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Oil change Question ?

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javtopgun View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote javtopgun Quote  Post ReplyReply Direct Link To This Post Topic: Oil change Question ?
    Posted: Sep/14/2021 at 7:13pm
K .. just changed the oil on my rebuilt 343 , 30 over 8 quart canton pan 280 lift 270 duration comp cam . It was 1/2 quart low per stock dip stick ( no modifications ) and the oil was dirtyyyy ! preety dark but no shavings at all ( refiltered the dirty oil ) .. was changed after breakin .. and after 800 miles .. just put 3000 miles on it .  used 15/40 rotilla all three changes .  Should i have concern about how dirty it was and being 1/2 quart down after 3000 miles or is it still going thru some things im not aware of. .. have run it kinda hard last 800 or so miles . Afew 6000 rpm pulls . Still have a few issues im working out , just now have time to complete them , change distributor with a very slight shaft wobble and do some compression checks and do recheck of the valve geometry as i suspect that a little off .  What im i looking at with 1/2 quart low and pretty dirty oil at 3000 miles from last oil change . Total on motor is about 3800 miles ???  
1968 Javelin SSt 343ci semi restomod .
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javtopgun View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote javtopgun Quote  Post ReplyReply Direct Link To This Post Posted: Sep/14/2021 at 9:28pm
20 looks and no opinions ?? Any guesses ... lol .. Should i be concerned or just see what happens next change .  The 1/2 quart low seems wrong to me , dirty is just that dirty oil !  All three changes , per the dip stick , with filter is 7.8 guarts to the full line .  i know there is enough oil that a 1/2 Q down will not hurt it with 8 Q pan but where is the 1/2 quart going ?? That be my concern . Non was missing after break in and non missing at 800 miles , Why at 3000 more is a 1/2 quart missing on dip stick before change ? I mean .. this eng is broke in at 3800 miles and no leaks i can find on ground !! Any ONE !! 
1968 Javelin SSt 343ci semi restomod .
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Post Options Post Options   Thanks (1) Thanks(1)   Quote troutwilly Quote  Post ReplyReply Direct Link To This Post Posted: Sep/14/2021 at 11:51pm
Well, I'll start you off with some thoughts.
I don't think an engine with only 3,800 miles is fully broke in, so some oil consumption is to be expected.  I'd go another couple oil changes to see if it improves (lessens).
And "dirty" is in the eye of the beholder.  Ever change the oil on a diesel engine.  Turns pitch black after 1,000 miles, and you've got 4,000 more to go.  I usually smear the oil between my fingers to see how slippery it is (pretty scientific, huh?).  But if you're really concerned, send a sample to a testing lab and let them tell you what's making it look dirty.
And finally, if it truly is down 1/2 quart, where did it go?  If its not leaking, its burning.  Have someone rev it while you watch the tail pipe.  You might be surprised.  Goes back to my thought that its still not broke in.
Bill O.
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Post Options Post Options   Thanks (1) Thanks(1)   Quote FSJunkie Quote  Post ReplyReply Direct Link To This Post Posted: Sep/15/2021 at 2:39am
Engines of this type and era normally use about 1 quart of oil per 3000 miles, and that is about the best they ever do. That's all they ever did when they were new. The higher rpm you spin them, the more oil they use. 

The oil after 3000 miles should be a dark brown in color if you wipe it onto a white paper towel but it should not be black. I bet your oil is actually dark brown if you wipe it onto a white towel.

Don't run that 15w-40 in weather that is below freezing if you can help it. Especially at 6000 rpm. 


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Post Options Post Options   Thanks (1) Thanks(1)   Quote Sonic Silver Quote  Post ReplyReply Direct Link To This Post Posted: Sep/15/2021 at 4:31am
I thought that 15W oil was safe to minus 25 degrees Celsius or minus 13 degrees F.
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Post Options Post Options   Thanks (1) Thanks(1)   Quote mbwicz Quote  Post ReplyReply Direct Link To This Post Posted: Sep/15/2021 at 5:21am
Check your PCV hose to see if that is wet with oil.  Like others said, your engine is still in the break in process.  You probably have a little more blowby at this point then you will after another oil change.  Are you running the shield under the intake manifold and sheet metal intake gasket?  

Using blackstone labs or someone else to analyze the oil is a good thing for your self confidence.  The test is about $30, send them a sample after the next oil change.

If you're running the Canton pan, did your pan come with a magnetic drain plug?  Was that a little furry or just dirty?  I'd expect that would trap a little of the piston ring/cylinder wall material that is scrubbed off as the engine breaks in.

Mike

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Post Options Post Options   Thanks (0) Thanks(0)   Quote javtopgun Quote  Post ReplyReply Direct Link To This Post Posted: Sep/15/2021 at 12:12pm
K... thanks all , guess im still in learn mode on amc's .. its dark brown not black .. yes on magnitic pan plug but no on furry but yes on dark .... LOL ... Yes to shield and yes to metal intake gasket with slightly higher layer of atv acrossed front and back of intake to block . No leaks apparent . Sonic and junkie , not to worry im in las vegas and i will never see any temp below 30 degrees here , unless i trip up to ski... But i dont ski.... lol .  So im all good on this front .  Is there better oil to use than 15/40 rottilla ? Seems slick enough , even dirty , but seems pretty thin right out the tub ! like a syn. 20/50 due to the extreme heat here 6 / 7 months a year ?? Ave during these months is about 104 degrees and since ive been here ive seen 118 degrees . You get use to it !!  No rain like STL a drizzle now and then till November . But a drizzle here FLOODS every thing .  So wired !!  
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Post Options Post Options   Thanks (0) Thanks(0)   Quote troutwilly Quote  Post ReplyReply Direct Link To This Post Posted: Sep/15/2021 at 12:33pm
Like mbwicz mentioned, pull the PCV hose off the carb and see if its overly oil soaked.  If yes, pop the carb off the intake, being careful not to squirt any fuel, and see if the plenum is oil soaked.  Maybe need a new PCV.  Also if yes, should be seeing a little blue smoke on throttle blips.
But I think you're OK.  Just overly surprised about brownish oil in a fresh engine.
Bill O.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote amcguru Quote  Post ReplyReply Direct Link To This Post Posted: Sep/15/2021 at 2:19pm
Diesel oil has a strong detergent pack, and dark oil means the detergent pack is doing its job.  1qt. per 3000 miles is nothing to get excited about, especially on such a new engine.  

Did you install a new intake without transferring the stock oil baffle or not use the factory style intake gasket? 

NAMDRA #3646

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Post Options Post Options   Thanks (0) Thanks(0)   Quote javtopgun Quote  Post ReplyReply Direct Link To This Post Posted: Sep/15/2021 at 2:25pm
Will check pvc hose post hast .  No blue smoke at all . The only smoke i have seen , and i confused it with possible head gasket prob or V seat prob but now know diff. is when i turn key to on and pump throttle 1 or 2 times and then start , it will puff a small white cloud . However if i give no pump of the throttle and start, no cloud no nothing . Starts that easy . figure with the 5 to 9  elec fuel pump it dumps much gas in if i pump throttle and its a gas cloud . Pretty strange how easy this car starts with the original AFB on her . Even revs at start and comes down 100 rpms to idle like a EFI !! Aint no EFI !!  Thanks guys . I figure im over worried about the 1/2 quart thing from what im hearing .  This thread can be closed as i got my lesson in over worrying i think !! lol  
1968 Javelin SSt 343ci semi restomod .
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