View Full Version : HELP!!! Fresh build knocking. Ka
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
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.
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