1917 D45 choke setting

[Robert Engle]

The choke linkage on my D45 came apart.  I removed the carb and setting rod and made repairs.  My question is:  when the setting rod is on choke, what should be the positioning of the choke opening on the carb?  

 

Bob Engle

[DonMicheletti]

I believe there are pins that limit the rotation of the barrel in each direction

The choke "pointer" should be straight up when the barrel of the choke is at the mid point of the rotation limits.

Does that make sense?

[Robert Engle]

Don, there are no pins on my carb that limit rotation.  The dash adjustment lever has choke at 5 oclock, heat at 12 oclock and cold at 7 oclock.

 

Bob

[Morgan Wright]

choke = air intake closed off

cold = air intake open to warm air around manifold

hot = air intake open to cold air

[Terry Wiegand]

Bob,

I am having a hard time trying to figure out why you have a Marvel Carburetor with the 'barrel type' of choke assembly on your engine.  The 1916 and 1917 engines were very similar except for the rocker post/arm assemblies.  I am not sure exactly when Buick engines went to the type of choke system that is on your engine.  My 1920 engine is not like your choke system.  My 1922 IS like what you have.  I would suspect that the carburetor on your engine has been changed out (upgraded) at some point in time.  Here is a photo of the Marvel unit that is original to our early 1916 D-45.  I am just not sure why you have what you do on your engine.

 

Terry Wiegand

South Hutchinson, Kansas

AACA Life Member #947918

[Robert Engle]

Terry you may be on the right track.

 

let me know your thoughts after looking at the attached photos.

 

BobEngle

[Mark Shaw]

Terry is correct.  You have the wrong choke assy. 

The slotted brass screw heads on either side of the intake opening is where the disc choke axle goes.  

 

[Terry Wiegand]

Bob and Mark,

I need to apologize to everyone about part of my earlier comment.  I got in a hurry and got my facts screwed up.  I will say that Bob does not have the correct Marvel unit on his 1917 D-45 and stand by that.  I believe that what he does have is the correct Marvel for a 1920 K-40 Series Buick.  That IS what is on my 1920 K-46 and I am posting photos of that carburetor.  The 1920 Six had a single heat tube coming off the exhaust manifold that went into the heat chamber on the carburetor upper body.  I do not know exactly what was used on the 1921 Sixes (maybe Pete Jolly can enlighten us), however my 1922 has the double heat tubes coming off the exhaust manifold diversion valve.  I do not want to mislead anyone with incorrect information about what should and should not be used in this situation.  The 1916 D-45 that I have was 100% complete when it came to the engine.  I had the folks at Classic Carburetors in Phoenix go through everything that was connected to the intake manifold that pertained to the Marvel Carburetor.  I left the heat muff and flexible tube that ran from the exhaust pipe into the carburetor intake off on the advice of those who told me that it might create problems with the modern fuels that are in use today.  I will post photos of that in a day or two when it warms up and I can get into the shop.

My 1922 Model 48 has the very same 'barrel choke' on its carburetor as what Bob has.  I will let the photos do the talking now.

 

Terry Wiegand

South Hutchinson, Kansas

AACA Life Member #947918

Edited February 15, 2023 by Terry Wiegand (see edit history)

[Terry Wiegand]

Here are a couple of photos of the heat 'muff' that rides the exhaust pipe and gets heated air sucked into the carburetor.  The end on the flexible tube fitting has a means of adjustment for the heated air going into the engine.  All D-40 Series Buicks left Flint with this in place.  I am very thankful to be able to have these pieces for the car.

 

Terry Wiegand

South Hutchinson, Kansas

AACA Life Member #947918

[Robert Engle]

So it is apparent that the carb on my   17 D45 was replaced.  I dug out my flee market spare parts carb and it has the choke plate on the intake with no barrel choke mechanism.  So I have a decision to make.  The linkage for the barrel intake is functional, It's just a question of how much to restrict the air intake.  If I switch to the spare parts carb, I do not have the linkage to operate the choke.  Any photos of this linkage would be much appreciated.  

 

Decisions?  decisions??

