Need PCV valve for low vacuum cam - Team Camaro Tech
Engine General Engine Discussion.

Reply
 
LinkBack Thread Tools Display Modes
post #1 of 29 (permalink) Old Oct 17th, 14, 07:51 PM Thread Starter
Senior Tech
Mark
 
Join Date: Sep 1998
Location: Ontario, Canada
Posts: 2,009
Garage
Need PCV valve for low vacuum cam

I'm using the 70 Z28 PCV valve CV746C and my vacuum reading at the oil dipstick is 6" when it should be 1-3". I checked for a vacuum leak at the intake with soapy water and there are no bubbles and all bolts are tight.

Will a fixed orfice GM 12572717 PCV valve (don't think it's avail any longer) or one for a Chevy 409 get my reading lower. I'm suspecting this has something to do with my oil consumption. I've got 11" of vacuum at idle using a B28 can with a limiter plate on a stock dizzy with a Crane Xri module.

The 70 Z28 had a higher idle vacuum reading than 11" so the Z pcv is not good. The 69 Z/28 used the same PCV valve as the 70 did. So I need to go with a PCV that was used for the more radical cams such as the L78, 409 etc. Any suggestions?

Mark 70 Z28 M22 3.73 Z21 Z87 - Lunati 20120121 Roller Cam

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
COPO is offline  
Sponsored Links
Advertisement
 
post #2 of 29 (permalink) Old Oct 17th, 14, 08:20 PM Thread Starter
Senior Tech
Mark
 
Join Date: Sep 1998
Location: Ontario, Canada
Posts: 2,009
Garage
Re: Need PCV valve for low vacuum cam

Also brand BWD PCV484 is the same as GM 12572717. I dought the BWD is here in Canada. Another good reason to live in the US.

Mark 70 Z28 M22 3.73 Z21 Z87 - Lunati 20120121 Roller Cam

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
COPO is offline  
post #3 of 29 (permalink) Old Oct 17th, 14, 08:50 PM Thread Starter
Senior Tech
Mark
 
Join Date: Sep 1998
Location: Ontario, Canada
Posts: 2,009
Garage
Re: Need PCV valve for low vacuum cam

Just found this.

Factory Number
ACDelco CV4000C
FRAM FV410
WELLS PCV371
DEFENSE FV410
AIRTEX 6P1241
CARQUEST 76-2698

Mark 70 Z28 M22 3.73 Z21 Z87 - Lunati 20120121 Roller Cam

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
COPO is offline  
 
post #4 of 29 (permalink) Old Oct 17th, 14, 09:10 PM
Gold Lifetime Member
John
 
Vintage 68's Avatar
 
Join Date: Mar 2002
Location: Moraga,Ca.,USA
Posts: 13,705
Re: Need PCV valve for low vacuum cam

Many of the solid-cammed engines specify the AC - CV749/769 (Fram FV178) PCV - you might want to try these first.

And the 'Fixed-Orifice' unit is often used for performance builds with good result. We are using them quit often in performance marine applications.
Don't know where you got your info, they are still available at most GM dealers as they are common for the Vortec series engines. Pace Performance had them last time I checked.
If you can't find the #12572717 unit try for an AC #CV4000C or even go to AutoZone and get the PCV1009 - they are all the same hole diameter.

If you don't get the results you wanted with those, consider a tunable unit - like this http://mewagner.com/?page_id=444

hope some of this helps

1968 Convertible
Some trucks
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Other V8 things - some of which float
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Other V6 things - none of which float
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Oh yeah, and 1 "Straight-Six" ...
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


If a man says something in the garage - and his wife can't hear him - is he still wrong !!!
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Vintage 68 is offline  
post #5 of 29 (permalink) Old Oct 17th, 14, 10:03 PM Thread Starter
Senior Tech
Mark
 
Join Date: Sep 1998
Location: Ontario, Canada
Posts: 2,009
Garage
Re: Need PCV valve for low vacuum cam

No Autozone in Canada. I did see the adjustable one today online.

