Hello, I'm a first timer here on this site and I consider myself a "somewhat advanced beginner" in the world of V8 engines and such. So a quick little background on my project...I'm building a reproduction 1936 Ventnor wood race boat and I purchased a 1965 GM 283 (Marine) engine to power it. It is a flywheel forward (Owen's Flagship Marine Engine) and has a Borg and Warner 1:1 Velvet Drive transmission along with a Carter WCF5 4 barrel carb. I think the current PCV/breather tube set up is incorrect or not efficient...So I did some searching around on this site on what the correct route/set up should be but I'm a little confused on how my engine compares to others. My overall goal is to eliminate the split breather tubes that are currently going to both valve covers and replace with a nice chrome finned valve covers with a good routed PCV/breather cap so it has overall cleaner look. I will be painting the engine as well. So my questions are... 1. Is the current breather tubes coming from the intake manifold splitting to both valve covers correct in terms of a proper PCV route? (I'm not sure where the initial breather spot would be coming from) 2. How would I convert the current valve covers to a finned designed covers and still route a PCV valve and breather cap? A couple things about the engine I noticed regarding the current breather tube routing is the oil fill vent/cap does not have a PCV threaded bung. There is a road draft tube hole on the block but has a rubber grommet/bolt plugging it up. The casted/threaded spot on the intake manifold where the tubes split from just goes to the actual air cavity that normal air being drawn in from the carb. (I'm not sure if there is a term for this spot on the intake manifold). The Carter WCF5 Carb did not have any sort of air tube going to it but does have a threaded plug where I think a air tube could go. Here are a couple pictures that I hope can make some sense for you all that know this stuff like the back of your hand. Thanks for the help!
take the plug out of thst back hole and get a factory "tepee" - take the pipe plug out of the baseplate of the carb and screw in a pcv valve - connect them with a va***e hose.....make sure the oil fill cap is the vented type....done
i would leave what is there. it has the pcv in the intake and draws through both valve covers and pulls fresh air in at the oil fill tube. should work fine.
Thanks for the explanations and photos! I think for the sake of keeping the PCV valve hoses to a minimum and for an overall cleaner look to the engine, I'll get that PCV valve that plugs into the road draft hole and run a hose up to the base plate of the carb. I ***ume I can then install a finned valve covers with no breather holes then?
As I learned here on the HAMB, the key to PCV is air intake and suction. As long as you have both, and enough size /cfm, routing is not as critical. Filtering the airflow into the pcv valve is nice to have, maybe less important on a boat, your oil fill cap may have steel wool in it or something. Some GM V8 cars had one breather plumbed to the underside of the air cleaner (air in, filtered) and the other breather plumbed with a PCV valve to the car base (suction). That always seemed simplest to me. BFC
There are probably baffles in the valve covers where the hose pickups are I'm guessing??? I would also guess the boat designers took everything into consideration so things functioned correctly. I do like that aluminum, open plenum, intake manifold, and the Mallory distributor with the crab-leg cap. IF you do decide to go with different valve covers, then the pickup point by the distributor will work fine. And I'm sure plenty of HAMBERS would like your "old" valve covers for their breather pickups. I'd probably add a short, open spacer below the carburetor, and use a Holley/Demon; the manifold is spaced for them, and an adapter is used to mount the WCFB to the intake; it's a small carburetor also with about 385 CFM. You could also use a 500 CFM Edelbrock badged AFB carburetor. You'll need a different flame arrestor/air cleaner for use with a different based carburetor. Interesting topic for us "car guy-landlubbers"; you could peruse some boat type forums for answers. I am Butch/56sedandelivery.
I haven't taken the intake off yet to verify if the baffle/filter (Also called ventilator?) is still there. Any reason why someone would take it out? The intake manifold gasket looks to be pretty new but I guess I'll find out soon... The valve covers did not have any sort of baffle inside, just a small compartment around the vent tube. Attached are a few pictures of the valve covers. I saw on a lot of description of new valve covers that they come with baffles that look to go on the inside of the covers. What exactly to these baffles do? 56sedandelivery - I thought that this Carter Carb is a little light on the CFM.... I'll look into some Holly marine version carbs and base plates that are a little larger like the 500 cfm you mentioned. I'm not looking to break any speed records, just want a good/reliable engine and will look kinda cool as well.
a couple of my thoughts.....i'd keep those valve covers just in case you switch to a later engine block. it will not have the provision for that little PCV ****** , you would probably need to switch them back. have you checked the condition of the 283? checked the compression? a lot of those boat motors got used hard. are you going to rebuild it? back in the early 90's i was 1/2 owner of a `67 Owens with a Flagship 327. after the 327 went to ****....a broken main web in the block...we installed a 350. as you probably know, the Flagship motors used a cast oil pan. found out the hard way the nuts on the 350 connecting rods would not clear the cast oil pan. had to do a bit of clearancing . thought you should know just in case the way the PCV is plumbed now is the way i remember it yes, this project is a bit off topic for this board, but what the heck...i'd like to see some pictures of the boat
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