famous bob
mopar misfit
The above car is pretty dam fast too !^^^^^^^^^^^^^^^^--just a casual observer .
Another "Is Fuel Injection a Worthwhile Upgrade?" Question
- Thread starter harrisonm
- Start date
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The above car is pretty dam fast too !^^^^^^^^^^^^^^^^--just a casual observer .
Sounds like you could make EFI work so it just comes down to the investment vs. the reward. If you like to tinker and tune then EFI can be rewarding. Between the digital control of the tune and the feedback from the data logger you can adjust the tune until the car is doing exactly what you want. But in your case you're going to have spend money twice since you already have a carb and a distributor. The wiring will need to be redone and you'll need to change the plumbing and maybe the fuel tank.
But you and your son might enjoy tuning the EFI system. You can drive the car and he can sit in the passenger seat with the laptop and dial in the timing and the AFR as you go down the road.
TT5.9mag
Two atmospheres are better than one
If you don’t use a roller cam, break the engine in on a known good carburetor and make the efi switch afterwards. There will be lots of cranking. Especially on your first go round.
Dartswinger70
Well-Known Member
Me thinks EFI would play nice on the post 87 magnum engines. Or at least have a roller cam etc. I dunno why I am thinking this...I also don't know why it wouldn't work, on an older engine, you'd need your intake air meter and a o2 sensor maybe something telling the computer where tdc is, is there anything else?
70chall440
Mopar or No Car...
It works well on an older engine even w/o a roller cam, I have 2 systems on older engines.
TT5.9mag
Two atmospheres are better than one
Efi will play nice on anything. It’s just more of adapting the technology to older engines, and using the technology on newer engines. You do not need to tell the computer where TDC is. It doesn’t care. You need an accurate crankshaft position sensor (with one of many patterns available) and a cam sync, (cam position sensor). The cam sync can be anywhere really. You dont necessarily need an “air flow meter” (mass airflow sensor) as most aftermarket efi systems use map, and you definitely need O2 sensors.
Bluecuda340
Well-Known Member
If you just throw the EFI system on and try to start it that might be true. If you check and double check the electrical side of the install and go over the manual for whatever system you choose you shouldn't have any trouble. I know people that have installed Fitech, MSD-Atomic, FAST EZ, and Holley sniper systems and they have all fired off first try. If it is a more involved system like megasquirt or something just a little research will help with your startup tune. Mine lit right off and idled like it had always been injected, I actually wasn't ready for that I was ready for a fight lol.
TT5.9mag
Two atmospheres are better than one
Ok you’re correct I should preface my statement a little. If you use one of the throttle body efi systems (fitech, sniper, etc) you can almost bolt them on and go so break in might not be a problem. But I was speaking of true MPFI and setting up a system from scratch, (AEM infinity, megasquirt, etc).
Firing up a new combination is just like anything else, it all depends on the details. If everything is assembled properly then an EFI setup will fire first crank. It isn't difficult to run thru a pre-start checklist.
We fire EFI engines on the dyno all the time without any issues. The drill is the same with carb or EFI. Spin the oil pump by hand to verify pressure and pre-oil the engine. Turn on the fuel pumps to verify pressure and check for leaks. Crank the engine by hand to verify rotor is pointing at #1 at 30 BTDC. Verify firing order on the engine matches the firing order on the cam card. Double check all connections. Spin it over and hit the ignition switch.
We fire EFI engines on the dyno all the time without any issues. The drill is the same with carb or EFI. Spin the oil pump by hand to verify pressure and pre-oil the engine. Turn on the fuel pumps to verify pressure and check for leaks. Crank the engine by hand to verify rotor is pointing at #1 at 30 BTDC. Verify firing order on the engine matches the firing order on the cam card. Double check all connections. Spin it over and hit the ignition switch.
The block is a 1998 5.9 magnum fr0m a Jeep Grand Cherokee. From what I've learned, the only year the 5.9 Magnum was offered in the Grand Cherokee. It sonic checked great, .030 overbore is no problem. As stated previously, I'm leaning towards a solid roller cam. Please guys, opinions, not attitudes. I'm getting old and this might be my last full engine rebuild. I love my 1970 Swinger 340, but I put it on a stand in the corner, as I want to run this old girl. The numbers matching motor is on the stand for possible resale value.
I also have the build sheet, that's why the original motor with all original parts, like the A/C 340 carb, distributor, and exhauast manifolds are tucked away on the original numbers matching block.
I'm not an expert in these areas, that's why I asked for assistance. I'm not an expert with fuel injection, that's why I asked for knowledge from this forum. I've helped members in the past unconditionally, with my own parts I've collected over the years. It seems that several "experts" have tried to take control of this site with their "expert" opinions. All I wanted was some helpful tips or suggestions for my old man build of my old classic muscle car build. I'm ashamed to belong to belong to a site that meant so much to me when I joined a long time ago. It's turned into a big pissing contest about who has the biggest opinion or who has the most posts. This isn't the site I joined long before I joined way earlier than most of y'all joined. I'm torn between leaving, or hoping people can work together. Paul.
my68barracuda
Well-Known Member
Actually no, the same engine skills it takes to tune a carb are used with FI, difference is the laptop is the tool, the same way a screwdriver is a tool.
