minutes but I think I would leave it. If that's where the breather is going to go then definitely leave it in . It will be a small pain to put oil in it but at least the breather will stay nice and dry.

Captainfab 04-28-2021 10:02 PM

Re: Remove baffle on new valve cover?
 
IMO you should be good to remove the baffle. For one a new engine should not have any blowby and secondly since it is the breather, there should be a small amount of air coming in thru the breather. Additionally the little 'walls' cast into the cover will help deflect oil splash from the rocker arms away from the breather. There's my .02.

Dead Parrot 04-29-2021 09:03 AM

Re: Remove baffle on new valve cover?
 
If the only use for that hole will be as an oil fill hole and it will have a solid oil fill cap/plug when not adding oil, then remove the baffle.

If is is going to be a dual use air breather - oil fill hole, then keep the baffle. The reason the OEM air breather filter is in the air cleaner is under some operating conditions, there is enough blowby that air comes out of the breather. With the OEM setup, that air gets sucked back into the motor and burned. Without the baffle, you could wind up with a lot of oil on the top of your nice valve cover.

KyFarm 04-29-2021 09:22 AM

Re: Remove baffle on new valve cover?
 
Quote:

Originally Posted by Dead Parrot (Post 8914780)
If the only use for that hole will be as an oil fill hole and it will have a solid oil fill cap/plug when not adding oil, then remove the baffle.

If is is going to be a dual use air breather - oil fill hole, then keep the baffle. The reason the OEM air breather filter is in the air cleaner is under some operating conditions, there is enough blowby that air comes out of the breather. With the OEM setup, that air gets sucked back into the motor and burned. Without the baffle, you could wind up with a lot of oil on the top of your nice valve cover.

thanks for the info, but it raises questions that I don't understand, maybe you could help.

I get that there is POSITIVE crankcase pressure that is being vented and regulated with the PCV, but why doesn't having basically an open, filtered port, the breather, destroy the point of the PCV valve. Isn't there the same pressure under each valve cover?

Dead Parrot 04-29-2021 11:13 AM

Re: Remove baffle on new valve cover?
 
Quote:

Originally Posted by KyFarm (Post 8914788)
thanks for the info, but it raises questions that I don't understand, maybe you could help.

I get that there is POSITIVE crankcase pressure that is being vented and regulated with the PCV, but why doesn't having basically an open, filtered port, the breather, destroy the point of the PCV valve. Isn't there the same pressure under each valve cover?

The way the OEM PCV system is designed, the PCV valve sucks air out of one valve cover which in turn pulls air from the crankcase which gets its air from the other valve cover via the hose connecting to the PCV air filter in the main air filter housing. Having the PCV air filter on the valve cover just means that extra blowby air is vented to the atmosphere instead of being burned by getting sucked down the carb. IIRC - the main time that there is too much blowby for the PCV valve is under high throttle or when the rings are near end of life. The main reason for the air breather on the opposite valve cover is to allow extra clean air into the motor guts for the times when the PCV valve is sucking more air then the motor is making via blowby.

KyFarm 04-29-2021 12:15 PM

Quote:

Originally Posted by Dead Parrot (Post 8914821)
The way the OEM PCV system is designed, the PCV valve sucks air out of one valve cover which in turn pulls air from the crankcase which gets its air from the other valve cover via the hose connecting to the PCV air filter in the main air filter housing. Having the PCV air filter on the valve cover just means that extra blowby air is vented to the atmosphere instead of being burned by getting sucked down the carb. IIRC - the main time that there is too much blowby for the PCV valve is under high throttle or when the rings are near end of life. The main reason for the air breather on the opposite valve cover is to allow extra clean air into the motor guts for the times when the PCV valve is sucking more air then the motor is making via blowby.

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KyFarm 04-29-2021 12:17 PM

Quote:

Originally Posted by KyFarm (Post 8914858)
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Thank for that. I didn’t realize that vacuum was actually pulling vapors out. Makes sense.

Thinking for now I’ll leave that baffle in place.
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Mike C 04-29-2021 08:02 PM

Re: Remove baffle on new valve cover?
 
The PCV doesn't do anything at wide open throttle because there is no engine vacuum WOT. But there is a vacuum over the top of the carburetor at full throttle. So at WOT and high crankcase pressure, the vent side is under a vacuum in the OEM plumbed setup.

weq92f 05-02-2021 10:56 PM

Re: Remove baffle on new valve cover?
 
.

Use spacers to give it a bit more gap for the oil flow. Use washers if need be, but make sure those don't back off with some thread locker. You'll need longer fasteners most likely.

EDIT: maybe just space out the end with the lone fastener... as that looks like an intentional gap and making it bigger isn't likely to cause interference with your rockers.

-klb

Ironangel 05-20-2021 09:09 PM

Re: Remove baffle on new valve cover?
 
Quote:

Originally Posted by Captainfab (Post 8914689)
IMO you should be good to remove the baffle. For one a new engine should not have any blowby and secondly since it is the breather, there should be a small amount of air coming in thru the breather. Additionally the little 'walls' cast into the cover will help deflect oil splash from the rocker arms away from the breather. There's my .02.

:rolleyes: This. Or, take the single screw out and bend the baffle tang down a bit...;)


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