KA/L-series block crankshaft specifications - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

geeaj · 05-13-2002, 09:54 PM

I was sitting on the shitter last night pinching a loaf and decided to pickup my old trusty "How to modify your Datsun OHC engine" book for some good reading....

Some interesting info:
- L20b, Z22, Z24 cranks have six 12mm flywheel bolts
- L20b cranks are fully counterweighted
- All Nissan/Datsun have the same 49.97 connecting rod journals. (now, i'm not sure what size the ka crank journals are, but they should be the same since a z24 crank is basically the same)

Stroke:

L20b - 86.0mm
Z22 - 92.0mm
Z24 - 96.0mm
KA24E(DE) - 96.0

Main Bearing Journal Diameter

KA24E(DE) - 59.942mm
Z24 - same
Z22 - same
L20b - same

So what does this mean? There seems to be tons of choice as far as building a destroked KA motor, one that can potentially rev with a sr20. How about a destroked ka running about 2.2liters with a Z22 crank? Perfect medium between sewing machine and stump puller. Don't like that, prefer to rev? Then you can put in a L20B crank (which are very cheap on the z and 510 boards) and turn the ka into a 2.0 liter buzzsaw. Being that the L20B crank is fully counterweighted, it should be very stable at high rpm.

Some food for thought, err, digestion..... <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/blush.gif" border="0" valign="absmiddle" alt=':blush:'>

BadMoJo · 05-13-2002, 10:22 PM

hmmmmmm, very interesting......except for the info about you on the shitter.  <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/crazy.gif" border="0" valign="absmiddle" alt=':crazy:'>  Has anyone ever tried this? I think that if was actually possible a 2.2 would be a very sweet engine. I want more info on this.  <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/notify.gif" border="0" valign="absmiddle" alt=':notify:'>

wherezmytofu · 05-14-2002, 12:17 AM

motion 2 archive <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt='

'> .......west? <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/thumbs-up.gif" border="0" valign="absmiddle" alt=':thumbsup:'>

geeaj · 05-14-2002, 10:05 AM

On the flip side, I am working on compiling data for various bore/piston combinations as well. Since crank journal sizes and main bearing sizes are similiar between KA and L series, the possibilities of piston configurations are endless as well.

Please post this in the FAQ, since I am sure that many may potentially benefit from it...

Hehe, I seen another Del Sol on the way to work this morning... <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/blush.gif" border="0" valign="absmiddle" alt=':blush:'>

*Jeff240sx* · 05-14-2002, 11:29 AM

geeaj,
edit that post and include the bores of each engine.
I'm not seeing how a l22 crank could make the ka a 2.2L engine.  Cuz with domestic iron, a 350 block with a 400 crank makes a 383cid engine.
I can see the l20 making a 2.2L with this logic, unless, the bores are the same.
And this whole ka22de makes a helluva good idea, seeing as the JUN kit for their precious SR makes it a 2.2L motor too.  Coincidence?
Someone try this!  Now!  Or buy me the crank and I'll try it!
-Jeff

S14lover · 05-14-2002, 11:36 AM

yes ..yes ..YES...DO IT....DO IT !!!!!i must have more power ..seriously though i really hope you guys can compile some raw data on this ...this could blow the whole KA haters world apart!(insert sinister laugh)  <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/sly.gif" border="0" valign="absmiddle" alt=':sly:'> P.S. tofu that axl sig you got is a fucking riot it makes me laugh everytime i read it <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/hehe.gif" border="0" valign="absmiddle" alt=':hehe:'>

*sykikchimp* · 05-14-2002, 12:43 PM

This is exactly what Ace was talking about doing a while back.  Maybe he will chime in with some extra useful info.

Isn't the KA 86mm bore?  if so you would have a square bore storke ratio..  can you say 9000 rpm KA???

TheTimanator · 05-14-2002, 02:58 PM

I was pondering this the other day. I didn't realize that Nissan engines were so interchangebale. What is the r/s ratio of the KA24DE? w/KA crank? w/L20B crank? and w/Z22 crank? Which is the closest to the magic 1.75?

