MattWalker Posted February 8, 2014 Report Share Posted February 8, 2014 I called vintage power wagons about a pcv system to replace my road draft tube but he told me to check tge intake manifold for a 5/8" inlet for the hose to attach to. Is it obvious where it is? Cuz I certainly don't see one. I believe my p15 has the original engine and manifold but I don't see any valve... Can I add one? Quote Link to comment Share on other sites More sharing options...
JBNeal Posted February 8, 2014 Report Share Posted February 8, 2014 (edited) additional information - partial PCV system upgrade? Edited May 31, 2021 by JBNeal revised information Quote Link to comment Share on other sites More sharing options...
Lumpy Posted February 8, 2014 Report Share Posted February 8, 2014 (edited) You can also just run a line, such as a fuel line from vacuum source to crank case, then put a carburetor main jet in the line. Or make your own plug and drill a small hole. That will do the same thing, and is not quite as big of a vacuum leak as most PCV valves. This has worked for me anyhow. Then modify the draft tube in any way that works for you, could probably stuff it with steel wool to act as an air cleaner. !! Well you get the basic idea. ! Or run a tube/line from the blocked off/modified draft tube to the air cleaner. That's my low-tech fix of the day. Just a thought. k. Edited February 8, 2014 by Lumpy Quote Link to comment Share on other sites More sharing options...
MattWalker Posted February 9, 2014 Author Report Share Posted February 9, 2014 Sorta, so is that the road draft tube on the passenger side of the crank case near the back? I don't have a tube coming out of there, looks like it has a metal plug? And I do see a brass valve on the manifold but the wiper hose is connected to it, can I use that? Quote Link to comment Share on other sites More sharing options...
Don Coatney Posted February 9, 2014 Report Share Posted February 9, 2014 Sorta, so is that the road draft tube on the passenger side of the crank case near the back? I don't have a tube coming out of there, looks like it has a metal plug? And I do see a brass valve on the manifold but the wiper hose is connected to it, can I use that? If you can post a picture it would be helpful. Quote Link to comment Share on other sites More sharing options...
Lumpy Posted February 9, 2014 Report Share Posted February 9, 2014 Just thought of something, since the filler tube does not seal, I suppose you could just block off the draft tube, and that, the filler tube, would allow somewhat filtered air into the crank case. ?? All things considered, that could cause a lot of blow-by to come out the filler tube under full throttle conditions, or any time vacuum falls below a certain point, so perhaps some kind of small air filter on the draft tube would be best. In that case, it might be best to cap off the filler tube with some kind of cap which seals, so that air is only coming into the crank case, and blow by going out, in one location which would be best more towards the bottom of the engine. (and not all over the top of the engine or the distributor) ? I wouldn't use the port for the wipers, that might rob some vacuum from them, possibly they might not wipe as well then. But I'm not sure about that. If you really only have one vacuum port on the manifold, you could put a small spacer between the carb and manifold, and run a port off that. Just some thoughts. k. Quote Link to comment Share on other sites More sharing options...
Don Coatney Posted February 9, 2014 Report Share Posted February 9, 2014 Why not leave the draft tube as is? In a healthy engine the factory draft tube system works. Perhaps not as well as a properly engineered PCV system but it does work. If the engine is not healthy then fix that problem. 1 Quote Link to comment Share on other sites More sharing options...
Lumpy Posted February 9, 2014 Report Share Posted February 9, 2014 I think that a pvc system removes more water vapor from the crankcase, with an open crank case it takes a while longer. Probably an issue with an engine that is used for short runs, and never gets totally warmed up for any significant period of time. Emission requirements may be another reason for the PVC. ? But yeah, my engine just breathes out the draft tube, have never really thought about putting any type of pvc system on it. K. Quote Link to comment Share on other sites More sharing options...
