Recommended Posts

I'm looking for a rebuilder for my Marvel carb.  Wont adjust. Its always  rich. Black smoke at any engine speed. No its not blue! lol.  Or a good carb to buy.  I'd be happy to swap out for another. Motor is fresh and I don't like running it this way. I look forward to any input and help to point to a competent person or business.

 

Thank you, Grant

Share this post


Link to post
Share on other sites

Grant:

 We with these 1920s Buicks with Marvel carbs all empathize with you. No matter what I have done with mine on my 25 Standard there seems to always be an issue. The way they are set up for the heavier fuel of the time makes them run rich. I am sure others will chime in about this. The "dashpot" design is quite touchy. When I first tried to adjust mine that dashpot spring adjusting knob had no effect. In or out. After reading the service manual on rebuilding the Marvel. (available through "BOBS") I refitted the air vane plate to match the bore of the carb throat. Also there is a tail clearance  to the Venturi block. Depending on your model carb. Mine is to be .007 to .009.

Of course the manual states that after so many miles this or that should be replaced with new parts from your distributor! Such as the dashpot spring. UNOBTANIUM Parts! The venturi block and air vane are "die cast" some survived in pretty good shape and others are very swollen and cracked. Mine are somewhere in between. I spent several hours filling and sanding on a flat plate to get the clearances correct. Once reassembled and all set up the dashpot brass knob will adjust very nicely and it is very sensitive.

Another issue is the high speed jet. To get a leaner discharge, others have suggested to solder the hole at the tip and re-drill with a smaller drill size. I have not done that yet. So mine is still running rich.

  In the late 1920s or early 1930s if you were having a richness issue your authorized Marvel distributor/supplier would provide different replaceable jets. UNOBTANIUM again.

 A word on rebuilders... There are a few who will do the job. Reluctantly. When I had my 1937 Special's carb rebuilt by Jim Alexandro in 1988 it was $100 and no winning and complaining about what a terrible carb the Marvels were.  I never had a chance to really drive the car much with that rebuilt carb. I picked up another one to have as a spare and had it sent out to Arizona for rebuilding. The estimate was for around $300. When I received it the price was over $650!!! So that is the carb on my 1937 now as I am trying to get some payback miles on it. Anyone who has had a Marvel professionally rebuilt will tell you the cost is somewhere between the $300 and the $650 I mentioned.

Best Of Luck:

Larry

  • Like 1

Share this post


Link to post
Share on other sites

Try contacting Tony Bult in Whitewater, Wisconsin. There was a feature about him in the October (?) 2016 Bugle. He does restorations and specializes in 27-29 vintage. He's a go to guy for 1929 Buicks. I don't recall whether he rebuilds carbs or not, but if not, he gets good results somewhere. He also has some parts. 

 

  • Like 1

Share this post


Link to post
Share on other sites

Grant, I am in complete agreement with what Larry says about these old Marvel carburetors.  In this day and age they are truly something else to deal with.  I will freely admit that at one point in time I was the poster boy for anything but a Marvel on any of my Buicks.  Then someone told me about Classic Carburetors down in Phoenix.  I ended up sending all three of the carburetors down to them for complete rebuilds.  When they came back they looked like the day that they were put on the cars new.  I got sucked into believing that a Carter BB1 was the answer to my prayers.  I was fleeced out of a lot of bucks for one of them before I got connected with the guys in Phoenix.  I was lucky that I never put the Carter in use and was able to resell it for what I had in it.  Now, back to the Marvels.  The first one that I had rebuilt was for my 1920 K-46.  When I put it back on the engine, it ran great for awhile.  Then it started acting up again.  Larry and Joannie stopped to see us on their way home from the Portland meet.  He got to drive the car and see first hand what I was griping about.  He dinkered around with the jet setting and got it to running a whole lot better for me.  He is right, they are touchy.  However, when a person hits that exact 'sweet spot' and things settle down, they are a really good running unit for these low compression engines in this era of Buicks.  There is absolutely nothing that anyone can say to convince me that this crap that we have for fuel these days does not contribute to the miserable performance of these old engines.  I haven't driven the car much these days and you all realize that talking about how well it was running just put a hex on it.

