Rhythmic smoke puffing out of oil input breather cap

[AnthonyG]

About a month ago Rhythmic crankcase smoke puffing out the oil neck intake tube started after I brought the rpm's up on a ride to blow out some carbon as I rarely drive the car very fast or hard so once in a while to clean it out before putting away at the end of the season I do. Engine is an 8BA 5 yrs old w 2000 miles on it built by United Engine Specialists Jerry Livingston, Wichita Ka.. It seemed to diminish after using Seafoam engine cleaner & compression was a bit better & more consistent @ about 75psi but came back a couple weeks ago. Checked compression again and found cyl 2 weak again 30psi to 95psi. This time removed right head to check cyl's for damage, saw none after a thorough inspection of #2 & top of piston & other 3 on that side all looked good. Also there is no smoke coming from tail pipes first time nor this time, exhaust looked fine. I can't think of what would cause this condition so I guess ill pull engine remove oil pan and check inside lower end? This engine has always had what I thought was a lot of mechanical noise but chalked off to the nature of Flattys as a novice to them. Any ideas or direction?

[Ggmac]

Aren't you also having the pvc issue ?
Have you hooked up a vacuum gauge ? Vacuum gauge will tell you conditions of motor . It's a lot easier than pulling apart your motor , DONT FORGET, when it gets cool a lot more smoke is visual !

[AnthonyG]

No, the question about the PCV was a question on why the PVC one way valve was needed. Answers made sense, to prevent backfire igniting fumes in crank case. My pcv was not working when testing to eliminate this problem so I hooked up vacuum hose direct to vac port w/o pcv for test ride. Replaced w new pcv the next day. These engines were designed w no pcv in mind & running w just draft tube which I tested as well shouldn’t let the crankcase smoke come out the oil input neck unless draft tube is clogged. I cleaned draft tube & if I plug the oil input the Rhythmic puff puff puff comes out the draft tube. Pretty sure shouldn’t come out in that way from either?

[AnthonyG]

Ggmac, sorry I didn’t realize that thread continued. I went & saw ur post & posted again “AnthonyG's Avatar
Re: PCV process
I have an electronic dist w no vac advance. Which is why it doesn’t notice the vac loss I guess. It is an 8BA, sorry should’ve said in 1st post.”

[AnthonyG]

Ggmac, sorry I didn’t realize that thread continued. I went & saw ur post & posted again “AnthonyG's Avatar
Re: PCV process
I have an electronic dist w no vac advance. Which is why it doesn’t notice the vac loss I guess. It is an 8BA, sorry should’ve said in 1st post.”

[AnthonyG]

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The Rhythm of the puffs indicate one cyl. causing, assuming #2. Not sure I’ll see anything from underneath but at a loss what else to do?

[aussie merc]

sounds like classic sitting syndrome you leave it sitting and it will seize up [ nature of the beast] valves will be open and air gets in causing the rings and valves to start to seize leave it long enough and it wont even turn over answer simple USE IT it was designed and built to be used and enjoyed mean while some MM oil might free things up Plugs out and soak and retry LOTS OF LUCK

[tubman]

I have always said that the worst thing you can do is to leave these things sit. Get them out and exercise them. I just finished cleaning the carbs on my old Yamaha snowmobile that I had let sit for 7 years. The good news is that I got it running; the bad news is that there were 4 carburetors that needed to be completely disassembled and cleaned.

[AnthonyG]

So u think put the head back on and just run it?

[tubman]

I'd try that (but use new gaskets). What do you have to lose?

[JSeery]

Anthony, you may have missed something on the PCV valve discussion, it does a lot more than protect from a backfire. When you install the PCV system you are creating a large vacuum leak and this involves more than vacuum advance on the distributor. You are allowing air to enter the intake manifold that has not gone through the carburetor ventures. So, you are leaning the A/F ratio way out. It is now running lean. The PCV valve limits the amount of air (vacuum) leakage at high intake vacuum conditions (idle and constant speeds). At low vacuum conditions the PCV allows more crankcase air into the intake. Under these conditions the engine is less sensitive to the vacuum leakage. It still has an impact on the A/F ratio during acceleration however and most likely the carburetor would need a power valve or accelerator pump adjustment to correct this.

[Tinker]

Typically a blowby issue.... but chastise me...

MMO it. Sticky valve from sitting. Simple, cheap, and if it doesn't work. well your out $6.

