04-12-2017 | #11 |
Join Date: Mar 2014
Location: Warrington PA
Posts: 1,913
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Re: PCV valve research...
Now to be even more
Here is a link to the AC DELCO catalog which shows 3 different PCV valves for the ZR-1 1990-1995. CV913C is shown and listed for the "Right" and #19303069 is listed for both "Left & Right". So is the "Right" really the driver's side and the "Left" really the passenger side??? Hmmmm to be determined!!! http://parts-catalog.acdelco.com/cat...log_search.php You will need to enter the info to get results....
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Tom 1994 ZR-1 #009 "captured test fleet car" 1974 LS4 454 Vert 1982 L83 CFI...now a retired "dd"....Sold WAZOO Member Last edited by Roadster; 04-12-2017 at 04:44 PM. |
04-12-2017 | #12 |
Join Date: Dec 2003
Location: Arcadia,OK
Posts: 3,391
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Re: PCV valve research...
The CV913C & CV895C may have an internal difference, specifically "crack" pressure. This could be determined by securing the valve, attaching a vacuum pump to the top connection & determining the vacuum needed to raise the valve off seat, i.e. "crack pressure.
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Jerry Downey JERRYS LT5 GASKETS & PARTS http://www.jerrysgaskets.com 1994 ZR-1, Black/Black, Lingenfelter Aerobody, 416cu in, 3.91 gears, coil-over susp, Brembo brakes, etc. 2016 Black-Red, 3LT-Z51 Auto 8-speed. |
04-12-2017 | #13 |
Join Date: Oct 2016
Location: Atlanta GA
Posts: 51
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Re: PCV valve research...
I researched this "taller" PCV Valve a while back and could not find the exact fit. So I soaked my original in a degreaser and placed back on thinking my idle would go down to 7500 rpm. Didn't happen so pulled the plenum and found the famous hose disconnection and repaired that and thus bringing idle down to 7500! Car has 61K miles.
Really like the ZR1 car but seems to have the old Porsche 928 dilemma where parts were somewhat scarce & expensive thus driving the price down. I owned a Porsche 928 years ago and the "older" gent owner told me when I bought it from him as a young 28 year old - "you are buying a $75K Super Car for only $15K and expect your monthly payment being repairs, parts, etc to keep it running" Really fortunate we have this website and self repairing of my ZR1. Enjoy the ZR1 performance and keep em running top notch! |
04-12-2017 | #14 | ||
Join Date: Mar 2014
Location: Warrington PA
Posts: 1,913
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Re: PCV valve research...
Quote:
Quote:
And are you meaning to bring down the idle to 750r's???
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Tom 1994 ZR-1 #009 "captured test fleet car" 1974 LS4 454 Vert 1982 L83 CFI...now a retired "dd"....Sold WAZOO Member |
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04-13-2017 | #15 | |
Join Date: Dec 2003
Location: Arcadia,OK
Posts: 3,391
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Re: PCV valve research...
Quote:
Imagine a check valve, which is the type of valve the subject PCV valve is. The PCV valve has a moveable valve that is weighted for specific conditions such as the LH LT5 valve (tall one), being one of 2 valves in the system and staged for opening under slightly different conditions from the RH valve. If both PCV valves had the same crack pressure, subject to the same vacuum pressure and same crankcase pressure, then there would be no purpose served by having two different valves side by side in the system. I suggested vacuum testing from the top connection over pressure testing at the bottom/inlet side because most of us own a hand vacuum tester that may be able to measure the anticipated low pressure without any special rigging. I would approach testing in the following manner. 1. Secure the valve to prevent movement during testing. Position vertically with bottom open to atmosphere. 2. connect hand vacuum hose to top connector. 3. gradually apply vacuum in small increments & verify vacuum holding before increasing to next increment. When vacuum no longer holds, crack pressure is at point above last increment held & point leakage observed. FYI: None of this may be achievable to a definitive end. The 895 valve may work even if it's not the same as Lotus spec'd 913 valve, just not exactly as designed. Effect may be inconsequential to the normal ZR-1 driver, and it may simply result in slightly more oil consumption that goes unnoticed.
