KA24DE Bottom End Modifications

Advanced discussion of improving KA-T components
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Aaj2k5
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KA24DE Bottom End Modifications

Post by Aaj2k5 » Thu Apr 07, 2011 11:01 am

It was recommended that I post this in here rather than my build thread.

The problem here is that I'm a nut and am never satisfied with the motor's I'm using.

Main problem: KA crank is half balanced.

Theoretical Solution: Almost have it figured out how to rock a fully counterweighted crank in a KA block with KA piston. I have based all my calcs off of DatzenMike's measurements, Internetz and Wiseco's Catalogue, nothing is definite.

Rod is out of a Ford 5.4 Modular Motor, longer rod than a KA by about 5mm (169.1mm to 165mm)

Bushings need to be drilled out or replaced, or the KA piston needs a 22mm pin instead of it's 21mm. Does KA have to have floating pin or is press fit allowed.

Crankshaft is a L20B/Z20E/Z20S U60 casting.

The other options I have listed include a Toyota Celica 20R 90mm Piston with various rods that will work - LS1, Viper V10, Ford w/ Chevy Pin, but I would like to try it with the KA piston first.

Braaap.
Image

Actual link: http://i243.photobucket.com/albums/ff28 ... dSheet.jpg

In due time, after some paychecks, I'll make this happen and post up how it is.

Until that time - does anyone see a fault in my calculations / logic / sanity? :twisted:[/url]

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Post by wannaboost? » Thu Apr 07, 2011 5:15 pm

Image


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Post by drivemarcusdrive » Thu Apr 07, 2011 5:21 pm

i like what youre doing here, but i cant read the spreadsheet. anyway to make it bigger??? :D

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Post by Aaj2k5 » Thu Apr 07, 2011 5:40 pm


Uhhhhhh.....

Brian Crowers kit lengthens the stroke, raising displacement but drops redline to 5500.

And is 3000+ dollars.


I am destroking, effectivly a 2.2L, that will push over 9000 rpm.

And is less than 800 dollars.

Thanks for coming out tho.

also i will send my spreadsheet to anyone that pm's me their email addy. it is not final measurements just calculations i did in about an hour or so at work so i take no responsibility for your spending actions lol.

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Post by smbonn2005 » Thu Apr 07, 2011 5:49 pm

Just wanted to point out Brian Crower does also make a stock specification (stroke) FCW crankshaft as well, you have to actually call/email to get it though as they don't list it on there site. If I remember correctly its about $1000 by itself.

And I definately would not want to DEstroke the KA. If you want a rev happy motor go with the SR. The extra displacement is awesome when spooling a turbo.

I'd spend the 1k to get that crank before I would redo my entire setup though.. Still awesome research and for people just starting off a build it may be a very viable option if everything does work. If you could send me the spreadsheet so I could go over everything that would be awesome.

Stephen

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Post by Aaj2k5 » Thu Apr 07, 2011 5:57 pm

i hear you on the spooling a bigger turbo and go get an SR I'm just trying to develop the KA as much as I can.

I didn't know BC had a 96mm stroke FCW - thats fairly interesting.

A new U60 FCW crankshaft is $133 online. So if rods and pistons can be had cheap, it would be a legit way to make some high rev power. And I'm 20 and in college so money isnt plentiful :D

And i seem to have an obsession with frankenstein'ing my projects lol KA in a datsun, R34 subframe, S13/S14 suspension..

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Post by smbonn2005 » Thu Apr 07, 2011 6:04 pm

Aaj2k5 wrote:i hear you on the spooling a bigger turbo and go get an SR I'm just trying to develop the KA as much as I can.

I didn't know BC had a 96mm stroke FCW - thats fairly interesting.

A new U60 FCW crankshaft is $133 online. So if rods and pistons can be had cheap, it would be a legit way to make some high rev power. And I'm 20 and in college so money isnt plentiful :D

And i seem to have an obsession with frankenstein'ing my projects lol KA in a datsun, R34 subframe, S13/S14 suspension..
Yeah they do, though they do not list it on the site anywhere. I emailed them about 4-5 months back to get proof and a price and they verified they do have a stock stroke FCW crank for the KA.

