Webers vs. EFI

Mike, I once adapted a pair of Porsche 40IDA3C Webers to a Corvair 6. After the adaption, it took me 3 full months of daily plug-chops and jet-drilling during lunch hour to zero in on the jetting. None of my co-workers would eat lunch with me 'cause I always smelled like gasoline! Webers have 5 removable jets and two air bleeds for each barrel, along with a replaceable venturi & emulsion tubes, and they all affect each other at various rpms. So as you probably know, its absurdly easy to get lost inside these carbs. And the cheapest Weber jet is about $5. I still have boxes full of jet$ & other parts. I now run a tuner-Holley opn our Pantera, and have a brand-new set of 48DCOEs sitting on a shelf that I can't bring myself to adapt to the Pantera.

Unless you are extremely familiar with them or have lots of patience, hiring an expert Weber tuner is the way to go. The two most common 'tunes' with Weber carbs is lots of power and 10 miles per gallon, or no power and 18 mpg- or some varient. I managed then, but that was a long time ago and my patience was lost somewhere along the line. EFI was not yet available but if it had been I would have jumped at it! You have the best possible rig now that only needs a tweek with a laptop. I would check with Kirby Schrader in Magnolia TX (kirby.schrader@gmail.com), who provided the tune that's in your system now, for advice. Kirby has (or had) two sets of EFI just like yours that apparently run just fine in his cars. He will also be at the national POCA Fun Rally next month in Houston with his car and will likely run it on the track.

Bosswrench, thanks very much for the advice!

I may be incorrectly assuming that I cannot tune my old Haltech unit, but I have not talked with Kirby yet either, so I don't know. I'll contact him for sure.

My car runs sweet as it sits. Goobs of power, idles smooth (needs a blip sometimes to get the idle to drop fully down sometimes)but it obviously runs really rich, confirmed by the really bad mileage and the smell of fuel. A friend driving behind me told me he could smell my car running rich.

Reading the plugs, the front four plugs were black, and the rear 4 were golden brown, and I'm not sure how I can adjust or tune to change this, as there's no adjuster screws, just capped tube nipples at the base of each stack.

I actually thought about connecting a piece of tubing and an air bleed valve to each of those nipples for fine tuning.

On my Porsche, I ran PMO carbs, which were based on Webers, used some Weber parts, but were huge (50mm) and FAR superior to Webers. I also had the luxury of the detailed information from the previous owner on jetting. I bought that car with no carbs or ignitions (he was going to Motec, sold those parts, and then retired from racing) so I had to replace those parts, but I was able to duplicate what he had already dialed in, so i hit the ground running and never had to mess with my Weber/PMO carbs or jetting.

I will call Kirby and inquire about my setup. I don't really have any complaints other than the rich running, and that I'd like to be able to fine tune the injection.

I'm fine with leaving the distributor alone, and running what I have if I can get it dialed in.

In the future, when I build/rebuild the engine, I will be upgrading for sure.

I am sure you could make a megasquirt system control it. I have include a picture of my friends street rod with a 12pack (three 4 barrel AFBs)on his 14-71 496bbc. You just have to ask yourself "At what point its for fun to drive instead of work on my toy"?

Im not familiar with webers but common sense says that 8 carbs to tune/sync is much harder than one.
I had the same ancient Haltech that you have. Any efi technician can tune with any software. The issue is whether they want to spend time getting familiar with unknown software. They all have their preferences. EFI tuners here in my area are EXPENSIVE.
I took my car to a couple of local guys and they literally laughed at the ancient Haltech software.
I bought FAST XFI module, sensors and harness for about $2500. Easy to install and come with many base maps.
The tuning part gets expensive if you don't have the knowledge to do it. Its not just changing jets. There are a lot of parameters that can be adjusted.
When its tuned though, its miles apart from a carb, IMH. Not to mention the incredible gas mileage you get.
Will

Sometimes EFI is just more work than its worth. I removed the EFI system from my Panter and went with a custom carb. I have a some experience with EFI systems (picture is of my EFI turbo twin engine landspeed bike).

