Efficiency & Reliability Q?!? KA24DE vs. CA18DET

[r0b]

which engine will last longer while outputting X?

}where X=MPG)

which engine has or can be made to get the best X @ Y lb.-ft. / Y hp?

}where Y = power output (the KA24DE makes 155/155 right? makes things easier).

i'm thinking the CA18DET would be more efficient because doesn't a turbo take advantage of already present exhaust gasses?

please provide multiple reasons that with an explanation why (use as much deep tech talk as possible,) i need to learn somehow.

newb here, so bear with me...

thanks
Modified by r0b at 2:03 AM 4/5/2005

[iliketocrash]

i'm not quite sure about the first question... what do you mean "last longer" on "x mpg"? anyway. Overall Efficiency and reliability is somewhat subjective issues, mainly because either engine you'll come across will more than likely be previously used. Some may argue that the CA would be more efficient because it is better engineered and such. It might help us answer your questions better if you just told us what your goals are. Do you plan on turboing the KA? Are you on a budget? Do you want a sporty street car? Do you want something with good gas mileage? Do you want a drag car? Do you want an autocross car? Do you want something a little out of the ordinary and a little more original? Do you want to really do all the work? i think you get the idea :-P

On a side note you might be interested in going to http://www.howstuffworks.com and looking up "turbo" and "horsepower". That should partially shed some light on your questions.

i hope this helps you help us... help you =)

[rico05]

A CA is a turbo motor, therefore it will use more gas than the KA. Also being a turbo motor, you only ever want to use Premium (91-93 octane) at a minimum. I trashed my KA because of the timing chain tensioner ate it and it munched through the water jacket. I have yet to hurt my CA in any signifigant way.

[81na ZX]

Stock for stock, they are equally reliable, with the KA getting marginally better milage (ofcourse if you stay off boost, the CA will kill it )

Modded, the KA will make more torque to a point.Modded, the CA will be more reliable at just about any power/price point due to the fact its turboed from the factory.

ex: a 300hp CA with $1000 spend on it will be more reliable than a 300hp KA with $1000 spend on it. When $$ -> infinity, both are reliable at any power point.

[cadet]

my ka got 23-25 mpg highway, around 20 in the city. the kaE lasted 190,000 miles before throwing in the towel, the ka24DE lasted around 5. thats right. 5....my ca18det gets 33-35 mpg on the highway, around 15-20 in the city depending on how hard you piss on it, and it lasted someone 88,000 km and its lasted me a few thousand miles with no problems...

I think the ka is a more "reliable" motor because you don't have to worry about intercooler piping, it runs much cooler under the hood because there is no turbo, compression ratio is about the same but there is no turbo, so a bad tank of gas won't hurt you... just less to go wrong on an NA engine....

[rico05]

Honestly, I have friends with all 3 major boosted Nissan 4s in S14s (CA, SR, KA-T) and the KA-T takes the cake for the cheapest power. Yuda spent like $600 on a 96 longblock, and pieced a turbo kit around a j-yard rebuilt T3 Super 60. At 7 pounds, he DESTROYS me at 11 pounds on a T25G and my buddy Keith with an SR with stcok turbo at 14psi. It is all about displacement. Total cost for my motor and power mods is around $3000 or so and Yuda has pent less than $1500. BUT I get the benefit of having a motor that is more prepared to be a power monster at a higher level of tune, but there is little that the KA needs to do the same. It is all just really about the level of modification you feel like doing. Any motor can make 500hp if built for it (and no sub 2 liter 4 banger will do it for long)