Info needed: Engine Pre-Lube after storage

[rob love]

The engine design dates back to the 30s. It was a car engine improved for use in the first Jeeps. There were some changes to the L head (commonly called flathead) engines for the M38, and to squeeze 12 more horsepower out of the engine, the intake valves were moved into the head (called an F head), resulting in the Hurricane. as used in the M38A1s. This was in the very early 50s. It was the same engine as in the 1971 M38A1Cdn3 engines. Below the early 50s head, you still had the late 30s mechanical design. The weaknesses were not something just in the military models, but rather the fairly early engine technology. Long piston stroke, poor air filtration, non-replaceable cam bearings which were part of the block...

I think time magazine had a story one time about Ronald Regan's old Willys Jeep he had on his property. The article mentioned something about it never really having any real problems aside from an engine replacement at some similar low mileage.

I'll likely be putting in a paper filter into my own Jeep this summer. Basically, you need to gut your aircleaner, and fine a cylindrical air filter with an appropriate size opening to match up to the top of the aircleaner. You will have to run a threaded rod down through with a rubber washer, a steel washer, and a wingnut to hold it up against the top. I have seen a few stories about this in the various forums.

The M151A2 filter housing was very nearly the same as the Cdn2 and Cdn3 air filter housings. If I recall, the mounting brackets were a bit different, there was a bit more plumbing for the smog control, and I think the bottom cup had an indentation for the fender(?). I would suggest that whatever filter the M38A1Cdn2 or 3 might use, will also fit the M151A2 filter housing.

One thing that will likely add to the longevity of our engines over the militiaries use is that we have to pay for the repairs, so we generally do not drive them as hard as they did in the military. As a young militiaman, I remember where we would brag that we could get certain jeeps up to the P in miles Per Hour on the speedometer. It had to be murder on those long stroke engines. Nowadays, I do not go over 50 when I drive my Jeep down the highway to work.

[Les Kovacs]

Hi Rob....thanks for the lengthy and detailed response as to the F 134 longevity. I have heard about the poor longevity of the L head design but did not think that it applied to the F head.....I assumed that the F head was better as it was also being used for civilian use.
There is an oil to paper conversion for the MB/GPW air filter using a Fram/Wix CA3445/42036 cylindrical paper air filter with two plumbing rubber grommets 5 3/8 od x 3 1 /2 id x 1 " thick with no air filter housing alterations....not sure if this works for the CDN2 filter housing.
Along with the very frequent oil replacement I have magnetic oil drain plugs on both axles, trans/transfer and oil pan.
There are many 60 & 80 km/hr lazy farm/country roads (no gravel) outside of Barrie that lead to other cities so I keep speeds to around 30-40 MPH and have only taken her up to 50 MPH once or twice. My biweekly drives are usually 20 to 80 kms in length. I also clean the air filter housing once a year (average 1200-1400 miles) and replace the cup oil as well.

Thanks a bunch for the info,

lesk

[rob love]

That is the type of system you want to set up with, but I suspect you can go to a larger filter than what you have shown, with the late M38A1 or M151A2 housings.

If you measure the dimensions inside the housing, you might be able to google up a suitable air filter.