THAT IS BADASS!

That's a fatty turbo on there.

I always wondered how the salt flat racers kept the salt out of their engines. I see many pics of guys running without air cleaners, and it seems like salt would just instantly score anything it got into.

In this pic, you can see the capped hose nipple at the base of the stack on the right (right next to the dipstick handle).

Each stack has one of these.

I'm wondering how any kind of fine tuning can happen on my system.

I can put a uni-sync tool on top of each stack and measure, but how would I adjust anything?

I was thinking maybe putting an inch of tubing with a small bleeder valve on each of those nipples might allow some adjustment at idle (as far as synchronizing at idle)?

No advantages to carbs. Stay with the EFI. The hard work was already done.

It's just a matter of needing to be retuned. Why needlessly complicate your life more?

The Webers are going to be 48mm. You are already at 50mm with the FI.

With that cam and FI you have little or no concern about fuel reversion. With carbs you will. Those air filter elements will be soaked with fuel and WILL catch fire.

You really can't run Webers with air cleaners unless you change to a special Weber grind with low overlap. You would HAVE to run with open stacks otherwise.

I can go on but this should be enough right?

OHHHH...PLEASE continue Doug...The horse still has a couple of breathes of life left in her... ...Mark

Yes,

Thank you Doug.

quote:

Originally posted by PanteraDoug:
No advantages to carbs. Stay with the EFI. The hard work was already done.

It's just a matter of needing to be retuned. Why needlessly complicate your life more?

The Webers are going to be 48mm. You are already at 50mm with the FI.

With that cam and FI you have little or no concern about fuel reversion. With carbs you will. Those air filter elements will be soaked with fuel and WILL catch fire.

You really can't run Webers with air cleaners unless you change to a special Weber grind with low overlap. You would HAVE to run with open stacks otherwise.

I can go on but this should be enough right?

DOOD! You and your friends play around with some massively awesome stuff!

quote:

Originally posted by 8pack:
I am sure you could make a megasquirt system control it. I have include a picture of my friends street rod with a 12pack (three 4 barrel AFBs)on his 14-71 496bbc. You just have to ask yourself "At what point its for fun to drive instead of work on my toy"?

I think my friends and I may have a problem with one ups-man-ship (not sure if that's a work if not note: work created). We normally complete a new toy every other year.

quote:

Originally posted by mike the snake:
DOOD! You and your friends play around with some massively awesome stuff!

quote:

Originally posted by 8pack:
I am sure you could make a megasquirt system control it. I have include a picture of my friends street rod with a 12pack (three 4 barrel AFBs)on his 14-71 496bbc. You just have to ask yourself "At what point its for fun to drive instead of work on my toy"?

quote:

Originally posted by PanteraDoug:
I can go on but this should be enough right?

You forgot the looks Doug!

Also advice you to stay with EFI
I change from an 20 years old Haltech F3 to a modern ECU (both fuel and ignition) that go closed loop and sequential.
SF

quote:

Originally posted by Kid:

quote:

Originally posted by PanteraDoug:
I can go on but this should be enough right?

You forgot the looks Doug!

Forgot? No! 7) The Webers are ugly too.

quote:

Originally posted by mike the snake:
In this pic, you can see the capped hose nipple at the base of the stack on the right (right next to the dipstick handle).



I was thinking maybe putting an inch of tubing with a small bleeder valve on each of those nipples might allow some adjustment at idle (as far as synchronizing at idle)?

You could do that as a means of getting more even mixtures at idle. It is a primitive form of idle air control (IAC).

IAC is widely used on modern injected cars and is usually computer controlled but i use a similar mechanical form of IAC on my injection.

It can work quite well but remember it only has a effect over idle mixture, if you have cylinder to cylinder distribution problems at a higher rpm you will need to address that by other means.


Don't be misled by mechanics turning their nose up at your "old" injection computer. If they don't want to work on it find someone else.