A 9000+ redline turbo RWD car would be awesome!

Edit: Anybody know what the SR r/s ratio is?

geeaj · 05-14-2002, 04:43 PM

KA bore size is 89mm i believe..I'll get some updated information later...

obruT ES 41S 79' · 05-14-2002, 05:32 PM

KA has a bore of 89mm. So does the Z24.

The cranks will interchange, it's just the matter of crank journal width.

The hot bearings for the KAT are the cutdown L series Nissan Motorsport rod bearings. KA uses narrower bearings.

The rod to stroke ratio for the KA is 1.71. SR is about 1.6x IIRC. KA with the 6.7" Carillo rods and the offset piston runs a ratio of 1.74. Even better.

The original thoughts as presented by several folks from way back in the days of the 240sx amarok list. There was already discussion about the possibility of destroking the KA. Ace picked up the discussion from my discussion on FA.

Sean1978 · 01-10-2006, 03:06 PM

did anyone ever get anywhere on this?

05-13-2002, 09:54 PM	#1
geeaj Zilvia Junkie Join Date: Dec 2001 Posts: 357 Trader Rating: (0) Feedback Score: 0 reviews	I was sitting on the shitter last night pinching a loaf and decided to pickup my old trusty "How to modify your Datsun OHC engine" book for some good reading.... Some interesting info: - L20b, Z22, Z24 cranks have six 12mm flywheel bolts - L20b cranks are fully counterweighted - All Nissan/Datsun have the same 49.97 connecting rod journals. (now, i'm not sure what size the ka crank journals are, but they should be the same since a z24 crank is basically the same) Stroke: L20b - 86.0mm Z22 - 92.0mm Z24 - 96.0mm KA24E(DE) - 96.0 Main Bearing Journal Diameter KA24E(DE) - 59.942mm Z24 - same Z22 - same L20b - same So what does this mean? There seems to be tons of choice as far as building a destroked KA motor, one that can potentially rev with a sr20. How about a destroked ka running about 2.2liters with a Z22 crank? Perfect medium between sewing machine and stump puller. Don't like that, prefer to rev? Then you can put in a L20B crank (which are very cheap on the z and 510 boards) and turn the ka into a 2.0 liter buzzsaw. Being that the L20B crank is fully counterweighted, it should be very stable at high rpm. Some food for thought, err, digestion..... <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/blush.gif" border="0" valign="absmiddle" alt=':blush:'> __________________ Beware the fury of a silent man, be more cautious of his silent farts....

05-13-2002, 10:22 PM	#2
BadMoJo Nissanaholic! Join Date: Sep 2001 Location: San Luis Obispo, Ca Age: 43 Posts: 1,931 Trader Rating: (0) Feedback Score: 0 reviews	hmmmmmm, very interesting......except for the info about you on the shitter.  <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/crazy.gif" border="0" valign="absmiddle" alt=':crazy:'>  Has anyone ever tried this? I think that if was actually possible a 2.2 would be a very sweet engine. I want more info on this.  <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/notify.gif" border="0" valign="absmiddle" alt=':notify:'> __________________ ----Gone----

05-14-2002, 12:17 AM	#3
wherezmytofu BANNED Join Date: Nov 2001 Posts: 1,873 Trader Rating: (0) Feedback Score: 0 reviews	motion 2 archive <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=''> .......west? <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/thumbs-up.gif" border="0" valign="absmiddle" alt=':thumbsup:'>

05-14-2002, 10:05 AM	#4
geeaj Zilvia Junkie Join Date: Dec 2001 Posts: 357 Trader Rating: (0) Feedback Score: 0 reviews	On the flip side, I am working on compiling data for various bore/piston combinations as well. Since crank journal sizes and main bearing sizes are similiar between KA and L series, the possibilities of piston configurations are endless as well. Please post this in the FAQ, since I am sure that many may potentially benefit from it... Hehe, I seen another Del Sol on the way to work this morning... <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/blush.gif" border="0" valign="absmiddle" alt=':blush:'> __________________ Beware the fury of a silent man, be more cautious of his silent farts....

