1953 pontiac chieftain custom catalina restoration

[PONTIAC1953]

3 minutes ago, pontiac1953 said:

I'm not using a Carter AFB, the 1957 four barrel intake manifold came with a rebuilt Rochester 4-jet carburetor.

[carbking]

1957 was the last year Pontiac used the 4-GC.

 

While the 4-GC is an excellent carburetor, this one is significantly smaller internally than the Carter AFB.

 

GUESSING, that with a LOT of recalibration (no specifications to go by, trial and error) that it would be good for cruising, but would leave significant power on the table under WOT conditions. 

 

Probably will be pretty rich with the factory 1957 calibration.

 

Jon

[PONTIAC1953]

On 11/11/2022 at 6:09 PM, carbking said:

While the 1957 Carter AFB and the 1959 Carter AFB are the same physical and internal size, the calibrations are quite different. Using the 1957 calibrations should work OK under normal cruise, but you are going to wash down the cylinders under power, and hide the rear of the car from traffic (maybe a getaway car???   or possibly a second job in mosquito control ). Would highly suggest either looking for a 1959 (or 1960, or 1961) carburetor, or installing 1959 main metering jets, step up springs, and step-up rods in the 1957 carburetor.

 

Jon

well I've been thinking about the 57 Rochester 4jet being too small on cfm's, 553, so I've been searching feebay for a larger 692 cfm version, and I found this one listed on feebay, came from a 1965-66 Oldsmoble 425 V8, has been rebuilt by a Canadian company, Auto Line, and their P/N C-979, I called them today, and they verified it being the 692 cfm version of the Rochester 4jet carburetor, feebay seller wanted $70.00 plus shipping, he accepted my $42.00 offer plus shipping. I'll check it out, and clean it where needed, may end up putting a new rebuild kit into it. 

[Pfeil]

On 12/20/2022 at 8:28 PM, pontiac1953 said:

well I've been thinking about the 57 Rochester 4jet being too small on cfm's, 553, so I've been searching feebay for a larger 692 cfm version, and I found this one listed on feebay, came from a 1965-66 Oldsmoble 425 V8, has been rebuilt by a Canadian company, Auto Line, and their P/N C-979, I called them today, and they verified it being the 692 cfm version of the Rochester 4jet carburetor, feebay seller wanted $70.00 plus shipping, he accepted my $42.00 offer plus shipping. I'll check it out, and clean it where needed, may end up putting a new rebuild kit into it. 

Hey Charles, can you tell me/ show me what if any are the identifying marks on that carburetor telling me if a certain carb is a 692CFM carb. Thanks in advance.👍

[PONTIAC1953]

9 hours ago, Pfeil said:

Hey Charles, can you tell me/ show me what if any are the identifying marks on that carburetor telling me if a certain carb is a 692CFM carb. Thanks in advance.👍

I'm told that having the four vertical vent tubes in pairs at both ends of the choke plate, is a strong indicator that the carburetor is the 692 cfm version, usually there's the last four numbers stamped on top of the carburetor, also the diameter of the primary and secondary butterflies will tell what the cfm is 

[PONTIAC1953]

10 hours ago, Pfeil said:

Hey Charles, can you tell me/ show me what if any are the identifying marks on that carburetor telling me if a certain carb is a 692CFM carb. Thanks in advance.👍

3 different size 4jet carb, 486, 553, 692,

486 had same size primary and secondary butterflies, 1 7/16"

 

553 has same primary has 486, and larger secondary 1 11/16"

 

692 has larger primary 1 9/16" and secondary 1 11/16"

[Pfeil]

11 hours ago, pontiac1953 said:

3 different size 4jet carb, 486, 553, 692,

486 had same size primary and secondary butterflies, 1 7/16"

 

553 has same primary has 486, and larger secondary 1 11/16"

 

692 has larger primary 1 9/16" and secondary 1 11/16"

Thank you, Charles, and Merry Christmas!

[PONTIAC1953]

25 minutes ago, Pfeil said:

Thank you, Charles, and Merry Christmas!

You're welcome, and Merry Christmas to you too.

[PONTIAC1953]

I transferred the vacuum fitting from the rear of the smaller 4gc carb to the larger one, and learned that the front corner vacuum port is used for the distributor advance.

[PONTIAC1953]

Here's how the 1956 Pontiac 4jet throttle lever looks like

[PONTIAC1953]

And here is how the 1965 Oldsmobile 4jet throttle lever looks.

