Another nailhead question

[dlcoop]

Alright everyone.  I started a new topic so I don't get confused with my old ones.  I pulled the timing cover off this a/m and here is what I found.  There are three holes in the front that look like they require a plug so the engine will oil pressurize.  My question does it take all three or just 2.  Front cam bearing seems to be in the right place.  (main oil hole on the left side looking at it. )

 

Am including a pic so that will help.

 

Many thanks to all who have contributed. COuld not have solved the problem without the help.

[Gene Brink]

Uncertain about whether or not you need plugs in the pictured holes but they do not appear to had plugs given the "old engine" discoloration of the metal. If they should be plugged I'd bet you would show oil leakage from your previous attempts to raise oil pressure by turning the oil pump as it certainly would flow oil freely if it were getting to them.

 

Your front cam bearing should have an elongated hole and two round holes in it and cannot see clearly enough in your picture to determine if yours does. Roughly speaking the elongated hole should be at the bottom (slightly to one side to align with the oil passage in the block) and the two round holes positioned like the upper arms of a Y (also aligned with holes in the block) so the oil can flow to the valve lifter oil galleries on each side as well as on to the rocker assemblies. As others have stated the front journal on the camshaft has to have a machined groove in it that will align with all three holes in the bearing to permit a volume of oil to circulate. From your previous descriptions of what you've tried, etc. I'd bet the camshaft bearing is incorrectly installed (or worse yet the machine shop inserted the wrong bearing in the front position) or, if replaced, the cam front journal does not have the necessary groove in it. A good oil flow diagram for your engine can be found at (fig 60-124) https://www.teambuick.com/reference/library/66_chassis/files/60-c.php. Good luck.

[dlcoop]

In looking at the holes closely, They do have a step in them. Meaning they are not the same diameter all the way through.

[old-tank]

Just now, dlcoop said:

In looking at the holes closely, They do have a step in them. Meaning they are not the same diameter all the way through.

The 3 holes require plugs.  Now you wonder what else the machine shop assembled and neglected to do right.

[Bhigdog]

Bottom hole is the main oil galley, two side holes are the galleys for the lifters. All three require cup type plugs, closed end down. All three galleys require plugs at the back end too. Without them you are pumping the pressurized  oil directly into the sump or over board. No where else. Other than failing to tighten the bearing caps (are you sure they did) I can't think of a more egregious shop failure. Are the ring gaps staggered? Are the bearing clearances too loose? Too tight?  Are the ring gaps at least .010? 

BTW. They have the oil slinger on backwards. The cupped side goes forward towards the oil seal.

Twer it me I would ask the shop to spring for an engine gasket set, tear it down myself and check at a minimum the above...............Bob

Edited March 3, 2018 by Bhigdog (see edit history)

[Rooster]

Lucky you checked for this !   

You can buy the new correct plugs from Russ Martin at Centerville Auto Repair in Grass valley California.   Same place you get the rear plugs from.

[old-tank]

25 minutes ago, Rooster said:

Lucky you checked for this !   

You can buy the new correct plugs from Russ Martin at Centerville Auto Repair in Grass valley California.   Same place you get the rear plugs from.

The plugs are hard to find.  Maybe they were looking for some and then forgot.

On one of mine we reused the old plugs (after brazing the dent puller hole); on another we tapped for a pipe plug.

[avgwarhawk]

Same shop did the heads? Check the rocker shafts are installed correctly as well. 

[dlcoop]

I just had the block hot tanked.  My fault for not checking the plugs. I also installed new rockers and shafts. I know there is an over size bolt hole on the front of the rocker and I hope I have it right.  If not will just keep changing until I have it right.  They all seem to be the same diameter.

 

Will order new plugs on Monday.

[Bhigdog]

16 minutes ago, dlcoop said:

I just had the block hot tanked.  My fault for not checking the plugs. I also installed new rockers and shafts. I know there is an over size bolt hole on the front of the rocker and I hope I have it right.  If not will just keep changing until I have it right.  They all seem to be the same diameter.

 

Will order new plugs on Monday.

If the rocker arms were removed from the shaft or new shafts, there is a notch on the ends of the shaft. Notch must be "up" or the rockers won't get oil..............Bob

[Beemon]

3 hours ago, avgwarhawk said:

Same shop did the heads? Check the rocker shafts are installed correctly as well. 

 

Also check for hardened seats.