The computer i use is even older and less sophisticated and in fact does not even have a processor. It still does the job, is easy to operate and i cannot justify the expence of replacement for the 5 or 10 hp i might gain.

I suggest you are in the same situation. A lot of people continue on with carburetors and that technology is over 100 years old, a 20 year old computer shouldn't be a big deal.

I really am starting from scratch here.

The plugs read funny colors, but that could have been due to the mal-fitting air cleaners.

The engine has mecahnical issues that I'm presently dealing with.

While it runs sweet, I KNOW it's running VERY rich.

SO, I've fixed the air cleaners so they don't block half of the stacks, soon the mechanical issues will be resolved, and then I want to get on with tuning my car a little leaner. If there's more power to be had, I'm all for it.

I'm just observing that there's no idle mixture adjustability on my system.

If I can get my car tuned with it's existing equipment I'd be happy as a peach!

If

Not to criticise but invidual runner carburetored systems do not like attempts at transforming them into common plenum systems.

The 48ida's on US V8's were "designed" as racing systems with "Devil may care" idling systems.

By the same token, the dual Holley Dominator induction on the Boss 302 Trans-am cars reacts almost identically.

I am advised by someone VERY experienced in that system, Randy Gillis, that the simplest compromise for it is to go to the 750 Holley Dominators and put a 1/2" open plenum spacer under them.

There are PERHAPS half a dozen people on this planet that are close to being experts on that system, and he is one of them.

Considering this is a change from whatever the originals are at 1050 or 1150, you are re-engineering the system, which is not really entirely possible.


IR carbs and IR FI are not necessarily equatable. There are some similarities, but not many.


Stay with your current FI setup. Especially if you think you may have suicidal tendencies and certainly if you insist, DON'T PLAY WITH MATCHES AROUND THEM? Badda boom...big bada boom!

quote:

Originally posted by mike the snake:
I really am starting from scratch here.

The plugs read funny colors, but that could have been due to the mal-fitting air cleaners.


While it runs sweet, I KNOW it's running VERY rich.

Running rich when ???

At idle ?

During transition ?

Part throttle ?

Full throttle ?

All the time ?

On all cylinders or just some ? All the time or just sometimes ?

You need to make more detailed observations of when, where, how !! Only then can you have any success in improving the tune.


Balancing idle air flow will have no effect on part throttle, full throttle, or transition and vice versa or any combination of the above.

You must know specifically what rpm and what load it is rich (or lean) to enable a suitable ajustment to be made. That's EFI and carbs.



.

I'd say rich at idle, and low partial throttle for sure (as reported by my friend smelling the car while driving behind me) and I suspect that at full throttle things are probably much closer to in-line, tune-wise.

Idle, part throttle, and transition the car runs perfectly. No pops, or hiccups, or stumbles, just smooth power on-tap from idle to full-throttle. No complaints as far as how the car is running.

The car does have really bad economy though, and smells badly of fuel at idle and low throttle (cruising where the throttle is barely opened).

The old air cleaners were ill-fitting (short), covering 1/3 of the 4 corner stacks, or 1/2 of each end stack, depending on how it was fitted.

This may have caused the funky plug colors I discovered when I removed them the first time.

Today probably, I'm pulling the intake manifold and center cover off to inspect my roller lifters.

In 2 weeks I have my reconditioned rockers coming, and I also hope to have new replacement valvesprings in place by then as well.

THEN, I plan to just drive the car for a while, make sure it is stable mechanically, and then I'll start dealing with getting the tune dialed in.

From what everyone has said, I'll definitely be keeping my EFI and not switch to Webers.

quote:

Originally posted by Aus Ford:

quote:

Originally posted by mike the snake:
I really am starting from scratch here.

The plugs read funny colors, but that could have been due to the mal-fitting air cleaners.


While it runs sweet, I KNOW it's running VERY rich.

Running rich when ???

At idle ?

During transition ?

Part throttle ?

Full throttle ?

All the time ?

On all cylinders or just some ? All the time or just sometimes ?

You need to make more detailed observations of when, where, how !! Only then can you have any success in improving the tune.