 

Bob Engle

[Morgan Wright]

I dont know if my E49 carb video will help but

 

 

[IFDPete]

1921 Carb / Choke / Heat Passage

 

Terry wanted me to comment on this thread.  My 1921 Model 46 Coupe engine is apart right now but I was able to place the pieces on the floor as they are set up on the car and get some photos.  

 

First thing is that the 21 did not use the "Heat Muff" tube that runs to the exhaust from the choke mechanism like what Terry has provided pictures of. 

 

Instead the fresh air intake opening is cast into the exhaust manifold and a long heated air duct runs along the bottom of the manifold.  Fresh unfiltered air enters via a small sideways teardrop opening at the front of the exhaust manifold.  The cast in air duct has a long heat sink cast down the center of the duct to allow the exhaust heated metal to heat the fresh air.  Heated fresh air flows into the choke mechanism similar to what Bob Engle has posted pictures of (his choke box may be from 1921) and then into the carburetor.  

 

I have spoken to Dean Tryon about the 1921 set up and he believes that this fresh air heating set up was a one year only arrangement.  I do not personally know what a 1920 or 1922 had from the factory.  

 

Pictures are below of the 1921 carb / intake / choke set up

 

[IFDPete]

1921 Carb / Choke / Heat Passage

 

Also my 1921 Marvel carburetor has different casting numbers.  My carburetor appears to be identical to Bob Engle's and Terry's "D44 D45" labeled carburetors.  That makes me believe that the 1921 choke assembly would fit on the earlier carb - but without seeing it up close and trying it...who knows.  Below are picures of the heat tube that runs from the exhaust to the carb and the 1921 carburetor itself.  This tube send hot exhaust gases to a heat chamber on the intake throat of the carburetor, further heating the fuel / air mix.  Maybe all of my posts on this is too much information but I thought you all might find the 1921 "One Year Only" air intake difference interesting.  Best of Luck Bob & Happy Motoring - Pete

Edited February 16, 2023 by IFDPete
wording (see edit history)

[Robert Engle]

 

I want to give an update on the choke for my 1917 D45.  There are two different choke systems used on 1916,1917 and 1918 D45 carbs.  At this point there is no info to identify how they determined which choke to install.  One choke type is very similar to what was used into the 50's for chocking.  There is a plate that rotates on an axis through the centerline of the carb intake.  This plate has a small approximately 3/16" diameter hole through the plate.  The choke is operated with a push/pull wire that is mounted on the left side of the dash and carb.  The hole is the choke area for air intake.  Pushing the choke wire in from the dash opens the choke plate for normal operation. 

 

The second system is referred to as a barrel choke.  It has a casting attached to the carb intake with an internal piece that rotates and opens or closes air intake to the carb. The bottom slot in the outer housing is to allow cold air into the carb for warm engine driving.  The horizontal slot is for warm air entering from the exhaust manifold into the carb. rotating the internal casting can expose the cold air intake, warm air intake or close off both openings.  For the choke operation,  both openings are closed and there is an small 3/16" hole that allow air to enter the carb.  This opening is blind and can only be seen by disassembling the barrel assembly.  The barrel is rotated by a linkage with a ujoint and rod to the dash on the right side of the steering column.  The mechanism is mounted to the bottom of the dash just under the oil flow indicator.  The location and type of knob (rotate or push/pull) will determine which choke system is installed.

I began my work on this choke because the car did not want to start and when running lacked any power.  Upon inspection, I found that the locking screw holding the rod to the ujoint assembly was loose.  this prevented a good choke for starting and limited air intake for normal operation.

In my first attempt at assembly of the barrel chock on my 17D45,  I assumed that part of the cold air opening needed to be exposed to allow some air to enter the carb. Now I know that it needs to be completely closed.  

 

I now have the carb ready for install and need a warm day to see if I have corrected the problem.  I'm optimistic!!

 

Thanks to the forum members that have helped me learn about these 2 different systems.  I hope others can help us learn about the why's and wherefores of the two different systems.

[carbking]

The below copied from a very early Marvel Master Parts Book. It would seem to indicate that the 1916 D-45 had the choke with the normal choke shaft and butterfly; whereas the 1917 used the heat trap. Marvel supplied the choke on the 1916; but evidently the heat trap on the 1917 was furnished by Buick, not Marvel.

 

Jon.