HELP!!! Fresh build knocking. Ka - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

kaytlin.240.love · 11-26-2016, 12:38 PM

Hey I have a fresh build ka-t right now I have it n/a to break motor in. It ran great it idle for about 10 mins then started knocking, sounded like bottom end, I shut motor off immediately.. more about build below

Je pistons 9:1 ratio, Manley rods, clevite bearings, new crank, arp studs and bolts, balanced rods and crank by machine shop. Head got cleaned and polished and valve spring retainers replaced, everything is cleaned really good, block bored 20 thousandths over(pistons match new size to bores) however I did not replace oil pump or water pump (looked fine, now thinking I should anyway). I am getting an adapter so I can fit the oil pressure gauge and see what it reads. I was told it may either be oil pump or clearances in the motor of like bearings maybe. Just need help, opinions and such thank you.

lunchmeat · 11-26-2016, 01:11 PM

I'd start draining oil, pulling the pan, and checking the filter for metal bits.

jedi03 · 11-26-2016, 10:29 PM

have seen ignition sound like knock too...

Kingtal0n · 11-27-2016, 02:28 AM

its hard to build an engine. I pray you got it right but the fact is, many fail after 15 or 150 miles. You might be joining the club.

Some random low mileage failures,
http://zilvia.net/f/showthread.php?t=535520
http://zilvia.net/f/showthread.php?t=569861
http://zilvia.net/f/showthread.php?p=5765974
http://zilvia.net/f/showthread.php?t=579996
http://zilvia.net/f/showthread.php?t=586960

I stopped keeping count

KAT-PWR · 11-28-2016, 08:50 AM

My first bet would be oil pump

2nd bet is incorrect bearing clearance

thegr8one013 · 11-28-2016, 09:19 AM

i see you wrote new crank? where did you buy this new crank? was it a cut crank? and did you check bearing clearances before it was put together?

kaytlin.240.love · 11-29-2016, 06:26 AM

I am hoping it is oil pump, is there a way to tell it's bad by taking it off and looking? Also I bought the crank from a machine shop and it was "stock specs" I took a micrometer to the journals to see if sizing was right and the same all across and it was but I didn't plastigauge bearings or anything. Now that I know a bit more than I did back then I should have plasti gauged it

*TheRealSy90* · 11-29-2016, 07:06 AM

You would have had to plastigage it to order the correct bearing sizes no?

jedi03 · 11-29-2016, 07:51 AM

not necessarily...properly measuring beforehand and ordering correct size bearings can work too...plastiguage is a new way to measure for people who don't know how to properly use a micrometer

lunchmeat · 11-29-2016, 08:03 AM

Bore gauge, micrometer, and math.

KAT-PWR · 11-29-2016, 08:35 AM

Quote:

Originally Posted by TheRealSy90

You would have had to plastigage it to order the correct bearing sizes no?

No. plastigauge is useful for a quick double check after the parts have been purchased. There are stampings to specify bearings (roughly measures journal to bearing clearance). Usually you would measure the journals of the crank, then use a bore gauge on the block/girdle and rods to determine bearing size for desired clearance (correct way)
Subtract journal size from rod bore, then subtract desired clearance and that will give you the remaining bearing width/clearance necessary for your selected tolerance.

11-26-2016, 12:38 PM	#1
kaytlin.240.love Join Date: Oct 2013 Location: Tampa Age: 28 Posts: 10 Trader Rating: (0) Feedback Score: 0 reviews	HELP!!! Fresh build knocking. Ka Hey I have a fresh build ka-t right now I have it n/a to break motor in. It ran great it idle for about 10 mins then started knocking, sounded like bottom end, I shut motor off immediately.. more about build below Je pistons 9:1 ratio, Manley rods, clevite bearings, new crank, arp studs and bolts, balanced rods and crank by machine shop. Head got cleaned and polished and valve spring retainers replaced, everything is cleaned really good, block bored 20 thousandths over(pistons match new size to bores) however I did not replace oil pump or water pump (looked fine, now thinking I should anyway). I am getting an adapter so I can fit the oil pressure gauge and see what it reads. I was told it may either be oil pump or clearances in the motor of like bearings maybe. Just need help, opinions and such thank you.

11-27-2016, 02:28 AM	#4
Kingtal0n Post Whore! Join Date: Jul 2005 Location: South Florida Age: 38 Posts: 4,649 Trader Rating: (17) Feedback Score: 17 reviews	its hard to build an engine. I pray you got it right but the fact is, many fail after 15 or 150 miles. You might be joining the club. Some random low mileage failures, http://zilvia.net/f/showthread.php?t=535520 http://zilvia.net/f/showthread.php?t=569861 http://zilvia.net/f/showthread.php?p=5765974 http://zilvia.net/f/showthread.php?t=579996 http://zilvia.net/f/showthread.php?t=586960 I stopped keeping count __________________ 5.3/4l80e/turbo 240sx playthrough: https://tinyurl.com/turbo240

11-28-2016, 08:50 AM	#5
KAT-PWR Nissanaholic! Join Date: Dec 2011 Location: US Posts: 2,040 Trader Rating: (11) Rides Gallery: KAT-PWR Feedback Score: 11 reviews	My first bet would be oil pump 2nd bet is incorrect bearing clearance __________________ MRP Manufacturing

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11-26-2016, 01:11 PM	#2
lunchmeat Zilvia Addict Join Date: Apr 2016 Location: Southaven, ms Age: 42 Posts: 951 Trader Rating: (0) Feedback Score: 0 reviews	I'd start draining oil, pulling the pan, and checking the filter for metal bits.

11-26-2016, 10:29 PM	#3
jedi03 Nissanaholic! Join Date: Jul 2008 Location: albuquerque Posts: 1,786 Trader Rating: (8) Feedback Score: 8 reviews	have seen ignition sound like knock too...

11-28-2016, 09:19 AM	#6
thegr8one013 Zilvia Junkie Join Date: Jun 2006 Location: nassau, ny Posts: 479 Trader Rating: (1) Feedback Score: 1 reviews	i see you wrote new crank? where did you buy this new crank? was it a cut crank? and did you check bearing clearances before it was put together?

11-29-2016, 06:26 AM	#7
kaytlin.240.love Join Date: Oct 2013 Location: Tampa Age: 28 Posts: 10 Trader Rating: (0) Feedback Score: 0 reviews	I am hoping it is oil pump, is there a way to tell it's bad by taking it off and looking? Also I bought the crank from a machine shop and it was "stock specs" I took a micrometer to the journals to see if sizing was right and the same all across and it was but I didn't plastigauge bearings or anything. Now that I know a bit more than I did back then I should have plasti gauged it

11-29-2016, 07:51 AM	#9
jedi03 Nissanaholic! Join Date: Jul 2008 Location: albuquerque Posts: 1,786 Trader Rating: (8) Feedback Score: 8 reviews	not necessarily...properly measuring beforehand and ordering correct size bearings can work too...plastiguage is a new way to measure for people who don't know how to properly use a micrometer

11-29-2016, 08:03 AM	#10
lunchmeat Zilvia Addict Join Date: Apr 2016 Location: Southaven, ms Age: 42 Posts: 951 Trader Rating: (0) Feedback Score: 0 reviews	Bore gauge, micrometer, and math.