1963 401 rocker arm oiling

[Pete Phillips]

Are these rocker arms on backwards? When the car idles, we get lots of oil dripping out the back of the rocker arms (opposite end from the top of the valves) and little if any dripping down onto the valve stems. 1963 Electra with a 401.

[60FlatTop]

The arms look right but the orientation notch on the shaft appears to be down. It should be on top to align the oil holes.

[avgwarhawk]

Yes, check the shafts are correctly installed.

[Aaron65]

Pete, did you ever figure this out?  I just reassembled the heads/valvetrain on my '63 401, and after running it for about 10 minutes at fast idle, I had a ton of oil coming out the bottom of the rockers and only about half of the rockers had oil seeping out the top oil port.  The shafts are definitely oriented correctly with the oil holes pointed down (I assembled them myself with new shafts).  My guess is that not a lot of oil is supposed to get to the end of the valve because they didn't use seals (until 1966), and that when the engine is at higher speeds, oil finally gets flung from that upper port to lube the valve tips.  

[NTX5467]

The lack of valve seals might have been motivated by economics, but I read (about 20 years ago) that as long as the valve stem-to-guide clearance was below the middle of the factory spec, a valve stem seal was really not needed.  Given Buick's use of a higher-nickel cast iron mix, so that hardened valve seats are not needed with unleaded fuels, I suspect the valve guides are also harder and less prone to wear?

 

Toward the later 1960s, I saw some "white" Perfect Circle seals used by an engine builder, in "HOT ROD" magazine, as a better seal.  Yet, years later, my late machine shop operative said they kept the guides too dry, not enough oil got past them to lube the guides even marginally well.  Might be fine for a race engine, but not for a street engine (and many miles between teardowns).  Chevrolet used what I term "o-ring" seals, which would contact the top of the guide only when the valve was full-open.  Otherwise, no seals as such.  With my machine shop guy terming the Umbrella seals with a retaining ring clamp as "Studebaker" seals.  FWIW  So, on the intake stroke, port air flow will create a vacuum to pull oil mist into the valve guide.  If the clearance is not too great, not much gets sucked in, but when clearances get toward the top end of the range, more oil than needed.

 

In modern times, engine internal oil control is outstandingly great.  Modern piston ring (especially the oil rings) and valve stem seal designs are one factor in this.

 

Just some thoughts and observations,

NTX5467

Edited April 4, 2023 by NTX5467 (see edit history)

[EmTee]

14 minutes ago, NTX5467 said:

Yet, years later, my late machine shop operative said they kept the guides too dry, not enough oil got past them to lube the guides even marginally well.

This ^^^ would be my concern as to retrofitting valve seals or shields to an engine originally designed without them.  As a band-aid on a high-mileage engine, maybe -- but not as part of a proper valve-job.

[60FlatTop]

In the 1980s I learned the same thing your machine shop man told you. I was looking at bronze valve guides and machining the the cylinder head valve prominence to accept cup style stem seals. I found I was potentially doing more damage than good. With the arrival of the 1990s I had given up modification in exchange for maintenance in all my endeavors. Life has been good. I think my last bit of resistance was accepting gasketless exhaust manifolds on my nailheads.

[avgwarhawk]

1 hour ago, NTX5467 said:

 

 

In modern times, engine internal oil control is outstandingly great.  Modern piston ring (especially the oil rings) and valve stem seal designs are one factor in this.

 

Just some thoughts and observations,

NTX5467

 

I concur. Todays engines tolerances(exacting fit) are fair greater than we have seen in the past.  

[NTX5467]

2 hours ago, EmTee said:

This ^^^ would be my concern as to retrofitting valve seals or shields to an engine originally designed without them.  As a band-aid on a high-mileage engine, maybe -- but not as part of a proper valve-job.

And THAT seems to be the "genius" behind the Chevy o-ring seals.  First time I saw them, I suspected "Mickey Mouse" and "what good do they do?  Then my late machine ship operative added that the o-rings "float" or "self-locate" after they hit the tops of the valve guides when the valve is open, only, thereby "sealing" them at full valve lift, the time when intake flow is highest.

 

By the earlier '70s, I was noticing that many engines, when firing up after sitting for a while, would initially emit exhaust oil smoke for about 10 seconds or so.  Reason?  No exhaust valve stem seals, it was claimed.  I wondered about "why" no seals on the exhaust?  The reasoning was that only pressure was in the exhaust side of things, unlike the intake side.  Economic reasons, too?

 

But when the ball stud/actuator rod interface on the EFE (vacuum-operated heat riser) valve on my '77 Camaro came apart one day, resulting in a "new" loud clanging noise, I became very aware of how strong the negative pressure pulses were in that rh exhaust manifold.  Sure, pressure on exhaust valve opening, but a negative pressure pulse during "overlap", rather than a smoooth flow (as suspected) at idle.  FWIW

 

When we had oil consumption concerns on the mid-'80s Chevy 305 engines, the TSB indicated a new valve stem seal kit.  When I saw it, it had EVERY type of valve stem oil seal which Chevrolet had used on their V-8 motors, up until that time in history.  O-rings to bonnet seals, take your pick.

