Club Cobra Vintage Motorsports - Backdraft  

Go Back   Club Cobra > Engine Building, Tuning, and Induction > Small Block Talk

Welcome to Club Cobra!  The World's largest non biased Shelby Cobra related site!

  •  » Representation from nearly all Cobra/Daytona/GT40 manufacturers
  •  » Help from all over the world for your questions
  •  » Build logs for you and all members
  •  » Blogs
  •  » Image Gallery
  •  » Many thousands of members and nearly 1 million posts! 

YES! I want to register an account for free right now!  p.s.: For registered members this ad will NOT show

Trigo Wheels
Nevada Classics
Main Menu
Module Jump:
Nevada Classics
Nevada Classics
Advertise at CC
Banner Ad Rates
Shell Valley Companies
Shell Valley Companies
July 2014
S M T W T F S
    1 2 3 4 5
6 7 8 9 10 11 12
13 14 15 16 17 18 19
20 21 22 23 24 25 26
27 28 29 30 31    
  #1 (permalink)  
Old 04-28-2008, 03:49 PM
Registered User
Visit my Photo Gallery

 
Join Date: Feb 2008
Location: SW Louisiana, LA
Cobra Make, Engine: ERA FIA #2128
Posts: 55
Not Ranked     
Default PCV Valve on intake manifold

If a carburetor doesn't have a PCV inlet, I understand you can go directly from the valve cover into the manifold.

On an RPM Air Gap, I'm assuming that's the front hole on the passenger side of the manifold, and the other hole on the driver's side is for the water temperature fitting?

First, is this correct? Second, what fitting is required to use this manifold PCV inlet?

Lastly, why do some folks use a carb spacer and others don't? I know some have a PCV valve fitting, but I would suspect there are other reasons as well.

Thanks in advance,

Doug
Reply With Quote
Sponsored Links
Sponsored Links
  #2 (permalink)  
Old 04-28-2008, 04:08 PM
CHANMADD's Avatar
Registered User
Visit my Photo Gallery

 
Join Date: Mar 2006
Location: San Marcos california, CA
Cobra Make, Engine: 1989 KCC from South Africa Right Hand Drive
Posts: 1,258
Not Ranked     
Default

Firstly,I think the hole you are talking about has coolant in it!! It would not be wise to connect a PCV to that!! You will most likely have to drill and tap a hole into the manifold ,and be sure that it does not hit coolant and goes into the crankcase.
A carb spacer first stops perculation, and second by increasing the distance from the throttle plates to the valve you increase torque!!
__________________
Slither Clothing/Kasanova Magazine
Reply With Quote
  #3 (permalink)  
Old 04-28-2008, 06:25 PM
lovehamr's Avatar
Stolen Avitar
Visit my Photo Gallery

 
Join Date: Oct 2004
Location: Brunswick, GA
Cobra Make, Engine: BDR 1311 428PI
Posts: 2,773
Not Ranked     
Default

I'll chime in here just because it sounds like there may be some confusion. First, Doug; you are referring to the vacuum side of the PCV system correct? In other words you're looking for a way to hook up your valve cover mounted PCV to the vacuum of the intake manifold. If this is the case I don't think that we need to be drilling through the intake manifold into the crankcase. If any drilling is needed at all then right under the carb, into the plenum area is more than enough. That being said; this should not be needed either. You also asked about carb spacers; assuming that you have the hood clearance for a spacer under the carb then the spacer is definitely the way to go. You'll gain a little plenum area which will help flow in its own right but you'll also have a very convenient place to hook your PVC up to. That's a win/win in my book and a no brainer. I wouldn't go drilling into the intake w/o knowing exactly what you're doing.

JMHO, Steve
Reply With Quote
  #4 (permalink)  
Old 04-28-2008, 08:07 PM
Registered User
Visit my Photo Gallery

 
Join Date: May 2006
Location: St. Louisville, Oh
Cobra Make, Engine: A&C 67 427 cobra SB
Posts: 1,512
Not Ranked     
Default

My Edelbrock Victor Jr has a threaded hole into #1 and #8 runners. The #8 is plugged and #1 has a temp sensor in it (it is modified for EFI). Either hole could be used for a PCV, but I would much rather the PCV go into the plenum area. A bad PVC going into a single runner would result in a lean cylinder.
Reply With Quote
  #5 (permalink)  
Old 04-29-2008, 06:50 AM
Registered User
Visit my Photo Gallery

 
Join Date: Feb 2008
Location: SW Louisiana, LA
Cobra Make, Engine: ERA FIA #2128
Posts: 55
Not Ranked     
Default

Thanks to all. I realized after I posted I was referencing the water coolant inlets!

I had the same issue with just having the inlet go into the one runner. It would seem to make sense that you'd want the vacuum to feed all cylinders, not just one.

