1926/27 Pontiac with Carter DR-0

[Guest rbjt]

Hello,

I have started restoring a 1927 Pontiac Tourer that was originally owned by my great, great Uncle.

I have a quick question about the carby on the original 186ci engine. From my research it would have been a Carter DR-0 single barrel updraft from new but must have been swapped with a Tillotson single barrel updraft at some stage.

It looks like it will need to be re-built so I was thinking of returning it to an original Carter unit.

I tracked one down at THE CARBURETOR SHOP however they are asking US$1200 and it would still need to be re-built (it does include what they call a minor kit) plus postage to Australia.

I’m not familiar with old carburettors, their availability or what you would expect to pay. This does seem expensive but I was hoping for your thoughts?

Thank you,

Ryan

[boler76]

My 27 Pontiac shop manual calls for same carb, I got a used carb from a chap in Alberta for less than 100$ and then bought a repair kit for it, But the car doesnt run well no matter what the adj of carb is . I have a carb that used to be on a Ford in service on it and the engine runs fine Dont pay big bucks for a bad carb, There was a reason they were changed yrs ago My 2 cents worth

[Guest rbjt]

Thank you very much for this information. Yes, it makes sense the carb was replaced for a good reason. I'll stick with what I have for now. Cheers, Ryan

[carbking]

The Carter DR-0 was not the world's best carburetor (on a scale of 1 awful to 10 wonderful, I would give it a 4).

The Tillotson replacement carburetors (JR series) were sold through such companies as J.C. Whitney and Warshawski to those customers too frugal to purchase a rebuilding kit for the original carb. (Yes Virginia, the whole Tillotson carburetor sold new for less than a rebuilding kit).

For a "show car" the DR-0 is original thus will not lose you points.

For a "driver" there are several decent aftermarket carburetors available.

Performance value on scale of 1-10 (my opinion, others will differ)

Tillotson JR series - 1

Carter DR-0 - 4

Zenith (modern 68 or 267) - 6

Carter BB1 - 9

Stromberg SF series - 9 1/2

Zenith 63AW series - 9 1/2

All of the above are replacement except the Carter DR-0.

Jon.

[carbking]

My 27 Pontiac shop manual calls for same carb, I got a used carb from a chap in Alberta for less than 100$ and then bought a repair kit for it, But the car doesnt run well no matter what the adj of carb is .

There are a host of issues that MUST be addressed by a rebuilder when rebuilding these carbs. Assuming that nothing is broken in the carburetor, the issue giving the most trouble is the idle tube. First getting it out without breaking it; and second, trying to reuse a used tube without modifying the tube. The upper end of the tube fits into a tapered passage. Thus the upper end of a new tube will be "squeezed" as the tube is screwed into the casting. This squeezing action creates the idle seal at the upper end. If reusing a used tube, the upper end MUST be expanded prior to use; so the expanded end will be squeezed into a seal. Failure to do this will cause an internal vacuum leak, and lean running.

Even assuming the carburetor is correctly rebuilt by someone who has made the mistakes before (a corrected mistake is the beginning of knowledge ); the DR-0 has an inverse idle circuit, which can bite a tuner that may be unaware of this fact. The idle mixture screw meters air, NOT FUEL! Thus turning the screw in will cause a RICHER mixture, instead of the normal idle circuit where turning in the screw will cause a leaner mixture.

Jon.

[Guest rbjt]

Thank you for taking the time to provide this information Jon