Head Sawp

Information on the naturally-aspirated KA24E and KA24DE engines.
spitz7985
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With 11.7:1 compression, I'm sure you have much less valve clearance then a KA24DE has (with 9.5:1 compression, it's already a interference motor!). Aftermarket cams may not be an option, idk.


S13ChucKAT
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I dont see why you couldnt swap in new cams.. just because the CR gets higher, doesnt necissarilly mean its going to be totally hitting the tip of the sparkplug or anything.. and the valves should be shut whenever the piston combust's..

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glacier985
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I am starting to get pissed, I can't figure out why I'm not getting spark anymore. I have tired everything, checked the distributor internals, checked all my wiring, checked all my fuses, checked everything I could think of that would cause it to not spark. And yet still, I have no ****ing spark, errr

nab911
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Get a multimeter, and run through the ignition system. Are your injectors fouled?

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glacier985
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I went back through and rewired everything, hooked the vaccum lines up correctly, double checked them, and still no spark. Coil is fine, i checked it with a multimeter, spark plugs wires were also checked, and i still have no spark. Anyone got any suggestions???

spitz7985
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S13ChucKAT wrote:I dont see why you couldnt swap in new cams.. just because the CR gets higher, doesnt necissarilly mean its going to be totally hitting the tip of the sparkplug or anything.. and the valves should be shut whenever the piston combust's..


I'm not sure if it would cause clearance problems. The valves are open when the piston is coming up during the exhaust stroke (not when it's at TDC, though).

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smug510
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damn , this is cool , you guys are really running with this idea , i would have never thought it would get so big , good job with the swap thats exactly how i did it , with the aluminium plate adapter , as for the spark thing i dont know, but when you do get that thing to run you better throw some sr injectors in it real quick , it needs them real bad , as for my motor its sitting in my garage waiting to be sold or put in a sandrail or something , well have fun with it and good luck ,

troy

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deviousKA
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The exhaust valves come the closest to the pistons, at stock and most common cam settings. ka24de with the pistons that can give 11.7:1 (early ka/nismo) will hit the exhaust valves. You cannot do this without flycutting, and yes a cam with more lift and/or duration can cause the valve to be closer to piston. 11.1:1 vs. 11.7:1 is roughly 4cc difference in volume in this situation. The 11.7:1 (or 9.1:1 in E) have a step flat dome volume of around 2.5cc. This raises the piston top about .025" or so, and in de, the valves will come way to close to un-flycut pistons. The late ka24e pistons, and most common, appear to be exactly flat top and this causes confusion. This setup alone majorly reduces valve to piston clearance, always clay it and check.

Just to show, here is a 9.1:1 nissan motorsports ka24e piston, notice the step dome volume.


nismojunkie
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anything new on this?

lovemysan2
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hey devious, you know that the 1mm over motorsports pistons are 9.5 to 1. Thats what I'm running.

SunshineAcid
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are you getting power to the plugs?my guess is that you are, but youre running unleaded, and your plugs are fouled beyond belief. (my guess)see if you are getting spark down the plug wire, to the plug, if you are, change your plug, and put some 104 octane boost in. itll be a bit high, but i think your engine will take it well.i used to have a friend that ran his formula firebird on 87 gas. it only had 11:1 comp and when he did that, i could beat it with my 88 civic dx (stock) yes. all 96 horses would win.youre running 11.7:1 to 1? you NEED supreme to even start, youre close to alky compression.and you may need to regap as well. but the high octane fuel is a must.

nab911
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So is this swap straight foward +- the front plate you made becuase thats not too bad. I may be picking up a ka24de this weekend for free and i plan on doing this to 1 of the 3 spare 24e motors im gonna have laying around.

