Jump to content

Me and my beautiful 1956 Buick


Recommended Posts

2 hours ago, carbking said:

Ben - the WOT from a stop sign was a minor issue from day 1. Remember there were many changes in engine size and carburetor design during this period. The modification of the idle tubes is a work-around, as is advancing the static timing a few degrees.

 

The actual problem is that the 1956 Rochester has no auxiliary air valve. For 1957, Rochester added the auxiliary valve to the secondary.

 

On the 1956 carb, WOT activates the secondary. On the 1957 carb, WOT opens the secondary throttle plates, but the auxiliary air valve prevents air from flowing in the secondary until a pre-determined vacuum is present in the intake. This solved the issue.

 

Opening the throttle maybe only half way for 1/2 a second and then flooring the throttle might also work, maybe worth a try.

 

Jon.

 

This hesitation issue has been widely reported. Since I had so much seat time with the 56 recently I noticed it was an intermittent thing.  Here's some points I noted from my experience:

1: it does not hesitate when the engine is still warming up.  Step on the gas and it just goes smoothly.

2: It does not hesitate if the car is on an angle foreward or reverse.  But it almost always happens when the car is level. 

3: It is intermittent hesitation if turning left from a stop, once warmed up it always hesitates when turning right, unless it's facing down hill.

4: It is intermittent if I accelerate lightly for the first brief second or two. 

5: It never hesitates, or at least I don't feel it,  while moving.

 

Sometimes I am tempted to adjust the choke so it is a little bit applied when the engine is warmed up, but right now it starts easily and we are headed into colder weather.  But now that Jon mentions the secondary air valve, and I noticed no hesitation when the engine is warming up, I wonder if it's possible to adjust the secondaries to open a few millimeters later  and if that would help the situation?

 

Link to post
Share on other sites

Ben - the 1957 design has an internal auxiliary air valve that is spring-loaded; same general principal as the Q-Jet. One piece of trivia you are not apt to ever see in factory or aftermarket documentation, is that the 4-GC with the auxiliary air valve uses the same spring as the Q-Jet air valve; and the adjustment is 1/2 turn past "touching" at an ambient of 65~70 degrees F.

 

John D - your comments reinforce the idle tube increase work around.

 

When the engine is warming up, the choke is still partially engaged, thus the mixture is slightly richer. If the vehicle is on an incline, the fuel level in the bowl may be slightly higher, thus making the mixture slightly richer. Changing the adjustment of the secondary engagement would make no difference at WOT. The engine needs slightly more fuel to eliminate the hesitation.

 

The idle mixture control screws are greatly misunderstood; THEY DO NOT ADJUST THE MIXTURE! The idle mixture is adjusted internally by the orifices in the idle tubes, the idle air bleeds, and the idle bypass (also air). The mixture screws control the VOLUME of pre-determined mixture. Thus opening up the idle tubes actually DOES richen the mixture.

 

The hesitation when turning right is a different issue, and a factory fix was issued by Rochester. Those who had their vehicles serviced at the dealership had the factory fix applied. When we were still restoring carbs, about 1 out of 3 had the patch, even those that had been "rebuilt". Apparently, the commercial rebuilders did not read the Rochester bulletins. 

 

Jon.

Edited by carbking (see edit history)
Link to post
Share on other sites

Thanks for the info John, I did not know that. Now i'm more inclined to play with an AFR gauge.  :P

 

It would honestly be interesting to see where the stock carb stacks on an AFR meter. It's not like they had the technology to measure lambda values in a shop in 56. I'm sure since 4 barrels were still new, it was probably looking at plugs and reading vacuum gauges on engine dynos after the what if math was done. 

Link to post
Share on other sites

I've got three 56 4 barrel intakes lying around. This one had the brass T broken off, so I think I'll drill it out and cap with a pipe plug since the extractor isn't working... Anyways, I wanted to experiment on the shop mill. I think it turned out alright.

 

43187003_10157744122950830_2214049705443

43045377_10157744123040830_1757959100987

43063114_10157744123125830_5715518645296

 

The casting for the adapter really sucks, and I found out its pretty porous. Regardless, it's way big on the old pattern side. I don't think I'll bother port matching here, since it doesn't really matter at the carb mouth anyways. At least, in this application, it's pretty negligible with an open plenum.

  • Like 3
Link to post
Share on other sites
1 hour ago, Beemon said:

This one is leaking from the passage plug and accelerator boot. 

You will have a real good leak when that plug comes out (and a krispy kritter too).  It didn't do me any good, but if you whine and cry enough maybe Jon will rebuild it for you:D.

  • Like 1
Link to post
Share on other sites

I have two of them, it would be interesting to see how these carbs perform with all the little mods you need to make to have them actually work right. 