Mark 70 Z28 M22 3.73 Z21 Z87 - Lunati 20120121 Roller Cam

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
COPO is offline  
post #6 of 29 (permalink) Old Oct 18th, 14, 02:45 AM
Senior Tech
Paul B
 
Join Date: Jul 2012
Location: Ontario
Posts: 273
Re: Need PCV valve for low vacuum cam

You can still get the 12572717 pcv, but you have to order hose part #12574660 to get it. PM me your email and I can send u a pic from the parts catalogue. Canadian trade price is $22.68.
paulsstuff is offline  
post #7 of 29 (permalink) Old Oct 18th, 14, 08:23 AM Thread Starter
Senior Tech
Mark
 
Join Date: Sep 1998
Location: Ontario, Canada
Posts: 2,009
Garage
Re: Need PCV valve for low vacuum cam

Ordered one from Carquest.

Mark 70 Z28 M22 3.73 Z21 Z87 - Lunati 20120121 Roller Cam

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
COPO is offline  
post #8 of 29 (permalink) Old Oct 18th, 14, 09:47 AM
Team Member
John
 
JohnZ's Avatar
 
Join Date: Sep 2000
Location: Washington, Michigan USA
Posts: 7,728
Re: Need PCV valve for low vacuum cam

Quote:
Originally Posted by COPO View Post
The 69 Z/28 used the same PCV valve as the 70 did. So I need to go with a PCV that was used for the more radical cams such as the L78, 409 etc. Any suggestions?
I'd stay with the '69 Z/28 PCV - it had the most radical camshaft ("30-30") that Chevy ever put in a production car.


JohnZ
CRG
JohnZ is offline  
post #9 of 29 (permalink) Old Oct 18th, 14, 10:17 AM Thread Starter
Senior Tech
Mark
 
Join Date: Sep 1998
Location: Ontario, Canada
Posts: 2,009
Garage
Re: Need PCV valve for low vacuum cam

Quote:
Originally Posted by JohnZ View Post
I'd stay with the '69 Z/28 PCV - it had the most radical camshaft ("30-30") that Chevy ever put in a production car.

I have it, there's too much vacuum going through. This isn't a stock motor I have.

Mark 70 Z28 M22 3.73 Z21 Z87 - Lunati 20120121 Roller Cam

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
COPO is offline  
post #10 of 29 (permalink) Old Oct 18th, 14, 11:06 AM
Gold Lifetime Member
Fred
 
Join Date: Nov 2006
Location: Seabeck WA
Posts: 8,375
Re: Need PCV valve for low vacuum cam

Remember back when PCV valves were a tune-up item @12K miles? Mine is still the original L78 that came with my car. Works great I might ad. Life would be good if I worked that well.

One owner 69 Camaro,(yep, bought it new
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
)
RS SS Hugger Orange, L88, 4:10's tru-tack posi, ducted hood, Endura, spoilers.
TH400 (CX) with Coan 8" converter, GV-OD, 8 track still on console and best et 10.495,
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
128.79mph 1.428 60'
All with 1960's stuff. (except tires and converter)
+ MT Super Scavenger headers & 3" full exhaust with X pipe. 3700 lbs. with me in it.
1000cfm AED and HD Harold-Lunati SR, 725 lift with shaft rockers too.
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Fred Ficarra is offline  
post #11 of 29 (permalink) Old Oct 18th, 14, 11:27 AM
Senior Tech
Brian
 
PA Camaro Guy's Avatar
 
Join Date: Apr 2008
Location: PA
Posts: 642
Re: Need PCV valve for low vacuum cam

Someone stated it already but Fram PV178 or Purolator PV736 x-ref to 302.