Haha believe me i know the young and in college spiel. I'm in the smae place right now, but at a auto/high performance tech college so I have access to all kinds of cool things =)

And this build is awesome, definately keeping an eye on it.

---BTW when you get more info on the Z33 trans adaptor please let me know as I will almost definately be interested in one =)

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Post by smbonn2005 » Fri Apr 08, 2011 6:00 pm

Went through your calculations over the day and everything looks correct to me. Damn good research there dude. Now if you can get everything to work together that would be amazing!

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Post by Drifting Kalamari » Sat Apr 09, 2011 1:42 am

I can't wait to see how this turns out! GL!!

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Post by KoukiKAT » Sat Apr 09, 2011 9:48 am

Just some fuel for the fire:

http://zilvia.net/f/tech-talk/52292-ka2 ... post461226

http://www.performanceforums.com/forums ... stcount=10

Aaj2k5, please upload your actual spreadsheet and not just a .jpg of it for us to check out. I like the fact that a set of 8 5.4 modular ford rods is about $500 and is enough for two motors.

KA vs. L20B crank:
Image

Z24 (not fully counterweighted) crank machined to fit L20B block. Not quite what we're looking for, but a good illustration of what's possible:
Image
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Post by Jus14 » Sat Apr 09, 2011 11:03 am

Hell yeah good work would love a de stroked KA !
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Post by Aaj2k5 » Sun Apr 10, 2011 8:37 am

Update - I have a friend with a L16 crank I could use for measurements. Exactly the same length wise dimensionally except L20 has a larger counterweight, L16 is shorter stroke, smaller diameter journals.

I'll post my pictures tonight as well as measurements but it fits in the KA girdle almost perfectly.

As my internetz research showed, the main journals are wider and would need thrust bearings/washers used to center the crank.

I'm making a solidworks part file of it and I'll post it once I make it and the KA.

Now I just need a damn L20 crank lol.

I will split a set of Rods with whoever wants to experiment this with me. Or just sell the other 4 once I buy a set.

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Post by schmauster920 » Sun Apr 10, 2011 10:17 am

Hey great job figuring this out.. Nissan is the king of parts bin mentality.. and it hasnt done anything but help me so far lol

Keeping my eye on this thread, ill be really really tempted to build a fully counter weighted KA
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Post by Aaj2k5 » Sun Apr 10, 2011 11:45 am

The only problem I can see thus far is that L cranks have a 5 bolts flywheel not 6. So a new flywheel/clutch setup must be made - any ideas?

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Post by KoukiKAT » Sun Apr 10, 2011 12:14 pm

You could do a custom two piece flywheel spacer for the Z33 trans setup that converts it from 5 to 6 bolt. Closest thing I could find: http://offroad-review.com/new/index.php ... 45&page=79

Or, you could mill the heads off of the flywheel bolts, weld them flush, and have a 6 bolt pattern drilled. Perhaps there's a 5-bolt flywheel from another Datsun or Nissan, but who wants a 5 bolt flywheel?
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Post by Aaj2k5 » Sun Apr 10, 2011 1:40 pm

My Z33 trans adaptor doesn't need a flywheel spacer :D but I'm liking the weld the holes and drill for 6 solution.

I have to check what the ka flywheel bolt size is - iirc it's 6xM8 - I believe the L is 5xM10, which if there is a legit bolt on 5 flywheel it would be handy for ease of swap.

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Post by Alonso » Sun Apr 10, 2011 9:00 pm

Ever looked into the ka20de? It sux the US never got them...idk about Canada, but I suspect Mexico may have...

