Developing your own cam specs for the KA24de!

[BigVinnie]

I thought I would make a thread to up some rep points for myself since I have been a jack ass lately. Mostly due to my own lame temper (I'll get over it).
So now I am kicking down info on how to make better cam specs for the KA than JWT or PDM racing.
First off this will take the use of your original cams for regrinds.
Secondly this will need the actual cams from a CA18DE, CA16DE, or a KA20DE found only in few markets from Japan and the U.K.
How do we know these cam specs will work?????
First off ignition timing amongst these engines werent to far off from each other.
Secondly they all ran on the EXACT same bucket style hydraulic assembly's, using the same shimming for correct valve lift.
Third they are all derived from the nissan parts bin which has been around since the 1960's.( Nissan/Datsun really hasn't changed there parts inventory until the creation of the SR). All these engines used the same geometry known as the 4 cylinder stroker principle. Where the rod/stroke ratio were all pretty consistent to it's stroke. If you do not know what R:S ratio is then SEARCH..
So to find out if the lift and duration specs are compatible from one of these engines to the other we need the R:S ratio's. Which I happen to collect for data for the last couple of years.

CA16DE 1.75:1 rod/stroke ratio
CA18E/CA18de 1.59:1 rod/stroke ratio
Z24/KA24e/KA24de 1.71:1 rod/stroke ratio
L16 1.80:1 rod/stroke ratio
L18/z18ET 1.62:1 rod/stroke ratio
L20b/Z20e/Z20s/KA20de 1.76:9 rod/stroke ratio
Z22e/Z22s 1.59:1 rod/stroke ratio
FJ20E/FJ20ET 1.75:1 rod/stroke ratio
FJ24 1.59:1 rod/stroke ratio


Technically the engine with the larger ratio will have the better duration. Not always true do to rules with smog emissions on USDM's, but in the case of using CA16de cams on the CA18de this lies true.
http://www.nissansilvia.com/forums/index.php?showtopic=861&pid=319569&st=0&#entry319569
Second question in the ask Sarah Column.
http://www.nissanperformancemag.com/april04/ask_sarah/

Technically if you think about it, if there were more specs available for the CA16 the KA would have many more options to chose from today being that there rod stroke ratio wasn't to different from each other. Butthat still doesn;'t mean you can't use specs from the CA18de or DET (Hint for you KADET guy's)
As an example: the KA's 242 intake duration VS. the CA16's 248 intake duration which also included a slightly larger lift for using smaller valves for it's engine. Kind of makes you think of swapping the KA's exhaust cam over of 248 duration on to the intake, doesn't it? All relative sence, all to the same spec comparisons.
So I had to think about this for awhile.... Why haven't shops caught onto specs from these similar engines? Tomei, Greddy, and HKS all make specs for the CA18de. Already R&D'd specs for a fraction of the cost of JWT or even PDM. I mean in all reality if a shop owned the cam with the specs they could relatively charge regrinds for atleast under $110, and then they would be true 270 duration cams or larger unlike JWT which actually fall's short.
To sum up this post you can use cam specs from any of these engines, it's just up to people how they chose to use this information to there advantage to building a better KA.

Also all SOHC engines that are listed in the R:S ratio that I listed can as well use the advantages of using other specs from one engine or the other( as long as that engine was a SOHC using either lifter or a rocker arm assembly).

All I wanted to do with this post is diversify cams and pricing to prove that the KA market isn't just singled out to using expensive PDM or JWT cams. I think after this post alot of shops will catch on (well maybe). Maybe some all ready have......

[ReLevent1]

so to get a better cam setup for my ka all i gotta do is pick up some CA18DE, CA16DE, or a KA20DE cams and have them reground to those specs you put up? sorry im not really understanding this.

[BigVinnie]

so to get a better cam setup for my ka all i gotta do is pick up some CA18DE, CA16DE, or a KA20DE cams and have them reground to those specs you put up? sorry im not really understanding this.


You need to regrind your KA cams, to CA18de or CA16de specs. This means you would need to purchase a performance cam from the U.K or Japan. Performance cams out in other countries for these older cars are cheaper anyways (under $450). But you need the actual cam in order to grind it onto the KA cam. If you get a hold of KA20de cams, they are a direct install.

[krustindumm]

why not just call delta camshafts and have them grind you a set.

[Sularus]

I would think that if you knew the specs from those cams, you can get like crower to regrind them. All you have to do is tell them the specs. I think it is under 200 for both cams at crower.