Thanks to all,

Doug
Reply With Quote
  #6 (permalink)  
Old 05-01-2008, 09:48 PM
Registered User
Visit my Photo Gallery

 
Join Date: Mar 2003
Location: Arkadelphia, AR, AR
Cobra Make, Engine: Kirkham 427 brushed aluminum with Keith Craft 527C.I. all aluminum FE
Posts: 977
Not Ranked     
Default PVC hook up

There should be a threaded hole in the intake that goes into one of the runners and this will work fine for the PVC system. You can use a spacer which will also help the power of the engine a little more than likely. There are several different typs of spacers out there for different intakes and applications. We have one that is special made for dual plane intakes. You can drill a hole into the back of the spacer and get the vacuum there for the PVC as well. Make sure that your valve cover has baffling in it so you do not suck oil into the intake manifold and make the engine smoke and use oil. Good luck, Keith
__________________
Keith C
Reply With Quote
  #7 (permalink)  
Old 05-02-2008, 11:47 AM
Registered User
Visit my Photo Gallery

 
Join Date: May 2007
Cobra Make, Engine: JCF supplied the body,frame,and some of the driveline-I completed it to be a very accurate 289 slabside
Posts: 99
Not Ranked     
Default

The baffle plate can really affect oil consumption. A plate the width of the cover and 3 or more inches long will increase the air flow area and reduce air velocity as it escapes the cover. This will reduce the atomization of the oil and eliminate oil loss thru the PCV valve.
Reply With Quote
  #8 (permalink)  
Old 05-02-2008, 02:54 PM
ou812545's Avatar
Registered User
Visit my Photo Gallery

 
Join Date: Oct 2007
Location: Livermore, CA
Cobra Make, Engine: SPF 2168, 418, TKO 600
Posts: 203
Not Ranked     
Default

Jon,
I have a strong running 418w stroker that consumes a lot of oil, so you have my attention. Currently I'm not running a PVC. I have baffle plates in both valve covers with breathers.

Any recommendations?

Thanks,
Dan
Reply With Quote
  #9 (permalink)  
Old 05-02-2008, 03:13 PM
Slick61's Avatar
Registered User
Visit my Photo Gallery

 
Join Date: Feb 2007
Location: Valencia, CA
Cobra Make, Engine: BDR #89, KCR aluminum 427 windsor
Posts: 308
Not Ranked     
Default

Quote:
Originally Posted by ou812545 View Post
Jon,
I have a strong running 418w stroker that consumes a lot of oil, so you have my attention. Currently I'm not running a PVC. I have baffle plates in both valve covers with breathers.

Any recommendations?

Thanks,
Dan
I hear ya... same issue. No consumption for the first 300-500 miles after an oil change, then it increases dramatically. Talked to Jim Grubbs Motorsports last night... he wondered if maybe the head gaskets had collapsed & were sucking oil that way. He suggested pulling the carb & looking inside the intake. Will get more info tomorrow when I drop by his shop.
__________________
R. Smith
Santa Clarita, CA
BDR #89- KCR aluminum 427 windsor, TKO-600
Reply With Quote
  #10 (permalink)  
Old 05-02-2008, 03:14 PM
CHANMADD's Avatar
Registered User
Visit my Photo Gallery

 
Join Date: Mar 2006
Location: San Marcos california, CA
Cobra Make, Engine: 1989 KCC from South Africa Right Hand Drive
Posts: 1,258
Not Ranked     
Default

A PCV makes a big difference (IMO) I used to run valve cover breathers and always had oil all over the place and seemed to use oil. I put a PCV valve and one breather in the valve cover( the baffle under the breather inside the valve cover is very important) and all those problems went away!!
__________________
Slither Clothing/Kasanova Magazine
Reply With Quote
  #11 (permalink)  
Old 05-02-2008, 05:44 PM
Registered User
Visit my Photo Gallery

 
Join Date: Aug 2004
Location: Rosamond, Ca
Cobra Make, Engine: FFR, 331 Sportsman block, T5Z, 3.55 IRS, Fuel Safe cell
Posts: 97
Not Ranked     
Default

I modified a Stefs catch can into an air/oil separator and PCV mount. It is connected to the left valve cover via a -10 hose, and the PCV is mounted in the top which is connected to the carb base plate. The right side VC provides a filtered air inlet. The catch can is filled with stainless expanded metal that traps any liquid oil before it gets to the PCV. I don't have any baffles in the valve covers, and the -10 hose will get oil in it, but it doesn't migrate to the PCV. I just pulled the carb off today to install an insulated spacer, and the inside of the intake manifold is as clean as the day I installed it. The air/oil separator has been on for about three years. Here's a photo.
__________________
FFR, 331 SBF dynoed 372RWHP@ 6100 RPM on 87 octane pump gas

Last edited by J Persons; 05-02-2008 at 05:46 PM..
Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -7. The time now is 01:39 PM.


Powered by vBulletin® Version 3.8.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0
The representations expressed are the representations and opinions of the clubcobra.com forum members and do not necessarily reflect the opinions and viewpoints of the site owners, moderators, Shelby American, any other replica manufacturer, Ford Motor Company. This website has been planned and developed by clubcobra.com and its forum members and should not be construed as being endorsed by Ford Motor Company, or Shelby American or any other manufacturer unless expressly noted by that entity. "Cobra" and the Cobra logo are registered trademarks for Ford Motor Co., Inc. clubcobra.com forum members agree not to post any copyrighted material unless the copyrighted material is owned by you. Although we do not and cannot review the messages posted and are not responsible for the content of any of these messages, we reserve the right to delete any message for any reason whatsoever. You remain solely responsible for the content of your messages, and you agree to indemnify and hold us harmless with respect to any claim based upon transmission of your message(s). Thank you for visiting clubcobra.com. For full policy documentation refer to the following link: CC Policy
Links monetized by VigLink