Author Topic: need help with 383 smoking  (Read 3391 times)

Offline svnty7

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need help with 383 smoking
« on: October 03, 2009, 01:37:27 pm »
Have a 383 built from a 1987 block.  Machine work done by a good shop with great reputation.  I built the engine myself, as I have done several others.  All clearance work was done by the machinist.  All eagle rotating assembly;speedpro pistons;moly rings.  Pro-comp aluminum heads. 
Engine has about 1000 miles and runs strong, however it smokes out the left bank back two cylinders when the motor isfull of oil( 5 quarts)  As soon as it burns off a quart the smoking stops. 
Changed intakes gaskets,pulled the left head, changed head gasked checked valve guide seals,
all i can tell is oil is going out back two cylinders 5,7, Im stumped on this one.  any help would be appreciated

Offline VileZambonie

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Re: need help with 383 smoking
« Reply #1 on: October 03, 2009, 01:43:59 pm »
What transmission do you have? If it has a modulator unplug the vacuum hose to check for atf just be sure you aren't burning atf. What do you have for a crankcase ventilation system?  Do you physically white or bluish grey smoke? Any oil leaks?
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74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline svnty7

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Re: need help with 383 smoking
« Reply #2 on: October 03, 2009, 02:14:25 pm »
Thanks for the reply definately not atf. Its a 79 C-10 shortbed 2wd.  Originally a 250 6/ 3 speed
Have had a 700r4 and now a th 400 stock crossmember with stock tranny mount.  Blue oil smoke for sure\
did compression check all cylinders are 175 on the nose except 5 which was 185 ishand 7 which was low 190s, both those plugs had evidence of oil burning

Offline eventhorizon66

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Re: need help with 383 smoking
« Reply #3 on: October 03, 2009, 06:08:50 pm »
As Vile asked earlier, what crank case ventilation are you running?  PCV and a breather?  The fact that the smoking stops after the oil level drops points in that direction.  Under what conditions does the oil burning occur?
'85 C10 SWB 350 700R4 TKO600

Offline svnty7

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Re: need help with 383 smoking
« Reply #4 on: October 03, 2009, 07:42:16 pm »
The motor smokes when revved, not on startup  like a typical valve seal problem.  When you wrap the throttle and then let off it puffs a cloud.  I was also thinking the pcv.  Ive got a set of cheap chrome covers with baffles and I also put on the grommet made to work without baffles to stop the pcv from sucking in oil.  PCV runs off the drivers side valve cover into the front of the carb ( Holley Avenger).  I have an open breather on the pass. side.    Ive tried with the pcv pulled out of the valve cover, It still continues to smoke.  Could this still be some kind of crankcase pressure problem.  Ive never had a motor smoke until the oil level reaches a certain point and then stops.  THis is really a baffling  Thanks again for any ideas
« Last Edit: October 05, 2009, 09:42:00 am by Captkaos »

Offline VileZambonie

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Re: need help with 383 smoking
« Reply #5 on: October 04, 2009, 09:17:03 pm »
If it's not a guide/seal issue, your choices are limited. Intake gasket or rings. Block your pcv andf breather port. See if your engine vacuum changes when you block and unblock it.
,                           ___ 
                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline maddog

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Re: need help with 383 smoking
« Reply #6 on: October 07, 2009, 09:41:13 am »
If spark plugs are oil soaked as stated it is coming from valve seal or intake, you have eliminated rings by your compression test, the quart low think is what is throwing everone off here, how long does it take to get to be a quart low? being a quart low shouldn't stop this from happening.
let us know what you find out