Joined: Nov 05, 2009 Posts: 174 Location: Florianopolis, Brazil
Posted: Tue Sep 13, 2011 7:55 pm Post subject: M606A3 crankcase breathing system
Hi dear Mjeepers, good evening!
My Kaiser 1969 M606A3 jeep - the military version of the CJ5 - is still under final step of restoration, requiring minor mechanical adjustments and final touches on the body. I expect I can post pictures in this site soon.
Now my question: I need to find out the correct connection of the breather system of crankcase, which fitting (neck) is placed on oil filling tube.
The only supposed connection of this crankcase breather hose is to the fitting placed on top of engine valve cover.
However this does not make sense for me, since the crankcase breathing should be connected to the air filter, and not to this engine valve cover fitting.
The original Donaldson filter of my jeep has no signs of having any fitting neck to connect any hose, as seen in many Willys CJ5 models with the same Hurricane-4 engine.
So, how should I do the connection of the crankcase breather?
I suppose that if I connect these two neck fittings (hose from oil filling tube to valve cover), I may have problems of oil leakage out of the engine (through gaskets), as a result of an overpressure in the crankcase.
Sorry if I did not explain my concern clearly. My english is poor.
Hi Claudio,
I have a M606A1 (mil.CJ5) here. The oil fill pipe connected to the air filter housing (Donaldson type) the valve cover fitting connected to the PCV valve under the carb. Engine just rebuilt (1500km) no leaks.
Zoli
A common problem with the M606 series is the operating agency has a tendency to mix early non-smog engines with later smog equipped engines. When an overhauled exchange engine is installed it may not match the the original's engine's breathing arrangement. Early engines have the PCV valve on the side valve cover and plumbed to the intake manifold. These engines have only one small tube nipple on the oil filler pipe that connects to the filtered air intake plumbing. Later engines have the PCV valve in the top rocker cover and the oil filler pipe has two small tube nipples. One connects to the filtered air system and the other to the PCV valve in the top rocker cover. _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
Joined: Nov 05, 2009 Posts: 174 Location: Florianopolis, Brazil
Posted: Wed Sep 14, 2011 11:23 am Post subject:
Thank you fellows.
I suppose that in my case it will remain the solution of connecting both nipples coming from rocker cover and oil fill into a "TEE" and then plumbing the base of the "TEE" to a hose and connecting it into the valve that is located under the carburator, on the intake manifold.
How does this sound to you?
In this case all blow-by gases coming from crankcase will be directed (forced in every way) into combustion again, via intake manifold.
Although being a late Hurricane engine (1969), the oil filler tube has only one nipple and the air filter has no nipples.
The PCV in the valve cover goes to the connection under the carburetor. Oil vapors get sucked out of the engine by the vacuum under the carburetor.
The connection on the oil inlet needs to connect to a fresh air inlet so the air being sucked out by the pcv is replaced by filtered air.
You don't want both connections tee'd together. The PCV valve is a restriction valve that only allows a metered amount of air to be sucked out of the engine. If you Tee the oil inlet to same line as the pcv, there will be too much air being drawn in and the engine won't run right. If at all. Also, if the engine does run, a vacuum will be pulled on the crankcase because you don't have a way for the air being sucked out to be replaced.
Joined: Nov 05, 2009 Posts: 174 Location: Florianopolis, Brazil
Posted: Thu Sep 15, 2011 4:22 am Post subject:
Thank you OldSalt, Wes and Zoli (GPA),
I will follow your hints. For my particular case I will need to open a hole on the air filter (and create a vent somehow) to let oil filler tube nipple be connected to it.
Rocker cover nipple will be connected to the pcv valve that, in the case of my jeep, is located UNDER the carburator, i.e., straight into intake manifold.
From thses considerations, I conclude that my air filter has been replaced by a non vented air filter. Maybe it was taken from a CJ3A jeep that has the same Donaldson type, although I am not sure if the CJ3A filter has a vent nipple or not. For sure my air filter has no signs of having any other air outlet, except the big one that goes to filter-to-carb crossover tube.
Only for your curiosity (forgive me if I am teaching the priest to pray), my jeep's Hurricane engine has no pcv valve on the top of the rocker cover (nor on side engine valve cover), but under the carburator. Instead of a thin orifice pcv valve (like the one seen on CJ3B), it is a needle with a spring, that lets air go through in only one direction, like a one-way valve. manufacturer's name of the pcv reads NoVo.
Joined: Nov 05, 2009 Posts: 174 Location: Florianopolis, Brazil
Posted: Thu Sep 15, 2011 8:33 pm Post subject:
The M38A1 has a small steel tube section in the halfway of the rubber hose that connects air filter to carburator.
The M606A3 - the jeep I own - has a very short bubber hose between them (air filter and carb) and no intermediate metal section. Air filter neck is approx. 3 to 4 inches far from the carburator horn. It has same configuration as the CJ5.
I am thinking about bolting a nipple from the inside of the air filter or something similar to avoid welding, since the painting of the filter is already done.
M606 CJ3B 12 volt
M606A2 CJ5 12 volt
M606A3 CJ5 with both a vehicle 12 volt system and an add-on 24 volt radio system with a separate 24 volt Motorola alternator mounted on the left side of the engine which utilzed two additional 12 volt batteries in the battery box ala M38A1 style. _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
Joined: Nov 05, 2009 Posts: 174 Location: Florianopolis, Brazil
Posted: Thu Sep 15, 2011 9:52 pm Post subject:
BTW: I have googled "M606A1" and there are some issues on these jeeps in Europe, no?
From the specs, I have records of A2's and A3's as well, although I am not sure about A1's.
Zoli: does your jeep has ID plates showing this model?
Best!
Claudio
Florianopolis, Brazil
42MB, 42WC57, 51 D&K M100, 52M38, 53Willys Truck, 62M170, 67M170, 69M606A3, 98Land Cruiser and 68 UW (Undestanding Wife).
The random A1 listings are from folks that do not know any better and assume there was an A1.
The bracket mounts on the left side just above the fuel pump. If you look closely at the illustration Fig 13 in the M606A2/A3 service manual supplement (SM-1041R2) it appears the bracket is under the alternator and probably mounts to the front studs of the exhaust manifold. _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
Joined: Nov 05, 2009 Posts: 174 Location: Florianopolis, Brazil
Posted: Fri Sep 16, 2011 6:57 am Post subject:
Do you occasionly have other pages of this suplement, next to page 10? Same supplement on page 10 mentions further figures that are probably in other pages.
Thanks
Claudio
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