PCV question
Printed From: CorrectCraftFan.com
Category: General Correct Craft Discussion
Forum Name: General Discussion
Forum Discription: Anything Correct Craft
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=36176
Printed Date: April-27-2024 at 6:20am
Topic: PCV question
Posted By: GMacLaren
Subject: PCV question
Date Posted: May-29-2015 at 5:06pm
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(Ford 302 V-8, circa 1974.) Here’s a photo of the “spacer” between the carburetor and intake manifold. It’s “upside down” showing the path it imposes on the crankcase fumes picked up via a PCV valve in valve cover. The “spacer” piece is 1-1/8 inches in height. I’d like to eliminate that 1-1/8 inch by routing fumes directly into the intake manifold. There is already a threaded hole in the manifold, now plugged with a pipe plug, making it a simple thing to unplug that hole, and route the fumes there, instead of into this “spacer." Your thoughts?  ------------- -=Grant MacLaren=- Retired Expert http://www.grantmaclaren.com/72skier" rel="nofollow - http://www.grantmaclaren.com/72skier |
Replies:
Posted By: GottaSki
Date Posted: May-29-2015 at 5:23pm
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I prefer to distribute the vapors amongst all runners vs one, so to not create a lean condition in one jug and risk burning a piston. That said, some route that way without incident. Newer carbs have the pvc port right on them. If your carb is on the way out, its a simple solution. ------------- "There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing." River Rat to Mole |
Posted By: 81nautique
Date Posted: May-29-2015 at 5:24pm
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you can certainly do that George although there is concern about leaning out the cylinder/s on that intake runner. Not sure that it's been proven to be a problem or not though and several, myself included, have a PCV plumbed that way. Can I ask why you are removing the spacer? |
Posted By: Hollywood
Date Posted: May-29-2015 at 5:35pm
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Because of the engine tilt, aren't the rear most cylinders fairly rich already? Given the choice you should plumb to back. ------------- |
Posted By: GMacLaren
Date Posted: May-29-2015 at 5:35pm
I'm trying to make the engine box smaller -- narrower and lower. It's always seemed (to me) to be "too big" for the boat. The "spacer" is 1-1/8 inches high, and employs two thick (@ 1/8" each) gaskets instead of one. -=Grant=- ------------- -=Grant MacLaren=- Retired Expert http://www.grantmaclaren.com/72skier" rel="nofollow - http://www.grantmaclaren.com/72skier |
81nautique wrote:Posted By: GMacLaren
Date Posted: May-29-2015 at 5:55pm
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If the "spacer" was phenolic, I thought it might be an insulator to help prevent carburetor boiling or heat soak. But being aluminum, I doubt if it helps much -- if at all. Could it be needed to improve vaporization? I'm not sure where the existing plugged hole enters the manifold circuit -- and would rather not remove manifold to see. If I do the plumbing, I'm quite sure it would be very tight fitting -- no risk of leak. ------------- -=Grant MacLaren=- Retired Expert http://www.grantmaclaren.com/72skier" rel="nofollow - http://www.grantmaclaren.com/72skier |
Posted By: cboland
Date Posted: May-29-2015 at 6:33pm
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I don't mean to threadjack here, but speaking of PCV valves, I've never paid much attention to mine. Is this a part that should be replaced periodically? I'm at 1100 hours on my engine and I know I haven't done anything and I doubt previous owners did. ------------- Bud 1999 Sport Nautique |
Posted By: GMacLaren
Date Posted: May-29-2015 at 6:42pm
There are some good descriptions of its care and function on the web. -=Grant=- http://www.agcoauto.com/content/images/engine/pcv_system_extracting_moisture.jpghttp://" rel="nofollow - http://www.agcoauto.com/content/images/engine/pcv_system_extracting_moisture.jpg ------------- -=Grant MacLaren=- Retired Expert http://www.grantmaclaren.com/72skier" rel="nofollow - http://www.grantmaclaren.com/72skier |
Posted By: GMacLaren
Date Posted: May-29-2015 at 6:49pm
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On my boat, the "clean air" intake is via the filler cap. And the blowby/oil vapor fumes are introduced via the spacer shown above.  ------------- -=Grant MacLaren=- Retired Expert http://www.grantmaclaren.com/72skier" rel="nofollow - http://www.grantmaclaren.com/72skier |