 

Terry Wiegand

South Hutchinson, Kansas

  • Like 2

Share this post


Link to post
Share on other sites

Terry:

 

Do you think ethanol free gas  is a good choice?  It is available at a number of stations locally.

 

Bob Engle 

Share this post


Link to post
Share on other sites

I second using Tony Bult . Sometimes he can be a little slow but he is very knowledgeable on the Marvels used on 1927-1930 Buicks . He has spare parts and carbs on hand. I sent mine to him to work out a few issues. He even test ran it on one of his own cars before sending it back. Find someone else who does that.  If you need a fresh fuel pump for a 29 let me know. I have one ready to go. Everyone needs a spare.

  • Like 1

Share this post


Link to post
Share on other sites

Bob, I do run pure gasoline in the Buicks because I have access to it and I do use it.  I even run it in my John Deere lawn mowers and leaf blower and weed eater.  My John Deere walk behind mower was extremely hard to get started with that ethanol junk.  It runs a lot better on the pure gasoline.  Bob, I am not an engineer by any means, but our old Buicks were built when the octane rating on fuel of the day was somewhere around 35 to 40.  Look at the pumps the next time you put fuel in your modern vehicle.  It is 88 or 89 for the octane rating.  The compression ratio in our early Buicks was probably 4 or 4.5 to 1.  I'd think it is double that today.  Does this make a difference in how the engine runs on modern fuel produced for much higher compression engines?  As I said, I'm not an engineer - you guys tell me.  I personally feel that it makes a huge difference in the way these old engines run on the modern fuels.

raydurr, 1927-1930 Buicks are a different cat compared to my '16, '20, and '22.  My cars do not have a heat riser tube in their carburetors.  I'm really sorta happy that they don't have that feature.  All that I can tell you guys is the folks at Classic Carburetors in Phoenix flow test every unit that comes through their shop.  They do not work on anything newer than about 1960-1965.  When I got the unit back for the 1920, there was a note written in big red letters in the box that said, "DON'T TOUCH ANYTHING - IF YOU DO WE WILL COME UP THERE AND BITE YOU ON THE BACK OF YOUR HAND!"  They had ran the unit on their engine long enough to get it dialed in so that I could get the engine started in my car.  I had to tweak it a bit after starting to get it settled down and running smoothly.  As Larry and I have found out, it seems to be a never ending issue to get and keep these old engines running smoothly.

 

Terry Wiegand

South Hutchinson, Kansas  America

  • Like 1

Share this post


Link to post
Share on other sites

I had it apart and put in a kit from Bob's.  New float also.  Wish I could get a new needle and seat too !  I have worked on lots of carbs over the years and back in my muscle car days I liked making Rochesters work. Learned a few tricks way before the internet could ever help!  (the80s).

I really want to be able to idle in parades and such and take Charon out for dinner at our favorite spot on Saturday nights! :) I will in time.

 

Well I'll start taking numbers as they say and start calling Tuesday to the couple people mentioned

 

thank you all once again! 

Grant

Share this post


Link to post
Share on other sites

I have a 26 and a 27 Buick which I turned intake upside down and used a down draft single barrel carb. I know it is nor orginal but sure runs a lot better with electric fuel and fuel regulator to about 2 1/2 pounds pressure.

  • Like 1

Share this post


Link to post
Share on other sites

Here are some before and after restoration photos of the Marvel Carburetor that goes on my 1916 D-45.  This was done by the folks at Classic Carburetors in Phoenix.  I am not going to get on here and tell you guys that this a cheap proposition to rebuild one of these old brass units properly.  You get what you pay for.  These guys know what they are doing and they are really good at it.  This unit had a price tag of around $575.00 from start to finish.  I am a huge fan of originality and when these things are rebuilt properly there is no good reason to not use them.  This is of course one person's humble opinion.  A picture is worth several thousand words as the old saying goes.