[BigVinnie]

It doesn't work that way...
You need a template of the specs in order to grind it onto KA cams. Crower nore, Delta have the specs from the manufacturers and I highly dought that they just hand specs out, simply for the fact that it infringes upon there patent.
Several things that manufacturers like HKS, Greddy, or even Tomei will not hand out all there information.
Shure they may tell you what the duration to the cam is but then there is also grind number, and lift needed to give the proper lobe in the cam. With out those specifics there isn't a proper spec for the cams that you would want.

[trsilvias13]

JG did this a while back ago . I have one prototype cam they were about to produce with parts# and everything. I might sell it though.

[ReLevent1]

You need to regrind your KA cams, to CA18de or CA16de specs. This means you would need to purchase a performance cam from the U.K or Japan. Performance cams out in other countries for these older cars are cheaper anyways (under $450). But you need the actual cam in order to grind it onto the KA cam. If you get a hold of KA20de cams, they are a direct install.
whoa you kinda lost me there:confused: .....so buy a perfomance cam for a CA18de or CA16de meaning? hks and whatnot? then use that cam as a template for the regrinding of the ka cams?.....and if a buy perfomance cams for a ka20de i can just drop them in instead of having the stock cams reground?.....haha im trying to figure this out.:tweak:

[NI_YON_Zenki]

Yeah, this shit is a bit complex. .. .

What you are stating from what i have briefed is:

The fact that the CA18DE/K20DE/ or FJ20E cam's setup are the best development option to associate R&D with when trying to design a strong higher lift/duration spec camshaft for a USDM KA24DE motor. .. .

Now, with doing so, you create a stronger load being placed upon the bottom end of the engines performance curve based on the amount of added air/fuel consumption when altering the state of the stock head unit on the KA24DE engine this design hypothesis is being tested first & foremost

. .. .I understand where you see a possible advantage

but here is where I can't fit in. .. .

When you go for a JDM aftermarket spec modification, then try to adhere those mods toward a USDM Spec Engine, you take the simple fact that the engines a layed out to certain criteria met to clear specific circumtances, pertaining to the emissions codes and regulations in comparison to the USDM specifications. .. .So when using Tomei, Greddy, HKS, etc to assist you in this development of a performance camshaft, you must also realize that the circumstances met here in the states may not comply with those of international specifications,and the simple fact that these R&D performance are dealing with specific criteria under their own ideologies within their own performance knowledge and experiences. thus the RB20-6 and or the SR20DET is not smog legal here in the states, due to the simple fact there is to much converting to go into the possible consideration of smog regulation clearing here stateside. .. .(just a speculation)

Its a beautiful, somewhat well thought out hypothesis, but I think you should research this a bit more, maybe practice on some of those JDM cams yourself, then get back to us with results that pertain to reality Results, not saying that none of these ideas would take in the market, or be efeective with those who try to develop the KA motor more in depth, but I think the amount of R&D with a project of this caliber should be left to the likes of. .. .

HKS, Greddy, Tomei, & all those other big name companies that have devoted the time and money Into the individuals who have the time & well. .. .Money. to make this shit a, well. Reality

[sideview_180sx]

skip. shut up. again. I live 8mins from Web Cams, I'll have them make a custom one. prob solved!


skip, when you run cams, the idea is not to pass emissions any longer.

[krustindumm]

It doesn't work that way...
You need a template of the specs in order to grind it onto KA cams. Crower nore, Delta have the specs from the manufacturers and I highly dought that they just hand specs out, simply for the fact that it infringes upon there patent.
Several things that manufacturers like HKS, Greddy, or even Tomei will not hand out all there information.
Shure they may tell you what the duration to the cam is but then there is also grind number, and lift needed to give the proper lobe in the cam. With out those specifics there isn't a proper spec for the cams that you would want.

Most of the time you can get specs for peak lift, duration, and duration at XX lift, which is generally enough to get you in the ballpark of ramp slope etc... You are talking about running cam specs from a different ENGINE and you are worried about minor details like not getting it exactly like something that is not perfect?

[daryl337]

well.. all their is to cam's is duration, lift, and lobe separation. Most factories wont have a problem telling their camshaft specs because... well.. they are outdated camshafts. Moreover, there are tools that people use in order to determine the camshaft specs. Determining lobe separation angle is simply the angle from peak to peak... lift is simply what it sounds like... and duration is the degrees that the valves are open during rotation.

