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John_Mc

Road Draft Tube Question?

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Hi, I spoke to an Zephyr vendor on the phone yesterday on a road draft issue and I’m more confused now more than ever.  I have a 1941 V-12 that has a tube that runs from the intake manifold to the air cleaner.  I also have a stub (port) coming out of the oil filler tube at the back of the engine.  Do I still need a road draft tube or can it just be capped off.  If I do need one, anyone know where I can find one at a reasonable price??   Thanks!

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Ken, that’s what I thought too.  Think I could just cap off the draft tube port?

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Not being familiar with the Zephyr I would nevertheless be cautious about blanking off any draft tube orifice. 

 

Most vehicles in this era had a draft inlet thru the oil filler cap and a draft tube exit from the rocker cover or side plate on the block, blanking off any of these ports will lead to over pressurisation within the crank case / block and thus the internal blow by pressures will seek an outlet, more often than not back thru the filler worse via the crank shaft seals.

 

It might be worth a bit more research before applying any blanks, or at the very least keep an eye out for any external oil leaks if you do go ahead.

Edited by hchris
error (see edit history)

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It has been a LONG time since I had a HV12, specifically a 1948 Continental, but I remember very well that one of the inherent issues of those engines is that they have insufficient venting of crankcase gases.  Therefore, don't plug the road draft tube but rather improve venting, perhaps by a PCV.  The Ocee Ritch book of the mid-1960s describes a number of modifications including adding a Y-block V8 crankcase vent, a fan to help disperse crankcase gases, and others.  I'm sure some of the current Lincoln owners will chime in with the latest and most optimal means of addressing this issue.  Please wait for them to provide the best information.  In this writing, I just wanted to ask you to hold your horses until more knowledgeable parties can give you the best guidance.

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2 minutes ago, Grimy said:

It has been a LONG time since I had a HV12, specifically a 1948 Continental, but I remember very well that one of the inherent issues of those engines is that they have insufficient venting of crankcase gases.  Therefore, don't plug the road draft tube but rather improve venting, perhaps by a PCV.  The Ocee Ritch book of the mid-1960s describes a number of modifications including adding a Y-block V8 crankcase vent, a fan to help disperse crankcase gases, and others.  I'm sure some of the current Lincoln owners will chime in with the latest and most optimal means of addressing this issue.  Please wait for them to provide the best information.  In this writing, I just wanted to ask you to hold your horses until more knowledgeable parties can give you the best guidance.

Great  advice, thanks!  I’ll hold off for now

 

2 minutes ago, Grimy said:

It has been a LONG time since I had a HV12, specifically a 1948 Continental, but I remember very well that one of the inherent issues of those engines is that they have insufficient venting of crankcase gases.  Therefore, don't plug the road draft tube but rather improve venting, perhaps by a PCV.  The Ocee Ritch book of the mid-1960s describes a number of modifications including adding a Y-block V8 crankcase vent, a fan to help disperse crankcase gases, and others.  I'm sure some of the current Lincoln owners will chime in with the latest and most optimal means of addressing this issue.  Please wait for them to provide the best information.  In this writing, I just wanted to ask you to hold your horses until more knowledgeable parties can give you the best guidance.

 

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36-38 HAVE A DRAFT TUBE AS PART OF THE OIL FILLER- 39-48 DO NOT, BUT HAVE A FORD STYLE CAP WITH OIL SCREEN TO FILTER INCOMMING 

AIR--DRAWN IN FROM THE AIR FILTER BREATHER TUBE-

JOHN YOU SNUBBED ME AT THE GILMORE WHEN I TRIED TO HELP YOU  SO I SELDOM REPLY TO YOUR STUFF, BUT YOU NEED

TO TALK TO PROF BOZARTH OR OTHERS WITH 37'S  40-ON HAD OIL MESH CAP, EARLIER HAS SEALED LID.