What are you gonna do about the oil pump? The 240sx DE crank looks a lot longer so it can drive the pump gears...may be easier to use a frontier block as its oil pump/distributor is set up like a SOHC KA/L20.
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Post by 1600dave » Mon Apr 11, 2011 5:31 am

schmauster920 wrote:Nissan is the king of parts bin mentality..
The reason the L20B crank fits in a KA24 is that the KA24 is simply another evolution of the good old L-series. L-series evolved into Z-series, which in turn evolved into the KA24.
Aaj2k5 wrote:The only problem I can see thus far is that L cranks have a 5 bolts flywheel not 6. So a new flywheel/clutch setup must be made - any ideas?
L16 and L18 are 5 bolt. L20B is 6 bolt.

I'm actually looking into a similar conversion for my old Datsun 510, I'm using a KA24DE head on a complete L20B bottom end.

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Post by Aaj2k5 » Mon Apr 11, 2011 6:01 am

I saw some pictures of L20 cranks and they never really showed the crank bolt pattern - thanks for confirming that Dave!!

phew. Yay for keeping RB flywheel / 350z clutch setup.

Solidworks model should be done today or tomorrow.

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Post by Aaj2k5 » Mon Apr 11, 2011 6:08 am

Alonso wrote:Ever looked into the ka20de? It sux the US never got them...idk about Canada, but I suspect Mexico may have...

What are you gonna do about the oil pump? The 240sx DE crank looks a lot longer so it can drive the pump gears...may be easier to use a frontier block as its oil pump/distributor is set up like a SOHC KA/L20.
The KA crank looks alot longer on the nose end because it doesnt have the sprocket on there like the L20 crank does in the pic. The major difference is the nose diameter and keyway which are peanuts to machine..

I'm also trying to make it work on S14 KA because 1) thats what I have, 2) frontier blocks are hard to come by where I live and 3) the # of people who would want to do this who already have S13/S14 blocks I'm assuming is far greater than # of people who have frontier ones.

KA20DE has a half weight crank as well, but for the most part Canada and US get the same parts. Thanks for the ideas though - any are welcome..

New things to add to my list of Frankenstein-age..

- Lose the girdle and use the beefier truck main caps.
- Lose the 240SX block and find a truck KA block in general (trying to find one.. Bigger cylinder wall thickness, truck main caps)
- When machining the snout down to KA diameter, drill the dampener bolt right through to journal #1 - SCCA guys do it to increase dampening and keeps the snout from snapping off at high rev's.
- Does anyone have any SE-R friends that can measure an 07+ QR25DE crank?
FCW, 100mm stroke. based off of some #'s I can find for crankshaft repair kits, they look to be very similar diameters and journal widths, but it is journal placement that I'm wondering about.

Edit: I downloaded the 08' Sentra FSM says crankshaft outer main dia journal is 2.1636-2,1645", QR pin journal dia is 1.7699 to 1.7706". KA24DE is outer main dia journal is 2.3603 to 2.3612", pin journal is 1.9668 to 1.9675. Looks like crank mains are just too small to use even if placement was proper :( unless people have used 0.100 thick bearings ??


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Post by Aaj2k5 » Mon Apr 11, 2011 11:22 am

Here is the pic of the L16 HCW crank in a KA girdle.

Image

It will not work as far as main journal diameters are concerned, but all I was looking for was placement of a L-series crank in a KA girdle.

Thrust washer will more than likely have to be used - I haven't looked into it yet but how is the KA crank located axially?

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Post by Niclas_AB » Wed Apr 13, 2011 3:31 am

This is very cool! Have a couple of questions, the L20B crankshaft seems very hard to find in Sweden. I did find a LD20 engine from a bluebird, it has exactly the same displacement as the L20B, do you think it has the same crank as the L20B?

And also where can I find a new L20B crank for 133$? :o

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Post by Aaj2k5 » Wed Apr 13, 2011 5:54 am

If you went and got the LD20 crank - I'll pay for it and for you to ship it to me and I'll try it out.

RockAuto.com I believe was the website.