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glacier985
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SunshineAcid wrote:are you getting power to the plugs?my guess is that you are, but youre running unleaded, and your plugs are fouled beyond belief. (my guess)see if you are getting spark down the plug wire, to the plug, if you are, change your plug, and put some 104 octane boost in. itll be a bit high, but i think your engine will take it well.i used to have a friend that ran his formula firebird on 87 gas. it only had 11:1 comp and when he did that, i could beat it with my 88 civic dx (stock) yes. all 96 horses would win.youre running 11.7:1 to 1? you NEED supreme to even start, youre close to alky compression.and you may need to regap as well. but the high octane fuel is a must.


I dont think I am even getting spark to the plug wires, its wierd, its gets the the rotor and the just stops. It has started on the 87 octane, it ran for about 20 secs and then died, hasnt started since, but Im gonna work on her tomorrow and hopefully I get it figured out.

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bokinsmowls
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pull your coil wire, you will see a spark from the coil to the body if it is good. Have you pulled the plugs? Everything turned over nicely (with a wrench) when you put it back together? stupid question-did the pistons hit the plugs?

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glacier985
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nothing hit, everything has clearance. the coil wire is good, I checked it with a multimeter and everything turned over nicely and it still does, it just wont fire.

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bokinsmowls
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Are the electronics the same between de and e?

SunshineAcid
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bokinsmowls wrote:Are the electronics the same between de and e?


ooo...thats a good question. if youve got the whole engine sitting there, id use the de wiring harness.and as far as the gas, it will run, but you can hurt your engine. you *have* to use premuim at that compression.

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glacier985
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I do have the whole engine, minus the wiring harness. For some odd reason I didnt take it when I got the engine from my friend, but the only things that I had to rewire were the fuel injectors.

SunshineAcid
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make sure your dist. is still good.why did he get rid of his engine? was he having problems?

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glacier985
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He swapped in a sr20 and gave me his KA for free, and the distributor should still be good, it worked before I did the head swap, dont know why it would work now.

SunshineAcid
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if youre losing spark at the rotor, see if youre getting spark to it. if you are, see if youre getting spark past it. if youre not, then diagnose the problem there, replace if necessary.also: are you running the e ecu or the de ecu? it might make a difference

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glacier985
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I been switching between the ecu's, lately I've been using the de one. I would replace the cap and rotor, but they only have 3000 miles on them. I think the wierdest part is I had spark and then I lost it all of a sudden.

JonnyB4Real
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what year motor was this that you got from your friend

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glacier985
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93

JonnyB4Real
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e and de wiring is a lot different, you have to use the de. I didnt even read that you didnt. That most definately is your problem

TeckniX
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Well I only stated he used the e wiring harness.. maybe he didn't.. and how much different are they? and why would u use the de harness if the rest of the engine is e. I mean the only difference is the bulk of metal on top of the block, and that doesn't have any wiring.. well tps is maybe different, and injectors definitely need to be re-wired.. but otherwise I really dunno wut else..

Anyway I'm gona do the swap, or try to , so I can show wuts up :)

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glacier985
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I'm using the E harness, because I used the E distributor and the only plugs different were the fuel injectors and the big connector that goes to the IACV, and two other things. And the adapter plate was made of sheet metal I bought from lowes and improving on it, the reason it leaked was because I bent the one side reallt bad. So I guess just try to keep the metal as straight as possible. I have both ECU's so I keep switching them. Im gonna work on it some more tonight, see if I can get her started again.

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glacier985
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I was so close tonight, she almost fired. I think I am going to go buy some 93 octane tomorrow, because she would fire when I put starting fluid in the intake, but then die 5 seconds later.

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sil80drifter
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how in the world are the two cams rotated? I see the big cam gear from the E in themiddle. but what is pushing the valves down, if there is no rocker arms and no dual cams? can you take your valve cover off and take another finished pic?

sil80

TeckniX
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I'm lovin' this more and more. :) Glacier985 did you look up the other post that suggested the 180 rotation, meaning that with de timing, you could be 180 off? Dunno if you saw it or not, but I know I had problems on an sr20 a few months back, and it ended up being 180 timing off. Take more pics of the setup, and it would be great if you could remember what other plugs u had to change. :)


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