Chevrolet engine question..

[minendrews68]

I have a 383 small block Chevrolet engine in my Camaro, with a six speed trans. Upon starting, running down the road, or in town, I can't see signs of smoke coming out of the tail pipes. The thing that concerns me is it blows blue smoke between shifts. After getting into a higher gear and going down the road I can't see anything. The motor has around 700 miles on it. Is this going to eventually go away after everything gets seated or is there more of a problem? Any help would be appreciated.

[andrewb70]

Smoking on shifts tends to be a valve oil control issue.

Andrew

[parsonsj]

Right: high vacuum since you let up on the throttle, with higher engine speed, and it sucks oil past the valves. Are you running a PCV?

[minendrews68]

I am, the only thing drawing vacuum is power brakes and pcv. Another thing I've noticed I'm using a quart of oil about every 100 miles or so. I have a small amount of oil on the garage floor, but the underside of the floor pan isn't covered, and I do not see any smoke while driving. My son drove on the bypass this morning and I followed The only smoke I was was between shifts. We weren't driving hard around 60 MPH. Any suggestions?

Andrew, valve oil control, meaning?

[Reckn8]

I agree with Andrew. Sounds like it's sucking oil past the intake valve seals

[parsonsj]

Carl, are you running a catch can for the PCV? If not, look in your intake manfold and see if it's wet with oil.

[kochevy67]

Tis thing must really be smoking to burn a quart in a 100 miles

[minendrews68]

John, I'm not running a catch can, and the intake is clean.

kochevy, I'm telling ya' this thing only puffs smoke between gear changes then nothing.

reckn8, I hope not, they would be a pain to replace, I've got angle plug heads and getting the apparatus in the spark plug hole (to pressurize the cylinder to hold the valves up) would be fun as well

Thanks for the replies so far, Keep the ideas coming.

[TheJDMan]

Carl,
What are you running for a PCV system? A pic of your system might help. A proper PCV system is pretty important for oil control. I have an adjustable PCV valve from ME Wagner and it is much more effective than the over the counter valve from the local auto parts store. http://mewagner.com/?p=444

Lance Hamilton is using a Mighty Mouse crankcase ventilation system and seems to be happy with that but I can't seem to figure out how it works.

You might be interested in this thread: https://www.pro-touring.com/threads/121314-Oil-from-breathers?highlight=pcv+valve

What kind of valve stem seals are you running? The O-ring style is basically worthless which is why I always use these on the intake valves.
https://www.summitracing.com/parts/fel-ss72527/overview/
and these on the exhaust valves.
https://www.summitracing.com/parts/fel-ss72526/overview/

[minendrews68]

Carl,
What are you running for a PCV system? A pic of your system might help. A proper PCV system is pretty important for oil control. I have an adjustable PCV valve from ME Wagner and it is much more effective than the over the counter valve from the local auto parts store. http://mewagner.com/?p=444

Lance Hamilton is using a Mighty Mouse crankcase ventilation system and seems to be happy with that but I can't seem to figure out how it works.

You might be interested in this thread: https://www.pro-touring.com/threads/121314-Oil-from-breathers?highlight=pcv+valve

What kind of valve stem seals are you running? The O-ring style is basically worthless which is why I always use these on the intake valves.
https://www.summitracing.com/parts/fel-ss72527/overview/
and these on the exhaust valves.
https://www.summitracing.com/parts/fel-ss72526/overview/

Hey Steve, the pcv system I have is just a hose coming out of the back of my carburetor straight to the pcv. The carb is a Holley double pumper.
Valve stem seals I'm betting are the "o" ring style. The engine has been built for about 7 years, but just been driven 700 miles recently. Most of the miles are from around town and not out on the highway. I've probably got 200 miles on the road. I'm wondering (hoping) my rings are not seated yet. But you never know.
I'm going to look at your site and see what's there. Thanks so far...

I've just got to say... That pcv valve has got to be one of the fanciest I've ever seen. Is this what you use?

[TheJDMan]

Carl,
I doubt the problem is your rings. Typically, rings not sealing results in smoke when under power. I think you have a couple of things going on. First, I would look at your valve stem seals especially on the intake side. As has been mentioned above when you shift you close the throttle which creates a high vacuum on the intake side which in turn sucks oil in through the valve guides. This is why I use the Fel-Pro valve seals I linked to above. Second, the other issue is a good PVC system. Interestingly enough a PCV system is the only emissions system that is actually beneficial to engine operation. You mentioned you have a hose from the carb base to the PCV valve but what do you have on the breather side? To have an effective system you need the PCV in one valve cover and some sort of filtered air intake on the opposite valve cover. The ME Wagner PCV is what I use and it is a major improvement over the parts store PCV valves. I have also been hearing good things about the Mighty Mouse system as well but I must admit I haven't figured out how it works yet.

[minendrews68]

Thanks Steve, I do have a regular pcv valve on the passenger side and a round breather on the drivers side. I'm thinking that if the guy that built this motor several years ago used the stock oring type valve seals, and it sat for about five years, then put into service, they could've gotten brittle and the rest is history. I'm going to order the FelPro seals and the pcv valve. Here I go again, copying you. You've got to admit though it's all been good advice.. Thanks for the help.

[71RS/SS396]

Do you have baffled valve covers? If not the pcv will suck oil out of the covers.
Valve seals could be the cause or I've seen bad intake manifold gaskets cause this too.

[minendrews68]

I do have baffles under both valve covers. I really don't think its intake gaskets, I'm not too sure about the valve stem seals though. Going to look at replacing them.

[icemanrd19]

Where did you get the 383? I know someone that is burning oil as well on a new one. Replaced the valve seals and still the same issue

[minendrews68]

A friend of mine that owned a automotive machine shop built it about 7 years ago. The motor itself has about 500 miles on it