Just installed a 305 chevy with the following new parts

• Cam
• Lifters
• Gaskets
• Rod bearings
• Rings

And it is smoking horribly when i start it to break in the cam. is there something i should be doing or is that normal for break-in. When we put the lifters in we had soaked them overnight in oil then put them in and got some oil in the lifter galley but other than that I dono what the problem would be. hear is a video of it running

http://www.youtube.com/watch?v=C1otvdAHZ1Y

 

That is oil smoke, right? Not steam? It looks like oil but I cant exactly smell it.

I'm thinking you'll need to tear it back down.

Maybe the valve seals? There's only two ways for oil to get into the exhaust that I can think of and thats through the rings or through the valve seals. Or maybe it's somehow coming through the intake? Not sure the pcv can possibly suck up that much oil though.

Something isnt quite right.

I'd pull it apart and look at the ports in the intake and heads to see if the intake has oil in it. Then I'd pull the heads and check the valve seals, then I'd probably re-ring it and make sure I got he ring gaps and locations right.

there's only so many things it can be. I wish I had more experience to be able to give you something more specific. Good luck.

 

it is oil, the camera makes it look white :/ but it was clearly blue smoke when your sitting in the car. lol. well the rings are the only thing i replaced not valve seals, because the engine had been reworked recently prior to buying it and was unsure of how to change them. this was my first teardown/rebuild.

it is smoking three times as much as it did before I tore the engine down and replaced the rings. will the rings set or do i need to go up to .10 mil oversize ? i just replaced them with standard rings. i just have never broken in an engine before and dont know whats normal and whats not.

 

Is it possible the motor was already bored over and you put the wrong size rings in? Im not sure that would be possible but...

 

could be possible. I searched the heads on the block to see if there was a stamp of how much someone bored the block over and found nothing. doesn't mean someone could have done it and not stamped it though.

I could turn the engine over with my hands on the flywheel before though, now with the new rings i need a ratchet on the crank pulley to turn it over by hand. so i suppose the rings are hugging the walls good. could see a difference in size from the old rings to the new ones when i bought them and put them side by side.

 

Did you hone the cylinder walls?

 

All I can say is...Wow....no, not right, not normal.

So many things to ask.
-Did the block go to a machine shop, were the bores measured?
-Did it get hot tanked and new cam bearings installed?
-Were the cylinders at least honed?
-How were the pistons prepped for the new rings? Did you clean out the grooves?

i can tell you what I'd try from here...
-while it's running, pull the PCV hose from the valve cover and check for blow-by. If there's a bunch of smoke flying and it seems to have some prssure behind it....may be a ring issue.
- Pull all the plugs, look for black oil soaked ones and do a compression check on all cylinders. Any that deviate more than 10 percent are suspect.
- Pull off the intake and look over the gasket/sealing surface carefully for any signs of leakage. A bad intake gasket could suck oil into the intake ports that is splashing up from the lifter valley.

That's a good start I think...

EDIT: Also, is your engine the original 1990 with a roller cam? No real break in needed for those....only applies to flat tappet...

 

You didn't line the gaps in the piston rings up in a nice little row did you?

Dan

 

the block did not go to the machine shop, bores had not been bored over before.

no hot tank or new cam bearings

cylinders where honed

cleaned out the grooves of the pistons with a old ring snapped in half

I will try what you have said later tonight/tomorrow. batts dead and no one to jump me at the moment. I did empty my oil after running it during the video and switch over from 10w-30 to straight 50w oil and a new filter. with the 50w in it, the car puts out just a tinny bit of smoke untill it warms up then its back to forrest fire status. have not driven it yet, would that do anything to help ?

will try what you said and get back to you

 

lol no they are 180* apart

 

Just check the plugs and see if it's all the cylinders or just one. That should give you a big clue.

 

Do a compression check.

Pull out all of the spark plugs out first. Charge the battery. Then check and record each cylinder pressure. Wedge open the throttle body or butterfly plate a bit. Crank it over ~3 revolutions each time. My 1987 305 TPI with 55K mi. was 162 psi +/- 3% on all cylinders, yours should be close to that.

 

what did you set the ring gap at?

 

Replace your valve seals. this is thee most over looked part of a rebuilt (for the first timers).

 

You should watch the video.

 

that is not a normal amount of smoke. what did you set the ring gap at? i agree you might have valve seal or guide problem. if the rings are right size and gap.

 

I already did. I had the same issue too! You may not know but let me school you a bit. You see, as oil travels up the hollow push rods, the oil leaks down the rocker, then down onto the spring. Inside the spring is what is called,,,,,you guessed it,,,, the valve stem. Now if you notice, once the rocker is loosened up and the spring has been removed with a spring compresser, you will notice a small rubber donut that hugs the valve stem. That rubber ring is tight around the valve stem to prevent oil from flowing down the valve stem. Do you know what is on the other end (below) of the valve stem Zwrench????? A valve that opens and closes, mechanicaly,,, by the help of a solid tappet camshaft or roller camshaft. Are you following me???? Good.... Now if the valve seal is bad, oil will leak passed the seal and down the stem and will leak into the combustion chamber via intake valve or exaust valve. Now that there is oil in the comustion chamber, once on compression stroke, the oil will burn up upon the ignition of the fuel. Does this make sense Zwrench??? That explains all that undesirable smoke coming out the muffler. Duhh.