 

Terry Wiegand

South Hutchinson, Kansas

1916 BUICK CARBURETOR 001.jpg

1916 BUICK CARBURETOR 004.jpg

1916 BUICK CARBURETOR 008.jpg

1916 BUICK CARBURETOR 010.jpg

1916 BUICK CARBURETOR 016.jpg

  • Like 3

Share this post


Link to post
Share on other sites

A couple of questions

 

are you using the original vacuum tank or have you converted to an electric fuel pump?

 

have you checked the heat riser tube?

Share this post


Link to post
Share on other sites

Stuart, I will be using the original (has been rebuilt) Stewart-Warner vacuum tank on this engine once it has been professionally rebuilt and back in the car.  This was one of the first things that the guys asked me, "are you going to be using the original vacuum tank system?"  It makes a difference for the needle and seat if a fuel pump is used.  Please refer to the last photo in my previous post.  These Marvel units do not have a heat riser in them.  That came later.  This carburetor bolts right up to the intake manifold just the way you see it in the photos.  Please let me clarify what I just said earlier in this post.  I am going to be pulling the engine out of this car and taking it to Davenport, Iowa to the folks at Davenport Machine Service for a complete professional rebuild.  The complete valve train has already been restored, vacuum tank restored, carburetor restored, intake and exhaust manifolds ceramic coated, and the water pump has been rebuilt.  This car has been in my family starting on 54 years next month.  It was a very nice original car when my Dad bought it.  The car has been re-upholstered, new top, new side curtains, new top boot,

six new tires, and a new set of wheels made for it - had to do that because the felloes were dry rotted and splitting.  We are putting it back as it was originally when it left Flint.

 

Terry Wiegand

South Hutchinson, Kansas

Share this post


Link to post
Share on other sites

Grant, here is the information for them -

 

Classic Carburetors

3217 East Shea Boulevard  #440

Phoenix, Arizona

                85028

Phone - (602) 971-3300

Ask for Mark Buber or Larry

 

Tell them that Terry Wiegand sent you their way.  I know these guys pretty well.  They have restored four, brass-bodied Marvel carburetors that went on old Buicks for me over the course of the last 8-10 years.

These guys are very good at what they do and I probably should warn you that there is more than likely a waiting list to get your unit done if you should want them to do it for you.  It will be worth the wait.

 

Terry Wiegand

South Hutchinson, Kansas

Share this post


Link to post
Share on other sites
On ‎29‎/‎05‎/‎2017 at 11:22 AM, Grant L. Meredith said:

the car came to me with a 6volt pump.  I put on a regulator and dialed it down to 1/2 pound (half) to not over power the float and needle

 

I could never get my 1928 Roadster to run correctly using an electric fuel pump. I rebuilt the original vacuum pump and the gravity feed to the carby from the vacuum tank eradicated similar problems on my car.

  • Like 2

Share this post


Link to post
Share on other sites

Update :  Had a chance this week finally to get back to sometime with the car. Found out spring in the brass adjuster for high speed air valve ( for lack of better description) is weak. Made a shim for it (temporary fix) made the carb balance out.  No more lean bog.  Also redid the packing on idle screw. No leaks there and got the needle to seat all the way and settled down the heavy rich smoke out the tail pipe. 

Still work to be done!!  Distributor needs its advancement worked on too.

 

Now my question, Where can I buy the correct spring to the brass screw barrel for the air board?  Car drove good tonight but lacking power. Struggle to get past 35mph.  I know the spring is coil binding most likely and motor isn't likely breathing enough air. Air board isn't traveling enough due to coil bind

 

Thank you for all the members help......sure glad I found this group!!!  :D

Share this post


Link to post
Share on other sites

If you can`t find anything wrong with your  Marvel carb,take a real look at your vacuum canister inside.If the neddle don`t  close the vacuum line to 100% the fuel will go thru the vacuum line to the inlet (backwards),and you can`t adjust  the carburetor as expected.

Leif in Sweden

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...