[NTX5467]

When I first saw those holes, I suspected the two top ones would be for the lifter oil galley.  Didn't suspect the lower one would be for the mains!

 

Chevy 454s used screw-in pipe plugs with a .020" hole in the middle of the Allen-head hex in the plug.  The earlier engines had a problem with the lifter galley getting air in it at oil drain/change time.  Eventually, the air would be purged and the lifters would get quiet.  The factory TSB and later model years spec'd the plugs with the holes in them.  Not sure of the size of the NHBuick plugs, but possibly the Chevy screw-in plugs might be an option if the sizing is correct (if the existing holes are drilled for such).

 

I concur that a new gasket set and some PlastiGage, along with a good torque wrench, might be in order.  Might be best to just get the gasket set on your own rather than bugging the machine shop for one.  Normally, they're not motivated to do such without the engine being in their possession.  At this stage of the game, might be best to fund it yourself and "go on down the road".

 

I also concur that since this glaring indiscretion has been discovered, it puts lots of other things in possibly question, too!

 

The "learning curve" has begun.

 

NTX5467

[avgwarhawk]

22 hours ago, Beemon said:

 

Also check for hardened seats.

Hardened seats can be hard on the wallet down the road. 

[Bhigdog]

45 minutes ago, avgwarhawk said:

Hardened seats can be hard on the wallet down the road. 

 

Any factual evidence/data on that or is it anecdotal?..................Bob

[Beemon]

I think he's eluding to the potential failure of hardened seats due to the thin waterjacket, and then having to find another pair of useable heads and having those rebuilt again, but without hardened seats.

[NTX5467]

Allegedly, the combination of valve material and cylinder head metal "blend", makes "hard seat inserts" not needed in Buick Nailheads, at least in the earlier ones.  Did the same materials exist in the 425s, too?

 

Similarly, the valve seat "meat" is less on the earlier Nailheads than on most other motors, which can help keep the valve seats cool.  Easy to "strike water".  Were the 425 castings the same way?

 

Just some thoughts from reading information in here,\

NTX5467

[Bhigdog]

41 minutes ago, Beemon said:

I think he's eluding to the potential failure of hardened seats due to the thin waterjacket, and then having to find another pair of useable heads and having those rebuilt again, but without hardened seats.

 

I'm aware of the theory. Is there anything more than "from what I understand"  or "I've heard" type of evidence.? Hey.........Just asking. I'm agnostic on the use of hard seats but if it's no more than scuttlebutt urban legend it serves no good purpose.

Has anyone produced engineering drawings showing the web thickness of the valve seat area? How about the alluded to nickle content of early/late blocks? Is the web thickness less than other blocks? By how much? How much block material is left under new seats?

Inquiring minds might like to know ................Bob

Edited March 5, 2018 by Bhigdog (see edit history)

[Beemon]

 

This is a picture from a HAMB thread of a 425 Nailhead cylinder head that was cut apart. You can see how close the seat comes to the waterjacket here. As for nickle content in cylinder heads, I have not found anything from Buick Motor Division that states what the cast iron alloy used for their cylinder heads and block are. However, since I have a few ruined heads, maybe I'll bring them back with me after spring break and do a Rockwell test to see how hard they truly are. I've also been told that Nailhead spring pressures aren't as extreme as other engines of the era because they have relatively low RPM numbers.

Edited March 5, 2018 by Beemon (see edit history)

[NTX5467]

From what I've observed about things over the years AND how design-year related to how things were done, I'll buy into the thinner seat area and the possible need for the high-nickel metal that Buick is reputed to have used.  The higher-nickel metal is harder than other blends of cast iron which GM used, which possibly had the double-edged benefit of not needing hardened seats for "white gas" use back then and to save money with less metal in the cylinder head.  So, a more expensive metal blend, but less of it.

 

Natural gas-fueled motors would have had hard seats in those heads, from the factory, if it was a more common Chevrolet V-8.  In the case of Chevy motors, when my machine shop operative was boring a normal Chevy 350 V-8, his boring bar made a "normal" noise as it did its thing.  When he was boring a Chevy 307 2bbl motor or an inline 6 cylinder motor, it was noticeably quieter.  Softer metal = less load and less operational noise.  There were some Chevy 283s with "HB" cast into the front side of the block.  Allegedly meant "Hard Block" due to a high-nickel cast iron metal blend.  At the time, they were desired for performance use.