 

Looks like someone missed their nap today.

What you've said is more or less correct. However, you don't get that much smoke from just bad valve seals. It's more likely a ring problem.

 

Well generally when you say "bad valve seals" they're seals that are a little bad. They only smoke at startup because the oil drains down as the motor sits and just pools over time. They stop smoking shortly thereafter because, on the whole, they seal fairly well. The amount of oil that leaks into the combustion chambers as it runs is so small you cant even notice during normal operation.

Perhaps if there's a serious problem and his valve seals arent sealing AT ALL, enough oil would drip down to cause that kind of smoke?

Generally bad valve seals dont cause that kind of smoke, but this is a new build and I dont think he has specified where those heads came from or how they ran in the previous motor it was in. He may not know. Maybe the valve seals that are in it were installed incorrectly or practically worn into uselessness by this point.

It's just as plausible as anything else. I have a hard time believing rings will smoke that much myself. I mean many of us have started new motors where teh rings havent seated yet, and I've never seen smoke that bad even when the rings are hardly sealed at all. Even used up, extremely worn out motors where the rings have disintegrated almost entirely blow out huge clouds of oil smoke only when a load is put on the engine. At idle they're fine, then as soon as they accelerate from the intersection you have a could of burnt oil.

There'd have to be a serious problem in either the rings, pistons, or valve seals to cause this amount of smoke and none of those options really seem all that plausible. So something weird is going on clearly. I'm starting to lean towards some sort of valve seal issue. Like maybe they forgot to put seals on the valve stems entirely? The good thing is that would be a pretty cheap fix if that's what it is.

 

Zwrench, your . For that much smoke to be present, they has to be a strong force which is called gravity. If the seals are bad, then there will be a tremendous amout of oil dripping, not leaking but basically pouring into the combustion chambers. Even if the gaps are all lined up or even if the rings are not creating a seal because they may be worn out or even if the guy installed a standard 4 inch ring into a .30 over block, there would not be so much oil into the chamber because of the forch of gravity. Its tough for oil to creep up and cause so much havoc. You can go ahead and keep on ,,, all you want. But you and I know that you are not sure of what you are saying. Believe me, I had the same issue with my cylinder heads. I know because of personal experience.

 

Sorry, Chevy86 IROC-Z, you seem very insecure about your knowledge of engines and get quite testy when challenged with an alternative view.

O.K. Valve seals are the only way to get that much smoke. Happy now?

However, I have seen engines that were so poorly maintained that the valve seals had cracked and fallen off AND the oil return holes plugged with so much gunk that the oil couldn't get back to the pan. Those engines didn't smoke like the one in the video.

Also, judging from what ziggy56 wrote, rings (and possibly gaskets) are the only things that he changed that would create the problem he's having. He even said that the engine didn't smoke like that before he started the work. He reused the heads with the same valve seals. I like to look at the evidence as it's presented and not offer anecdotes about past misdiagnosis.

Now, you can be childish and flame me some more (I can take it) or, you can present your ideas and opinions in a mature and lucid manner. Your choice.

 

Not really worth arguing about guys. I wouldn't take anything off the table. I've heard of some cases where the valve seals didn't leak through so bad prior to a bottom end rebuild, and after the rebuild they leaked much worse due to the added compression and "vacuum" so to speak on the piston downstroke which pulls more "vacuum" or oil past the seals than it used to. That's why I've always read it's always a good idea to go over the heads when you rebuild the bottom end. Only troubleshooting will narrow down the cause.

Like mentioned above, start with removing and looking at each plug and note any oil fouled ones. Do a dry compression check, and then put a tablespoon of oil in the cylinder and do a "wet" test. If the compression improves drastically, it's most likely a ring problem (the oil seals up the rings)....low readings on two adjoining cylinders could signify a bad head gasket.

If nothing unusual there, you're down to a bad intake gasket, or perhaps valve seals.

- Do those things and let us know.

 

confuzed has got it right. ill bet youll find the problem following his advice.

 

Zwrench, as much as you say that Im childish, you yourself are being childish too. I make a comment, and you jump right back at me. Childs play. Its all good though. We have our own opinions and thoughts. I stated my thoughts due to experience. Then you came along and challenged me. All Im saying is that our fellow board member needs help and from my experience, i gave him my solutions. I agree with many that there are other things that can cause the same issues, but chill my man. Dont come at me and say "Watch the video" or "someone missed theyre nap today." I speak what I know, not what I think I know. Now if your cool and want to forget that this ever happened, then Im down because this is someone elses thread and I dont want to be wasting anybodies time.

