blow by???
Team Owner
Joined: Aug 2000
Posts: 24,125
Likes: 3
St. Jude Donor '14
Originally Posted by ar91c4
how much blow by should a 383 with 1000 miles on it have???
Some engines have a little more than others. With 1000 miles your rings should be seated. I would ventilate thru the valve cover with a filter, and see how she does. There's lots of very strong running engines out there some show more some less. Concentrate on keeping the oil out of the combusion by ventilating how ever much you need.
Former Vendor
Joined: Jun 2001
Posts: 7,204
Likes: 6
From: St Marys PA
Originally Posted by ar91c4
how much blow by should a 383 with 1000 miles on it have???
With the engine components nowdays, plasmamoly rings and all, the seal is nearly instant the moment you start the motor up.
If you experiencing oil out the covers....chances are you have WAY too much oil in your crank case. Every pan I have measured, is about 2 quarts UNDER its spec'ed size.
If you put in 6 quarts in a advertised 6 quart pan, the crank is swimming in the oil. 
Plus that makes for more crank case pressure.Just some things to think about.
Le Mans Master
Joined: Feb 1999
Posts: 6,172
Likes: 11
From: somers, ny
Is the car still smoking and comsuming oil with the PCV disconnected?
As i mentioned in the other post, i had similar problems. My fresh 406 seems to have more blowby than my 90K 350 did, however a leakdown test shows only about 4% leakdown, so maybe it's my imagination or something. But i too, was pushing out a lot of oil until i reduced the amount of oil i was using and put the filter in the PCV line. The car uses very little oil in normal use now and is capable of running 10s in the 1/4 mile, but i've never really figured out why i was pulling so much oil from the valve covers.
I don't know if there is some way of measuring blowby. I know mine will puff smoke out of the valve covers at idle if the PCV is not connected (more so than the old 350). It's not the tightest engine i've ever seen, but it seems to be running ok and not consuming excess oil.
As i mentioned in the other post, i had similar problems. My fresh 406 seems to have more blowby than my 90K 350 did, however a leakdown test shows only about 4% leakdown, so maybe it's my imagination or something. But i too, was pushing out a lot of oil until i reduced the amount of oil i was using and put the filter in the PCV line. The car uses very little oil in normal use now and is capable of running 10s in the 1/4 mile, but i've never really figured out why i was pulling so much oil from the valve covers.
I don't know if there is some way of measuring blowby. I know mine will puff smoke out of the valve covers at idle if the PCV is not connected (more so than the old 350). It's not the tightest engine i've ever seen, but it seems to be running ok and not consuming excess oil.
Thread Starter
Racer
Joined: Jan 2005
Posts: 315
Likes: 0
From: tomahawk wisconsin
Originally Posted by ralph
Is the car still smoking and comsuming oil with the PCV disconnected?
As i mentioned in the other post, i had similar problems. My fresh 406 seems to have more blowby than my 90K 350 did, however a leakdown test shows only about 4% leakdown, so maybe it's my imagination or something. But i too, was pushing out a lot of oil until i reduced the amount of oil i was using and put the filter in the PCV line. The car uses very little oil in normal use now and is capable of running 10s in the 1/4 mile, but i've never really figured out why i was pulling so much oil from the valve covers.
I don't know if there is some way of measuring blowby. I know mine will puff smoke out of the valve covers at idle if the PCV is not connected (more so than the old 350). It's not the tightest engine i've ever seen, but it seems to be running ok and not consuming excess oil.
As i mentioned in the other post, i had similar problems. My fresh 406 seems to have more blowby than my 90K 350 did, however a leakdown test shows only about 4% leakdown, so maybe it's my imagination or something. But i too, was pushing out a lot of oil until i reduced the amount of oil i was using and put the filter in the PCV line. The car uses very little oil in normal use now and is capable of running 10s in the 1/4 mile, but i've never really figured out why i was pulling so much oil from the valve covers.
I don't know if there is some way of measuring blowby. I know mine will puff smoke out of the valve covers at idle if the PCV is not connected (more so than the old 350). It's not the tightest engine i've ever seen, but it seems to be running ok and not consuming excess oil.
I have the pcv nd tb tube disconected and it did help but I still have alot of smoke, exspecialy if I let the car sit and idle for any amount of time.it seems the longer it idles the worse it gets.I think I have more than one issue here and hopefully I will get it figured out soon.
I have also done a leak down and every cylinder shows 2% to 4% leakage.my compression check showed 170lbs accross the board.does that seem about right for a 10.1 motor?also someone else mentioned that a leak down will not give me a accurate reading because the rings will be soaked in oil.If that was the case wouldnt they very from cylinder to cylinder?Also the car puffs steam out the pcv hole like a freight train..I have a filter where my oil cap should be and that even has a bit of steam/smoke coming out it..
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Le Mans Master
Joined: Feb 1999
Posts: 6,172
Likes: 11
From: somers, ny
When i was pulling oil from the PCV, it was entering all the runners in the base. Since there is a lot of pulsation in the intake track, oil was splattering into the plenum.......however it was fairly clear that the source was from the lower base and not from the plenum area. Can you tell the source in your case? If it appears to be coming in from the plenum, you might have a breach into the EGR system. There are several plugs that go into the base of a tpi......is there a chance one if missing or loose?
Also, is your problem with one cyl in particular? In which case, the plenum is likely not the source.
Just throw'n out ideas.
Also, is your problem with one cyl in particular? In which case, the plenum is likely not the source.
Just throw'n out ideas.
Last edited by ralph; May 24, 2005 at 03:34 PM.
Thread Starter
Racer
Joined: Jan 2005
Posts: 315
Likes: 0
From: tomahawk wisconsin
I removed the lower pan off the base for just that reason...everything looks fine there. and yes sir, it does seem to be entering the lower intake first...theres just to much to tell where it is entering from.the whole base is coated with a thin layer of fresh oil.
Former Vendor
Joined: Jun 2001
Posts: 7,204
Likes: 6
From: St Marys PA
aftermarket valve coves by any chance?
I know that my aftermarket ones do not have baffles and they get oil out of them and into the intake - just something I learned to live with. It is not real bad, but enough that you can see it.
I know that my aftermarket ones do not have baffles and they get oil out of them and into the intake - just something I learned to live with. It is not real bad, but enough that you can see it.
Thread Starter
Racer
Joined: Jan 2005
Posts: 315
Likes: 0
From: tomahawk wisconsin
Originally Posted by dave_85
2,4,6,8 maybe the intake gasket shifted when you installed it. 1,3,5 clean and # 7 bad, maybe a bad valve seal.
