1st Generation 1964 1/2 - 1973 - Questions & general discussions that apply to a specific year > 1965 - 1970 Shelby General
The Holley Carburetor Company(R) "3259" Family of Carburetors.
Dan Case:
Like a great many of the subjects involving Ford Motor Company and Shelby American, Inc. the subject of the 4V high performance carburetor developed for 1965 MUSTANG GT350s is far from simple. There was not "a" model but a sequential series of five (5) of them that I know well. If a sixth exists I have not found one since the mid 1970s when I started working on them. Users and fans usually refer to any original version and or version created by rebuilders, remanufacturers, and restorers as a "3259" model or a "715" model in reference to one of the published nominal maximum flow ratings. (I have seen rating values of 700 to 725 c.f.m. in period literature.)
My commentary is strictly concerning what Holley made for Ford and not the countless 'new' assemblies somebody can create by mixing modern versions of parts, reproduction parts, and different in period parts or revisions into new assemblies not just like any old production ones. (Think of mixing April 1964 Mustang parts of all kinds with late 1966 made Mustang parts of all kinds.)
Intended for GT350s but just as a side note two street and one race Cobra were documented as getting some version of the carburetor (CSX2555 was fitted with a R-3259A design level assembly.) A few street GT40s received the R-3259-1AAS models. (I have the only known surviving one never apart since Ford Advanced Vehicles modified it for a GT40 and installed it.)
Here is how I know them. I have a table of revision levels and changes between revision levels I have been collecting for years. It is too large to paste into one of these forum thread 'posts'. It is in digital form and available upon request. The blanks in my table are mostly for R-3259-1A examples dated between 612 and 633 inclusive. If you have an unrestored carburetor in that time frame and I willing to share information I would love to hear from you.
Dan
Texas Swede:
Hi Dan,
I have two 3259 Holley bottom plates. Both have the same marking number but one has a grove and the other does not
See picture, The one without the grove came off a 3259 dated 552 I bought from Walter Walls 20 years ago for $5
The one with the grove came off a 3259 dated 581 but I have seen much earlier dated with the grove. The 513 dated in my 65, 5S275
has the grove as well.
What purpose does the grove have?
Texas Swede
Dan Case:
--- Quote from: Texas Swede on August 01, 2019, 08:11:54 PM ---Hi Dan,
I have two 3259 Holley bottom plates. Both have the same marking number but one has a grove and the other does not
See picture, The one without the grove came off a 3259 dated 552 I bought from Walter Walls 20 years ago for $5
The one with the grove came off a 3259 dated 581 but I have seen much earlier dated with the grove. The 513 dated in my 65, 5S275
has the grove as well.
What purpose does the grove have?
Texas Swede
--- End quote ---
I could only guess. I have both styles in house right now and have pictures of unrestored carburetors exhibiting both styles. The ones with extra slots I have here currently all do nothing with those slots, the slots dead end. The machined die casting was nothing special until it was used to assembly a throttle plate assembly with the Ford style of primary throttle lever. Ford and Chrysler throttle plate assemblies used the same casting and most of the same machining details in multiple different carburetor assemblies. I have the left over throttle plate assembly the Holley Custom Shop® made for 1966 426 HEMI engines in late model (at the time) cars run on ¼ mile NASCAR tracks. It has an extra slot also that dead ends, just looked at it again.
Parts in hand or archive pictures, extra slot no or yes.
R-3259 unrestored (prototype) from second half 1964 = no
R-3259-1A early (the throttle plate assembly that was the only thing worth keeping I still have after an engine fire) = no
R-3259-1A unrestored dated 643 = yes
R-3259-1AAS unrestored dated 755 = yes
J_Speegle:
Thanks for sharing
Dan Case:
--- Quote from: J_Speegle on August 01, 2019, 09:59:05 PM ---Thanks for sharing
--- End quote ---
You are welcome. I have been repairing and tuning this family of carburetors since the mid 1970s. I am still learning the details that changed over time.
The first time I became aware that there was not "a 3259" but a family of them was in the mid 1980s when a co-worker bought a basket case 1967 GT350. It was a challenge to come up with a carburetor with every part every detail just like the carburetors used on unrestored GT350s in the same time frame. To do so required buying multiple parts carburetors to harvest matching pieces from. The hardest part to find was a main body casting of the matching date and matching casting number. Holley(R) was much like Ford and most mass production companies in that they constantly worked on carburetor assembly revisions to improve performance (example: tweak air fuel ratio curves), lower cost, or address warrantee issues. In this study, five (5) different engineering assemblies between December 2, 1964 (Holley engineering specifications for the original production model released to production operations.) and June 1966 (R-3259-1AAS listed as service replacement for R-3259-1A by June 1966 in Issue 2 of the 1964-66 Holley master listing.)
In my table so far:
Main Body Die Castings = 3
Primary Metering Block Assembly = 2
Secondary Metering Block Assembly = 2
Brass Hex Head Pipe Plugs = 4
Vacuum Secondary Drive Cover Assembly = 3
Secondary Throttle Cancel Link Design = 2
Secondary Throttle Cancel Link Finish = 2 ( the first used, dropped, come back to, dropped again)
Acceleration Pump Cover Casting = 2
Threaded Plug For "Spark" Vacuum Port = 2
My factorials math is very rusty but I believe with just this list one could mix and match versions to build up more than forty (40) assemblies I have no record of Holley ever making. That is exactly what has happened to many carburetors that have gone through a commercial rebuild or restoration. One fellow sent me pictures of his unrestored carburetor before and after a friend of his overhauled it for him. My immediate response to the after rebuild pictures was find out if the rebuilder has already sent the original small parts to the local trash dump. Fortunately the parts had not left the work bench yet and got reunited with the carburetor Holley assembled in 1964. That is not the only time some GT350, Cobra, 427 Cobra, 1967 GT500, Boss 302, or Boss 429 owner has sent me before and after pictures I sent them to go find the rare little pieces now missing in action. Some parts are extremely hard to replace with other original ones.
PS One subject has popped up twice in inquiries to me this year. The issue, finding some transfer tube fittings 100% exactly the same as Holley used 1964-67 in making new carburetors for Ford that are undamaged unmolested (i.e. can be used in a top tier restoration with careful cleaning). In both cases each professionally restored carburetor had non-stock fittings and modern tubing material tubes.
The fitting assembly Holley chose was the Imperial Eastman FLEX(R) "IMPERIAL FLEX PAT'D 1-4" model. It was an industrial and instruments tube fitting and not something custom for Holley. Today Parker Hannifin Corporation offers direct replacement assemblies and Parker 60VL Buna-N Sleeve replacement flareless elastomeric seals.
The exact details of the Imperial Eastman brass nuts in their assemblies changed over time more than once. In the mid 1970s through mid 1980s I would order large selections of small parts in quantity to repair various Shelby and Boss Mustang carburetors from tiny screws up. The first time I ordered "3259" specific parts the fitting assemblies I received were already different than what I ever found on unmolested "3259" carburetors. I still have a couple I bought decades ago. For a long time I robbed the seals out of new assemblies and tossed the brass. Today any Parker Hannifin instrument fitting supplier can obtain new replacement seals for repairs. Side note; the replacement transfer tubes Holley sold by the mid 1970s had different bends in them that the originals I had handled. I still have a new old replacement stock one I purchased decades ago as an example. My solution decades ago was fabricate my own bent tubes myself as required but I have long since run out of 1960s tubing stock.
Navigation
[0] Message Index
[#] Next page
Go to full version