 

 

lincoln-v12-06.jpg

37 LZ WITH DRAW TUBE SPOUT.jpg

s-l225.jpg

Edited by Mssr. Bwatoe (see edit history)

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9 hours ago, Mssr. Bwatoe said:

36-38 HAVE A DRAFT TUBE AS PART OF THE OIL FILLER- 39-48 DO NOT, BUT HAVE A FORD STYLE CAP WITH OIL SCREEN TO FILTER INCOMMING 

AIR--DRAWN IN FROM THE AIR FILTER BREATHER TUBE-

JOHN YOU SNUBBED ME AT THE GILMORE WHEN I TRIED TO HELP YOU  SO I SELDOM REPLY TO YOUR STUFF, BUT YOU NEED

TO TALK TO PROF BOZARTH OR OTHERS WITH 37'S  40-ON HAD OIL MESH CAP, EARLIER HAS SEALED LID.

  

I snubbed you at the Gilmore???  Please explain in a PM or here, as I have no idea about what you are speaking.  Gilmore was a wonderful event and I had no friction with anyone over anything that I recall and don't remember meeting or having any trouble that needed assistance.  Are confusing me with someone else? 

 

lincoln-v12-06.jpg

37 LZ WITH DRAW TUBE SPOUT.jpg

s-l225.jpg

 

Edited by John_Mc (see edit history)

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Thank you for all the input, I should have posted a picture of what I currently have with a mesh air cleaner and an intake breather.

 

image.jpeg

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Yes, I thought the heater setup was strange too but it does work.

 

The picture that I posted yesterday was terrible, here is a better one that shows my air cleaner, intake tube that feeds the air cleaner and my oil filler pipe that has the road draft tube.  So here is my predicament:  My car is a '37 but my engine is a '41.  I would like to replicate the 1937 look as closely as I can.  Should I cap off the port since none was offered in 1941?  Or should I put the road draft tube on the filler pipe??  Also have to write that I have a really nice square oil filler cap that I would like to keep using.  Would there be any harm done by using BOTH a road draft tube and the open air cleaner with an intake tube???  I can pick up a road draft tube at a reasonable price off of Ebay.   The previous owner just stuck a rubber hose on there which really looked like hell.  ANy input would be appreciated.

IMG_2545.JPG

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After reading Mssr. Bwatoe post, IMHO, if you want to add the draft tube, you will have to still use the filter filler pipe cap and block the end of the draft tube, so you will maintain the correct air flow. The draft tube acted as the exit for the vapors on the 37, the pipe to the air cleaner is now the exit for the fumes. An open draft tube would have a vacuum as you drove down the road sucking air from the filter filler pipe. This may not relieve all of the pressure in the crankcase.

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John,
my humble opinion, disregarding originality,   on a rebuilt  motor {no fumes} you could use  "either",  "neither", or" both" as long as you use a breather cap{ not sealed} on the oil filler tube.    When using the air cleaner vent tube system the inlet manifold gasket may need a vent hole punched out below  the vent tube.  I have found some gaskets don't have that hole.
Roy

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Excellent advice Roy, thank you.  I might just have to forget the original oil cap and use the breather type cap.

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John, after doing some research in the Chassis Parts Catalog and the Shop Notes, I believe that you can block the hole in the intake where the pipe goes to the air cleaner and use the 37 carburetor air cleaner and draft tube with the 37 filler tube cap. I cannot find the crankcase air flow diagram for the V-12 engines, so I don;t know for sure where the air intake is when the draft tube is used. I am assuming that the vacuum created at the draft tube will remove the fumes and prevent a build up of pressure in the crankcase.

 

The parts catalog shows that the later intake can be used on the earlier cars by plugging the intake to air cleaner plug. The shop notes state:

"Crankcase ventilation: 36-38 Breather outlet under the car, 39-41, Breather outlet into carburetor air cleaner."

 

Of course you will not fool anyone that knows the Lincoln Zephyr engine changes, just dummies like me.

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If you want good crankcase ventilation you should search for posts by Dee Peecher on the subject.On his advice I added a Columbia vacuum takeoff block under the carb that connects to a PCV valve threaded into the vacuum port of the intake manifold on my '41. Not correct, but like Melling oil pumps and solid valve guides with seals, are an improvement on the original design. I haven't had any points taken off in the two shows where I've been judged.

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I dont mean to hijack this thread but I am in the same dilemma- I also am running an early draft tube on my 41-My question is the oil fill cap on mine is solid and not like the later breather type caps-I assume that is ok? I also am running a pcv valve-

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