 

I'm going to have to pull the aluminum valve covers off, too. They have a lip that goes around the gasket and I think it's not letting the cork seal. It will most likely need to be planed because I don't think there are regular gaskets that don't have the fat edge. 

 

I'm not going to do that on the club mill by any means. When I did the intake, the chuck was out of plane 3 degrees somehow. It's since been zeroed, but I think I'd rather have it done professionally. I'd also need to make a jig and find some aluminum soft jaws. 

 

I can't wait to be done with school and have my own mill.

  • Like 2
Link to post
Share on other sites

Started blowing blue smoke. I know it was inevitable, but looks like I'm blowing out the worn bottom end with my tight top end. Compression readings seem to still be good, and I have seals on the valve guides.

 

Edit: Or black smoke, it's intermittent. Not like my first engine.

Edited by Beemon (see edit history)
Link to post
Share on other sites

We'll see. I'm meeting with a local hot rodder soon to use their acid bath for my modified intake manifold. I also finalized my switch for 3D printing... I went through a painstaking process of modeling every component in the system to a degree of accuracy that makes sense to me.

 

BMf8g.jpg

BMf9a.jpg

BMfO7.jpg

 

In the shop here on campus, it's about a $10 job since its relatively small and hollow. It shouldn't see any crazy stresses unless the switch bottoms out, which it shouldn't. I also need to refine the mounting arm strength and switch lever length. I'll most likely increase the radius of the fillet and add an additional rib to the mounting arm after an FEA study. The holes in the arm are not final, either. I don't have a modern carburetor on hand, but it should be arriving soon, or so I'm told. The switch lever has a hole on the other side that needs to be tapped for a machine screw and washer to hold it against that side of the housing, while the lever side will have a light spring between the main body and the lever. The dimensions for the switch are pretty close. I purposely made it a little short so I can shim the end if needed. Also, all clearances are within 5 thousandths, just like the original switch. The printers are campus are stupid accurate, and 5 thousandths isn't impossible. I'm excited to see how it turns out! Also, in case you were wondering, this will mount towards the front of the carb. This keeps it from cluttering the coil and makes for easy access. I'm thinking of using a clevis for both the carb and the switch lever.

 

Oh! A family member dredged through the family albums and is uploading them to the internet on a personal cloud. I'm not really a huge fan of that type of thing, but I did find one picture I believe is from before 1958. It's in the bottom right, with my grandparents and their Great Dane.

 

Edit: I'm sure it's going to come up at some point, but yes I am aware of the switch orientation pushing the bull upwards. 

44173735_10215972249373337_4556501830477021184_o.jpg

Edited by Beemon (see edit history)
  • Like 4
Link to post
Share on other sites
On 10/8/2018 at 5:17 PM, Beemon said:

I'd also need to make a jig and find some aluminum soft jaws. 

 

I can't wait to be done with school and have my own mill.

 

For a jig, how about a wood box built to be slightly oversize of the valve covers, filled with bondo.  Grease the valve covers or use plastic wrap on the top side of the valve cover, turn them over with the flange up and sink them into the bondo.

 

Maybe plaster instead of bondo, then just use the box to secure the valve cover for your work.

Edited by kgreen
more stuff (see edit history)
Link to post
Share on other sites

I'd be hesitant using a wood box on the mill, but I'm sure with enough patience it could be leveled out.

 

BNok9.jpg

 

This is more or less the final iteration of the switch. Looks like its going to work. Right now it fails under 5lbs applied to the nose, so I'm trying to justify beefing up the mounting arm versus the real life application of 5lbs on the body. It kind of sucks because I wanted the switch to face the other way, but that's not how its going to work. I guess I could rotate the switch so it sits vertical almost, like the old Stromberg carbs.

  • Like 2
Link to post
Share on other sites

Yeah the top is will be an NPT tapped barb fitting. 

 

The alternator issue is relatively easy, but requires another relay in the circuit to ground the switch and open the circuit without grounding the alternator. The big thing to overcome is the fact that it's the motor mount that needs to be modified. 

 

I am keeping the generator, but if I were to switch to an alternator, I would either find the high mount off of a late 401 or cut the generator bracket off the motor mount.. or ideally go to a powergen, if needed. 

  • Like 1
Link to post
Share on other sites

Okay, I nailed it. Orienting the switch at an 85 degree angle is pretty stout. I applied 10 lbs of force to the outside edge and it has a factor of safety of 1.7. The program is pretty accurate so I believe it. That's good enough for what it will be doing, too. Now I just need to get it printed! 

 

BO4D4.jpg

Switch3-Static 2-Image-1.png

  • Like 1
Link to post
Share on other sites

44519406_10157814678714115_5901419694748

 

Today my grandfather was found deceased in his home. I don't usually share these types of things, but without him I wouldn't be here with a beautiful 1956 Buick Century. He's with my grandmother now, in a better place. I just wish we could have gone to Thanksgiving, where I could have spent more time. 

