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Weber 2.8 carb conversion on 3.4 v6

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stone4140 Daniel Schuler
Caledonia, NY, USA   USA
1978 MG MGB
I'm still in the research stage before I start purchasing parts for my conversion. Lots of great info on this site. Has anyone put an old s10 intake manifold on a 3.4 and used the Weber 2.8 carb conversion. The link below is for an aftermarket Weber on Amazon. The actual Weber kit is $399. I know the best carb setup would probably be the Edelbrock lower with the classic conversion top end and the Holley 390. This would be a pretty cheap alternative if it had the ability to function well on the 3.4 with a used s10 intake.

Thanks

https://www.amazon.com/Elec-Choke-83-88-Blazer-Cherokee/dp/B01C4ND74G#customerReviews

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260mgb Jim Nichols
Sequim,WA, USA   USA
Probably work fine. I and others have adapted the 350 Holley 2 barrel sideways also. You need the 83-84 S10 or 84 Cherokee distributor too.

stone4140 Daniel Schuler
Caledonia, NY, USA   USA
1978 MG MGB
Yes I’ve read your posts. I’ve gone between many of these ideas. Lots of great info to digest. I haven’t settled on one way as of yet. The Weber gets good responses on the S10 and Jeep forums I just wonder if it would be to tall to close the hood/bonnet...

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ohlord Avatar
ohlord Gold Member Rob C
North of Seattle, N.W., USA   USA
1957 Land Rover Series I "EYEYIYI"
1971 MG MGB
1971 MG MGB "Bedouin 2"
Save a bit more and get the new 2bbl F.I.thumbs up



"I'm a long way gone down this wild road I'm on
It's gonna take me where I'm bound
It's a long way around"



"These are the days that must happen to you"

RD2 Radar/ Electronic Warfare Technician
Vietnam 1969-1972

260mgb Jim Nichols
Sequim,WA, USA   USA
I agree with Rob but budgets overrule. I think there is an adapter to use a conventional round air filter for that carb. I don't think it would be any taller than a Holley with adapter. Maybe a drop base?



Edited 1 time(s). Last edit at 2018-03-13 09:34 PM by 260mgb.

260mgb Jim Nichols
Sequim,WA, USA   USA
Here is the adapter. You could use a low profile carb hat with fresh air hose also.

https://www.lceperformance.com/Weber-32-36-38-Carb-to-K-N-Filter-Adapter-Kit-p/1033030.htm

ohlord Avatar
ohlord Gold Member Rob C
North of Seattle, N.W., USA   USA
1957 Land Rover Series I "EYEYIYI"
1971 MG MGB
1971 MG MGB "Bedouin 2"
Fitech is only $400 morewinking smiley



"I'm a long way gone down this wild road I'm on
It's gonna take me where I'm bound
It's a long way around"



"These are the days that must happen to you"

RD2 Radar/ Electronic Warfare Technician
Vietnam 1969-1972



Edited 1 time(s). Last edit at 2018-03-13 11:01 PM by ohlord.

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stone4140 Daniel Schuler
Caledonia, NY, USA   USA
1978 MG MGB
Like I said I’m still in the R&D stage here. I haven’t ruled anything out. Can you give me some more details on the Fitech? I did some searching last night and it looks like a simplified EFI that mounts as a carb would? Does it still require the extensive wiring? If someone has done this with a 3.4 I’d love to see it. Budget to me is flexible if the components don’t add major complexity to the process.

ohlord Avatar
ohlord Gold Member Rob C
North of Seattle, N.W., USA   USA
1957 Land Rover Series I "EYEYIYI"
1971 MG MGB
1971 MG MGB "Bedouin 2"
Pre-programmed with Bolt-N-Go technology for out of the box performance with no tuning required.
EZ-tach input, reads tach signal from: Coil, HEI, MSD/CDI and many other brand ignitions (no timing
Hand held performance tuner
No complexity



"I'm a long way gone down this wild road I'm on
It's gonna take me where I'm bound
It's a long way around"



"These are the days that must happen to you"

RD2 Radar/ Electronic Warfare Technician
Vietnam 1969-1972

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stone4140 Daniel Schuler
Caledonia, NY, USA   USA
1978 MG MGB
The Fitech would need an updated fuel pump and lines correct?

If sticking with the Weber or Holley carb is the stock MGB fuel pump adequate?

260mgb Jim Nichols
Sequim,WA, USA   USA
Higher pressure pump for EFI. Higher than stock for Holley and Weber carb at 6psi.

BMC Avatar
BMC Gold Member Brian Mc Cullough
Minneapolis, Minnesota, USA   USA
I am bias but also logical about these items.

What I see is death by a thousand cuts credit card swipes and a lot more head scratching to figure out the next problem that crops up.

If you are willing to take the stock system and rebuild the wiring loom (pending the plastic bits are still in good sorts) then the stock system should be the least costly.