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Post by Niclas_AB » Wed Apr 13, 2011 6:26 am

Well since I'm Sweden it will be alot cheaper for you just to buy a brand new from rockauto.com, they want 169$ for one with casting number U6040, and it seems to include new rod and main bearings aswell.
I probably have to pay about they same for the used LD20 Crank and then the shipping to US would probably be over 250$ :(
Edit... Oh I see you are in Canada but it would still cost as much to have it shipped there I'm afraid :(

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Post by Aaj2k5 » Wed Apr 13, 2011 6:45 am

If you could still get me a price on a LD20 crank shipped here I'd be grateful - they are supposedly stronger than the L20B but I'm not sure if it will fit yet.

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Post by Niclas_AB » Wed Apr 13, 2011 7:21 am

Ok, this is about what it would cost.
The LD20 is a complete engine and the scrapyard only wan't to sell it as a complete unit since they will never get rid of the other parts... :roll:
The engine costs about 575$, then shipping across Sweden to me is another 125$, then if I brake it apart and only send you the crank the shipping to Canada wasn't that terrible, about 155$.
So that will be a total of 850-900US$ :roll:

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Post by Aaj2k5 » Wed Apr 13, 2011 7:47 am

LOL nice. Still beats buying the crank out of NOS for $1790 USD ahaha.

Sorry man, I thought the crank was in a local yard that would seperate the motor haha.

I'll just use a L20B crank and if for some god-awful reason I break it I'll step it up and get a diesel one.
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Post by Niclas_AB » Wed Apr 13, 2011 11:24 pm

No sorry, it's almost as far away as it can get in Sweden :( We have a big database where I can search throu al the scrapyards in Sweden, thats where i found it :)
Just did a quick calculation and with a 86mm stroke you can rev about 1000rpm more than with the stock ka crank before you hit the same piston speed wich should be the limiting factor. Is it really worth the work involved for 1000rpm more?
Anyway it's a really cool project and I really hope you kan get it together soon! I'm going to be following this thread closely :)

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Post by Aaj2k5 » Thu Apr 14, 2011 5:28 am

We have the beginnings of a database like that but its still pretty cruddy.

As far as revving 1000 rpm more thats not entirely the case. Yes the piston speed would be the same but you are saving it from the first, second and third order of harmonics caused by HCW cranks. This allows a higher piston speed to be used safely, as long as you have all necessary mods to continue at those higher speeds - forged rods, pistons, balanced assembly, valvetrain, massively better airflow through the head and i may go even as far as an ATI dampener when I push the limits of it.

Also, this isn't a great ordeal of work to make it work.. It bolts into the block, I just need thrust washer/bearings as well as to machine 1mm out of the pin of the piston (Wiseco will do this for me) and a very tiny amount out of the crank end of the rod bushing. Using the KA frontier block, the oiling is *apparently* the same, and the Z33 clutch and RB flywheel will still bolt on.

If it fails, I spent a grand total of $133 on a crank, $250 on rods and some machine work (free).. Much better than >$1000 for the BC one.

And if I blow a motor in the research of it? **** happens - somebody has to push it. What if the motor doesn't blow.. :D

I will make sure my tune is as close to dead on as possible before I start giving er.

The crank can also be machined up to a 90mm stroke if you were ambitious and stupid enough (pin journal would be crazy small.) I am going to keep it at 86mm stroke.
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Post by KoukiKAT » Thu Apr 14, 2011 7:17 am

The 86mm vs. 96mm crank throw gives an 11.5% reduction in throw, makes it an oversquare KA22DE-T, reduces piston speed by 10% at the same RPM, reduces engine harmonics for a smoother, higher revving motor, allows increased RPM range and powerband, while (hopefully) still maintaining good torque and equal (or better?) horsepower.

The ratio of airflow capability of the head in relation to the volume of the cylinder that needs to be filled is improved with the smaller stroke as well. Ultimately, you just want to be able to move as much air as possible. If you can do it better with less stroke and more RPM, then you'll make more power.

If only to see what happens, and because I have spare blocks in good shape but cranks with spun journals that may need to be replaced anyhow, I'll egg Aaj2k5 on.
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