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| | | | Joined: Sep 2004 Posts: 241 'Bolter | | 'Bolter Joined: Sep 2004 Posts: 241 | My current pcv system has a hose running from the side of the valve cover to the intake. I then have a hose running from the air cleaner back to the top of the valve cover. It looks like hell but works.
I just got a new valve cover for my 235 inline. Is there a way to install a pcv system without drilling into the valve cover?
Also, how does a breather cap with a pcv fitting work? Wouldn't I still need another place for air to enter the crankcase?
Thanks.
Mark
| | | | | Joined: Apr 2005 Posts: 2,097 'Bolter | | 'Bolter Joined: Apr 2005 Posts: 2,097 | Many use a hose from the breather (providing it has one) to the intake and a breather cap on the rocker cover. It's not real pretty either. It worked on mine OK but did cause some condensation to build up in the hose. It's still better than cutting holes in the rocker cover.
Fred
Correction:I used the term breather, should be road draft tube.
Last edited by rfs56trk; 09/11/2013 11:28 AM.
1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes
1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes
2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans
1947 Willys CJ2A w/F-Head engine
| | | | | Joined: Sep 2004 Posts: 241 'Bolter | | 'Bolter Joined: Sep 2004 Posts: 241 | Thanks Fred. Where is the breather on your truck that goes to the intake? I've seen them where a freeze plug has been modified with a grommet and the pcv plugged in. | | | | | Joined: Sep 2004 Posts: 241 'Bolter | | 'Bolter Joined: Sep 2004 Posts: 241 | Sorry. Not freeze plug but plug for old vapor vent. | | | | | Joined: Sep 2004 Posts: 241 'Bolter | | 'Bolter Joined: Sep 2004 Posts: 241 | Does anyone know where the outlet for the old road draft tube is located on the 235? | | | | | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 | Are you asking about a non-PCV "stock" 235? If yes, the outlet of the road draft tube is at the end of the tube/pipe - that end is under the oil pan and is open, so the "road draft" (suction from moving air) can "suck" vapors out of the bottom of the engine. here is a good explanation | | | | | Joined: Oct 2010 Posts: 1,232 'Bolter | | 'Bolter Joined: Oct 2010 Posts: 1,232 | Mark - Your setup looks similar to the PCV that was on my '54 3104 when I bought it. I have since eliminated it and replaced it with an unmolested '54 valve cover and a road draft tube. I posted a similar question with pics in Jan, 2011, but the new forum software hid it. Here is part of my original post and a great response by "CrankyOldDude" ======== The valve cover is vented to a PVC valve in the intake manifold. Pic #1Pic #2The PVC valve (AC Sparkplug Type OV-693G) is screwed into the intake manifold. The truck has electric wipers. A rubber hose runs between the PVC valve and a pipe that is bolted into the valve cover.A bent rubber pipe is press-fit into a hole on the top of the valve cover. Looks like there was a mounting plate for the rubber pipe at one time. The four slots on the valve cover are open. There is no road draft tube. A freeze plug covers the opening. I believe that the truck was restored in California. Possibly altered to meet emissions requirements? Engine serial number: 0369873F54U Block Date Casting Code: CON4 B264 Vin # H54O007554 Thanks in advance for any insight that you can give me. - Lonnie That is pieces of the AC (AC spark plug of General Motors Corporation) "California State Approved" crankcase ventilation system. California required most 1950 and later cars and trucks to be retrofitted with a PVC system when a used vehicle was sold. The program originally started from January 1, 1964 and ran through January 1, 1966.
The installation required two kits, CV3 and KV1002. CV3 consisted of an intake manifold fitting, 3/8 hose, CV609 PCV valve, hose clamps and fitting to the valve cover for an open PVC system. KV1002 closed the system, it consisted of 5/8 inch hose fittings, 5/8 hose to connect air cleaner to the valve cover for clean air induction, sealed oil fill cap and a plug to close up the hole after the road draft tube was removed. The slots on the valve cover were soldered closed.
I believe your PCV valve is a CV693C. If so, it is installed backwards so the flow is backwards. CV693C is designed to mount on the ventilator for the factory installed PVC system on 261 engines as well as California 1960-62 235 engines.
If you want to keep this setup, I would recommend finding a CV609 valve. I would reconnect the open hole on your valve cover with a 5/8 hose to your air cleaner. The CV609 valve is spliced into the hose that connects the valve cover to the manifold fitting. You will need to find some hose fittings, hoses and a CV609 PCV valve. ======== Tracking the history of these old trucks is part of the joy of owning them! - Lonnie
- Lonnie My '54 3104Photos that I have shared on Stovebolt via PhotoBucket are no longer available. Please contact me if you want a photo from an old post. lonniecook [at] aol [dot] com. I sold my '54 3104 12/12/2017, but I still visit Stovebolt. OLD STUFF ... houses, furniture, cars, wine ... I love it all | | | | | Joined: Jan 2013 Posts: 1,518 'Bolter | | 'Bolter Joined: Jan 2013 Posts: 1,518 | Interested to hear if anyone using pcv in lieu of a road draft tube had to increase the main jet in the carb to avoid over lean conditions during main metering and full power?
1953 Chevrolet 3100261 cu inch, sm420, 3.55 rear, torque tube still,omaha orange, still 6 volt, RPO green glass, side carrier spare, all done In the DITY GalleryVideo of the 261 running1964 GMC 1000305 Big Block V6, sm420, the next cab off restoration
| | | | | Joined: Aug 2005 Posts: 1,186 Shop Shark | | Shop Shark Joined: Aug 2005 Posts: 1,186 | Here's mine.
Picture 1
Picture 2
Bruce | | | | | Joined: Sep 2004 Posts: 241 'Bolter | | 'Bolter Joined: Sep 2004 Posts: 241 | Thanks very much for the info. My truck was upgraded to a pcv system long before I bought it. I have a freeze plug over the road draft pipe outlet. | | | | | Joined: Sep 2004 Posts: 241 'Bolter | | 'Bolter Joined: Sep 2004 Posts: 241 | Does it matter much as to what PCV valve is used on these old trucks? Deve's website shows him installing a PCV valve that is used on a late model car. It is a standard valve. http://www.speedprint.com/deves50/pcvinstall.php | | | | | Joined: Dec 2000 Posts: 3,399 Gas Pumper | | Gas Pumper Joined: Dec 2000 Posts: 3,399 | Works great too Mark. I have been running it for a few years now with no problems at all. And no more oil leak under the old road tube. | | | | | Joined: Sep 2004 Posts: 241 'Bolter | | 'Bolter Joined: Sep 2004 Posts: 241 | Deve - your website is great. Thanks. | | |
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