327 Not Breathing Right?!?!
 

I need some of you breather gurus to check this out for me. The oilfiller cap popped off from the crankcase pressure. It WAS routed to the PVC on the manifold, but now I know that was incorrect. I realize that the PVC needs to be replaced with a 90 fitting to the brake booster, but where can I get enough vacuum with no holes in the valve covers???? The engine is a fresh engine that has not been broke in yet so this also adds to the equation. Longhorn Man, chime in!!!
Attachment 796953

Attachment 796954

Attachment 796955

Re: 327 Not Breathing Right?!?!
 

http://i306.photobucket.com/albums/n...1/SAM_1340.jpg

Where i drew the arrow, there is a 1.375" hole that used to have an old drain pipe connected to it, (it is now clearly capped off, and very common on old blocks). And you have valve covers with no holes for a breather or a PCV, but you do have a breather on the front of the intake.

So it looks to me like you need to either put the old drain pipe back on, or get some valve covers with holes for a breather and PCV

Re: 327 Not Breathing Right?!?!
 

either one of the "large" ports at the base of the carb should be fine.

my 327 has ALOT of crankcase pressure aka "blowby" so I have to run 2 PCV valves into my carb,
one on the front port and one on the back port.
If I don't I get oil out of the breather on the valve cover, even with baffled ports.

http://lh6.googleusercontent.com/-S3...0/DSCF0388.JPG

Re: 327 Not Breathing Right?!?!
 

I could not find any indication that there was a hole on the back of the block. My goal is to keep the valve covers clean, but not at the expense of issues with the engine running properly. If I run the hose from the breather cap to the PCV in the manifold and another Tee'd off to the carb base plate would that be an option?

Re: 327 Not Breathing Right?!?!
 

There has to be points for crankcase venting to work. Your set up there is really only one. In the original set up for an early 265/283/327 the hole back by the distributor is where the "road draft tube" would go and on the later PCV vehicles it would have an oil seperator that had a hose run to the air cleaner. The PCV valve screwed into the oil fill tube on the front with a non-vented oil cap. Look at the way the later valve cover systems work, one side is fresh air pull from the air cleaner (or filter air) and the other side is has the PCV valve placed in the valve cover and the hose attached to a full manifold vacuum source. You need a place for filter air to replace the fumes being pulled by the PCV system or your going to have oil leak problems in after awhile.

Re: 327 Not Breathing Right?!?!
 

Where you have the arrow, there should be a hole in the block for a special fitting that a hose attached to for pc valve to carb base. I have one that I'll take a photo of later this morning. There was also a canister that bolted inside the lifter gallery which kept oil from being sucked up from the gallery.

Re: 327 Not Breathing Right?!?!
 

So without the road draft tube the only other option is to ventilate the valve covers and run the vacuum lines as usual?

Re: 327 Not Breathing Right?!?!
 

Correct...

Re: 327 Not Breathing Right?!?!
 

Here's what I was talking about. Someone must have put an inch and a quarter freeze plug in your block where this went?

http://i249.photobucket.com/albums/g...t/CIMG2970.jpg

Re: 327 Not Breathing Right?!?!
 

One of these on the back end of each valve cover should cure my issue. And will look pretty slick while maintaining the integrity of the factory script valve covers that I am running. The hole should be drilled as high as possible on the vc's to allow for inertia oil movement upon acceleration.
http://www.summitracing.com/parts/SUM-440332/

Re: 327 Not Breathing Right?!?!
 

Kinda strange, but there is absolutely no signs of the block even being machined in that area from the factory. The casting numbers show it is a 1966 Corvette block so it may have never had one to begin with.

Re: 327 Not Breathing Right?!?!
 

Another thought, how much oil accumulates in the valve covers that could possible slosh to the rear inside valve cover? I do not see it being enough to cause any issues, but I could be wrong!!! It is not a race truck so no huge takeoffs from the line, just a weekend driver show truck.

Re: 327 Not Breathing Right?!?!
 

here is a pic of the back of the block with the thingy in it:lol: and check out this threadhttp://67-72chevytrucks.com/vboard/s...d.php?t=366853

Re: 327 Not Breathing Right?!?!
 

Check out PMC valve covers. They look like the old school chevrolet but have holes in the side so you can vent and use a pcv valve. They are cast aluminum with the chevrolet script.

Re: 327 Not Breathing Right?!?!
 

This is toooo cool and I would not mind that at all...........but, I don't have the hole for the thingy in my block. The block is solid there and has not been filled in. I actually found that thread while researching this problem and wanted to look at it again...Thanks!!!

Couldn't find the PMC valve covers, do you have a url? They sound cool and I would like to check into them.

Re: 327 Not Breathing Right?!?!
 

I gotta keep these valve covers if I can simply because I think they just look super cool. I hate to drill in the back of them, but it is for the greater good of the engine.
Attachment 797762

Re: 327 Not Breathing Right?!?!
 

I thought the set-up in the pic that 'rsavage' showed were used up to 1967 on 283 & 327, so why would a 1966 motor not have the hole unless there was something different with the Corvette motors like, maybe it was once a fuel injection factory set-up. But that's now going way out of my league.

Re: 327 Not Breathing Right?!?!
 

Way outta my league too. In the end if the engine breaths right I'll be happy. I have some valve covers with holes in them so I am going to try those on to see if it makes a huge difference. It should. I will post pics of what I am trying before I tap holes into the valve covers I am using.

Re: 327 Not Breathing Right?!?!
 

:lol:try some nasal strips.....that should get her breathin right....haha:lol:

Re: 327 Not Breathing Right?!?!
 

Funny guy huh! She sounds alot better than she did. Routed the oil filler to the carb, the power booster to the manifold and the trans to the front of the carb on the small tube. It seems to be fine now, we'll see after I run it a little bit.

Re: 327 Not Breathing Right?!?!
 

i hope it works out i love the look of those valve covers on it :metal:

Re: 327 Not Breathing Right?!?!
 

Thanks dude! I think they look right at home on it too. No holes is even better.

Re: 327 Not Breathing Right?!?!
 

Slick67, love that engine, it is sharp!

I'm a little confused, unless I'm reading the above wrong, you ran the filler tube cap to one of the large carb "vacuum" sources and swapped the booster to the manifold source. also you're now running the tranny off one of the smaller carb sources.

If that's the case, as far as your crankcase ventilation goes, I don't see where you changed anything. And if you now have the tranny hooked to the passenger side port on the front of the carb it is no longer getting a vacuum signal at idle.

it appears to me you are still pulling a low pressure on the crankcase with no cross ventilation.

Sorry, I may be missing something

Re: 327 Not Breathing Right?!?!
 

Thanks! The trans is going to be hooked to the small driver side tube on the front of the carb. The booster is hooked to the manifold, which is correct according to other vehicles. But I am still questioning the ventilation also. There should be a entrance for fresh air, correct?

Re: 327 Not Breathing Right?!?!
 

valve covers cool?

without a proper PVC system the old school result was SLUDGE heavy thick and grimey NOT COOL