 

As the higher carlines had a little more money to spend, due to the vehicles' higher price point, Buick could justify spending the higher price for the high-nickel block and head blends of cast iron.  This was somewhat offset by their lower production volume than what Chevy had, I suspect.

 

Not that a Buick nailhead cylinder head can't "take" hard seats, but it appears the machining needs to be more precise and any core shift would need to be at a minimum.  There have been comments about people "striking water" in order to have the hard seats installed.  As if that ruined the heads in the process, or were they ruined as they might then be prone to cracks around the new seats and the new seats would not seal the water from their interference fit?  Machine shop work being more critical, too?

 

A side issue could have been that many Buicks were not driven "hard" for very long and the engines would last longer than the car body did.  By the time they got to the salvage yard, few people wanted the engines, desiring the beloved Chevy engines more.  The Buick heads didn't "breathe" as good as the Chevy heads, so nobody wanted them.

 

So, with no natural gas motors, limited use of "white gas" in that design era, or later unleaded gas use, no real need to put enough meat in the valve seat area to support the installation of hard seats.  Therefore, I'm buying into the "urban legend".

 

NTX5467

[NTX5467]

unleaGenerally lower rpm levels (due to head port issues) and lighter (smaller "nail head size") valves.

 

When GM went to 'unleaded fuel capability" in April, 1971, as Buick engineer Denny Manner told us at a seminar at the Buick 100 meet in Flint, the corporate edict was that all engines would have induction hardened valve seats. after April 15, 1971.  Combined with 8.5 to 1 compression ratios, would operate on 91 Research Octane unleaded fuels across the board.  Buick engineers resisted as they claimed, due to the high-nickel content in their heads combined with the material in the valves, if they followed the GM directive, they'd "downgrade" their materials to meet that standard.  In other words, they were already there.  So they had to downgrade their cast iron mix to accommodate the induction hardening of the valve seats.  I heard that with my own ears.  This would have been post-Nailhead production years.

 

It might be interesting to see how the images which Beemon posted compare with the small block Chevy V-8 cylinder head valve seat castings.  There might be some blueprints of that in the Chevrolet High Performance manual which Petersen Publications did in the earlier 1960s?

 

NTX5467

Edited March 5, 2018 by NTX5467 (see edit history)

[Bhigdog]

Does look thin. I'd like to see some other, non Buick, heads  sectioned. Wondering if smaller, earlier year heads are "meatier". Thing is, in this computer driven, info sharing climate, I'm wondering if one guy "hits water" machining a head with a displaced core when cast. Then shares his experience over the internet and suddenly it's "you can't put hardened seats in a nail head". As I said, I'm agnostic but would like to get to the facts (if that's possible)................Bob

[avgwarhawk]

12 hours ago, Bhigdog said:

 

Any factual evidence/data on that or is it anecdotal?..................Bob

 

 

Factual sir.   My nailhead was rebuilt by an outfit in VA(previous owner).   Seats were installed. One failed.  Head destroyed.  Both heads were fitted with seats.  Both heads became boat anchors.  The cost of replacement heads and rebuilding these replacement heads is what cost the wallet. 

 

Among other things found wrong with the rebuild,  rocker shafts installed upside down.  Fortunately the rebuilder did manage to install the camshaft bearing correctly.     

[avgwarhawk]

11 hours ago, Bhigdog said:

 

I'm aware of the theory. Is there anything more than "from what I understand"  or "I've heard" type of evidence.? Hey.........Just asking. I'm agnostic on the use of hard seats but if it's no more than scuttlebutt urban legend it serves no good purpose.

Has anyone produced engineering drawings showing the web thickness of the valve seat area? How about the alluded to nickle content of early/late blocks? Is the web thickness less than other blocks? By how much? How much block material is left under new seats?

Inquiring minds might like to know ................Bob

 

 

Not legend at all.   The heads I sent to Martin's for rebuild as there was smoke/tapping on the driver side head.  Russ found a seat that failed after a pressure check.  Heads were kaput.  Now it is not to say the hardened seats do not work as it did get about 7-8 thousand miles on these heads.  But, at the end of the day a seat failed.   

 

Before I dug deeper for the smoke I had checked the rocker shaft.  Found these were upside down.  Corrected.   Smoke still present.  Replaced the fuel pump.  Found oil leaking through vacuum pump portion.  Smoke still present.   Tapping in head.  Removed heads. Found failed seat.  In the meantime I pulled each piston, honed the cylinders and installed with new rings.  All is well that ends well.  Just costly.           

