S13 KA24DE Cam Alignment

Information on the naturally-aspirated KA24E and KA24DE engines.
jmhalder
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how much was your gas mileage effected, is it still aproximatly over 20mpg


initial_d_s14
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jmhalder wrote:how much was your gas mileage effected, is it still aproximatly over 20mpg
yeha its still over 20mpg, 2 weeks in a row it was 19.xxmpg. now its back up to 23. Id say the average is around 21 city, 26 Hwy

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chandler
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I looked at my cams, there are no engravings on the cams themselves, the caps on the head have them, but not the cams

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Shift__BODOM
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hmm, i just swapped my old '93 cams into my new '96 motor, and i've run across a few problems. that image is my '96 cams before i attacked them. i dont have an after pic, but i can tell you that the '93 cams don't look exactly like that...

the cams at TDC on cyl #1 with the old '93 cams installed don't point exactly outwards like the other ones did, but point slightly more at an upward angle from the center. this is the only way to angle them so that the valves are all closed. i think that with this setup the intake cam is slightly advanced, and the exhaust cam is slightly retarted by a tooth on the cam gears or a few degrees. with the #1 cyl. lobes pointing out like they should be at TDC, the #3 cyl intake valves and #2 cyl exhaust valves are depressed slightly. i wish i had a picture of the cams the way they are now. btw both cam sprockets are stock, non adjustable ones. i just need to confirm that the cams are off timing...and what about those valves being pushed down slightly? is that a problem or should i focus on putting #1 cyl cams at TDC?

AAAH! HELP!

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Shift__BODOM
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nevermind. the intake sprocket was off by a whole tooth. got it rotated to spec and everything fell into place. go team!

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InsanityInc
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Can anyone with an S13 with cams they haven't messed with tell me if the cams point directly away from eachother or not, and also could they tell me how many links (inclusive) are between the little circular marks on the cam sprockets?

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tryiian
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just go back to the top of the thread and check there, you`ll get both answers.

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InsanityInc
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Shift__BODOM wrote:hmm, i just swapped my old '93 cams into my new '96 motor, and i've run across a few problems. that image is my '96 cams before i attacked them. i dont have an after pic, but i can tell you that the '93 cams don't look exactly like that...

the cams at TDC on cyl #1 with the old '93 cams installed don't point exactly outwards like the other ones did, but point slightly more at an upward angle from the center. this is the only way to angle them so that the valves are all closed. i think that with this setup the intake cam is slightly advanced, and the exhaust cam is slightly retarted by a tooth on the cam gears or a few degrees. with the #1 cyl. lobes pointing out like they should be at TDC, the #3 cyl intake valves and #2 cyl exhaust valves are depressed slightly. i wish i had a picture of the cams the way they are now. btw both cam sprockets are stock, non adjustable ones. i just need to confirm that the cams are off timing...and what about those valves being pushed down slightly? is that a problem or should i focus on putting #1 cyl cams at TDC?

AAAH! HELP!
I think the LCA is just different between the two sets of cams. If compression checks out then you're fine.

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s13sr20chris
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IMPORTANT

DONT GO BY THE COLOR OF THE PAINT ON THE CAMS

i have just confirmed that some s13 ka24de's have orange on the intake and green on the exhaust while some others have it exactly opposite. i know this because i just rebuilt 2 heads side by side. they were both from 91 s13's and they were exact opposites. i even installed them both ways and was stumped as to why the lobes were not pointed the right way. then i just swapped them around and found this out.

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InsanityInc
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s13sr20chris wrote:IMPORTANT

DONT GO BY THE COLOR OF THE PAINT ON THE CAMS

i have just confirmed that some s13 ka24de's have orange on the intake and green on the exhaust while some others have it exactly opposite. i know this because i just rebuilt 2 heads side by side. they were both from 91 s13's and they were exact opposites. i even installed them both ways and was stumped as to why the lobes were not pointed the right way. then i just swapped them around and found this out.
Interesting. If I recall, the cams have a little I and E engraved on them, don't they?

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oneline180
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so what if you put the motor together and found out you have the cams backwards? can you just get the lobes to point outwards (facing away from each other) or should you flip them the way they are supposed to be?

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s13sr20chris
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InsanityInc wrote:
Interesting. If I recall, the cams have a little I and E engraved on them, don't they?
nope, most other nissan stock cams do but not ka cams.

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s13sr20chris
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oneline180 wrote:so what if you put the motor together and found out you have the cams backwards? can you just get the lobes to point outwards (facing away from each other) or should you flip them the way they are supposed to be?
no, you must swap them.

