Author Topic: 17059250  (Read 1605 times)

Offline 53Olds

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17059250
« on: August 06, 2018, 11:33:10 AM »
Finally reaching the initial start-up on my long-delayed project.

1953 Olds 88, subframed with the front end of a 1965 Delta 88. Final objective: just a fun runner aimed at low end to mid-range performance. Not a show car, not going to the track, not trying for top speed (anyone wanting to take a car of this vintage past 100 is just plain suicidal), just a fun street car that looks original everywhere but under the hood. I do like a maximum combination of performance, efficiency, and reliability, and have been known to go to great lengths to either improve gas mileage without compromising performance or vice-versa, depending on the car.

The engine was originally a low compression 2-barrel, and I rebuilt this Q-jet when I converted it to 4-barrel six or seven years ago. The car ran quite well at the time, but the engine was worn factory stock and had an exhaust valve that was not closely fully. Five years ago I decided to rebuild the engine, went overboard with the MAWs, then things kept getting in the way. After rechecking assembly, I dropped it back in the car and am now fiddling with all the small bits, including refreshing the carb.

Engine: 1965 425, bored .030, balanced, A heads with 3-angle valve job, 9.5-1 pistons (probable actual compression ratio 9.25 with new gaskets). Erson cam E550000 (110+4 lobe separation angle, 64.00 overlap, .504/.504 valve lift, 284/284 duration), 1.7 Harland Sharp rockers, Edelbrock Performer 2151 intake, Pertronix Ignitor III ignition.

TH400 transmission with electronically-controlled switchpitch, 3.23 factory single rear end, dual exhaust (no crossover; x-frame of car makes that a bridge too far), 235-15 tires.

The carb is a 17059250, as I wanted the adjustable part throttle without dealing with electronic controls. Current specs:

Primary jets: 74
Primary rods: 55P
Secondary hanger: E
Secondary rods: DA
Power spring: unknown

It has an electric choke and two pulloffs, and a brass float. The secondary throttle plates are not opening to 90

Offline 53Olds

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Re: 17059250
« Reply #1 on: August 06, 2018, 12:48:37 PM »
End of previous post, which won't allow me to modify:

It has an electric choke and two pulloffs, and a brass float. The secondary throttle plates are not opening to 90

Offline 53Olds

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Re: 17059250
« Reply #2 on: August 06, 2018, 12:52:47 PM »
Very odd board behavior - attempt above to add to original post didn't contain all info, can't edit/modify. Trying again here:

It has an electric choke and two pulloffs, and a brass float. The secondary throttle plates are not opening to 90

Offline 53Olds

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Re: 17059250
« Reply #3 on: August 06, 2018, 03:22:55 PM »
One last try to finish:

It has an electric choke and two pulloffs, and a brass float. The secondary throttle plates are not opening to 90 degrees, more like 80 or so. It's entirely possible that any of the jets, rods, spring or hanger are not stock - I can't remember if I did any tuning when I rebuilt it the first time. Bushings are good.

In addition to the Quadrajet HP rebuild kit, I'm looking for advice on jet/rod/spring combinations. The existing parts would probably work for start-up and break-in, but it would be nice to have a close combination to start with given all the changes in the engine.

TIA.

Offline Cliff Ruggles

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Re: 17059250
« Reply #4 on: August 07, 2018, 04:01:10 AM »
Nice carb, we'll spec out exactly what you need for it when you call and place the order......tks....Cliff