If you are going to use a fuel injection wiring system like we offer at BMC, use as much stock as possible of the engine, sensors, and so on. Install a wiring loom that the wires have been run, sized and enclosed in a wiring loom and the wire colors on the GM side are still GM and the MG/Lucas wiring are properly 'colour' coded to make it all new and all drop in and everything is still the same factory equipment. There is no power loss for using factory tested and proven equipment.

Another direction to go sounds like only one-or-two purchases but is going to end up truly costing more than most realise. First in actual money, second in time. Everyone realises that there is a manifold and a fuel system but what about all the rest?

I have calls often about the wrong manifolds with the cost of price of bodywork because nothing fits below the bonnet. Hey, we sell the wonderful MGRV8 Bonnet but it requires paint to match your car!
Manifold choice is critical just for fit.

If a used TBI or Carb manifold is used, a loss of power should be expected or at least No gain, a height issue is to be expected and since it is used, needs to be checked to see that it is straight and does not require milling. So far, for a used manifold, I have named: price of manifold, possible price of bodywork, cleaning, paint, machining, gaskets. Now if a manifold is chosen, it will need hardware to hold it in place. Most manifolds have 3 to 6 lengths and types of bolts and studs holding it down, plus thermostat bolts, carb/FI bolts, gaskets, thermostat type different thermostat housing to face the water pipes in the correct direction. If no power loss over stock is desired for the 3.4L, I recommend the Edelbrock lower, the CCE upper, a phenolic spacer, hardware on this stuff and a carb or FI. If going carb or Aftermarket FI (FITech or other), you must purchase and Recurve and Rebuild mechanical distributor. Fuel injection with a mechanical distributor is going backwards in technology, in comparison to the stock SFI, but it works. The ignition needs to be rebuilt and a lot of parts replaced to have a good curve and build for the change of vehicles and use. I have not named a lot of parts but this is a lot of nickel and dime and the end cost will be no less than factory items. It's much like carb vs. fuel injection on an engine that is already injected- you CAN make carb cheaper and you CAN make FI lower priced as well. Build your own wiring- SFI on the 3.4L is way lower price. Build a 2 barrel carb version by getting all the parts off an old carb S10 (and Do NOT rebuild otherwise it will cost you about $500 to rebuild the carb and rebuild/recurve the distributor Properly) and that will be lower price at a huge power loss. The "advantage" that aftermarket fuel injection might have is the tunability without a special program like we use. If you are supercharging or going for a race engine, it may help but unless it is one of those extremes AND you plan to keep a mechanically tuned (a Distributor type) ignition system (in my books, that's backwards- tuneable injectors but not unable ignition) means it is not properly tunable and will offer ZERO gain over a stock program. Dyno runs on most gas engines retuned over stock programs offer Extremely low power gain unless cams, compression, valve size, porting or some other items is improved first- factory programming is better than you have been led to believe in most cases on most engines.

This may sounds single sided coming from our shop but I look at the costs of everything and why any system makes sense:
I think the FITech systems (and similar) are most-probably a very good upgrade for (V8) engines built in 1955-1985 that already have a manifold, a car that has a Lot of room to spare between the bottom of the sheetmetal and the top of the intake, never were manufactured with factory bolt on parts or converting them over would be costly due to age, currently Already have a distributor and all the ignition coil and bits and pieces in good known working condition and otherwise are looking for minor updates to give a little more performance than the carb dribbling (overfueling) or starving (underfueling/running lean) into the engine at various engine speeds. I expect that there will be more systems like this coming along in the near future that I can appreciate for side carb engines such as the Austin B series engine originally found in the MGB.


I expect that if a person wants a proper FI system, it's Not just fuel but ignition that needs to be looked at as a package. The overall cost of the FITech and others is FAR more when considering: Manifold and all the associated pieces, the fuel injection, the ignition, the wire by wire placement for one particular build that will be no easier (possibly shinier advertisements though!) and other items that I am sure have been missed. That said, All systems are going to have a nickel and dime cost and this should be looked at in total, which is missing in the posts to the point I have read.

-BMC.


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stone4140 Daniel Schuler
Caledonia, NY, USA   USA
1978 MG MGB
As usual lots of great info. I've learned more in a week from this forum and the posts than in some classes I took in college. If going with the EFI, what is the average cost of updating the fuel delivery system? Updating to a 6psi pump for a carb setup seems pretty straightforward with a good pump going for around $125. High pressure seems to have more involved (internal pump etc..) if someone wanted to do it well.

Thanks,

Ichi Avatar
Ichi Scott Martin
Kenora, ON, Canada   CAN
Not sure of the average cost, but an in-line/external high pressure fuel pump can be had for around $125 as well. Just run another hard line for fuel delivery and use the old line for fuel return. not a big deal, not hard and not much more expensive.
Scott

ohlord Avatar
ohlord Gold Member Rob C
North of Seattle, N.W., USA   USA
1957 Land Rover Series I "EYEYIYI"
1971 MG MGB
1971 MG MGB "Bedouin 2"
The fitech bolts on to a standard 4bbl manifold used with any carb.
It is standalone
You use the distribiutor as in a carb v6 60
You can use an on demand hp pump no return line or a fi pump and return
Its also shorter than the carb
So simple a child can hook it up

In reply to # 3697430 by BMC I am bias but also logical about these items.

