adding a PCV valve, possible drawbacks?

[KJSmitty]

Re: adding a PCV valve, possible drawbacks?

Either way... if you have 2 breather tubes (1 in each valve cover) Replace both of those with pcv valves and aim the hoses as close as ya can to the flame arrestor. Don't listen to these monkeys who are telling you to grab intake vacuum. All thats going to do is creat an air leak and cause your engine to run terrible and probably not idle.

Nice "monkey" comment,

Anyone that "actually" understands a PCV Valve let alone an actual PCV setup, (that by the way requires a vacuum source), had a good laugh at your suggestion/comments.

I myself will refrain from any "monkey" comments. However, "monkey" isn't what comes to mind...

Gadget - not that I need to mention it again but a breather tube from one valve cover to the arrestor, and then an actual PCV valve (other valve cover)plumbed to a constant vacuum source is the proper setup. Not sure if it will help your issues but that is a typical PCV system - and the same that is on my boat/5.7, OEM.

Also - No drawbacks to having a PCV (with valve) type system. It is an easy/cheap install thus the cost/risk of seeing if it helps your issue is minimal.

Cheers

 

[JustJason]

Re: adding a PCV valve, possible drawbacks?

Anyone that "actually" understands a PCV Valve let alone an actual PCV setup, (that by the way requires a vacuum source), had a good laugh at your suggestion/comments

Okay... School me then Smitty... please school me..... Tell me what it is, how it works, and why it works.... Because I know the answer to all 3.
You cannot allow unmetered air under the carb...... and if do that.... then you run lean plain and simple. It's a ventillation valve.... doesn't need vacuum

 

[KJSmitty]

Re: adding a PCV valve, possible drawbacks?

Okay... School me then Smitty... please school me..... Tell me what it is, how it works, and why it works.... Because I know the answer to all 3.
You cannot allow unmetered air under the carb...... and if do that.... then you run lean plain and simple. It's a ventillation valve.... doesn't need vacuum

Sorry for the semi-hijack of your thread Gadget73,

This here is for "JJ".
-OK Jason, the below link will hopefully "really" allow you to know all 3 of your above questions. It even has pictures for ya.

And yes, old/some "crankcase ventilation" systems - as you are no doubt most familiar with, did not use a valve or require a vacuum source. But if it's a "Positive" Crankcase Ventilation system with a "PCV Valve",,, well, in my near 4 decades of being a professional/personal "grease monkey", I have yet to encounter one that did not require a vacuum source - and all were manifold vacuum.

Sorry for my sarcasm - you did crack me up however.

Cheers

http://en.wikipedia.org/wiki/PCV_valve

 

[Mkos1980]

Re: adding a PCV valve, possible drawbacks?

I run the PCV valve because it keeps my FA cleaner too. When I added the PCV all I did was change my idle air/fuel screws. You can see what I plumbed my PCV Valve in.

 

[WizeOne]

Re: adding a PCV valve, possible drawbacks?

Ford had a better idea. Just use one of these under your square bore 4 bbl Holley or Edelbrock. This spacer is flat on it's topside. All my markings were done for another purpose. Specifically if one were to be used on an Edelbrock intake manifold whose mounting pad is a full one inch narrower than an OEM squarebore cast iron intake.

A huge vacumm leak would ensue if the wrong spacer were used.

 

[gadget73]

Re: adding a PCV valve, possible drawbacks?

Just a for the record, I know where they hook up: manifold vacuum. The plumbing wasn't really a problem, I was just curious if anyone else had added one in a similar manner and had noticed any issues. If I have to tweak the fuel mix, its not that big of a deal.

I'll run things with the new motors and see how it goes. If the oil smell is gone with a motor that doesn't burn and leak oil, I'll let it be. If I continue to get oil fumes, I'll give this a shot. I like to toss around a lot more ideas than I actually put to use, just to get a feel for possible outcomes.

Thanks for the input everyone.

 

[BLinindoll]

Re: adding a PCV valve, possible drawbacks?

Replace both of those with pcv valves and aim the hoses as close as ya can to the flame arrestor.

You don't need PCV valves to do this. This is how any non-pcv engine works. Essentially, the fumes just "ooze" (for lack of a better term) out of the crankcase and are hopefully sucked into the intake.

The point of a PCV system is to actually PULL the fumes out and circulate fresh air through the crankcase.

With all due respect, Jason, I'm not sure you understand what PCV valves actually do.

They are used to control a small vacuum "leak". That's all a PCV system is, a controlled vacuum leak which pulls fumes from the crankcase and burns them in the combustion chamber.

Yes, you NEED manifold vacuum on a PCV system... it is what "pulls" the fumes out of the crankcase. The other "vent" side is where clean air enters the system/crankcase. No PCV valve goes there, just fresh air.

Yes, you will create a lean condition on a carbed engine, but you can adjust for it. On an EFI engine, you will essential create a vacuum leak. Normally, EFI engines with a PCV system from the factory account for the "controlled leak" of a PCV system. I'm not sure what would need to be done to add a PCV system to an EFI engine that doesn't have one, but I'm not even sure if that's what were talking about here. Just figured I'd throw that in for good measure.

 

[dan t.]

Re: adding a PCV valve, possible drawbacks?

I always run pcv,standard breather to the spark arrestor on one side,pcv valve to the base of the carb on the other. why? #1 condensation, ever see a valve cover rust out from the inside? I have seen several. #2 do your bit for the planet, it cost nothing. #3your oil will stay cleaner,so will your spark arrestor.#4 no fumes in the engine compartment,etc. etc. JJ you obviosly dont know how or why a pcv works, I think you should do a little research. as for you people who run pcv good for you

 

[KJSmitty]

Re: adding a PCV valve, possible drawbacks?

Ford had a better idea. Just use one of these under your square bore 4 bbl Holley or Edelbrock. This spacer is flat on it's topside. All my markings were done for another purpose. Specifically if one were to be used on an Edelbrock intake manifold whose mounting pad is a full one inch narrower than an OEM squarebore cast iron intake.

A huge vacumm leak would ensue if the wrong spacer were used.

Perfect vacuum source for a PCV/valve. Most Holley and other carbs have that port built into the carb base-plate. Typically used for either power steering on a car and/or PCV etc.


Cheers