05-14-2002, 11:29 AM	#5
Jeff240sx I hate you too... Join Date: Jul 2001 Location: Tampa, FL Age: 42 Posts: 5,828 Trader Rating: (0) Rides Gallery: Jeff240sx Feedback Score: 0 reviews	geeaj, edit that post and include the bores of each engine. I'm not seeing how a l22 crank could make the ka a 2.2L engine.  Cuz with domestic iron, a 350 block with a 400 crank makes a 383cid engine. I can see the l20 making a 2.2L with this logic, unless, the bores are the same. And this whole ka22de makes a helluva good idea, seeing as the JUN kit for their precious SR makes it a 2.2L motor too.  Coincidence? Someone try this!  Now!  Or buy me the crank and I'll try it! -Jeff __________________ Whatup?

05-14-2002, 11:36 AM	#6
S14lover Zilvia Member Join Date: May 2002 Location: Colombus GA Posts: 162 Trader Rating: (0) Feedback Score: 0 reviews	yes ..yes ..YES...DO IT....DO IT !!!!!i must have more power ..seriously though i really hope you guys can compile some raw data on this ...this could blow the whole KA haters world apart!(insert sinister laugh)  <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/sly.gif" border="0" valign="absmiddle" alt=':sly:'> P.S. tofu that axl sig you got is a fucking riot it makes me laugh everytime i read it <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/hehe.gif" border="0" valign="absmiddle" alt=':hehe:'> __________________ She ****ing hates me ....TRUST!

05-14-2002, 12:43 PM	#7
sykikchimp WOW addicted Join Date: Dec 2001 Location: the moon Age: 44 Posts: 6,525 Trader Rating: (0) Feedback Score: 0 reviews	This is exactly what Ace was talking about doing a while back.  Maybe he will chime in with some extra useful info. Isn't the KA 86mm bore?  if so you would have a square bore storke ratio..  can you say 9000 rpm KA??? __________________

05-14-2002, 02:58 PM	#8
TheTimanator Post Whore! Join Date: Apr 2002 Location: Nashville Age: 41 Posts: 2,535 Trader Rating: (1) Rides Gallery: TheTimanator Feedback Score: 1 reviews	I was pondering this the other day. I didn't realize that Nissan engines were so interchangebale. What is the r/s ratio of the KA24DE? w/KA crank? w/L20B crank? and w/Z22 crank? Which is the closest to the magic 1.75? A 9000+ redline turbo RWD car would be awesome! Edit: Anybody know what the SR r/s ratio is? __________________ 89 S13 hatch/////98 Subaru 2.5RS

05-14-2002, 04:43 PM	#9
geeaj Zilvia Junkie Join Date: Dec 2001 Posts: 357 Trader Rating: (0) Feedback Score: 0 reviews	KA bore size is 89mm i believe..I'll get some updated information later... __________________ Beware the fury of a silent man, be more cautious of his silent farts....

05-14-2002, 05:32 PM	#10
obruT ES 41S 79' Join Date: May 2002 Posts: 18 Trader Rating: (0) Feedback Score: 0 reviews	KA has a bore of 89mm. So does the Z24. The cranks will interchange, it's just the matter of crank journal width. The hot bearings for the KAT are the cutdown L series Nissan Motorsport rod bearings. KA uses narrower bearings. The rod to stroke ratio for the KA is 1.71. SR is about 1.6x IIRC. KA with the 6.7" Carillo rods and the offset piston runs a ratio of 1.74. Even better. The original thoughts as presented by several folks from way back in the days of the 240sx amarok list. There was already discussion about the possibility of destroking the KA. Ace picked up the discussion from my discussion on FA.

01-10-2006, 03:06 PM	#11
Sean1978 Zilvia Member Join Date: Apr 2005 Location: Havelock / Chery Point N.C. Age: 46 Posts: 190 Trader Rating: (0) Feedback Score: 0 reviews	did anyone ever get anywhere on this? __________________ My Datsun 510 Wagon