[PONTIAC1953]

this is a GM Rochester throttle lever assembly I believe I can use to modify the 1965 Oldsmobile 4jet throttle lever to become pushed movement instead of the pull movement.

[PONTIAC1953]

I used my craftsman rotary tool with a small wire brush attachment to clean up the butterflies and the mounting surface of the throttle plate, looks good.

[PONTIAC1953]

here's the throttle lever after I grind off the weld attaching it to the bearing and shaft assembly, now I'll need to drill one small hole in both it and the 65 Oldsmobile lever so i can mount and secure it to the 4jet carburetor.

[PONTIAC1953]

Used my craftsman rotary tool with small wire brush attachment, to clean up the mounting surface and butterflies.

[PONTIAC1953]

I'm finished with the metal removing on the throttle lever, all that's needed is to drill two small holes to attach it to the 65 Oldsmobile throttle lever.

[PONTIAC1953]

I'm almost finished adapting the new throttle lever to the 65 Olds throttle lever, still have one more hole to drill, so that the new lever is secured to the Oldsmobile lever with two bolts.

[PONTIAC1953]

Finished modifying the new lever, have 2 bolts securing the the new lever to the carburetor's lever, just need to get matching bolts and nuts. 

[PONTIAC1953]

Have been giving some thoughts about if the Pontiac's original 10 spline rear axles and spider gears would last with the increase torque and horsepower of a four barrel fed high compression 389 V8, not wanting to find out the hard way, learned that although Pontiac & Oldsmobile shared the same rear end, Oldsmobile upgraded their rear ends in 1954, increasing the number of splines on the rear axles and spider gears, from 10 to 16, making the rear end 60% stronger than the 1953 and older rear ends, my friend Jim bought my spare 1954 Pontiac rear end, having 3.23 gear ratio, a couple of years ago, that's the desired ratio I want for my rear end, currently still have the original 3.08, so we're going to trade, and the 3.08 will go in Jim's 1953 Chieftain still powered with the 268 straight eight engine. In a 1955 Oldsmobile facebook group, a new friend Kevin is parting out a half-dozen 54-56 Oldsmobiles, he's selling me a pair of 1956 Olds 16 spline axles and spider gears for my rear end modification, the 56 axles and gears only cost me $175.00 shipping cost included. I'm a Happy Camper.

[Pfeil]

13 minutes ago, PONTIAC1953 said:

Have been giving some thoughts about if the Pontiac's original 10 spline rear axles and spider gears would last with the increase torque and horsepower of a four barrel fed high compression 389 V8, not wanting to find out the hard way, learned that although Pontiac & Oldsmobile shared the same rear end, Oldsmobile upgraded their rear ends in 1954, increasing the number of splines on the rear axles and spider gears, from 10 to 16, making the rear end 60% stronger than the 1953 and older rear ends, my friend Jim bought my spare 1954 Pontiac rear end, having 3.23 gear ratio, a couple of years ago, that's the desired ratio I want for my rear end, currently still have the original 3.08, so we're going to trade, and the 3.08 will go in Jim's 1953 Chieftain still powered with the 268 straight eight engine. In a 1955 Oldsmobile facebook group, a new friend Kevin is parting out a half-dozen 54-56 Oldsmobiles, he's selling me a pair of 1956 Olds 16 spline axles and spider gears for my rear end modification, the 56 axles and gears only cost me $175.00 shipping cost included. I'm a Happy Camper.

Charles, the answer to that question depends on how you drive that car. If you drive it like a normal law-abiding citizen, it will last forever. If you drive a 53 sensibly, I would put in a (if you could find the cogs) 2.56-2.78 ratio and believe me you will still smoke the tires, but you will get great gas mileage. To get that great mileage out of that 389 you should use the 518111 (A) camshaft with the small AFB. Make SURE your intake valves are ground at 30 degrees (some builders don't know this) BTW that camshaft gave a 1959 Pontiac with super hydra-matic an "average" 21 mpg going coast to coast. That car is about 450-500 lbs heavier than your Chieftain.