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InsanityInc
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oneline180 wrote:so what if you put the motor together and found out you have the cams backwards? can you just get the lobes to point outwards (facing away from each other) or should you flip them the way they are supposed to be?
Well, you CAN keep the cams as 248/240 so long as you can get them aligned right. But it will change the performance of the car. And whatever you do, DO NOT try to start the engine before you have thoroughly rotated it by hand.

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Chezedik
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When hand rotating, I will not bend a valve right? Because I am having a hell of a time here, and I did hand rotate first. Not with any force but I did hit a valve I believe.

Skidmark
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Unless you really wrenched the crap out of it you won't bend any valves. In the future I would reccommend doing what I did. TDC #1, take a center punch and LIGHTLY put corresponding numbered tick marks on the chain and the sprocket. * for intake, ** for exhaust, *** for intermediate sprocket, then do the same for the rear chain. As long as you TDC the motor before you put it back together, it's pretty much impossible to mess it up. I know this doesn't really help you guys who have already disassembled your heads. Just for future reference I guess.

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Chezedik
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I'm not sure I have F'ed it up, but something is seriously wrong with compression, and I am getting tired of working on this motor. I will just take the cams out and see if I can get proper numbers then. If I can, then I know it is timing. If I can't then I add oil to the cyls and see if compression rises, if so, the head comes off and I figure out something with the pistons and wrings. If not, then I bent a valve on my expensive head. So we will see after finals.

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Loofee95SE
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does this mean: S13 exhaust cam not worth my time??? I have a set of cams, not sure which 1 is Exhaust or Intake..but it's S13 ka for sure..I believe that the exhaust has orange paint on it before I uplled it out. but it seems like its too much trouble installing it. anybody want it?? make me an offer [email protected]

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Chezedik
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I am concerned myself, because I have the S13, w/o the SCVs or almost any of the other emissions stuff. But I have heard the biggest part of the gains on the S14 came from not having the SCVs, so umm, I guess that is your answer. If anyone else can back it up.

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Suicide.Veteran
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I have a question about the cam brackets. I pulled my cover off cuz im doin a rebuild, and when i looked at the cam brackets some of the I (intake) ones were on the exhaust side, and so on. As long as i have the right numbered bracket in place, does it matter if its intake or exhaust?

tre
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Dial indicators and marking the crank when the intake side on cylinder one starts opening is the BEST way to do it. IF the engine is in the car.

Skinsk
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H.D.HUMPERDINK wrote:I have a question: I know that on push rod motors you have to break the cam in, and I was wondering if you have break in cams on our cars?
I think that you would have to break in a new cam aswell on a dual (or single for that matter) overhead cam. As an in block cam you would want to be shure everything was in working order before road testing.

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rsmithdrift
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This seems to be the place to ask.....

I've heard swapping in a exhaust cam out of another 240sx DOHC in place of the intake cam will get you your top end to a good level. I was wondering what would happen if you simply swapped the exhaust and intake cams. Meaning the exhaust cam is now intake cam and intake cam is now the exhaust cam.

Intake (green) is 240 and exhaust (orange) is 248 right??? What effect will swapping them have??

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seanman
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that would probably mess your **** up considering the intake cam is usually earlly to allow intake flow to push out the excess exhaust. is it not possible to look in a chilton for all the cam timing info and what not? and another question, do you have to worry about your pistons slamming into your valves if your timing becomes off?

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ka24dave
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seanman wrote:that would probably mess your **** up considering the intake cam is usually earlly to allow intake flow to push out the excess exhaust. is it not possible to look in a chilton for all the cam timing info and what not? and another question, do you have to worry about your pistons slamming into your valves if your timing becomes off?
ouch.

dkdeleon68
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To answer the question about how to tell which cam is intake and which is exhaust, If you look at the cams they both have a metal dowel pin to keep the sprocket from spinning, the dowel lines up with the first lobe on the intake cam. see the pic below.
Modified by dkdeleon68 at 7:08 AM 3/21/2007

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Chezedik
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Would having the cams in the wrong position cause low vacuum? That is, if you have the exhaust in the intake spot, and vice versa, would your overlap be high enough to cause a vacuum leak?

dkdeleon68
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you would bend valves.

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Chezedik
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Not if they were set opposite of each other at TDC. The timing is correct, but the cams may be in the wrong place. That would not bend valves but would it cause low vacuum?

neogeoss4
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If you look closely at the Cams, because im stuck doing this job too, mines werent colored so i had to figure out on my own, lucky us when we first installed them wrong and we ran the engine it didnt bend a valve, but if you clean the cams and look closely they are numbered, 1 for intake and 2 for exhaust. also be careful when taking out the cams, it needs to be a rather delicate process.


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