Balancing idle air flow will have no effect on part throttle, full throttle, or transition and vice versa or any combination of the above.

You must know specifically what rpm and what load it is rich (or lean) to enable a suitable ajustment to be made. That's EFI and carbs.



.

I also plan on installing a wideband 02 sensor and gauge so I can see where I am running rich.

quote:

Originally posted by mike the snake:
I also plan on installing a wideband 02 sensor and gauge so I can see where I am running rich.

Are you going to run an AEM system?

quote:

Originally posted by mike the snake:


You must know specifically what rpm and what load it is rich (or lean) to enable a suitable ajustment to be made. That's EFI and carbs.

[/QUOTE]

Absolutely correct. Understand I am not arguing but, 8) the carbs are not going to have the same degree of "digital" tuning as the EFI has now.

quote:

Originally posted by mike the snake:
I'd say rich at idle, and low partial throttle for sure (as reported by my friend smelling the car while driving behind me) and I suspect that at full throttle things are probably much closer to in-line, tune-wise.

Idle, part throttle, and transition the car runs perfectly. No pops, or hiccups, or stumbles, just smooth power on-tap from idle to full-throttle. No complaints as far as how the car is running.

The car does have really bad economy though, and smells badly of fuel at idle and low throttle (cruising where the throttle is barely opened).

You may want to try adjusting the Throttle Position Sensor. You need to measure the resistance across the sensor with a multimeter beforehand with it disconnected and everything switched off. Take note of the resistance so you can reset it to that if the result is no good.

Adjust the body of the TPS slightly in the direction the throttle blades turn as they open. This should make it leaner everywhere, idle, part throttle full throttle ect but it will be the most noticeable at idle. Move it a tiny amount !

The other idea you had with a small needle valve on each of the runners should give you cylinder to cylinder adjustment at idle. Remember to get air from the air filters or the fine valves will get jammed up with dust.


.

At some point, I plan to upgrade to a modern system that controls everything. Presently my Haltech only controls the fuel, not timing.

If I can get my engine tuned with it's present equipment, I'll opt for that, because in a year or so I'll be rebuilding/replacing this engine, and will probably do the engine management upgrade at that time.

quote:

Originally posted by 8pack:

quote:

Originally posted by mike the snake:
I also plan on installing a wideband 02 sensor and gauge so I can see where I am running rich.

Are you going to run an AEM system?

What has NOT be considered nor spoken about is Mike's FAULTY rockers after being inspected by Sheldon at T&D.

Possibly & I repeat "Possibly" some of Mike's throttle/idle conditions can be attributed to the inconsistent valve opening/closing of the 16 valves.

I personally would WAIT till the rebuilt rockers are installed..."PROPERLY Adjusted"...THEN see the running qualities or lack thereof of the fuel delivery system!!!...Mark

quote:

Originally posted by 1Rocketship:


I personally would WAIT till the rebuilt rockers are installed..."PROPERLY Adjusted"...THEN see the running qualities or lack thereof of the fuel delivery system!!!...Mark

Absolutely....

I think he will find it very difficult to tune the engine until the rocker arms are reinstalled and adjusted.

quote:

Originally posted by Aus Ford:

quote:

Originally posted by 1Rocketship:


I personally would WAIT till the rebuilt rockers are installed..."PROPERLY Adjusted"...THEN see the running qualities or lack thereof of the fuel delivery system!!!...Mark

Absolutely....

I think he will find it very difficult to tune the engine until the rocker arms are reinstalled and adjusted.

Oye!

+1

TOUGH CROWD!!!

I made my observation based on ALL running characteristics of Mike's engine have been based on the engine running with BAD rockers...Mark

Considering that Mike hasn't looked at the plugs since he fixed the air cleaners, there are a few things to consider.

It will take a little time to get a picture of what is happening.

I agree completely.

There's lots going on here. There were a lot of issues I found and dealt with, as well as the rockers.

Luckily, I found the deteriorating rockers before they exploded.

