l have a 1998 Eclipse and im looking to make it faster without doing a turbo upgrade.l want it to be all engine as far as l can get, then l might think about getting a turbo.l dont really know a whole lot about engines but l am willing to learn.So, is it possible and would it be wise to do the swap?
The 420a in my car had an oil leak that l didnt catch and ended up spinning a bearing.Then, come to find out, it has a coolant leak as well.the car has 121,000 miles on it and really hasnt given me any problems up until now.l have always wanted an eclipse and now that l have one l wanna keep it and build it up.Right now, im trying to do an in-frame on the engine.But now, l cant decide on doing a COMPLETE rebuild of the 420a or just swapping it out with something better.Eventually, l want a high performance, fast eclipse that will turn heads.l wanna put ALOT of time and money into this car.please give me some advice.Thanks!

i've never heard of a 420a, but i've heard of a 4g63 and l believe that is the best engine you can get for an eclipse. so l would go for it

The 420A engine is basically a big paperweight that Chrysler designed & stuffed in the Neon so it would have something under the hood.

Since you're willing to learn, be sure to google for a good DSM (Diamond Star Motors, AKA Eclipse/Talon/Laser) forum. The one thing l can tell u is that if you're planning to turbo it at all, do it right from the start. The 4G63 (non-turbo) has a higher compression ratio & is not as sturdy internally as its turbo sibling, the 4G63T.

Swapping engines is a big job. You will have to replace the harness, ECU & probably a lot more, so it might be simpler & cheaper to just trade for one with a 4G63/4G63T already in it.

first, the 420a is a great engine! secondly, the 420a is mounted with the engine on the pass. side & transmission on the driver. the 4g63 & 4g64 r mounted with the engine on the driver & transmission on the pass. side. the cost to do this swap is insane. just ''some'' of the parts needed to do the swap: computer, motor mounts, transmission, axles, wire harness, radiator, etc. you're looking at an easy $4000-$5000 to do a proper swap. l own a 98 gs with a 420a pushing 340hp WITHOUT a turbo. go to howellautomotive.com, they have all kinds of performance stuff for the 420a. if u want the turbo, hahn racecraft it the best for the 420a. they have perfected it. good luck & stick with the 420a. if u just gotta have the 4g63, sell the gs & get a gs-t (turbo), or the gs-x (all wheel drive with turbo). both use the 4g63.

Depends on how much power you want, l mean if you keep the 420a motor is the NA motor and the 4G63 motor for the eclipse only comes as a 4G63 so if you swaped the motor then the turbo would come along with it so. If anything l would do the 4G63 motor.. If you just stick with your 420A and turbo charge it yeah it will be fun but your compression will still be too high to boost as much as the 4G63 will.

wont work at all the motors are completely different...you would have to make custom motor mounts because the both mount up different spots, on top of needed everything for the 4g63.

Neglected to say that the FRAMERAILS are different, so it ai not gonna happen.