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  • November 26, 2022, 08:15:11 AM

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Author Topic: Carburetor options  (Read 493 times)

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Offline tgotr

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Carburetor options
« on: September 19, 2022, 12:38:58 PM »
So, I am getting ready to put together my 4.7L Stroker for my Eagle (had to get my $100 4.0L block bored, may as well swap the Eagle's original crank and rods in). I do want to stay carbureted for a time, at least through break in. Apparently at 4.7L, the Carter and Motorcraft 2100 seem to be too small for the higher displacement. Depending on performance, I may want to swap to a bigger carb. Going EFI would require a similar ordeal. How hard is it to modify the throttle cable to use bigger carbs? I mean it must be able to be done, otherwise 4 barrel 258 intakes wouldn't be a thing, right?

https://forums.amceaglesden.com/index.php?topic=46486.0

This thread by Vangremlin shows he fabricated an adapter bracket bolted onto the carbs throttle lever. How reliable would this be? As reliable as the person doing the mod I assume.

Offline Mr_Roboto

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Re: Carburetor options
« Reply #1 on: September 20, 2022, 02:08:07 PM »
If it's just for the break in you may lose some power up top but it would probably run fine. They apparently made a bunch of variants of this in different flow rates.

I would run it then hook a vacuum gauge up, do some pulls and see if you get into vacuum at WOT near your redline. If so size up at that point or wait until you're past break in. They used some of these on pretty big engines (400+CI) and I'm not saying they'd be an end all be all but I wouldn't discount it so quick especially if you're not going all out.

Things like head flow and cam selection will determine a lot as well.

Offline atmafox

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Re: Carburetor options
« Reply #2 on: September 20, 2022, 06:14:29 PM »
I might suggest a Weber 38/38, Clifford performance sells kits for 258s and such and can work with you on your specific application.
Mine:
- 1980 AMC Eagle 2dr Sedan
- 2009 BMW 335i xDrive Coupe

Ours:
- 1986 Toyota Pickup

Hers:
- 1988 Toyota Supra Turbo
- 1988 Toyota Celica All-Trac
- 1997 Toyota RAV4 2dr 4x4

His:
- 1985 Nissan 720 Pickup Deluxe King Cab 4x4

Offline amcfool1

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Re: Carburetor options
« Reply #3 on: September 20, 2022, 11:52:59 PM »
hi, check out the Holley Sniper BBD, made for 258s. good luck, gz

Offline Artmodels

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Re: Carburetor options
« Reply #4 on: September 21, 2022, 01:46:53 AM »
On a slightly related topic, has anyone used an auto altitude adjuster on the 2150 style carbs, do they work?  We are constantly going from 7000 feet to lowlands, and wish to find the type of adjuster that uses ambient air pressure to open and close extra air to the manifold side of the carb automatically.

Offline tgotr

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Re: Carburetor options
« Reply #5 on: October 03, 2022, 02:58:04 PM »
hi, check out the Holley Sniper BBD, made for 258s. good luck, gz

That's my plan in the long run.

Offline djm3452004

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Re: Carburetor options
« Reply #6 on: October 03, 2022, 08:07:10 PM »
hi, check out the Holley Sniper BBD, made for 258s. good luck, gz

That's my plan in the long run.



+1 on the Sniper system.  It has made a huge driveability improvement since installed. 

I bought one of the Clifford Webers originally, along with their 6=8 intake and Eagle exhaust header.  I found the Weber finicky and troublesome to adjust.  The carb linkage was sloppy and prevented really dialing-in a good idle.  Clifford's tech help was an absolute joke.  Some of their install advice about not running a return fuel line back to the tank is a guaranteed recipe for horrible vapor lock in any kind of realistic driving situation. 

I even bought one of Gronk's Motorcraft kits to replace the Weber but was so disgusted with the lack of quality and terrible communication that I ditched it too.  The throttle linkage adapter seemed made of sheet metal and held on with self-tapping screws.  I get that these cars aren't Mercedes, there was no reason for making a cheap car look even chintzier.

Neither carburetor kit addressed the lack of a throttle -to- A904/998 kickdown linkage that is lost if you ditch the factory throttle belcrank assembly.  If you have an automatic, setting this up right is a necessity to not burning up your transmission.  I had to modify the original belcrank setup extensively to work properly.  This was easily the most-tedious part of the job.

When you do get to the Sniper kit eventually, I'd really recommend NOT using rubber fuel line all the way back to the rail-mounted, high-pressure fuel pump.  I made my own lines with NiCopp brake line, double-flaring tool and fittings.  My personal opinion was the even the high-pressure rated fuel-injection rubber hose was too vulnerable to undercar damage while driving than a hard line nicely tucked along the unibody rail.

For your sanity when driving, use rubber isolators to mount the high-pressure pump.  The rubber-lined clamps the kit provided to mount the pump to the rail were inadequate and transmitted all the pump vibration and very loud noise directly through the car body into the passenger compartment.

Good luck with your decisions going forward.  I spent waaaay too much on (3) separate fuel setups getting this car to run well, and regret wasting the first ~$600 on the junky carburetor setups that don't hold a candle to the $1200 Sniper setup.

Regards--
David

Current Project: 1983 Eagle Wagon 258
Past AMC Project(s):  1979 Spirit Liftback 232
                                1968 Ambassador 287

Offline amcfool1

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Re: Carburetor options
« Reply #7 on: October 04, 2022, 11:38:20 AM »
hi, Holley makes an in tank fuel pump assembly for the 15 gallon JEEP tank. It will fit into an Eagle/Hornet tank no problem. The float arm has to be bent a bit to work properly. good luck, gz

 

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