Thread: Smoker

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I am running a 400 sbc which I recently rebuilt. New rings, block was honed, guides seemed fine, new valve seals, etc.

When I drive reasonably, no sign of smoke anywhere, not even if I rev it in neutral. But when I go for four barrels, a cloud of smoke is sure to appear.

Well, I have been waiting for the rings to break in, but no luck, at least so I thought. I checked the compression today and they range from 195-220 psi. No idea why they aren’t all equal seeing as I even decked the block to make sure all four corners were bang on.......

So, I replaced the rocker studs but I never put thread sealant on the intake studs and they definitely end in the intake runners, so I am going to do that right now, plus I am thinking that my intake gasket might not be sealing in the valley.

Any ideas????

Doesn't sound like oil smoke....probably that the carb is way too rich when the secondaries open.

hmmm, might be rich. But I am using oil as well. Would AV gas burn blue smoke if it was rich? All I use is Aviation fuel.

Maby Typhoon, I always thought that a motor running rich could cause oil usage but, I could be wrong.

Maybe its valve float?

Matt, if running rich causes oil consumption, it might be due to the rings not seating because the cylinder walls are being washed. However most of my plugs look great. Several (2) were filled with carbon deposits. But I haven’t used nitrous with this motor as of yet.

As for valve float, I know I can rule that out M&M Jr. I have 200 lbs of pressure closed and well over 500 open. I am running solid rollers.

I have added thread sealant to all the rocker studs and installed a new intake gasket, so tomorrow we will see! In three areas of the intake gasket the gasket was sagging so as to allow for fresh air into the plenum. None of these areas were directed towards the valley so as to inhale oil. However, the bolts were rather on the loose side and so just maybe the runner were sucking oil from the valley, I am keeping my fingers crossed on this one. I will update you all within a day or two.

TyphoonZR
Black smoke= Rich to much fuel
Blue smoke= Oil burning
White smoke= Antifreeze/Water
On a fresh rebuild you might notice some blue smoke from the rings, That normially should go away after just a few houndred miles. Who told you that the valve guides wher Ok and did U replace the seals, and where thay installed corectly? I hope this helps.

Originally posted by Bo-Ti Guy
TyphoonZR
Black smoke= Rich to much fuel
Blue smoke= Oil burning
White smoke= Antifreeze/Water
On a fresh rebuild you might notice some blue smoke from the rings, That normially should go away after just a few houndred miles. Who told you that the valve guides wher Ok and did U replace the seals, and where thay installed corectly? I hope this helps.

I just about missed this post, I guess I can't count on the "recent posts" to display everything.

Anyways, yes, I agree with your understadning of determining the origin of the smoke. Mine is oil. I must have 1000 miles on my motor by now, and it isn't letting up. I had a machinists check the guides and I installed positive seals, correctly. I checked to see if we had clearance and I did.

I have placed sealant on all the intake rocker studs ( I am wondering, should I have removed the studs or is dabbing a little white sealant on the top of each adjusting nut ok?j/k) and also changed the intake gasket, and still no luck. My guess is that the rings aren't seating, ***k in the net! We score! Canucks all the way.

Typhoon thats to bad, what kind of Titanium, Diamond chromeolly rings did u put in that thing!!!! I was told buy and old, middle aged young man that when he used to rebuild motors for customers who could'nt understand why a BRAND NEW/REbuilt motor whould do such a thing in there fully restored vette. Sooooo what he used to do was use Marvile MYstery Oil on the rings cause that would burn away clean and not carbon up the rings. I dont know personialy if that works or not, but he does Know his sht
Travis

Originally posted by Bo-Ti Guy
what kind of Titanium, Diamond chromeolly rings did u put in that thing!!!! ]

hehhehehe, dem iz da ones! All of the above.

Marvile MYstery Oil on the rings cause that would burn away clean and not carbon up the rings.

I never heard of such a product. I am thinking of pouring the nitrous to it and see what happens!

Yaaaaa If that wont do it then I dont know what will
Ya man that Marvile oil is the sht. It is a reel light oil, I think U should be able to find it at the parts store. Good luck man and give that baby the bottle!!!!!

Typhoon, look for this stuff, this is Marvles mystery oil.

I bought a 57 chev from a guy one time that rebuilt the engine and it smoked bad from day one and after 2000 miles I got it for a song due to mass frustration. They only thing he had done was he didn't stagger the gap in the rings and the oil just poured into 5 of the cylinders. I staggered the rings, put it back together and my wife drove it for 2 years.

yea if you didnt stagger the rings that will definatley make it smoke but thyphoon seams pretty knowledgeable and thats kind of a givin if you have ever built a motor...

Man, last year when I freshend my midget engine my machinist had been on me about using Total Seal Rings so I let him get me what he thought I should run (they where chrome mollys) & that thing had so much blow by and leak down it was silly,so I tore it down and put Total Seals back in it and on first fire up the dry sump would actually pull a vacume on the breather, I'll never put chrome mollys in anything again.