question on non vented valve covers

[ratterman]

this may be a stupid question to some but i have been wanting a set of the old cal custom valve covers for my project but the ones i like are the non vented ones with no holes. my question is will i need to run an intake with the oil fill tube on it like an old 283 intake? I don't mind that and actually like the look but will the older 283 intakes work on my newer 350 engine? And is there a 4 barrel version? all i find are 2 barrel intakes. And what vents the engine with those intakes? I've read something about a road draft tube but have no idea what that is or if it even pertains to what I'm trying to do.

 

[Willowbilly3]

Many of the aftermarket intakes have a place for the oil fill tube. I suppose some early 327 hipo engines had a big flange carb base and fill tube bit one of those will cost more than an after market unit.

 

[Gastrick]

ratterman,

All the sbc intakes will interchange up until 1986. after that, the angle of the threaded holes in the heads changed where the intake bolts on. You can still use an early intake on the 86 and later engine if you use a wedge shaped washer/spacer under the bolt. If you use the unvented valve covers, you'll have to vent the engine somwhere and you'll need an intake with a an oil fill/breather tube.

A road draft tube was an early crankcase venting system. It consisted of a tube that usually exited the engine at the top rear of the block and ran down the back of the engine and terminated under the car. When the car was moving, air passed over the end of the road draft tube and pulled fumes out of the crankcase vent. This system still required a breather, usually in the form of a vented fill tube at the front of the intake manifold as you are describing.

I still use this crude system on my early Chrysler hemi. The modern way to do it would be to rig up a PCV valve directly in to your intake manifold. NOT in one of the runners but in an area of the manifold with access to the valley.

 

[ratterman]

gastrick,

Thanks for the info, it was exactly what i was after. My 350 is a 92 block but i am using a set of 882 heads so i should be good on bolting up a early intake. I've seen some of the early 4 barrel vent tube intakes on ebay so i will most likely pick one up(unless someone on here has one to sell) Does the cap on the oil fill tube double as the vent as well? to me the caps resemble a valve cover breather.

 

[Gastrick]

ratterman,

Offy still makes an intake with a hole for a an oil fill tube and like you say, they are still readily available used. Also, some new Edelbrock performer intakes still have a pad for the oil fill tube but you have to drill the hole yourself. In most cases the oil fill tube uses a breather cap but some of the 60's Corvettes used a tube with a sealed cap and had a provision for a PCV valve in the fill tube. See the below link for those, They are available from Eckler's.

http://www.ecklers.com/product.asp?pf_id=A2353&dept_id=1219

 

[ratterman]

I just scored me a nice set of original cal custom finned covers off ebay so now I'm after an original 4 barrel intake with oil fill tube. I have a edelbrock 2101 intake and it does have the pad to drill out for the fill tube so i may just go that route with the oil fill tube in the link provided.

 

[Gastrick]

If you use the filler tube with the sealed cap like the one in the link, you'll still need a breather somewhere. Good score on the valve covers.