Quick turbo qestion - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

rubbersidedown · 02-20-2002, 01:35 PM

i'm thinking about having and overbore done. Not sure exactly how much yet. My question is "If i overbored would i have any problem w/ the cylinder walls flexing if i use a turbo? and does the KA have any history of flexing problems w/ turbo applications?" btw i'm using a ka24de.

Nismos14 · 02-20-2002, 01:39 PM

im not sure but wouldnt it be better not to bore it out with the turbo kit? im clueless dont mind me <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'>

rubbersidedown · 02-20-2002, 01:43 PM

well i wanna try and get as much possible power out of the engine as i possibly can. i've got big plans for the car :-)

*sykikchimp* · 02-20-2002, 01:46 PM

I've seen N/A apps bored out to 2.445 or something close to that. *The KA's Cylinder walls a Very close together as is. *I wouldn't think that it would be a very god idea to bore out the KA, then turbo. *Especially since the KA is already a stroker engine.

(Edited by sykikchimp at 4:36 pm on Feb. 20, 2002)

BadMoJo · 02-20-2002, 01:47 PM

well, i have heard the KA block if pretty strong, and there is room to over bore. But I dont know the numbers on it so I am useless as well. One thing I do know is that there is no replacement for displacement. *<img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'> * That was my domestic side speaking there. mmmmm torque. <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'>

(Edited by BadMoJo at 12:48 pm on Feb. 20, 2002)

boosteds14 · 02-20-2002, 02:41 PM

if you want the power, stroke the motor, man i was going to do this but the price was unbelievable. get a custom crank, rods , and pistons and the thing would haul ass, but the ka is an iron block and can be bored alot but remember you weaken the block, and with turbo, i wouldnt risk it, but i cant state this is true because i never hear of a big bore w/turbo

Gismo R · 02-20-2002, 03:14 PM

I've heard that with a turbo application you want a smaller compression ratio than N/A. Wouldn't boring it out create a higher compression ratio? I say save the money you'd have to spend on a over bore and through that at a nice turbo upgrade, BOV, front-mont intercooler, etc, etc.

*LanceS13* · 02-20-2002, 03:35 PM

sykikchimp, I hope that 2.445 is mm and not inches.

Both Mark's (WeST) and PSI240SX's turbo KA's were bored over...I think .04".
Bore has nothing to do with compression.
I'd rather overbore than stroke the KA...it's already a stroker.

*sykikchimp* · 02-20-2002, 03:37 PM

no..  normally 2.400  now 2.445  

*LanceS13* · 02-20-2002, 03:46 PM

oh...gotcha
so  .045 over

boosteds14 · 02-20-2002, 08:16 PM

ya i got mine bored .050

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02-20-2002, 01:35 PM	#1
rubbersidedown Zilvia Junkie Join Date: Aug 2001 Posts: 343 Trader Rating: (0) Feedback Score: 0 reviews	i'm thinking about having and overbore done. Not sure exactly how much yet. My question is "If i overbored would i have any problem w/ the cylinder walls flexing if i use a turbo? and does the KA have any history of flexing problems w/ turbo applications?" btw i'm using a ka24de.

02-20-2002, 01:39 PM	#2
Nismos14 Zilvia FREAK! Join Date: Jun 2001 Location: New Jersey Age: 32 Posts: 1,213 Trader Rating: (0) Feedback Score: 0 reviews	im not sure but wouldnt it be better not to bore it out with the turbo kit? im clueless dont mind me <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'>

02-20-2002, 01:43 PM	#3
rubbersidedown Zilvia Junkie Join Date: Aug 2001 Posts: 343 Trader Rating: (0) Feedback Score: 0 reviews	well i wanna try and get as much possible power out of the engine as i possibly can. i've got big plans for the car :-)

02-20-2002, 01:46 PM	#4
sykikchimp WOW addicted Join Date: Dec 2001 Location: the moon Age: 32 Posts: 6,518 Trader Rating: (0) Feedback Score: 0 reviews	I've seen N/A apps bored out to 2.445 or something close to that. The KA's Cylinder walls a Very close together as is. I wouldn't think that it would be a very god idea to bore out the KA, then turbo. *Especially since the KA is already a stroker engine. (Edited by sykikchimp at 4:36 pm on Feb. 20, 2002)

02-20-2002, 01:47 PM	#5
BadMoJo Nissanaholic! Join Date: Sep 2001 Location: San Luis Obispo, Ca Age: 31 Posts: 1,933 Trader Rating: (0) Feedback Score: 0 reviews	well, i have heard the KA block if pretty strong, and there is room to over bore. But I dont know the numbers on it so I am useless as well. One thing I do know is that there is no replacement for displacement. <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'> That was my domestic side speaking there. mmmmm torque. <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'> (Edited by BadMoJo at 12:48 pm on Feb. 20, 2002)

02-20-2002, 02:41 PM	#6
boosteds14 Zilvia.net Advertiser Join Date: Jan 2002 Location: CIPmotorsports Age: 31 Posts: 1,612 Trader Rating: (0) Feedback Score: 0 reviews	if you want the power, stroke the motor, man i was going to do this but the price was unbelievable. get a custom crank, rods , and pistons and the thing would haul ass, but the ka is an iron block and can be bored alot but remember you weaken the block, and with turbo, i wouldnt risk it, but i cant state this is true because i never hear of a big bore w/turbo

02-20-2002, 03:14 PM	#7
Gismo R Zilvia Member Join Date: Feb 2002 Posts: 167 Trader Rating: (0) Feedback Score: 0 reviews	I've heard that with a turbo application you want a smaller compression ratio than N/A. Wouldn't boring it out create a higher compression ratio? I say save the money you'd have to spend on a over bore and through that at a nice turbo upgrade, BOV, front-mont intercooler, etc, etc.

02-20-2002, 03:35 PM	#8
LanceS13 AutoX Junkie Join Date: Jun 2001 Location: MS Age: 31 Posts: 2,044 Trader Rating: (0) Feedback Score: 0 reviews	sykikchimp, I hope that 2.445 is mm and not inches. Both Mark's (WeST) and PSI240SX's turbo KA's were bored over...I think .04". Bore has nothing to do with compression. I'd rather overbore than stroke the KA...it's already a stroker.

02-20-2002, 03:37 PM	#9
sykikchimp WOW addicted Join Date: Dec 2001 Location: the moon Age: 32 Posts: 6,518 Trader Rating: (0) Feedback Score: 0 reviews	no..  normally 2.400  now 2.445

02-20-2002, 03:46 PM	#10
LanceS13 AutoX Junkie Join Date: Jun 2001 Location: MS Age: 31 Posts: 2,044 Trader Rating: (0) Feedback Score: 0 reviews	oh...gotcha so  .045 over

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02-20-2002, 08:16 PM	#11
boosteds14 Zilvia.net Advertiser Join Date: Jan 2002 Location: CIPmotorsports Age: 31 Posts: 1,612 Trader Rating: (0) Feedback Score: 0 reviews	ya i got mine bored .050