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Old 05-13-2022, 09:17 AM   #10
hatzie
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Join Date: Oct 2008
Location: Wentworth, NH
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Re: Turbo 6.2 or 292 swap

Quote:
Originally Posted by special-K View Post
The 6.2s I've run, three and all with 35" tires, had grunt right off the line. I think yours isn't running right. I'd look into fixing that, first. I think the 6.2 will last longer w/o a turbo. From what I have seen, 6.2s outlive 6.5TDs. That has been my experience. I love the 292s and had no idea they got any better MPG than a small block. But I did used to get that kind of mileage from a 307, which I had in a 4spd '71 K/20 set up like your '87. I ran 37/14.50 rubber on that one and it was always loaded up, bed, bins, and rack.

It's fun to swap things around, so the 292 would be cool. I'd put a small spread bore 4bbl on it. My experience has been better mileage from a spread bore 4bbl than a 2bbl. Primaries are way less CFM that the factory 2bbl
The 6.x comes apart with a turbo. Fun to play with for a while but they get expensive.
The 307 was really a pretty good engine without some of the design problems of the 305.

The Rochester Quadrajet is a progressive carburetor. It has two throttle shafts opening two small primary bores that you use most of the time and two large secondary bores that open past half throttle for more power. It's a lot more common than any two barrel progressives, much easier to bolt onto the 292, and should be noticeably better on fuel than the Rochester Monojet 1G & Rochester 2G carbs if you stay out of the secondaries.

Your garden variety two barrel Rochester 2G, Carter 2 barrel, Holley 2 barrel, Motorcraft 2100, ... have two throttle plates on the same throttle shaft.

The VW Zenith Solex 2B2, Mopar Mikuni Solex, and Weber Progressive two barrel carbs are similar to the Quadrajet. Progressive two barrels have two separately actuated throttle shafts like all four barrel carbs. Progressive two barrels run a single small primary bore and a single large secondary bore that opens past half throttle like the Quadrajet.

Having used both a Rochester Quad and a Weber 32/36 Progressive two barrel on my AMC I can tell you the Weber Progressive will use less fuel than the four barrel but they don't have the ease of install that you'll get with the Rochester Quadrajet. I did kindof abuse the fun pedal just a little bit tho. It's actually kinda miserable to tune the Weber but once it's properly setup it's a really good all around carb.

The Spreadbore four barrel manifold can be adapted to a two barrel or TBI throttle body with a bolt-on plate or left as is, depending on what direction you want to go with it.

Good luck finding a VW Zenith Solex 2B2 and you really don't want to. Jetting the 2B2 for the 292 would be a special kind of torture. I had one that came stock on my 1975 Scirocco. It was an uncommon carburetor even in the 1970s. All kinds of nasty to rebuild that one. Super complicated with lots of fiddly adjustments off and then on the engine.

I bought a RAM50 in the late 1980s with a gummed up Mikuni progressive two barrel carb. WOW!! I figure the Germans in Wolfsburg said to the Japanese at Mikuni "You can't make anything more complicated than the Zenith Solex 2B2" and the Mikuni engineers said "We'll take that challenge". The Mikuni Solex Carburetor on my 1983 Dodge RAM 50 took miserable and fiddly to the next level. I actually fixed the little bugger but I think that's just a testament to my stubborn streak.
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