Carb for my 1929 Graham Paige?

[GrahamPaige29]

Hi guys.  I'm restoring my 1929 Graham Paige model 612.  It has a Zenith carb installed.  I'm not sure this is original to the car.  This model of carb has a "power pump" installed in it which seems to run off vacuum pressure from a manifold.  My question is: is this a suitable carb?  I'm not sure if this model is similar to the one that the car had originally.  Since the vacuum feature seems to be not needed, perhaps I should seek out the same style of carb the car originally had.  Anybody know what that would be?  1929 Graham Paige model 612 first series.  Thanks!

[carbking]

Graham, with their 2 series/year, is one of the most confusing makes to me. My records show that in 1929 the model 612 used a Johnson carburetor. And in late 1929, the 612 MAY have used a Detroit Lubricator. I have seen Detroit Lubricator carbs which are marked 612, but too lazy to go the the warehouse and pull one to look at the date code.

 

The Johnson was one of the early zinc alloy (pot metal) carburetors. You have a much better chance of winning an argument with the IRS than finding one with castings that are usable; so call it made from "unobtanium".

 

The Detroit Lubricator carbs ARE available, but many of the components are interchangeable with V-16 Cadillac carbs, so the Detroits are made from "verypricium".

 

Depending on which Zenith you have, it may be a better carb than the Detroit, and is certainly less expensive.

 

The word "restore" which you used has many meanings to different individuals. If you are truly restoring [verb - repair or renovate (a building, work of art, vehicle, etc.) so as to return it to its original condition. "the building has been lovingly restored" synonyms: repair, fix, mend, refurbish, recondition, rehabilitate, rebuild, remodel redevelop, renovate, etc.]  then you are looking for either a Johnson which is sufficiently complete to use as patterns to cast new castings or a Detroit Lubricator. If, on the other hand, you are building a really nice car to drive and enjoy, the Zenith you have might be the perfect carburetor for you.

 

Jon.

 

Edited May 11, 2017 by carbking (see edit history)

[GrahamPaige29]

31 minutes ago, carbking said:

Thanks Jon.  Really, I just want the car to run well.  I want a driver.  I was just confused when I looked at the rebuild kit in reference to the "power pump" vacuum valve which seems to be for a higher performance engine's needs.  I don't think I'll be in any drag races with my Graham.  I'll rebuild the Zenith carb with the kit I got from "Carb Doctor" and see how she runs.  Just  wish I hadn't bent the throttle plate rod when removing it!!  Rrrgh.  Will do my best to straighten it with a blunt axe...

 

[carbking]

Don't recognize the term "power pump".

 

Some carburetors have an accelerator pump which can minimize or eliminate hesitation when changing from a lower to a higher engine RPM (accelerating).

 

Some carburetors have a power valve which is used to augment the main metering circuit with additional fuel at wide open throttle (passing, climbing a hill, etc.).

 

Neither or necessarily components for a high performance engine, rather features of better carburetors for more consistant engine operation.

 

Zenith made some of the very best (opinion) updraft carburetors, and their better models have these features. Some of their less expensive models do not have these features. If yours does, and the carburetor was correctly sized to the engine, then it could work very well for you.

 

Incidentally, the Detroit carbs were excellent carbs, but today, many of the special parts for these carbs are extremely expensive, and very few can properly redo them.

 

Since you have it, suggest you try it.

 

Jon.

[GrahamPaige29]

On 2017-05-11 at 7:46 PM, carbking said:

Don't recognize the term "power pump".

 

Some carburetors have an accelerator pump which can minimize or eliminate hesitation when changing from a lower to a higher engine RPM (accelerating).

 

Some carburetors have a power valve which is used to augment the main metering circuit with additional fuel at wide open throttle (passing, climbing a hill, etc.).

 

Neither or necessarily components for a high performance engine, rather features of better carburetors for more consistant engine operation.

 

Zenith made some of the very best (opinion) updraft carburetors, and their better models have these features. Some of their less expensive models do not have these features. If yours does, and the carburetor was correctly sized to the engine, then it could work very well for you.

 

Incidentally, the Detroit carbs were excellent carbs, but today, many of the special parts for these carbs are extremely expensive, and very few can properly redo them.

 

Since you have it, suggest you try it.

 

Jon.

Thanks Jon.  I got a rebuild kit for that carb and I'm going to try it.

[Graham Man]

Jon is correct and an awesome wealth of information!  There was also a Carter used in 28/29 not BB1.  My favorite to use is the Carter BB1 with adaptor plate, they are pretty easy to find and the adjustable main jet is great over the fixed jets that can be hard to find.... Jon describes it best (see below)...I would think the 245 (small) would work great (this is what I have on my 610 Graham-Paige).  The Johnson is horrible on a good day.  If the Zenith is working well I would run that.

 

On the model year it is pretty simple.  Graham-Paige and others introduced the new cars 6 months early, so August 1928 you could buy a new 1929 Model.  Just another way to compete with the big boys.  The problem was now you have cars titled 1928 that can be a 1928 or 1929 Model, so first and second series.  I think now when you buy a new 2018 car in 2017, it is titled as a 2018, eliminating the problem.

 

Carter

Carter produced the BB updraft series carburetor beginning with the 1932 model year. These were originally sold to Chrysler Corporation for use on Plymouth, De Soto, and Chrysler engines. However, these carbs were so far advanced that many mechanics would substitute these units on older vehicles that were daily drivers in this era. Carter recognized this fact, and came out with 3 different models of the BB-1 specifically for the aftermarket. These are: 245s (S.A.E. size 1); BB1A (S.A.E. size 2); and 289s (S.A.E. size 3). These models featured cast iron bodies, extended throttle shafts with universal clamp-type lever, a fast idle circuit, an externally adjustable main metering jet, an accelerator pump, an adjustable idle circuit, and a power circuit. These carburetors are fairly compact, and will fit a few applications where other universals will not fit. These units have been in favor for many years with many who participate in the Great American Race, which has significantly driven up the price. Rebuilding kits are readily available, and reasonable. Many other parts are available, but not inexpensive. In all, Carter produced 69 DIFFERENT versions of the BB updraft carburetor; MOST of which were sold as original equipment on trucks. Because of the high price of the aftermarket units; some enthusiasts are trying to make the truck units work. The truck units may be converted; but the following part (not commercially available) must be fabricated: (A) extended throttle shaft, (B) universal throttle arm, (C) adjustable main metering jet, (D) fast idle parts (if the installer wishes the fast idle to function).

These (opinion) are really excellent carburetors. My only complaint (other than the artificially high price) is the mechanical accelerator pump. Accelerator pumps on updraft carburetors come in two types: (A) mechanical, and (B) vacuum. The mechanical pump is attached directly to the throttle and pumps fuel if the throttle is moved. This can create a fire hazard if a novice attempts to start the vehicle, and like with a downdraft, pumps the footfeed several times. This will result in fuel being pumped out of the air intake onto the ground under the engine. The vacuum accelerator pump has a vacuum piston, which is pulled, into a vacuum chamber by engine vacuum after the engine starts. This action charges a heavy spring. When the engine is accelerated, and vacuum is reduced, the energy stored in the spring drives the pump and pumps the fuel. With a vacuum pump, working the footfeed with the engine off results only in the exercise of the operator’s ankle. And vehicles with updraft carburetors should always be started via the use of the choke NOT a pump.

 

http://www.thecarburetorshop.com/Aftermarketupdraftcarburetors.htm#Carter

[C Carl]

Please see ad in Buy/Sell.  "1928 Graham Paige"  To me , it almost looks like a complete engine and trans for about carb price.  Be the first ..........   - Carl