You need to run it hard for a bit, so... maybe when it's warm.

.

[AnthonyG]

Got the new Felpro composite gaskets will install head w new Spark Plugs after clearance check, put MMO thru it & in the gas tank & run it as much as possible thru the winter. & hope she straightens out. To JSeery, I only did the one test drive to see if it still was pushing the smoke tru the oil neck. Next day put new pcv valve in it. Thx for the additional information & the site w all the info to.
Thx guys

[Bored&Stroked]

Question: Did you ever do a compression check in the past with this new engine? Do you know if it ever had good compression in all cylinders? Maybe the rings never seated in it? I would do what the other say and run it hard a few times -- full acceleration and lots of RPM changes and see if the compression gets better. If that doesn't work (and the valves are seating/sealing well), then you might need to pull it down, have the cylinders honed and put new rings in it -- and then run it hard to ensure that seat well.

Good luck!
B&S

[AnthonyG]

Thx B&S, that’s the plan.

[Ggmac]

Originally Posted by AnthonyG

Thx B&S, that’s the plan.

If you don't fix it , it's about to just get worse , sell it to me or trade me for one or two of mine ! I think I have one I can make smoke continuous, on all 8 cyl !
Seriously, I think the random low compression is either a faulty gauge or less possibly a floating piece of carbon , which I've seen happen .
Good luck and keep us posted , watch those knuckles when torquing.

[frnkeore]

I'm late to this but, here is my take on it.

Normally you will get that with a broken ring or broken ring land. It usually won't cure itself. Since yours has stopped doing once, my guess is that a ring is sticking in it's groove.

I think you'd be better served by putting the MM, in the offending cylinder, let it set one day, then spin the engine, first with the plug out, then again with it in. Let it set, one more day and drive it.

It can't be the valves, as they can only leak to the intake or exhaust. Valve guilds, can't leak enough, to cause a puff.

[Tinker]

Well on a new engine I guess you could have a ring broke. or bad install Also if you just bench run this you could have glazed the cylinders. Interested in the results.

[4dFord/SC]

"Rhythmic Smoke" sounds like the name of a new wave band

[Bored&Stroked]

Originally Posted by 4dFord/SC

"Rhythmic Smoke" sounds like the name of a new wave band

Or possibly Reggae . . . depending on the type of smoke!

[rotorwrench]

If it has a busted ring it will eventually score the cylinder & burn a piston. A person could do a single cylinder if it was traced back well enough as suspect. If it wasn't long since the last overhaul it could be deglazed an re-ringed on just the one bore. Usually all the cylinders will break in and all will have problems if it sets too long. Just one cylinder low make a person scratch their head for sure. Oil users can be brought back to life some times but compression is another thing. Sticky valves will cause a miss or intermittent flutter but it won't affect the crank case pressure. A good amount of compression is getting by somewhere if it's trying to make smoke signals out the filler tube.

[AnthonyG]

After checking cylinders from top side (Suspect cyl looked fine as did all on right side) replaced head gasket reassembled ran a few times & issue remained the same. Still had odd compression readings in #2. This will be a first for me on a Flatty, I’ll be removing the engine & putting on an indexing stand removing head on #2 cyl side again flipping engine 180 degrees to remove piston # 2. I don’t think it’s any different then other engines for this process but any experience otherwise is appreciated.

[big job]

back when I had a real job police dept. my detail was to run the generator each Friday night and switch the power for at least two hours 'work it'.. This generator a free WWII
army surplus free bee . It was a rabbit dist.so that says 59A; think it was around 10klwatt
It had a belt driven governor and ran about 1500 rpms. OD Drab green ran perfectly hour
meter around oh 500hrs or so. Bottom line Ya gotta run them. I ran that for my 25yrs
and I bet my life these new kids got rid of that for some new generack or something.
may have a broken ring ????? so my thoughts are to put your self in cold storage ok
and don't expect to get wake'd up after a long sleep to shovel snow...

[AnthonyG]

Reporting back. Removed piston #2, piston cracked between 2 top ring grooves. Rings had no damage. Sides of piston rubbing also one side of top edge.aluminum piston marked cyl but No damage to cyl. Aluminum scuffs came off easily w scotch bright cylinder wall smooth no damage. Will replace piston, rings & bearings.

[Tinker]

Cracked piston. who'd a thonk on a new rebuild. Good catch, Explains the blowby. Is it the engine on your aviator?