[PONTIAC1953]

22 minutes ago, Pfeil said:

Charles, the answer to that question depends on how you drive that car. If you drive it like a normal law-abiding citizen, it will last forever. If you drive a 53 sensibly, I would put in a (if you could find the cogs) 2.56-2.78 ratio and believe me you will still smoke the tires, but you will get great gas mileage. To get that great mileage out of that 389 you should use the 518111 (A) camshaft with the small AFB. Make SURE your intake valves are ground at 30 degrees (some builders don't know this) BTW that camshaft gave a 1959 Pontiac with super hydra-matic an "average" 21 mpg going coast to coast. That car is about 450-500 lbs heavier than your Chieftain.

well I'm going with the 692 cfm rochester 4jet carb, Pontiac's 886 camshaft, rhoads lifters, sending the 59 389 heads out to be machined for screw in rocker arm studs, changing the head/valve oiling to pushrod oiling and rockers with oiling spit holes, new cam bearings to stop original oiling up through the block and head oiling passages, dual idler gear drive for the camshaft, Pontiac 287 distributor with dual points conversion and high performance ignition coil, B&M Hydro Stick Hydra-Matic transmission, and the above mentioned rear end improvements.

[Pfeil]

3 minutes ago, PONTIAC1953 said:

well I'm going with the 692 cfm rochester 4jet carb, Pontiac's 886 camshaft, rhoads lifters, sending the 59 389 heads out to be machined for screw in rocker arm studs, changing the head/valve oiling to pushrod oiling and rockers with oiling spit holes, new cam bearings to stop original oiling up through the block and head oiling passages, dual idler gear drive for the camshaft, Pontiac 287 distributor with dual points conversion and high performance ignition coil, B&M Hydro Stick Hydra-Matic transmission, and the above mentioned rear end improvements.

Put a 57 9.3" rear end in. I believe you can just bolt it in.

[PONTIAC1953]

4 hours ago, Pfeil said:

Put a 57 9.3" rear end in. I believe you can just bolt it in.

That would be nice, but can't be done for $175.00

[PONTIAC1953]

5 hours ago, Pfeil said:

Put a 57 9.3" rear end in. I believe you can just bolt it in.

I do believe the size of the 9.3 housing in the center rear would hit the front of the Pontiac's fuel tank.

[PONTIAC1953]

the 1956 Oldsmobile 16 spline rear axle shafts and side gears should arrive friday, I've learned that the 1952 and older 10 spline Olds side gears (same as what my 1953 10 spline Pontiac carrier has) and the side gears for Olds 53-56 16 spline carrier are the same except for the number of splines, why Pontiac didn't change to 16 spline in 1953 I'll never know, as I stated earlier, I want to ensure the 1953-54 Pontiac carrier is strong enough to handle the horsepower and torque of a 320-325 horse powered 389 V8, so I want increase the number of splines where the carrier turns the rear axles.

[PONTIAC1953]

The Oldsmobile 16 spline axles and spider gears came this morning, also a pilot shaft bearing retaining spacer I was missing from the Hydro Stick Hydra-Matic trans, without this spacer keeping the pilot shaft bearing in place, damage would occur in the fluid coupling and perhaps even the trans front pump.

[PONTIAC1953]

Inspecting the 53-56 Oldsmobile 16 spline rear axles and spider gears I bought. 

[PONTIAC1953]

Been thinking the two axle gears should keep engaging the two pinion gears from the same 56 Oldsmobile carrier they came from, I did some research in the 1960 Pontiac Master Parts Catalog, and my copy of the 1955 Pontiac Interchange Book, which lists every part shared between Pontiac, and Buick, Oldsmobile, and Chevrolet, I was concern if there may have been a change in the pinion shaft diameter when Oldsmobile went from 10 spline to 16 spline axles and gears in 1953, But according to the MPC and the Interchange book, I learned that the pinion shaft size never change from 1937 to 1960 for both Pontiac and Oldsmobile, except for 58-60 with positraction, I had contacted Kevin, who I bought the 56 Olds axles and spider gears from, he's sending me the two pinion gears shown here, so far everything is looking good to change out my 53 Pontiac 3.08 ten spline carrier, ten spline axles, for a 54 Pontiac 3.23 carrier that will get the four gears changed, and install the Olds 16 spline axles.

[PONTIAC1953]

Received the two pinion gears today, put them together with the two 16 spline axles gears.

[PONTIAC1953]

On 1/12/2023 at 12:19 PM, PONTIAC1953 said:

Finished modifying the new lever, have 2 bolts securing the the new lever to the carburetor's lever, just need to get matching bolts and nuts. 