As I've said, I'm going to check the roller lifters, install new rockers, and new valvesprings, and THEN, after I've confirmed I have a solid, mechanically reliable engine, I'll look into tuning the engine, hopefully with the system I have presently if it can be adjusted. It requires a REALLY old computer to connect to to be tuned.

I did remove my #1 plug, because before it was the worst looking,wet and black with some carbon, but after a couple tanks of fuel it actually looked really good, a little dark, but good. I realize this is not really enough time to run it and get a real plug reading.

I just want to get this engine back running (and hopefully tuned) for as little money as I can, with checking and replacing what parts I need to to keep it running until I build/rebuild a new engine.

To date, the few hours I have on the engine, it has actually run great, just really rich.

I contacted Kirby, and he said he'd help if he could when the time came, so first things first.

I need to inspect the lifters, then replace the upper engine parts, install and adjust the new rockers, and run the engine for a while, check everything, make sure it's all stable.

quote:

Originally posted by 1Rocketship:
What has NOT be considered nor spoken about is Mike's FAULTY rockers after being inspected by Sheldon at T&D.

Possibly & I repeat "Possibly" some of Mike's throttle/idle conditions can be attributed to the inconsistent valve opening/closing of the 16 valves.

I personally would WAIT till the rebuilt rockers are installed..."PROPERLY Adjusted"...THEN see the running qualities or lack thereof of the fuel delivery system!!!...Mark

AHA!

I figured out how I can have the four front plugs reading differently than the rear 4 holes.

The stacks are split! Kind of like separate 2 barrel carbs.

So my front four or rear four holes can simply be out of adjustment.

I had thought there was just one shaft that went through all four bodies. I had thought maybe the shaft was twisted slightly or something, but there's actually a screw there to balance the two in-line stacks.

I'd not really inspected the system that closely. But today, I'm looking at it all very closely, looking at what I need to do to remove the manifolds/stacks and center plate so I can inspect my lifters.

Nothing too complex going on there, but I'm hesitant because it DOES look like it might be difficult to put back exactly as it all was (linkage-wise).

I just have to dive in and do it. First I have to vacum off any dust and dirt from all the nooks and crannies.

Read a few of your other posts Mike and I'm genuinely concerned. wanting to build a new motor and trading a yates port EFI IR intake for a Weber 4v iron intake? You already have one of the more radical 9.2 deck engines here. I realize you went through some initial hardships with the used rockershaft setup. That is part of the deal when hunting parts for yates heads, nothing is cheap even used! Can't blame the prior owner for that. But just because the rockers were used does not mean the whole motor is shit or that you were lied to on everything. But you need some serious advice here as a new owner before you get taken to the cleaners while people happily pick your parts from you for crap. Take some time to realize what you have. Your yates c3l topend setup is one of the if not the best naturally aspirated setup you could put on a pantera, GT40, w/e. yeah the haltech may not be the latest EFI computer but it is still worlds from tuning some weber setup. The only reason to even monkey with a weber setup is for nostalgia or class racing, and I won't make friends with that statement. Take the car to a chassis dyno and figure out what it makes, that thing will be a beast, rich or not. If you want to make more power you would have to go to forced induction or a big block with the weight penalty and then deal with your ZF wanting to shit itself.

If you just want to change things to make the car your own I get it, been there done that. But before you unload what someone else did, spend time to figure out what you have. Joules mentioned going to a newer Accel Gen7 which is good advice. If the whole DOS based interface with the haltech is intimidating, there are other newer ECU's which can be adapted to your setup to replace the haltech. FAST EFI 2.0 could also be adapted as well as a Holley EFI kit. They all have modern Windows User Interfaces making them easier to navigate and tune. What you have to decide is whether you want to tune it or someone else. If someone else will tune it that you trust, find out what system they are proficient at and make that part of the decision.

Thanks for your input Hustler, but I'd come to the same conclusions as you quite a while ago.

I'm not considering going to webers.

I plan to rebuild what I have, probably detune it slightly, run modern electronics, and enjoy, in a year.