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RICKG Member
Joined: Aug 31, 2010 Posts: 1744 Location: SO IDAHO
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Posted: Sat Sep 15, 2012 10:01 am Post subject: venting |
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http://www.cj3a.info/sibling/cjv35u/v1.jpg
on the link above item 4 is described as "metered".
i believe this means that the fittings are of the restricted type
with aprox .040 orifices, am i correct? btw there are many other great
drawings that i am referring to while building my vent system.. _________________ keep 'em rollin'
RICKG MC 51986 DOD 01-52, '50 CJ3a |
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wesk Site Administrator
Joined: Apr 04, 2005 Posts: 16358 Location: Wisconsin
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BobW Moderator
Joined: Apr 04, 2005 Posts: 220 Location: Monticello, NY
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Posted: Sun Sep 16, 2012 6:36 pm Post subject: |
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Everyone is correct.
Item 1 is metered crankcase vacuum, it is "metered" by the PCV valve.
Item 4 is metered distributor vacuum, it is "metered" by the orifice fitting in the wiper tee.
Rick, do you have a CJV35? _________________ Bob W. Monticello, NY. 1952 CJ3A, 1952 M38, 1950 CJV-35/U |
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oilleaker1 Member
Joined: May 14, 2009 Posts: 972 Location: South Dakota
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Posted: Mon Sep 17, 2012 12:16 am Post subject: |
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So, item 4 "T" sucks on the distributor which gets it's air supply in the crossover tube. I just put a 1/8 inch flare T there. If it doesn't have a .040 hole, what happens? John ( does the M38A1 have a metered fitting also like this?) |
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evanso1975 Member
Joined: May 10, 2010 Posts: 615 Location: North Yorkshire, UK
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Posted: Mon Sep 17, 2012 1:11 am Post subject: |
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You can fabricate that 0.040" fitting using a standard male connector:
http://www.cj3a.info/sibling/m38vent/vent3.htm
Owen. _________________ Owen
1951 US Air Force M38
1944 F-1 1/2-ton Airdrome Trailer
1940 C15 Chevrolet CMP 11-cab
1939 DKW KS200 Motorcycle
MVT # 19406 |
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oilleaker1 Member
Joined: May 14, 2009 Posts: 972 Location: South Dakota
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Posted: Mon Sep 17, 2012 5:52 am Post subject: |
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Thanks Owen! I had a similar modification in mind, but getting the other T would be a simple change out. The ball check fitting was a mystery also and you answered that too! The question still remains: What happens if you don't install the T restriction? Wipers work like crap????? John |
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RICKG Member
Joined: Aug 31, 2010 Posts: 1744 Location: SO IDAHO
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Posted: Mon Sep 17, 2012 9:14 am Post subject: |
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BobW wrote: | Rick, do you have a CJV35? |
No, i have M-38 MC51986, eng MC74754. Tom M indicated to me
once that it was on the tail end of a 102 unit production run
starting with MC51887 and ending with MC51989. This run
utilized the closed style vent system according to Tom. I'll
model my vent sys after this drawing if you agree..
http://www.cj3a.info/sibling/m38vent/ventq.jpg
Thx for sharing your knowledge of the various vent systems
with the group, Bob.. _________________ keep 'em rollin'
RICKG MC 51986 DOD 01-52, '50 CJ3a |
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wesk Site Administrator
Joined: Apr 04, 2005 Posts: 16358 Location: Wisconsin
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Posted: Mon Sep 17, 2012 9:31 am Post subject: |
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John,
The wiper "T" gets the resticted orifice in all M38's on the port of the "T" that goes to the distributor. The distributor venting system and the PCV valve are considered calibrated vacuum losses. This means the engineer took their use of vacuum into consideration when the carb metering schedule was developed. When you increase the amount of vacuum loss at either of these restrictions it causes an upset in carb metering resulting in overly lean mixtures.
Rick,
Quote: | 102 unit production run
starting with MC51887 and ending with MC51989 |
That was a pilot run with the newer engine, late starter and late vent system. It is announced in the PS Magazine articles Ryan posted. _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
Mjeeps photo album: http://www.willysmjeeps.com/v2/modules.php?set_albumName=Wes-Knettle&op=modload&name=gallery&file=index&include=view_album.php |
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RICKG Member
Joined: Aug 31, 2010 Posts: 1744 Location: SO IDAHO
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Posted: Mon Sep 17, 2012 10:04 am Post subject: |
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http://www.cj3a.info/sibling/m38vent/ventq.jpg
Wes, would you agree that im building my vent system to
the right drawing? _________________ keep 'em rollin'
RICKG MC 51986 DOD 01-52, '50 CJ3a |
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oilleaker1 Member
Joined: May 14, 2009 Posts: 972 Location: South Dakota
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Posted: Mon Sep 17, 2012 12:37 pm Post subject: |
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This is a great thread! Thanks all. Now , did the M38A1 also have the orifice and at what location? I'm going back to it now and take a look. John |
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evanso1975 Member
Joined: May 10, 2010 Posts: 615 Location: North Yorkshire, UK
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Posted: Mon Sep 17, 2012 1:00 pm Post subject: |
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Check this vent parts list for the M38:
http://www.cj3a.info/sibling/m38vent/vent4.htm
If you look about 1/3 of the way down that list, the special fitting is part number 7348568. Now, page 87 of the G758 ORD 9 shows that same part number. So the M38A1 had the same fitting, apparently on the distributor vent line to the tee fitting. Seems logical so far.
This is my best guess for the location:
If you look at the diagram on page 70 of the ORD 9, then I would say that the special fitting is on the end of line EE that goes into the wiper tee fitting DD.
Hopefully, other members more clued up on the M38A1 vent system than me can confirm the location.
Owen. _________________ Owen
1951 US Air Force M38
1944 F-1 1/2-ton Airdrome Trailer
1940 C15 Chevrolet CMP 11-cab
1939 DKW KS200 Motorcycle
MVT # 19406 |
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wesk Site Administrator
Joined: Apr 04, 2005 Posts: 16358 Location: Wisconsin
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oilleaker1 Member
Joined: May 14, 2009 Posts: 972 Location: South Dakota
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Posted: Mon Sep 17, 2012 5:57 pm Post subject: |
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OK, thanks much. John |
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wesk Site Administrator
Joined: Apr 04, 2005 Posts: 16358 Location: Wisconsin
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