1969 Camaro 383
2.02/1.63 & 234/244 Vortec
TH350 / 12 bolt 3.73
PA Camaro Guy is offline  
post #12 of 29 (permalink) Old Oct 18th, 14, 11:39 AM Thread Starter
Senior Tech
Mark
 
Join Date: Sep 1998
Location: Ontario, Canada
Posts: 2,009
Garage
Re: Need PCV valve for low vacuum cam

302 and 70 Z28 use the same PCV. That's what I currently have but I need less vacuum going in so I'll try the hallow one.

Mark 70 Z28 M22 3.73 Z21 Z87 - Lunati 20120121 Roller Cam

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
COPO is offline  
post #13 of 29 (permalink) Old Oct 19th, 14, 03:29 AM
Tech Team
Steve
 
Join Date: Jul 2014
Location: CT
Posts: 35
Re: Need PCV valve for low vacuum cam

Sorry to highjack the thread, but I think I have the same problem.. I have a brand new sbc 427 with a lot of crankcase pressure.. Motor has about 10 miles on it, and already went through a intake gasket, I replaced it on Friday, and took it for a ride, and now its leaking out the front.. I have the pcv in the pass side valve cover and on the drivers side is just a oil cap with no breather.. I am also hearing a Pssssst noise when decelerating from about 5000 rpm..
Heatmaker is offline  
post #14 of 29 (permalink) Old Oct 19th, 14, 05:52 AM Thread Starter
Senior Tech
Mark
 
Join Date: Sep 1998
Location: Ontario, Canada
Posts: 2,009
Garage
Re: Need PCV valve for low vacuum cam

You need a hose running from the valve cover to the breather for your fresh air.
To measure how much vacuum I have I removed the pass side tube and covered the hole with
a piece of duct tape and attached a vacuum gauge in the oil dip stick with an old straight spark
plug boot. Check reading at idle when the car is at op temp. It should be 1-3". I have 6" with the
70 Z28 PCV valve.



I've ordered a PCV that's hallow with a small hole.

Mark 70 Z28 M22 3.73 Z21 Z87 - Lunati 20120121 Roller Cam

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
COPO is offline  
post #15 of 29 (permalink) Old Oct 19th, 14, 12:04 PM
Gold Lifetime Member
Fred
 
Join Date: Nov 2006
Location: Seabeck WA
Posts: 8,375
Re: Need PCV valve for low vacuum cam

Quote:
Originally Posted by Heatmaker View Post
Sorry to highjack the thread, but I think I have the same problem.. I have a brand new sbc 427 with a lot of crankcase pressure.. Motor has about 10 miles on it, and already went through a intake gasket, I replaced it on Friday, and took it for a ride, and now its leaking out the front.. I have the pcv in the pass side valve cover and on the drivers side is just a oil cap with no breather.. I am also hearing a Pssssst noise when decelerating from about 5000 rpm..
From one fellow hijacker to another, no problem.
Your system is not workable. You must redesign it.
The PCV valve MUST be at the DRIVERS valve cover. The reason is because of the direction of crankshaft rotation. And the breather (filtered) must be located at or near the passenger valve cover.
As to a manifold leak, and a PSSST, that could well be another problem.

One owner 69 Camaro,(yep, bought it new
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
)
RS SS Hugger Orange, L88, 4:10's tru-tack posi, ducted hood, Endura, spoilers.
TH400 (CX) with Coan 8" converter, GV-OD, 8 track still on console and best et 10.495,
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
128.79mph 1.428 60'
All with 1960's stuff. (except tires and converter)
+ MT Super Scavenger headers & 3" full exhaust with X pipe. 3700 lbs. with me in it.
1000cfm AED and HD Harold-Lunati SR, 725 lift with shaft rockers too.
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Fred Ficarra is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Team Camaro Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address.
NOTE we receive a lot of registrations with bad email addresses. IF you do not receive your confirmation email you will not be able to post. contact support and we will try and help.
Be sure you enter a valid email address and check your spam folder as well.



Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may 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

 
For the best viewing experience please update your browser to Google Chrome