What really is worth looking into in modifying your camshafts would have to do with what kind of modifications you have on the car, and what you are hoping to get to. A high revving motor would like to have a high duration cam... and depending on your desired operating style... a certain amount of overlap. For instance... on motorcycle motors (talking crotch rockets) like the cbr600... they run high lift, high duration cams with extremely low overlap and a tight lobe separation... giving you that *braap* style rev... and a high rpm powerband which (according to physics) translates to pretty high horsepower numbers. If you want a torquey tire burner (but kinda lacking in the high end)... a mid duration, high lift cam is the way to go.

On Ka motors... I feel that the 5600 rpm peak hp.. (6500 redline) is just not enough... and if I had not have gone for the SR.. I would have gone with about a mm increase in lift and about 6-8 more degrees of duration... =)

[BigVinnie]

lift is simply what it sounds like... and duration is the degrees that the valves are open during rotation.




That is correct.
Lift is only determined by the factory setting of the head and what the buckets are shimmed out too. You just can't grab any specs from any engine and say that it will work with that particular valve train. The consistency in lobe and duration for that particular valve train will make a certain lift that is required to the rod/stroke ratio of that engine.
I think the other main concern to worry about is valve overlap. Too much overlap is bad.

[BigVinnie]

Yeah, this shit is a bit complex. .. .
here is where I can't fit in. .. .

When you go for a JDM aftermarket spec modification, then try to adhere those mods toward a USDM Spec Engine, you take the simple fact that the engines a layed out to certain criteria met to clear specific circumtances, pertaining to the emissions codes and regulations in comparison to the USDM specifications. .. .So when using Tomei, Greddy, HKS, etc to assist you in this development of a performance camshaft, you must also realize that the circumstances met here in the states may not comply with those of international specifications,and the simple fact that these R&D performance are dealing with specific criteria under their own ideologies within their own performance knowledge and experiences. thus the RB20-6 and or the SR20DET is not smog legal here in the states, due to the simple fact there is to much converting to go into the possible consideration of smog regulation clearing here stateside. .. .(just a speculation)


Damn sorry for the double post but you just made an excellent point to cause debate. Really one of the more educated opinions I've heard in a while.
One main reason that forced induction cars don't make it into the U.S is literally due to consumption of fuel and how well it performs to smog emissions. I don't wan't to bite my tounge on this issue either. Most cam swapping deals with retuning the ecu to allow the engine to run much more effeciently with the newer cams that would be put into place, (installing cams without retuning the ecu with longer durations cams sometimes make an engine worse from a non streetable idle, as well as making a A/F mixture to lean to pass smog, actually raising NOX emissions).
A lot of fuel on boosted engines is actually just really used to cool chamber tempratures in order to prevent detonation. This causes higher content in CO, and CO2, obviously if it is to high it is a less reliable engine to passing smog emissions.Obviously the reason why the EPA didn't allow the RB or SR into the states. If cams were the problem then there would be higher NOX levels from increased duration to leaning fuel and reducing richness.
At WOT fuel defenitely isn't conserved as more power output is achieved to it's RPM, actually making it less effecient than a Naturally Aspirated V8 that could accomidate that same HP using smaller flow rate injection as well as shorter pulse width.
Plus I don't think insurance companies like the idea of you or I driving a car that could be boosted to an outrageous amount of HP, it throws there whole rating system out the window on what they charge you a month to drive that vehicle at it's stock specs. (Good example look at the STI or EVO the price tag is $40,000 to buy new, and insurance rates are rediculous.) Probably why the 240sx was an economical car with the KA.
I respect your speculation it was a good one.




Its a beautiful, somewhat well thought out hypothesis, but I think you should research this a bit more, maybe practice on some of those JDM cams yourself, then get back to us with results that pertain to reality Results, not saying that none of these ideas would take in the market, or be efeective with those who try to develop the KA motor more in depth, but I think the amount of R&D with a project of this caliber should be left to the likes of. .. .

HKS, Greddy, Tomei, & all those other big name companies that have devoted the time and money Into the individuals who have the time & well. .. .Money. to make this shit a, well. Reality

But the fact is none of these manufacturers took the initiative to make cams for the KA for as long as it has been around for almost 20years now. Maybe we need to take some initiative of our own to make the KA a better engine to the builders conception.
This wasn't any hypothesis of mine either as I have just taken this info that was given to me from other shops and oldschoolers that have already done this procedure as well, I thought that I would contribute something to the table, that could be used as positive info.