Supersonic test run

[garage gnome]

I took my 53 for a test run in the freshly fallen snow. A few things.

1. I miss my OD.
2. It idles smoother and has a bit more power at low RPMs.
3. I took the driver's seat back cushion off and I fit much better, kinda like a wheelhouse notch.
4. Harrison heater + original half cab = comfortable temperature.

Come spring, it should be dialed right in!

[49willyz]

Again with the snow pics of running Jeeps! You guys are killing me! I now understand why you won't be crawling that rig, she IS too purty Nice pics of a beautiful rig

[Gunslinger]

GG, Once again with the photo ops, nice!!!

Tell me what tires you have on your rig, I'm in need and am torn as to what I should buy.  I like the price of the NDCCs but I like the ride of the Off Road Radials.

Need your valued opinion.
Todd

[F Bill]

Nate, I asked about the higher compression head on the DJ over on the Dispatcher board, and Ken Oldtime told us the DJ used the same head as a 3A  but an optional high compression head was available. I haven't found the part numbers used yet.

Here's what he said:

6.48 / 1 CR head was standard on all DJ prior to 1962.
7.1 / 1 CR head was optional on all CJ-3A and DJ-3A.
In 1962 the 7.0 / 1 CR head became standard on DJ-3A.
What is the CR of the Supersonic?

[garage gnome]

I don't know Bill. I wish I had done a compression test prior to the swap so I could compare. Another member on the 2A page is going to do the swap also in the spring.

I'm running the super tractions from Walcks. These are far better than the NDTs in snow, ice, water, ect. They are a vintage snow tire. They have the siping in them and holes for studs. I'm a big fan of them. After driving with them, I'll never put NDTs on my jeeps. When I can, I'm going to get a set for the '49.

[F Bill]

Here's something that Ken added to the discussion  about different Willys heads:


.........
Willys part numbers for various "L" heads.

#639660 XXX ratio... production ends sometime in the late 40's
#640035 7.0 / 1 ratio... was both a CJ-3A and DJ-3A option
#640161 6.48 / 1 ratio... was standard on all CJ-3A and pre 1963 DJ-3A
#649172 XXX ratio... was used with very early SW and PU
#807763 6.48 / 1 ratio... I believe this head begin production around 1953

From my observations the specific compression ratio (CR) was not always noted on the head itself.

Increasing the CR is the most logical way to increase engine torque for all 134 engines.
Increasing the CR simply makes more efficient use of the much higher fuel octane that we currently have available.
The low CR engines were designed to operate on uncracked petroleum.
That's roughly a 69 octane rating.

The only drawback to increasing the CR is that it makes hand cranking more difficult.