 

Take care,

NTX5467

[avgwarhawk]

1 hour ago, NTX5467 said:

 

 

When we had oil consumption concerns on the mid-'80s Chevy 305 engines, the TSB indicated a new valve stem seal kit.  When I saw it, it had EVERY type of valve stem oil seal which Chevrolet had used on their V-8 motors, up until that time in history.  O-rings to bonnet seals, take your pick.

 

Take care,

NTX5467

 

Yep, my 88 Monte Carlo 305 ate valve seals like candy.  

[NTX5467]

1 minute ago, avgwarhawk said:

 

Yep, my 88 Monte Carlo 305 ate valve seals like candy.  

Probably because it needed the valve guides done, I suspect.  Just as with the trans output shaft seal, when the valve wobbles in the guide, the seal gets degraded, too.

 

Just a suspicion . . .

NTX5467

[avgwarhawk]

1 hour ago, NTX5467 said:

Probably because it needed the valve guides done, I suspect.  Just as with the trans output shaft seal, when the valve wobbles in the guide, the seal gets degraded, too.

 

Just a suspicion . . .

NTX5467

No sir.  Brand new car.  At 27k miles started lowing blue at first start up in the morning.  Dealer under warranty pulled the heads for inspection.  Installed new valve seals.  56k miles, blowing blue once again.  This time I installed racing valve seals.  Sold the car not soon after as it was loaded with other issues since taking it off the lot with 38 miles on it.  It was a pile of you know what....     

Edited April 4, 2023 by avgwarhawk (see edit history)

[NTX5467]

We did a good number of valve jobs on '78 Monte Carlo 305s when the cars would come in running bad.  Cars we'd sold new.  A tune-up was the "cure", but most ended up getting a valve job.  Seemed to be MCs more than Caprices, for some reason.  There was a pattern.  And no 350s in pickup trucks, either.

 

By '86, it was alleged "soft camshafts" that caused issues on many 305s.  Usually, a new cam/lifters (under warranty) took care of that.  Then there was the "hot re-start" and vapor lock on Camaros and Firebirds.  Considering the small float bowl on the QJets, and the fact that due to the hose routings, NO air could get to the carb to cool it.  A TSB and lots of hose relocations for minimal betterment, by observation.  As the engineers knew that EFI was coming in a year, "Band-Aid" fixes at best, from what I could tell.  Of course, after the cars got out of warranty, we didn't see them again.

 

On the "soft camshaft" issue, never did know if perhaps the lobe which ran the fuel pump was "soft", too, resulting a shorter stroke and less fuel pumped per stroke.  Reason I mention that is that during this time, a motorhome from west TX came in, with a complaint that it only would run 55mph on flat land.  They had spent the day in service depts between Midland and us.  One place put on a booster fuel pump, which helped.  Hearing the story, our tech came in and asked for a carb jet, so I got him one.  This was after he clamped shut the return fuel line.  Then he came back and asked for a smaller one.  Then we saw the motorhome leave.  When I asked him what he did, he said that apparently the orifice for the return line, in the fuel pump, was too big.  That when he clamped the line shut with vice grips, it would run 80mph (as the owner smiled!), so the carb jet was placed into the return line at the pump, to do the same thing.  75mph was no problem for that 454 after that and the customer was extremely happy.  That made me wonder if those "soft cams" were all really about the valves opening enough rather than about fuel supply?  But never did get to find out.

 

The only issues with 350 cars back then were on 1985 9C1 Caprice police cars.  Some would only run 100mph and others could go 130mph.  Which came to light in a multi-department chase on I-20.  Funny thing was the 318 4bbl Plymouths and Dodges would match or best the fastest Chevrolet 350s.  The box of parts Chevy provided, per TSB, to address that issue must have cost well past $1000.00.  BTAIM

 

Those were the FUN times,  Sorry for the diversion.

NTX5467

 

 

 

 

[60FlatTop]

14 minutes ago, NTX5467 said:

That made me wonder if those "soft cams" were all really about the valves opening enough rather than about fuel supply?

Reminds me of a Easter story. A woman came to her daughter's house for Easter dinner. While preparing the ham to bake her daughter cut a slice off each end and placed it in the baking pan. Her mother asked "Why do you cut the slices off like that?" Her daughter answered "I learned that from watching you while I was growing up." Her mother replied "I didn't have a nice big pan like you!" Engineering solutions at the TSB level, as in many of the operations I have been involved in, are usually solved by groups. And a lot of assumptions are made by the ones who hate to ask questions. I remember coming back to places I had worked and saw some emergency actions I took that had been placed into Standard Operating Procedure. When I asked why they did that I got answers like "Anytime it goes over 85 degrees me have to do that". I'd ask where the other four monkeys were.

 

[Aaron65]

In case anyone ever looks at this topic again, I PM'ed Pete about it.  After a short trip at higher engine speed, he said that the upper rocker arm orifice on his engine was oiling as it should.  I haven't pulled my valve cover to check yet, but I imagine mine will be fine, too.  

Thanks to Pete for posting this and getting back to me.