DonaldSmith Posted February 9, 2014 Report Share Posted February 9, 2014 About 5 years ago, I added a PCV system to my DeSoto, following details that were posted somewhere in the forum. The system sucks the fumes from the crankcase at the draft tube location, and the crankcase gets fresh air from the air cleaner. Photos follow. (My first attempt at posting photos.) 1 Quote Link to comment Share on other sites More sharing options...
DonaldSmith Posted February 9, 2014 Report Share Posted February 9, 2014 Here are a few more photos. (I should learn how to downsize them.) 1 Quote Link to comment Share on other sites More sharing options...
MattWalker Posted February 11, 2014 Author Report Share Posted February 11, 2014 Here are some pics, it was hard to photograph the plug but I think that is the hole where the road draft tube went. Also in the other pic you can see the one port for the wiper but its the only port I see. Quote Link to comment Share on other sites More sharing options...
Niel Hoback Posted February 11, 2014 Report Share Posted February 11, 2014 Check that can, it may have the hole in it where the draft tube used to be. Quote Link to comment Share on other sites More sharing options...
MattWalker Posted February 11, 2014 Author Report Share Posted February 11, 2014 Yep, you are 100% right. I didn't realize it was a can and separate tube. so can I simply add another tube? how the heck did that come off? maybe that's y I get so much smoke in the cabin? Quote Link to comment Share on other sites More sharing options...
Niel Hoback Posted February 11, 2014 Report Share Posted February 11, 2014 Sure, you can put a tube inn the hole and long enough to reach the bottom of the engine. That would definitely direct the odor out under the car and away from the firewall. Quote Link to comment Share on other sites More sharing options...
JBNeal Posted February 11, 2014 Report Share Posted February 11, 2014 (edited) the vacuum source for the windshield wiper motor can be tee'd to accept the circuit with the pcv valve. As for that can, that looks very similar to a draft tube filter housing that I've seen on other flatheads engines, Plymouth, Dodge Trucks & Industrials. Edited August 27, 2021 by JBNeal revised pictures Quote Link to comment Share on other sites More sharing options...
MattWalker Posted February 11, 2014 Author Report Share Posted February 11, 2014 I agree that is definitely the can for the draft tube. Where can I get all the parts for the PCV, is vintage power wagons the best bet? Quote Link to comment Share on other sites More sharing options...
DonaldSmith Posted February 11, 2014 Report Share Posted February 11, 2014 (edited) You can piece together a PVC system from a standard PCV valve from an auto store, and fittings from the hardware store. Here's how: (See also the photos I posted earlier) PCV System DIY Draft tube opening to manifold: From Dwane, forum member, 01/06/2005 1-inch black iron cap. Grind a flat spot on the top of the cap, and drill a hole for the existing bolt from the downdraft tube. Provide a lock washer and gasket for under the bolt head. 1-inch by 3-inch black pipe nipple. Cut the nipple in half, and thread one half into the cap. Use thread sealer. Make a gasket for the cut edge of the nipple, where it will seat in the draft tube opening. 1/4 x 1/8 Compression connector 1/4-inch tubing to 1/8-inch pipe threads. Drill through the side of the cap and through the nipple and tap in threads with a 1/8-27 pipe tap. Screw the connector into the tapped hole. PCV valve: Listed models: Fram FV-333, AC Delco CV-1007C, Purolator PV-1029. Manifold fittings: Provide bushings, tees, nipples, etc., to take off the PCV valve from the intake manifold under the carburetor. Thread the PCV valve into the fittings. Copper tubing, Etc. 1/4-inch copper tubing, rubber hose, hose clamps: Connect the tubing to the PCV valve. CRANKCASE AIR INTAKE: (My own adaptation) 1/4-inch copper tubing and fittings: Remove the oil filler cap, and blank off the side opening with sheet metal. Drill a hole in the side of the oil filler tube, facing the rear of the engine. Secure a fitting in the hole (I forget how I did this) and provide a compression fitting for the tubing. Run the tubing up the air cleaner brace toward the bottom of the air cleaner. Drill a hole in the underside of the air cleaner and secure a short length of copper tube pointing toward the tube from the oil filler tube. Provide a length of rubber hose to connect the two tubes and to allow removal of the air cleaner. Edited February 11, 2014 by DonaldSmith 2 Quote Link to comment Share on other sites More sharing options...