Edited March 5, 2018 by avgwarhawk (see edit history)

[avgwarhawk]

Smoke at tailpipe.  Seat failed. 

 

 

 

 

Heads rebuilt and replaced :

 

 

[Bhigdog]

You say one seat failed. Can you define "failure". Did it break through into the water jacket. Seat loose, cracked, head cracked etc etc etc. Not doubting you just trying to get more facts..........Bob

[avgwarhawk]

34 minutes ago, Bhigdog said:

You say one seat failed. Can you define "failure". Did it break through into the water jacket. Seat loose, cracked, head cracked etc etc etc. Not doubting you just trying to get more facts..........Bob

 

From my understanding the seat fell out of the head as a cracked formed.  It was clattering and smoking as the valve opened and closed.   I believe there was some, although very little, antifreeze leaking into the cylinder.  Emissions from the tailpipe had water(although normal depending on time of year) but this was during warmer days and it was spitting rusty crap. The nose of my KIA in the video if you look close has rusty specks that were spattered from the tailpipe.  Plus the puddle formed on the garage floor was rusty.    Since the rebuild that has not happened at all.     

Edited March 5, 2018 by avgwarhawk
spelling (see edit history)

[Bhigdog]

50 minutes ago, avgwarhawk said:

 It was clattering and smoking as the valve opened and closed.

 

Clattering makes sense but the oil smoke not so much. If the seat fell out of the head it would be retained by the valve but you would think it would get cocked under the valve and cause more symptoms than just a clatter or tapping. just sayin......................Bob

[Bill Stoneberg]

I had a machine shop treat the heads like they were SB 350 heads and as they were tryng to put seats in the, hit the water jacket.

Ruicned a good set of heads.  

[Bhigdog]

57 minutes ago, Bill Stoneberg said:

I had a machine shop treat the heads like they were SB 350 heads

 

Can you clarify that, Bill. Are SB Chev heads treated a special way? If you had not requested that treatment would they have been successful? What year/engine heads ..........Bob

Edited March 5, 2018 by Bhigdog (see edit history)

[avgwarhawk]

1 hour ago, Bhigdog said:

 

Clattering makes sense but the oil smoke not so much. If the seat fell out of the head it would be retained by the valve but you would think it would get cocked under the valve and cause more symptoms than just a clatter or tapping. just sayin......................Bob

 

 

There was other issues.  When I pulled the heads every cylinder was coked and full of oil deposits. Could have been from the fuel pump vacuum side and rocker shafts upside down.  Accumulated over time.  Never really smoked the 2-3 years before the clatter and smoke became very evident.   For this reason I honed each cylinder, cleaned up the pistons and used new rings.  Corrected all the other found issues.  Runs like a champ now.         

 

 

What my valves looked like:

 

 

Edited March 5, 2018 by avgwarhawk (see edit history)

[old-tank]

When I rebuilt the engine on my blue/white 55 the heads had severe valve seat recession to the point of being unusable, so inserts were installed.  After 85,000 miles, I had combustion chamber water and found a leak around one of the seat inserts.  I replaced the head without installing seats inserts and cut out the seat on the old one:  it was installed with some kind of putty (JBWeld?) and the water jacket was exposed.  I had to replace the other head later due to a crack around a valve guide.  Machine shops have caused me so much grief and in this case, I would have replaced the head if I had known about the intrusion into the water jacket.  They said it was my fault for driving so much.  I'm sure that carefully choosing seats and cutting they can be successful, but really that is just 8 more things to go wrong!

[avgwarhawk]

4 minutes ago, old-tank said:

  They said it was my fault for driving so much.  

 

 

The nerve of you!!!!  

Edited March 5, 2018 by avgwarhawk (see edit history)

[avgwarhawk]

3 hours ago, Bhigdog said:

 

Clattering makes sense but the oil smoke not so much. If the seat fell out of the head it would be retained by the valve but you would think it would get cocked under the valve and cause more symptoms than just a clatter or tapping. just sayin......................Bob

 

 

Bob,

 

I did find the video of the noise at idle   As I pan the camera towards the firewall you will hear the tap, tap , tap.     I do not think the seat was cocked but simply falling as the valve opened and went back into the head. The valve does not open all that far.   What really threw me off is it never lost power.  Just smoke.  Sometimes after it completely warmed and driven the smoke would stop.  Like the seat was stuffed in the head and swollen to keep it from falling out.  Other item I did before pulling the heads...replaced all the lifters(since I was in there replacing the lifter on the noisy cylinder) thinking this was the problem.  Corrected the oiling issue with the rocker shaft.  The oil from the vacuum pump was a really cute deal.....the rubber hose off the pump to the hard line to the wiper motor was pinched from the bend that it allowed just a drop to be sucked into the motor.   Not enough to see smoke but probably enough to allow coking over time.  Needless to say the wipers never worked well until I corrected the hose, rebuilt the fuel pump and wiper motor.     It was very frustrating to say the least.   However, my efforts did not go to waste.  It was all done in my garage.   

