Offenhauser 5041 in later year ‘75 /6

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Jax_1975_Dart

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I recently saw a fellow FABO member post their dual 1 BBL Offenhauser setup and am really considering this exact intake for my ‘75 Slant Six. I’ve noticed the manufacturer (or should I say Re-sellers) only list years ‘60-‘67. Am I going to run into compatibility issues with a later year setup? Would be going into a stock OEM setup ‘75 Dart Sport.

Assuming compatibility isn’t a huge issue, I would be running two 1BBL Holley 1945’s.
 
Those manifolds will fit any year slant. One of your biggest issues will be kick down linkage to the trans.
jus sayin....
 
Was that me :).... Likely because those are the only years that they make a plug and play linkage kit for it? If the directions are correct all I need to do is cut my rotating throttle linkage shaft to length and it just bolts up. Also '68 was the first year that EPA emission started... that may be the real reason.
 
Was that me :).... Likely because those are the only years that they make a plug and play linkage kit for it? If the directions are correct all I need to do is cut my rotating throttle linkage shaft to length and it just bolts up. Also '68 was the first year that EPA emission started... that may be the real reason.

Hey Jim, it was a post from August by HotRod77 but, I just now saw your thread for your wife’s ride and am following you! I also read up on several other members discussing pros/cons for this I take versus Super 6, Aussiespeed and a few other 4 bbl intakes.

I’m fairly crafty and am used to tuning my father’s dual 4 bbl carb setup on his 426 Hemi. While this def. won’t be nearly as many horses, I’m looking forward to more even fuel distribution into the manifold (plus, having some extra “ooomph” behind the peddle would be very welcomed).

Which 1 bbl’s are you running 1920’s? Carter’s?
 
probably when they introduced EGR so there is no provision for an EGR valve. Does it have a heat riser? You can still run EGR, just plumb a line (balance tube?) below the carbs and run an external EGR setup. Its not a bad system and does not hurt performance.
 
Hey Jim, it was a post from August by HotRod77 but, I just now saw your thread for your wife’s ride and am following you! I also read up on several other members discussing pros/cons for this I take versus Super 6, Aussiespeed and a few other 4 bbl intakes.

I’m fairly crafty and am used to tuning my father’s dual 4 bbl carb setup on his 426 Hemi. While this def. won’t be nearly as many horses, I’m looking forward to more even fuel distribution into the manifold (plus, having some extra “ooomph” behind the peddle would be very welcomed).

Which 1 bbl’s are you running 1920’s? Carter’s?

2 New

Standard and Universal Carburetors

Copies of Holley 1904's

DSC_1110.jpg
 
It will fit but you will never feel the performance upgrade by simply slapping a bigger or more carbs to it. The exhaust is more important to upgrade than the intake side. For 75, you probably have a catalytic convertor that would be put to better use by being thrown in a ditch.

Ideally the engine should be built up but at the bare minimum the exhaust should be upgraded to really feel the benefits of increased intake capacity.
 
probably when they introduced EGR so there is no provision for an EGR valve. Does it have a heat riser? You can still run EGR, just plumb a line (balance tube?) below the carbs and run an external EGR setup. Its not a bad system and does not hurt performance.

Thanks for the EGR mention! I’ll need to look into this further but, I like your suggestion for external EGR. I’ll search here and slant six dot org to see if/how this can be setup.
 
It will fit but you will never feel the performance upgrade by simply slapping a bigger or more carbs to it. The exhaust is more important to upgrade than the intake side. For 75, you probably have a catalytic convertor that would be put to better use by being thrown in a ditch.

Ideally the engine should be built up but at the bare minimum the exhaust should be upgraded to really feel the benefits of increased intake capacity.

That is where the Dutra Duals and the HP option from Accurate Exhaust comes in!
 
Thanks for the EGR mention! I’ll need to look into this further but, I like your suggestion for external EGR. I’ll search here and slant six dot org to see if/how this can be setup.
Get a simple one like this universal type (Ford and slant six) and make a flange for it with 2 holes, one goes to exhaust manifold and one goes to carb balance tube. The EGR valve will open when needed (part throttle) and allow inert exhaust gasses into the intake manifold, cooling the cumbustion chamber temperature (less O2 to burn)thereby reducing NOx and CO2 emissions. Mot mandatory unless your in a smog check state, usually deleted because the EGR valve goes bad and people dont know how insignificant the performance loss is compared to what it does to clean up your exhaust.

s-l225.jpg
 
That "external EGR" idea is going to be a lot of work for no tangible benefit. Just delete the EGR system entire and recurve your distributor (good excuse to do the HEI upgrade ) for optimal advance.

