valve cover openings

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diymirage

diymirage

HP@idle > hondaHP@redline
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hey guys, i just picked up a great set of valve covers, the cast aluminum ones i like


both the covers have bosses cast in them (one for a 710 cap, one for a PCV) so it shouldnt be to hard to open, but what is the correct way?

drill bit?

end mill ?

dremel ?

i figured i would put a PCV on the passenger side and a oil filler and breather on the other side right ?

and what is the correct size?
 
Did you look under the bottom to see if they punch out? Some do, some don't. If not an end mill will no doubt do the neatest job if you have the means. If not a good drill bit will work fine. PCV grommets and filler/breathers come in a few different sizes. Your best bet is to look on Summit or JEGS and find what you like and drill the hole sizes they call for.

PCV on pass side and fill on drivers side is the way I always do it but it's not written in stone you have to do it that way. Just have to have one on one side and one on the other

Oh yeah, make sure to install baffles if they don't have them. Without baffles the PCV valve can suck up oil splashed on it and the breather may spit out oil splashed on it.
 
fishy68 said:
Did you look under the bottom to see if they punch out? Some do, some don't. If not an end mill will no doubt do the neatest job if you have the means. If not a good drill bit will work fine. PCV grommets and filler/breathers come in a few different sizes. Your best bet is to look on Summit or JEGS and find what you like and drill the hole sizes they call for.

PCV on pass side and fill on drivers side is the way I always do it but it's not written in stone you have to do it that way. Just have to have one on one side and one on the other

Oh yeah, make sure to install baffles if they don't have them. Without baffles the PCV valve can suck up oil splashed on it and the breather may spit out oil splashed on it.
Click to expand...

^^^^^^ Xs2
 
diymirage said:
hey guys, i just picked up a great set of valve covers, the cast aluminum ones i like
Click to expand...

What kind of valve covers are they? I've got a nice set of the early M/T cast ones that are raw, with none of the caps or grommets that I'll be needing eventually. Not sure where or how to find them.
 
bighammer said:
What kind of valve covers are they? I've got a nice set of the early M/T cast ones that are raw, with none of the caps or grommets that I'll be needing eventually. Not sure where or how to find them.
Click to expand...

I had a heck of a hard time finding grommets to fit M/T valve covers. I don't remember where I eventually came up with them. - But today I was looking through a McMaster/Carr catalog and it seemed like they handle almost every conceivable grommet size. They're an industrial supply outlet.
 
I cut those knockouts all the time as part of my custom / resto work. My favorite way is with a hole saw in the drill press. I've got a sweet Irwin 2 1/4" reserved just for aluminum valve covers. Protect any nice existing finish from your drill press table as necessary in case it gets away from you. Cut from the inside out.

Great advice on holding off on any cutting until you have the proper grommets in hand! :-D The ones that will fit aren't usually available in the Help section at the parts store either.

You didn't mention which supplier made the ones you bought diymirage, but most are fairly thick (some nearly a half inch). The thick grommets to fit the MPs et al. are getting tough to find but I've had good luck with Jeg's lately. They seem to have more in stock than Summit. I personally have had trouble locating suitable baffles for any aftermarket valve covers and have resorted to making them out of sheet metal as the need arises.

Post up some pics of your score when you get a chance! I LOVE valve covers. :-D
 
thanks for all the advice guys

the valve covers are holleys and they seem to have a knockout cast into them which makes the oil cap side simple enough but the breather/PCV side is one large blank

at my job i have access to a full machine shop so that shouldnt be a problem, its just picking which one would be best

the did not come with baffles but those should be a breeze to make too

the plan is to media blast the valve covers and install them on the engine
then ill paint the whole thing and polish up the raised edges

ill try to get some pics of them later tonight :)
 
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