   

[Bhigdog]

That's not a very good sound, for sure.

It appears that seat inserts in a nail head are a hit or miss deal. Some shops say it can be done but the shop has to know what they are doing. That makes little sense. There is enough "meat" in the head or there isn't. It's possible the sand core in a given head may have shifted a bit during the pour  making that head a good candidate or not. No way to tell in advance.

There also may be some insert brands/types better than others. Too heavy a press fit may cause problems too.

I'm guessing the best advice is to not re-seat.

That does bring up the question of seat recession with no lead fuel. I've heard lots of pro/con on that subject. There are lead substitute additives available but they may be "snake oil". I wouldn't be a bit surprised...........Bob

[avgwarhawk]

10 minutes ago, Bhigdog said:

That's not a very good sound, for sure.

It appears that seat inserts in a nail head are a hit or miss deal. Some shops say it can be done but the shop has to know what they are doing. That makes little sense. There is enough "meat" in the head or there isn't. It's possible the sand core in a given head may have shifted a bit during the pour  making that head a good candidate or not. No way to tell in advance.

There also may be some insert brands/types better than others. Too heavy a press fit may cause problems too.

I'm guessing the best advice is to not re-seat.

That does bring up the question of seat recession with no lead fuel. I've heard lots of pro/con on that subject. There are lead substitute additives available but they may be "snake oil". I wouldn't be a bit surprised...........Bob

 

 

I think the question is why install seats if metallurgy(current opinion/real world experience) claims the content of heads allows for no hardened seat operation.   I would say  to look at really world data.  Who has put on 100k plus miles with a set of heads without  hardened seats running unleaded?   

 

 

 

         

[old-tank]

39 minutes ago, Bhigdog said:

That does bring up the question of seat recession with no lead fuel. I've heard lots of pro/con on that subject. There are lead substitute additives available but they may be "snake oil".

Snake oil for sure....and recession does occur.  Years ago I rebuilt a Ford flathead v8 for my F1 truck.  The machine shop talked me out of new seats since seats were already installed from the factory.  Apparently not hard enough since I had to adjust the valves (used adjustable lifters) every 15K miles.  At 90K miles all of the adjustment was gone; you could see the exhaust valve sunk into the head through the sparkplug hole and the valve springs were stretched so much that the valves floated at 3000 rpm.  That truck was my daily driver and I ran it hard:  hooked to a 2000# trailer with a 4000# Buick on it; 3.9 rear gears.  Not all bad news since I replaced it with a 264 nailhead.

[old-tank]

1 hour ago, Bhigdog said:

Too heavy a press fit may cause problems too.

No pressing...pounded in with a BFH!

[Bhigdog]

1 minute ago, old-tank said:

No pressing...pounded in with a BFH!

 

A manly man. Doing manly things with manly tools. Yeah Baby.........................Bob

[Bill Stoneberg]

5 hours ago, Bhigdog said:

Can you clarify that, Bill. Are SB Chev heads treated a special way? If you had not requested that treatment would they have been successful? What year/engine heads ..........Bob

 

1962   401    No  SB 350 heads are not treated differently, its just what they were used to doing and they acted the same way with my nailhead heads.  Even though I told them what I wanted.

They are no longer in business but not till they ruined an engine.

 

 

[Beemon]

I have only had about 2 years I  the hobby thus far and I distrust any and all mechanics and restoration services and shops. I have been burned at every corner in my journey. If the shop says they can do it, they just want more $$$. Everything I've had rebuilt or worked on "professionally" be people with "years of experience" have failed me all except for the Dynaflow which was built buy a young, humble Latino man who was not much older than myself (mid to late 20s) and had no experience himself with Dynaflows and worked in a strip mall transmission shop. My only complaint is the front seal dribbles a bit but it's nothing to worry about because the dipstick level never changes. Those who claim to know, know nothing and those who claim to know nothing, know a lot.