[AnthonyG]

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Yep

[Tinker]

AnthonyG, if the "yep" is to the picture of your aviator. I've seen that posted for a long time. Not a new rebuild, maybe I assumed.. my bad. Great car and engine.

[JSeery]

Believe he is referring to the number of miles on the engine, not the time duration since the rebuild. That's why it is not a warranty issue, way past the time period.

[V8COOPMAN]

Originally Posted by Tinker

AnthonyG, if the "yep" is to the picture of your aviator. I've seen that posted for a long time. Not a new rebuild, maybe I assumed.. my bad. Great car and engine.

As Anthony noted early-on..." Engine is an 8BA 5 yrs old w 2000 miles on it...". DD

[Mart]

I'm struggling to imagine how a piston could fail like that. Anyone have any theories?

Mart.

[frnkeore]

Originally Posted by Mart

I'm struggling to imagine how a piston could fail like that. Anyone have any theories?

Mart.

My only thought on it is, when the piston was installed, the ring compressor wasn't engaged properly on the piston and when the piston was struck, that second rig, popped out, initiating, a small surface crack, that finally migrated threw the land and the balance of the piston.

A good reason to always tap the ring compressor, down against the block, before tapping it down. It also needs to be done in one continuous stroke and not multiple strokes, because the compressor can bounce up, allowing a ring to pop out, on each stroke.

That actually happened to me, in my early days as a mechanic.

[Tinker]

Originally Posted by V8COOPMAN

As Anthony noted early-on..." Engine is an 8BA 5 yrs old w 2000 miles on it...". DD

Yes I see that now, just getting it broke in. I also suggested blowby. I'm super happy for Anthony for his findings and work.

[AnthonyG]

More to the story! As I had engine apart w heads off I descovered an issue w the Offy heads & a common issue of spark plug reach. Thinking it caused detonation issues that created the piston issues. On the advise of many I pulled all pistons & saw the same issue & worse on 3 more pistons 2, 4, & 5. I believe the Offy head spark plug reach issue caused serious detonation issues & mess up plug firing causing detonation issues that cracked the lands between the rings! Order new forged pistons, resolved Offy head issue countersinking w 120degree countersink to open 437 reach plug to firing chamber & not contained in threaded hole for plug. Will Report back!

[Sid]

What's the possibility of those pistons being Egge pistons?

[AnthonyG]

Don’t know what Egge pistons r? Busted pistons were domed cast type. See pics 2 c if u recognize?

[Mart]

spam post reported

[Bored&Stroked]

I saw the first post with the cracked piston and I was just going to say that I'd be checking for detonation . . . then you found the rest. Detonation does very bad things to pistons - especially cast ones (not that forged ones last a whole lot longer). Hopefully the spark plug issue was the main issue. I'd surely mark your crank pulley with timing marks - such that you can accurately check your timing once the thing is back together . . . no reason not too. (You'll need a degree wheel).

Hopefully you plan to hone the cylinders for the new rings/pistons. What bore size are you running? You might see if Ross has a set of forged pistons with 1.5, 1.5, 3.0 metric rings - which is what I try to run on everything (depending on the bore size).

In December I had a set of custom Ross pistons made - 3.361 bore - just so I could run 1.5, 1.5, 3.0 moly metric rings. In today's world, we're coming to the point where the availability of quality rings - determines the final bore size of the pistons (not the other way around).

[Steve in Denver]

Where is the PVC valve on an 8BA?

[AnthonyG]

Steve, I think u mean where is the PCV valve on mine? No flatheads have PCV valves unless u convert crankcase draft tube to a PCV system. I set my 8BA up using vac port under carb to PCV initially too draft tube but changed to Mopar style oil breather cap w tube for PCV https://www.google.com/search?client...10.SwD4lfXV-ZM

[AnthonyG]

Bored&Stroked, sent original builder all piston assy’s along w conversation posts on the spark plug reach issues w Offy heads. He’s giving me a set of Ross Forged pistons, new rings & bearings @ cost & setting up new assy’s on his dime. As I believe i it was detonation caused by the messed up Offy head design w the 437 reach plugs being 4 threads.shy of reaching the firing chamber I don’t blame him & think he’s being fair throwing in his labor costs.
Yes I will be honing cyl’s even though the original cross hatching from original build is still visible which convinced builder I only had a couple thousand miles on it!