What I see is death by a thousand cuts credit card swipes and a lot more head scratching to figure out the next problem that crops up.

If you are willing to take the stock system and rebuild the wiring loom (pending the plastic bits are still in good sorts) then the stock system should be the least costly.

If you are going to use a fuel injection wiring system like we offer at BMC, use as much stock as possible of the engine, sensors, and so on. Install a wiring loom that the wires have been run, sized and enclosed in a wiring loom and the wire colors on the GM side are still GM and the MG/Lucas wiring are properly 'colour' coded to make it all new and all drop in and everything is still the same factory equipment. There is no power loss for using factory tested and proven equipment.

Another direction to go sounds like only one-or-two purchases but is going to end up truly costing more than most realise. First in actual money, second in time. Everyone realises that there is a manifold and a fuel system but what about all the rest?

I have calls often about the wrong manifolds with the cost of price of bodywork because nothing fits below the bonnet. Hey, we sell the wonderful MGRV8 Bonnet but it requires paint to match your car!
Manifold choice is critical just for fit.

If a used TBI or Carb manifold is used, a loss of power should be expected or at least No gain, a height issue is to be expected and since it is used, needs to be checked to see that it is straight and does not require milling. So far, for a used manifold, I have named: price of manifold, possible price of bodywork, cleaning, paint, machining, gaskets. Now if a manifold is chosen, it will need hardware to hold it in place. Most manifolds have 3 to 6 lengths and types of bolts and studs holding it down, plus thermostat bolts, carb/FI bolts, gaskets, thermostat type different thermostat housing to face the water pipes in the correct direction. If no power loss over stock is desired for the 3.4L, I recommend the Edelbrock lower, the CCE upper, a phenolic spacer, hardware on this stuff and a carb or FI. If going carb or Aftermarket FI (FITech or other), you must purchase and Recurve and Rebuild mechanical distributor. Fuel injection with a mechanical distributor is going backwards in technology, in comparison to the stock SFI, but it works. The ignition needs to be rebuilt and a lot of parts replaced to have a good curve and build for the change of vehicles and use. I have not named a lot of parts but this is a lot of nickel and dime and the end cost will be no less than factory items. It's much like carb vs. fuel injection on an engine that is already injected- you CAN make carb cheaper and you CAN make FI lower priced as well. Build your own wiring- SFI on the 3.4L is way lower price. Build a 2 barrel carb version by getting all the parts off an old carb S10 (and Do NOT rebuild otherwise it will cost you about $500 to rebuild the carb and rebuild/recurve the distributor Properly) and that will be lower price at a huge power loss. The "advantage" that aftermarket fuel injection might have is the tunability without a special program like we use. If you are supercharging or going for a race engine, it may help but unless it is one of those extremes AND you plan to keep a mechanically tuned (a Distributor type) ignition system (in my books, that's backwards- tuneable injectors but not unable ignition) means it is not properly tunable and will offer ZERO gain over a stock program. Dyno runs on most gas engines retuned over stock programs offer Extremely low power gain unless cams, compression, valve size, porting or some other items is improved first- factory programming is better than you have been led to believe in most cases on most engines.

This may sounds single sided coming from our shop but I look at the costs of everything and why any system makes sense:
I think the FITech systems (and similar) are most-probably a very good upgrade for (V8) engines built in 1955-1985 that already have a manifold, a car that has a Lot of room to spare between the bottom of the sheetmetal and the top of the intake, never were manufactured with factory bolt on parts or converting them over would be costly due to age, currently Already have a distributor and all the ignition coil and bits and pieces in good known working condition and otherwise are looking for minor updates to give a little more performance than the carb dribbling (overfueling) or starving (underfueling/running lean) into the engine at various engine speeds. I expect that there will be more systems like this coming along in the near future that I can appreciate for side carb engines such as the Austin B series engine originally found in the MGB.


I expect that if a person wants a proper FI system, it's Not just fuel but ignition that needs to be looked at as a package. The overall cost of the FITech and others is FAR more when considering: Manifold and all the associated pieces, the fuel injection, the ignition, the wire by wire placement for one particular build that will be no easier (possibly shinier advertisements though!) and other items that I am sure have been missed. That said, All systems are going to have a nickel and dime cost and this should be looked at in total, which is missing in the posts to the point I have read.

-BMC.



"I'm a long way gone down this wild road I'm on
It's gonna take me where I'm bound
It's a long way around"



"These are the days that must happen to you"

RD2 Radar/ Electronic Warfare Technician
Vietnam 1969-1972

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