Found out the 692 cfm 4jet choke/high idle cam & screw would contact the intake manifold surface before the carburetor was sitting on the intake manifold, my solution was a one inch spacer to raise the carburetor, giving the linkage & screw needed space to operate freely, I bought two 1/2" phenolic spacers to stack, I had to trim the sides of the spacers for the linkage to freely operate. 

[Roger Zimmermann]

Is there enough space between the air cleaner and the hood?

[PONTIAC1953]

1 minute ago, Roger Zimmermann said:

Is there enough space between the air cleaner and the hood?

I think so, won't actually find that out for a while. 

[PONTIAC1953]

[PONTIAC1953]

[PONTIAC1953]

I was concerned how well the phenolic spacer would hold up to the constant exposure to hot exhaust gases that will travel up to the carburetor mounting area on the intake manifold, so I changed the bottom gasket to the thick heat resistant base gasket that have no holes to allow the hot exhaust gases to reach the phenolic spacer, but with the thick gasket, there wasn't enough exposed threads on the new long mounting studs for full contact with the nuts, even without the washers, so I doubled the heat resistant thick base gaskets, used only one phenolic spacer, and a thick and a thin gaskets under the carburetor, the carburetor linkage still moves freely and there is more than enough threads for stud/nut contact, even with the washers.

[Pfeil]

13 minutes ago, PONTIAC1953 said:

I was concerned how well the phenolic spacer would hold up to the constant exposure to hot exhaust gases that will travel up to the carburetor mounting area on the intake manifold, so I changed the bottom gasket to the thick heat resistant base gasket that have no holes to allow the hot exhaust gases to reach the phenolic spacer, but with the thick gasket, there wasn't enough exposed threads on the new long mounting studs for full contact with the nuts, even without the washers, so I doubled the heat resistant thick base gaskets, used only one phenolic spacer, and a thick and a thin gaskets under the carburetor, the carburetor linkage still moves freely and there is more than enough threads for stud/nut contact, even with the washers.

What is the reason for the spacer?

[PONTIAC1953]

4 minutes ago, Pfeil said:

What is the reason for the spacer?

To give the high idle/choke linkage screw and cam space to operate freely without contacting the exhaust crossover portion of the right side of the intake manifold, the added bonus was to allow the carburetor and fuel inside the carburetor to stay much cooler than the engine, the drop in temperature will be at least 50 degrees. 

[Pfeil]

16 minutes ago, PONTIAC1953 said:

To give the high idle/choke linkage screw and cam space to operate freely without contacting the exhaust crossover portion of the right side of the intake manifold, the added bonus was to allow the carburetor and fuel inside the carburetor to stay much cooler than the engine, the drop in temperature will be at least 50 degrees. 

Well, I've had good luck with mine with a Q-Jet sitting on a RA4 intake with no heat crossover pipe. I also don't have a choke and prefer to start the engine the old Porsche way. Which is to crank the engine for oil pressure. Stop cranking and depress the pedal for about 4-5 times then crank and use the throttle blades as the choke. I've had the car start this way with temps below 17 degrees and never had a hard start issue. So, periodically I have inspected the spacer in the 31 years it's been on the engine, and I see no deterioration. The reason I used it was to keep heat away from the carb and to keep the throttle blades out of the intake manifold.

[PONTIAC1953]

Received the long air cleaner stud today, had to trim down 1 1/2"

[PONTIAC1953]

have been researching for rear axle, axle seals, axle retainer gaskets, and axle bearings being shared by Pontiac and Oldsmobile, Pontiac and Oldsmobile shared more rear end parts up to 1952, then for 1953 to 1956 Oldsmobile changed from 10 spline axles and side gears to 16 spline, it appears that the 1953 Olds 16 spline axles have a different part number than the 16 spline axles for 1954-56 axles, my 1955 Pontiac parts interchange manual says that 37-55 Pontiacs & 37-57 Oldsmobiles shared axle bearing #954848, and 39-54 Pontiacs & 39-54 Oldsmobiles shared the axle seal #412111, 1955 Pontiacs & Oldsmobiles shared axle seal #1455257, which I believe is also the Timkin seal #T50059 and National seal #50059, the 1956-57 Oldsmobile axle seal appears to be #568690, the gasket used for sealing the axle bearing retainer to the axle housing for 1937-1958 Pontiacs and Oldsmobiles is #231888. I bought a set of seal #T50059, will see how they fit the 1956 Oldsmobile axles, the #412111 seals are very costly and hard to find.