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Real Four Wheel Drive
Motivation by (un)Innovation

What magical force propels the Eagle along the highway? Is it some sub-atomic power plant known only by a select few? Is it (GASP!) a wankel? Diesel (Knock, Knock)? Or a radical 64 valve, dual overhead cam, fuel injected monster? No! It is none of these. Instead AMC used the tried and true 258 cubic inline six. Based on technology from the sixties the six was nothing short of a RUN OF THE MILL SIX!!!!

With six cylinders in a line, torque was its middle name. A cam in block and push rod operated over head valves the 4.2 was nothing short of ordinary. Gobs of low end torque, long stroke, and a red line that seems to take a half a year to reach are one of the many characteristics of this streight six. Some what of a heavy wieght this engine never seems at a loss for pure lugging power. It falls short on the horse power thang tho'. One hundred and ten hard workin' ponies strain to pull the Eagle's 4500 LBS GVW around (Station wagon). Like I said before, the low end torque is awesome. It really shines off road where full throttle is often suicide.

So why the low horse power? One may ask. Well in 1973 the six had 150 horse power and before that it had even more (say around 170 hp range). What happen was the dreaded emissions equipment. The 4.2 all ready had a hard time breathing as it was, constrictive intake and exaughst manifolds and small ports in the head definately were not cool. Back in the sixties such things where not considered to be important. Want power? Just add a couple carbs or a few extra barrels. A high lift cam might do the trick as well. Or just get a big V-8. But then came the federal air regulations. All this high horsepower fun came to a screeching halt. Suddenly hp of engines of all makes started goin' down. So down that even the monster bad boy 500 cubic inch Cad motor with 400 horsepower and 500 feet of torque dropped to (yawn) 190 hp and a lousy 350 foot pounds of tourque. High compression, multi barrel carbs, high lift cams, all got the death knell when the feds got to Detroit (and Kenosha). In their place, smog pumps, low octane fuel, and the evil catylitic converter filled the spots. Headers were but a memory, high rise intakes squashed, and performance was replaced with peppy.

But don't dispair! There is hope in the darkness! A light at the end of the tunnel in the shape of fuel injection! Ah yes, the 4.0 High Output six, the last and the greatest AMC six of all time! What does this mean for your Eagle? P E R F O R M A N C E! Power! And better gas milage. And did I say POWER!!! A few web surfers will read this and say, "Swap my 4.2 for a 4.0, no way! I don't know how or wanna do a swap." Now did I say SWAP! No! Where is this going, well by swapping the head off of a 4.0 six onto your 4.2 the result is: increased breathability = more power (some people claim 25-35 extra ponies) and better gas milage. But wait! There's more! Most likely your're a cheap skate and got an 4.0 head with out the exaughst manifold. But then by trial and error found out that your exaughst manifold wasn't a perfect fit. In fact it was a perfectly LOUSY FIT!!! Now go out and get the next thing, a header. Once again I hear people naying, "But headers for a six are expensive." Well be prepared for a surprise! Eighty-nine and up 4.0 H.O sixes were equipped with them STOCK!! And we all know what stock means, cheap.

Now that we got the lungs back into the engine we can concontrate on the intake side of things. Carbs off of different engines will work, as long as they are two barrel. But this means custom adapter WORK!. And to some, more work is a dirty word. Then there is this one guy, just not any one guy, but the guy with the only Eagle X in the world!!!! By taking the top part of a Carter carb from say a old early seventies Dodge 318 V-8 and combining it with the lower part of the BBD a real carb was made. Need more info, need to ask the man himself, just click here . Needless to say performance was greatly increased.

And finally for those of you who have the bread there is one final thing you can do, take the F.I (that's fuel injection for those of you who don't know) off of the 4.0 and presto!!! 180 total hp or more!!! Get more power, less stops at the gas station, and the ability to run your engine upside down!!! Finally in this saga is one last thing. And it is cheap. For Eagle pilots with the Pulse Air system there is one thing you can do to turn this thing into an asset. Unplug the rubber hoses from the cat and the pipe and plug and place them where the other ends are supposta go. After all this nifty work take the check valves and remove them. Guess what this does! Instead of sucking the air out of the engine it pushes it into it. Kinda like a mini supercharger! Neato!

With all these mods the 4.2 will be a real screamer, I guestimate that the engine will have anywhere from 180-200+ horse power. Torque should go up from a okay 212 foot pounds to about 260+ foot pounds. And with higher compression pistons and a wild cam plus a mod chip for the computer, and a K&N air filter, hp might get over the 250 mark. In the links section there are a couple helpfull websites to turn your six from stocker to something to brag about.

Next Page or page 4! The other engines (GM 2.5 and AMC 2.5)

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