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Discussion Starter #1
Looking to switch to EFI from MC2100 on my 4.2L....anyone have any pros and cons between the Howell TBI and the Holley Sniper
 

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I'm currently happy with my non-stepper Carter BBD carb. However....
I live in a non-emissions county. The way this "New Green Deal" is headed, I'm thinking the entire state might require all on road vehicles to be emission tested.
If that happens, I'd do my research (just as OP is doing now).

A couple things come to mind.

1- The Howel system is legal in California. Depending on how the Colorado law gets written might determine which system I look at buying. I don't know if the Holly system will pass Colorado muster. It depends on how blue the state becomes.

2- There are several threads here and probably UTUBE videos on installing a 4.0 head on a 4.2 block. Doing so makes sense if a guy goes to FI.

Other posters can comment on the relative merits of each system.

Good Luck, L.M.
 

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The big difference between the two boils down to ignition more than fuel. The Howell completely replaces fuel and spark with a mapped system that matches a specific engine profile. That's fine if you have a good stock 4.2 motor.


The Holley system on the other hand relies on a stock ignition system (fixed by the existing timing curve of the distributor) and adds a superior self calibrating 'wide band' O2 sensor. With the wide band, the computer will tune to the engine as it is, modified or stock to a programmed Air Fuel Raito (AFR). With this syetem, you could add a cam,ratio rockers,intake or headers and still have a smooth running motor.


It's your choice.
 

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Discussion Starter #4
I'm currently happy with my non-stepper Carter BBD carb. However....
I live in a non-emissions county. The way this "New Green Deal" is headed, I'm thinking the entire state might require all on road vehicles to be emission tested.
If that happens, I'd do my research (just as OP is doing now).

A couple things come to mind.

1- The Howel system is legal in California. Depending on how the Colorado law gets written might determine which system I look at buying. I don't know if the Holly system will pass Colorado muster. It depends on how blue the state becomes.

2- There are several threads here and probably UTUBE videos on installing a 4.0 head on a 4.2 block. Doing so makes sense if a guy goes to FI.

Other posters can comment on the relative merits of each system.

Good Luck, L.M.
Im in SC so not concerned with Cali legal....Planning on using a fresh rebuilt 4.2, and you're saying I SHOULD do the 4.0 head swap with either the Howell or the Holley? Hesco sells an out of the box swap.....been looking at that as well
 

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Discussion Starter #5
The big difference between the two boils down to ignition more than fuel. The Howell completely replaces fuel and spark with a mapped system that matches a specific engine profile. That's fine if you have a good stock 4.2 motor.


The Holley system on the other hand relies on a stock ignition system (fixed by the existing timing curve of the distributor) and adds a superior self calibrating 'wide band' O2 sensor. With the wide band, the computer will tune to the engine as it is, modified or stock to a programmed Air Fuel Raito (AFR). With this syetem, you could add a cam,ratio rockers,intake or headers and still have a smooth running motor.


It's your choice.
Thanks for the info.....They both seem to be comparable in price....Im not a wiring /electrical person, so really looking for ease of install as well as function
 

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Im in SC so not concerned with Cali legal....Planning on using a fresh rebuilt 4.2, and you're saying I SHOULD do the 4.0 head swap with either the Howell or the Holley? Hesco sells an out of the box swap.....been looking at that as well
What I'm saying is the 4.0 head swap is something would consider if I were to look at aftermarket fuel injection systems.
Cornchip points out the differences in two of the available systems.

As part of my research into which system would work best for me, I'd contact each manufacturer's technical department and ask them what impact (if any) the head swap would have on the usability of their system.

The 4.0 head is reported to breathe better. Depending on the casting number, some are better than others. Other posters might chime in with the particular number that's supposed to be better than the others.

I mention that the Howel system is California legal because I would only consider a FI system if it was necessary to pass emissions. Depending on how the CO law might be written (if ever), the local politicians might simply copy the CA law rather than thoughtfully ask for citizen input.

I assume you're planning on FI to gain the benefits of better trail manners and hopefully better fuel economy. Be glad you're in SC rather than CA.

Good Luck, L.M.
 

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Having owned a holly F.I. system on a 350 Chevy I would say for me never again

One battery temp disconnect reconnect even unintentional (think loose dirty or corroded battery cable or ground)with the engine running will make a voltage spike that completely fried the brain box

A factory efi system from a 4.0 YJ or XJ would be more reliable more robust much much less expensive to gather up at salvage yard and have reliable off the shelf replacement parts if needed








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Discussion Starter #8
Having owned a holly F.I. system on a 350 Chevy I would say for me never again

One battery temp disconnect reconnect even unintentional (think loose dirty or corroded battery cable or ground)with the engine running will make a voltage spike that completely fried the brain box

A factory efi system from a 4.0 YJ or XJ would be more reliable more robust much much less expensive to gather up at salvage yard and have reliable off the shelf replacement parts if needed








Sent from my iPhone using Tapatalk
Ouch...Thanks for the input

Sent from my SM-G965U using Tapatalk
 

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Discussion Starter #9
What I'm saying is the 4.0 head swap is something would consider if I were to look at aftermarket fuel injection systems.

Cornchip points out the differences in two of the available systems.



As part of my research into which system would work best for me, I'd contact each manufacturer's technical department and ask them what impact (if any) the head swap would have on the usability of their system.



The 4.0 head is reported to breathe better. Depending on the casting number, some are better than others. Other posters might chime in with the particular number that's supposed to be better than the others.



I mention that the Howel system is California legal because I would only consider a FI system if it was necessary to pass emissions. Depending on how the CO law might be written (if ever), the local politicians might simply copy the CA law rather than thoughtfully ask for citizen input.



I assume you're planning on FI to gain the benefits of better trail manners and hopefully better fuel economy. Be glad you're in SC rather than CA.



Good Luck, L.M.
Thanks LuckyMac....

Sent from my SM-G965U using Tapatalk
 
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