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Jerry Downey JERRYS LT5 GASKETS & PARTS http://www.jerrysgaskets.com 1994 ZR-1, Black/Black, Lingenfelter Aerobody, 416cu in, 3.91 gears, coil-over susp, Brembo brakes, etc. 2016 Black-Red, 3LT-Z51 Auto 8-speed. |
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04-13-2017 | #16 | |
Join Date: Mar 2014
Location: Warrington PA
Posts: 1,913
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Re: PCV valve research...
Quote:
Did it again a few minutes ago exactly as stated in #3, but the gauge would not register until I closed off the bottom of the valve with my thumb. Which resulted in the same readings as last night. When I have the valve closed, the pump works fine, with the bottom opened, again not registering. An interesting discussion.....
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Tom 1994 ZR-1 #009 "captured test fleet car" 1974 LS4 454 Vert 1982 L83 CFI...now a retired "dd"....Sold WAZOO Member |
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04-14-2017 | #17 |
Join Date: Mar 2014
Location: Warrington PA
Posts: 1,913
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Re: PCV valve research...
Just got back from getting the 94 inspected. No emissions needed as I was just under 5000 miles....
FYI, spoke to the parts person and he verified that both CV913C & CV895C PCV valves are discontinued from GM. Then again most of you may already have known that. They just are very hard to find. Was lucky to get some 895's on the bay, but no luck on the 913's.
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Tom 1994 ZR-1 #009 "captured test fleet car" 1974 LS4 454 Vert 1982 L83 CFI...now a retired "dd"....Sold WAZOO Member |
04-20-2017 | #18 |
Join Date: Mar 2014
Location: Warrington PA
Posts: 1,913
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Re: PCV valve research...
Just received delivery today of an original NOS CV913C "double hump" PCV valve. I was notified by a member that he had found some 913 valves. I made the call, and between the two of us, we now have NOS 913's. Feeling very thankful for the info which led to the purchase. Thank you again sir, it is very much appreciated.
Unfortunately the source is now out of 913's. In the pic, you will notice that once again the packaging is the old style AC box from many years ago. Also interesting to note is that this NOS 913 does not have "AC ROCHESTER" stamped on the valve, rather it has "AC SPARK PLUG" stamped on it instead. the new NOS valve is on the left, the "original" or I think original from my 94, unless it had been replaced years ago on the right....
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Tom 1994 ZR-1 #009 "captured test fleet car" 1974 LS4 454 Vert 1982 L83 CFI...now a retired "dd"....Sold WAZOO Member Last edited by Roadster; 04-20-2017 at 05:19 PM. |
04-26-2017 | #19 |
Join Date: Mar 2014
Location: Warrington PA
Posts: 1,913
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Re: PCV valve research...
Did a little more research and found a listing by Corvette Central for a LT1
92-96 Corvette PCV valve. Sent an email about the length and it is 1 7/8". Which is the correct size and their current listing shows it is a CV895C, but number is not shown in the pic. Also has the application guide which is including ZR-1's. http://www.ebay.com/itm/1992-1996-Co...777325?vxp=mtr Corvette Central #: 304577 Original GM #: 25095452 So another source for some 895 "double hump" valves, just in case. And I now have some extras if anyone has a problem with locating one when ready...
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Tom 1994 ZR-1 #009 "captured test fleet car" 1974 LS4 454 Vert 1982 L83 CFI...now a retired "dd"....Sold WAZOO Member Last edited by Roadster; 04-26-2017 at 04:59 PM. |
04-26-2017 | #20 |
Join Date: Jul 2007
Location: Bartlett, IL
Posts: 7,161
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Re: PCV valve research...
But is the function of each game Benin the correct size the same? I have a feeling they are different despite the size
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1990 Corvette ZR-1 #1051 Watson Headers (2" Primary) - Flowmaster Cats - Borla Catback Late Model IH - Plenum Coilovers - 4.10s Custom Interior NCM Lifetime Member #978 |
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