Link to post
Share on other sites

Oh no.  This is a sad turn of events.  You have included him in enough of your posts that I feel like I knew him!  I still recall that picture, that last photo you put up, with him inspecting the paint job!  I imagine he was very proud of all you accomplished putting his Buick back together!  And I imagine he will continue to send you his help in the future!  You may not see those events at the time, but in retrospect things sometimes seem clearer.  Meanwhile, my sincerest condolences on your loss  Ben! 

  • Like 2
Link to post
Share on other sites
6 hours ago, old-tank said:

Sadly that is a universal emotion.

My condolences, Ben.

 

Before I went to school, I was the only grandchild that regularly visited. I'd take him to the store or the doctor's, and we'd show up in the old iron. We were pretty famous at the blood clinic at Valley Medical Center, Haha. Anyways, he always called me the enemy because I went to Washington State and he went to UW, and it was tough moving 5 hors away. Granted, my mother did more than I did for him (we both lived 5 minutes away), so he wasn't without help. We would talk at least twice a week, depending on school work loads. And let me tell you, depending on how my head hurts, I don't get up until 1 on Saturday mornings. So I was late to the news by 3 hours.

 

He always told me to get my junk out of his house: a used 56 Dynaflow,  a 322 engine block and various other parts lying around in and out of the car port. Joking of course, but now I have 30 days.

 

On the bright side, I don't have to go to two different places to show off the car to my grandparents anymore. 

 

The Buick is going to lead the procession to his final resting place.

 

Thank you all for the kind words. 

  • Like 2
  • Thanks 2
Link to post
Share on other sites

Ben, sorry to hear this, but consider the connection you had with him that was enabled and solidified with that old Buick.  Though my '56 Bel Air is not currently road-worthy, it's sitting quietly in my garage waiting for its next (and probably last) rejuvenation.  Often while in the middle of some other mundane task I'll pause and look at it for a minute and recall some memory of my grandparents when the car was still in their garage.  Coincidentally, just this morning at breakfast my father happened to mention his memory of watching my grandfather pull into my grandparent's driveway on Christmas Eve 1955, as the car was my Grandmother's Christmas gift.  It's nice to still have that connection...  -Tim

  • Like 4
  • Thanks 1
Link to post
Share on other sites

A little bit happier news tonight, my prototype was printed and mocked up. 

 

44475393_10157792603695830_8352976723679

44471207_10157792603630830_5456917852655

44460880_10157792603755830_1737485378434

44514324_10157792603820830_2592979727778

 

It works as it should, but needs a lot of post processing. For instance, although the shaft works fine, it's prone to minor bending. It's nothing to worry about, I must have cycled the linkage a hundred times or more, but I'd prefer it solid instead of with a little flex. I don't have an air cleaner on this side of the mountains, so I might stomach the $25 for a store bought one. I'm heading back home this weekend to visit with the family, and I'll be coming back with a spare stock filter bottom. I'm going to chuck it up on the lathe and spin down the inside, then probably weld in a bottom from the store bought air cleaner. The air valve secondary on this carb makes it very difficult to use adapters.

  • Like 3
Link to post
Share on other sites

We found some literature today at my grandpa's house. The original bill of sale and all the showroom tags were found. The car was delivered June 2, 1956. Pictures are soon to follow. 

  • Like 8
Link to post
Share on other sites

Okay, I told a fib. No pictures yet, and I ran out of time - already back at school after a very emotional weekend for the family.

 

I have noticed after my drive back that I'm consuming oil again. I can't find any leaks. I swapped out the aluminum valve covers for my good chrome ones that actually seal, and I'm loosing more. Nothing off the back of the engine that I can see. A lot of the oil marks seem to be below the cylinder heads, but that could also be because I didn't clean the block before putting the heads back on. Last time I checked, compression was good. The valve stems have viton seals.

 

Any guesses?

 

I don't have anywhere to work or store the car anymore, so I'm at a complete loss in terms of getting stuff done now. I have teased the idea of removing the engine from the car and going through the bottom end pretty comprehensively. The machine shop that did the heads said it would be about $300 to bore the block and balance the rotating assembly.

Link to post
Share on other sites
8 hours ago, Beemon said:

I have noticed after my drive back that I'm consuming oil again. I can't find any leaks. I swapped out the aluminum valve covers for my good chrome ones that actually seal, and I'm loosing more. Nothing off the back of the engine that I can see. A lot of the oil marks seem to be below the cylinder heads, but that could also be because I didn't clean the block before putting the heads back on. Last time I checked, compression was good. The valve stems have viton seals.

 

Any guesses?

 

What volume are you noticing? Pints or quarts per ??? # of miles?

  • Like 1
Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...