Those "reproduction" carburetors are a primitive, not-very-good, grossly overpriced option and they aren't very compatible with your '75 car. Two matched new (not "remanufactured") 1945s will be a very good pick and will simplify the installation with their built-in throttle return springs.

Get a № 1234 electric choke kit and make a new pushrod for it as described and pictured here.

All that said, unless the primary main goal is the "Wow, cool!" factor when you p

See this thread for kickdown options.

You'll need to either use the '63-'67 small/tall (9") air cleaners shown in Jim Kueneman's post, or fabricate your own air cleaner. If you fab your own, you might build it around the oval filter element from a 2-4bbl or 3-2bbl setup. And that would also let you keep the very beneficial thermostatic snorkel.
 
That "external EGR" idea is going to be a lot of work for no tangible benefit. Just delete the EGR system entire and recurve your distributor (good excuse to do the HEI upgrade ) for optimal advance.

Those "reproduction" carburetors are a primitive, not-very-good, grossly overpriced option and they aren't very compatible with your '75 car. Two matched new (not "remanufactured") 1945s will be a very good pick and will simplify the installation with their built-in throttle return springs.

Get a № 1234 electric choke kit and make a new pushrod for it as described and pictured here.

All that said, unless the primary main goal is the "Wow, cool!" factor when you p

See this thread for kickdown options.

You'll need to either use the '63-'67 small/tall (9") air cleaners shown in Jim Kueneman's post, or fabricate your own air cleaner. If you fab your own, you might build it around the oval filter element from a 2-4bbl or 3-2bbl setup. And that would also let you keep the very beneficial thermostatic snorkel.

Curious about the carb comment? There are a lot of folks that have found the Daytona's to be great replacement carbs and a few carb places I talked to really like them. What sold me on them was you can adjust the main jet with a screwdriver external to the carb. An O2 sensor, a screwdriver and a deserted road and I can get it all tuned in. Do you have experience with the Daytona's?
 
Those carbs are made in Argentina by an outfit called CARESA; their site is here. Daytona brings 'em in and marks 'em (way!) up. Fine, we have capitalism; that's how things work, but at the price they charge I don't consider this a cost-effective option. Yes, the external adjustability is nifty, but overall this is a copy of a very primitive carburetor, with none of the many great engineering advances made in carburetion since about 1960. Add that to the basic fumbles in in the design (vertical bowl gasket and mixture adjustment seal below fuel level = leaks waiting to happen; side-hung float = tendency to stall in hard cornering) and the hassle of cobbling up choke, throttle, and kickdown linkages because these carbs were not made for this application, and the lack of provisions for various vacuum hookups on a '75 car that are well worth preserving…I just really think this isn't the optimal way to go. Not with NOS 1945s regularly going by on eBay.

At $100 or $150, the Argentinian carb would be an attractive option, because the lower price would offset some of the hassle and cobble-up.

All that said, unless the primary main goal is "Whoah, lookit!" when you open the hood at car shows (or just wanting twin carbs because you want twin carbs) you're usually better off with a thoughtfully-chosen and -configured single 2bbl setup.
 
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Those carbs are made in Argentina by an outfit called CARESA; their site is here. Daytona brings 'em in and marks 'em (way!) up. Fine, we have capitalism; that's how things work, but at the price they charge I don't consider this a cost-effective option. Yes, the external adjustability is nifty, but overall this is a copy of a very primitive carburetor, with none of the many great engineering advances made in carburetion since about 1960. Add that to the basic fumbles in in the design (vertical bowl gasket and mixture adjustment seal below fuel level = leaks waiting to happen; side-hung float = tendency to stall in hard cornering) and the hassle of cobbling up choke, throttle, and kickdown linkages because these carbs were not made for this application, and the lack of provisions for various vacuum hookups on a '75 car that are well worth preserving…I just really think this isn't the optimal way to go. Not with NOS 1945s regularly going by on eBay.

At $100 or $150, the Argentinian carb would be an attractive option, because the lower price would offset some of the hassle and cobble-up.

Some of that depends on application. With the Offy dual and the Offy linkage kit on an early A with the rotational throttle rod it has been simply plug and play with throttle linkage, kick down and air cleaners. The choke is the only thing I will need to cobble. On newer applications yea the rest of it will take effort. Only time will tell on the leaks and this is a cruiser and not a track car so the corning is not an issue.
 
I agree with you that they're quite a bit better suited to the early cars than to the later ones. And new original-type carbs for the early cars have grown very scarce and costly, so in that context they look more attractive.
 
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