JBNeal Posted February 11, 2014 Report Share Posted February 11, 2014 VPW can sell ya the parts, but they may not be exactly what you need as there are at least 2 different intake manifold setups for the PCV valve circuit. The fittings & hydraulic tube can be found at a good hardware parts store, with the hydraulic tube to be formed to your needs. The cast adapter occasionally pops up on eBay, but VPW usually has those in stock. If ya want to save a few bucks, you can make your own adapter using the draft tube as a base or get creative with a cast iron pipe tee & a close nipple, or you can make an adapter for that PCV filter housing to take advantage of its base. The VPW PCV valve will cost a few $$$, and finding a modern equivalent can be a bit tricky, as a PCV that is too small will not allow much vapor to pass, and one too large will cause the charge air mixture to be lean at higher rpms. Before NAPA redesigned their website a couple of years ago, it was possible to look at PCV valves by engine displacement & input/output specifications (threaded, hose barb, grommet seat), and I had compiled a short list of possible equivalents to the VPW threaded PCV valve. After NAPA redesigned their website so that it was not as easy to look up PCV valve specs, I located a lot of PCV valves on eBay that are dead ringers for the VPW valves. I managed to purchase a PCV valve similar to this NAPA valve, but have since misplaced that equivalent list and the original box to verify any alternatives. If I can get caught up on a few chores, I have a PCV conversion project that is similar to the original listed in the downloads section. I think I have solved the issue of installing the crankcase draw tube to the base of the air filter, which would require cutting a hole in the air filter base neck to braze the tube that draws from the crankcase filler neck. A modified original draft tube, along with the air cleaner modification, the assorted fittings & plumbing, and an equivalent PCV valve, might could get this material list cost down to less than $40. But I'll experiment on some spare parts and document that progress later Quote Link to comment Share on other sites More sharing options...
Lumpy Posted February 11, 2014 Report Share Posted February 11, 2014 I would agree that a do-it-your-self set up would be just as good or better than buying a ready made deal, which will probably have to be modified anyways. k. Quote Link to comment Share on other sites More sharing options...
MattWalker Posted February 11, 2014 Author Report Share Posted February 11, 2014 I got that can off, this is all that was there. Looks like the cap and the filter element, no tube... Quote Link to comment Share on other sites More sharing options...
JBNeal Posted February 11, 2014 Report Share Posted February 11, 2014 that is not surprising to see the draft tube nipple gone, as the tube is usually made of a slightly thicker material than the filter housing, and tube vibrations could cause the housing to tear. I was originally going to utilize the housing I had in the PCV valve circuit, but I reconsidered due to the lack of robustness of that design. Quote Link to comment Share on other sites More sharing options...
Don Coatney Posted February 11, 2014 Report Share Posted February 11, 2014 Makes me wonder if one could use PVC to make a PCV system? 1 Quote Link to comment Share on other sites More sharing options...
Niel Hoback Posted February 11, 2014 Report Share Posted February 11, 2014 Yeah, there used to be a sheet metal tube spot welded to that cap. If you can't find one, it shouldn't be hard to make one. Or give me some time to get out to the garage for a dig-around. Sposed to warm up some next week. Quote Link to comment Share on other sites More sharing options...
Niel Hoback Posted February 11, 2014 Report Share Posted February 11, 2014 Yes, Don, I be you could, but would it be PC? Quote Link to comment Share on other sites More sharing options...
Don Coatney Posted February 11, 2014 Report Share Posted February 11, 2014 I thought you would say that Quote Link to comment Share on other sites More sharing options...
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