 

Ummm, no. Let's look back. You called me crazy for having a different opinion. That's fine, I can deal with that. You lectured me on gravity... GRAVITY! I didn't impugn your intelligence or mental state in my responses. Nor, did I say that you were wrong. That alone makes my posts mature in nature. That is something you can't claim.

But, you presented your opinion as the only possible cause. I challenged that assertion. Yeah, maybe I could have done it differently to spare your delicate feelings but, that's not how I am.

I'll stand by my diagnosis... I read the posts by ziggy56 and I can only put 2 and 2 together from what he has said.

Can I forget this exchange happened? Not likely. Can I forgive? Yeah, I can. No grudges here.

I'm done here.

 

alright guys no need to fight over this. I will write the whole story out here...

1. I had a 1988 chevy pickup that I had put this engine in, and the engine smoked, but not nearly as bad as it is now.
2. once my tranny died in my truck I pulled the motor out, sold the truck and got the camaro.
3. I then rebuilt the engine using the same cylinder heads. I put new standard size rings in, not over-sized. the man at napa said it would be fine if they had not been bored out and to check where the cylinder heads meet the block for a stamp such as ".10 over .20 over" etc. I saw nothing so continued with the standard rings.
4. I then put new rod bearings in, the old ones where alright but what the hell already had the pistons out might as well.
5. After that I put in a new melling cam and lifter set, used break-in lube and marked the timing gears before we took the chain of to make sure put it back where it went.
6. Then I put the cylinder heads back on with new gaskets and copper seal, same as the intake gaskets.
7. after that I started it up and ran it for about 5mins and it did not smoke hardly at all. The next morning I go out to attach the shift linkage, then start it up again and it is smoking really bad, that was when the video was taken. I then emptied the 10w-30 oil and filled it with 50w thinking heaver oil would set the rings.
8. Now I have 50w oil in it, and when i start the engine, it runs fine until the coolant temp gets right up to 160, then it just puffs billows of smoke again just like in the video.

thats all that has been done to it so far, the following is a video of my truck with the same engine that is in my camaro now, before the rebuild

http://www.youtube.com/watch?v=YvAmWvNEvCY

at 6:00 I Rev it to around 5000RPM I believe, which shows a little smoke coming out but I mean thats the main reason I rebuilt the engine was because of the smoke and now it smokes worse. The truck had headers and cherrybombs, no cats, just curved up from the cherrybombs into stacks.

I am pretty knowledgeable about engines, and have done many swaps, but this is my first rebuild and I am by far no genius when it comes to em. just do it as a hobby. this car is supposed to be my daily driver and now that its tagged i have paid 2 months of insurance on it while it sat in the yard would like to get it running soon. thanks for the posts guys ! will check back with ya

 

you didnt check the ring end gap did you. never seen a block stamped when it was bored out. but every over size piston ive seen is marked as such. still i lean toward the problem being guide seals. did you check the heads for flatness?cracks?

 

Coo, Im done too bro. I do have a opinion too. So I may of had gotten off on the wrong foot. Will I forget? Nope. But the show must go on right. No hard feelings.

 

Do the compression test. There is something seriously wrong here.

Dan

 

Check your heads!

 

Head gaskets? bad valve guides? hell on mine the intake had come loose and was pulling oil into the heads, I also had bad valve guides. But I also got the car used and the PO didnt know what they were doing. They brazed the rocker nuts in place so they wouldnt back off. So I just replaced the heads and intake.

 

I just got done replacing my intake gaskets because the motor was smoking bad at idle. Not quite as bad as yours, but bad none the less. I agree with everyone else. Pull plugs and see which cylinders it is. If the comression check shows up ok, then pull the inake. On mine, the back side of the intake gaskets were completely wet and I could see an oil track going down the inake runner on the head. I could also see oil puddled up on the intake valves that were closed. If you pull the inake and see no tracks, then look at the valves. You will probably see oil dripping down the valve. I really doubt its the exhaust valves as the exhaust side is under pressure, not vacuum.

 

Do not doubt it for a moment. I just pulled a super smoker 305 with under 100,000 and the rings were so bad the piston moved side to side. So yes they can smoke that bad.And no the gaps were not off.

 

On a newly "rebuilt" motor, I'd suspect the intake gaskets, damaged across the bottom. There's vacuum on one side (the port) and oil on the other (the crankcase). Guess what happens if that little bit of paper fails.

A compression test won't necessarily tell you anything about oil control.

You can take out the PCV valve and plug that hole in the VC, plug the other VC hole as well, and check for vacuum at the oil dipstick tube. If you find there's vacuum there, then .... intake gaskets it is.

 

Brought back from the dead a year later w/o the OP coming back in, and then brought back AGAIN 6 months later...

Something tells me the OP isn't still looking for answers...

 

Prolly not...

But in case anybody ever searches and finds it, maybe they'll get some sound advice to go along with a bunch of juvenile bickering and name-calling...

 

I wasnt name calling or bickering. I was just adding my 2 cents. I came across what the op was talking about. and had to point out that yes bad rings can smoke bad.