And Rusty, you are a good guy, but you can’t have it both ways. In post #175 you say you don’t have the skills to tune a throttle body FI system, however in post # 170 you say the lap top does all the work, implying that you do have knowledge on how FI is tuned and the part the laptop plays in the process. I am inclined to believe post # 175
And that is Ok, to say again what about everyone that has made a positive comment about FI has said, run the fuel system that you choose to. It’s your car.
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You make good points, John. It could be that I am so set in my ways, I just don't want to learn any more about EFI. LOL You never know. These slants are the one thing that might break the ice.
yellow rose
Overnight Sensation
You have the answer, you just don’t like it.
You have to decide what YOU want. And whatever that is, you have to chose which system fits that the best.
After that, it will all depend on how much effort you put into them. Neither option is bolt on a go. Any one who says that is a liar.
The success of either a carb or EFI depends on your primary selection and then how much effort you put into it. Nothing else.
For example, if you buy some off the shelf carb and slap it on there, you can expect piss poor performance, and the only way to get it back is to work on it. Or, you can call an actual carb guy like Thumpr Carbs or Mark Whitner who owns Lightning Carbs and let them PICK a carb for you and it will come with their tune up on it.
Or, you can buy an EFI system. If you buy a low end system, expect that it will work at a minimum to get you by. Or, you can buy something where you can tune everything (if I was doing EFI I would never start with a low end system...BTDT and they aren’t worth it unless it’s bone stock) and then spend you time learning the system and how to tune with it.
Those are your options. The argument is with the fools who think “technology” is whatever they define it as.
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You have SO much to offer and then you say this and negate every good point you made. Figure out where to stop and do it.
yellow rose
Overnight Sensation
You may not be wrong, but saying it seriously diminishes your message.
goldduster318
Overzealous Car Modifier
I'm with Rusty on this one, I think your post #290 is fair except the last line. To the OP, apologize for going off track. My original intention was to be able to get a consensus on what the drawbacks were to carbs and what EFI could do for someone assuming that whoever was installing it is willing to put in the work there.
The Holley Sniper does seem to have options that can be tuned manually if desired. I would say at minimum someone would need to avoid a system with no user changeable tables.
I had the same carb you do, and it does have the capability to be tuned to run well for your application and I doubt if you got there you would have much of a concern with it's performance so long as the engine is warm and you aren't looking for good fuel mileage (and it sounds like you aren't). At a minimum, I would say you'll be into the power valve, air bleeds, accellerator pump cams and squirters to dial it in. The converter will mask some of it. The power valve is almost certainly wrong, I don't know why they say anything about idle vaccum for the power valve because you absolutely do not get good performance if you use that advice. You want to get it running okay at cruise in a high vacuum situation with a vacuum gauge handy and then try driving up a hill where the load would be increased and see when it goes lean and try to have the power valve open just before that. Carbs should probably come with a 9.5 or 10.5 power valve instead of a 6.5. Then you get into air bleeds and squirters and the like to get everything where it performs the best. Same with timing, its very unlikely you engine likes anything near a stock amount of timing up front, fairly likely it will be in the 15-25 range from my experience, but this is an easy one to find at idle and then you can adjust the total in your e-curve distributor accordingly. That's a big advantage over a stock distributor.
If you go the Sniper route, you will spend a lot more time making a fuel system, since you really should have an in tank pump and a return system with a bypass regulator. Its significantly more up front effort than a carb fuel system since most of us can get by with the OE tank/line and just run a dead head on a mechanical pump, and maybe not need a regulator. Then you do the wiring. Once you get past that, I think you can close in on the tune to be driving in a satisfactory way a faster even with the autotune feature (but not going to say you won't be tweaking manually). I think you run the same distributor on both in this case since you have it and only have the sniper do fuel. So that won't change. I think you will pick up MPG with the sniper and the cold engine performance will likely be better but if that's not a concern no worries. It also costs money to do it.
You already spent the money so if you are really on the fence, maybe trying what you have already is the right move.
The Holley Sniper does seem to have options that can be tuned manually if desired. I would say at minimum someone would need to avoid a system with no user changeable tables.
I had the same carb you do, and it does have the capability to be tuned to run well for your application and I doubt if you got there you would have much of a concern with it's performance so long as the engine is warm and you aren't looking for good fuel mileage (and it sounds like you aren't). At a minimum, I would say you'll be into the power valve, air bleeds, accellerator pump cams and squirters to dial it in. The converter will mask some of it. The power valve is almost certainly wrong, I don't know why they say anything about idle vaccum for the power valve because you absolutely do not get good performance if you use that advice. You want to get it running okay at cruise in a high vacuum situation with a vacuum gauge handy and then try driving up a hill where the load would be increased and see when it goes lean and try to have the power valve open just before that. Carbs should probably come with a 9.5 or 10.5 power valve instead of a 6.5. Then you get into air bleeds and squirters and the like to get everything where it performs the best. Same with timing, its very unlikely you engine likes anything near a stock amount of timing up front, fairly likely it will be in the 15-25 range from my experience, but this is an easy one to find at idle and then you can adjust the total in your e-curve distributor accordingly. That's a big advantage over a stock distributor.
If you go the Sniper route, you will spend a lot more time making a fuel system, since you really should have an in tank pump and a return system with a bypass regulator. Its significantly more up front effort than a carb fuel system since most of us can get by with the OE tank/line and just run a dead head on a mechanical pump, and maybe not need a regulator. Then you do the wiring. Once you get past that, I think you can close in on the tune to be driving in a satisfactory way a faster even with the autotune feature (but not going to say you won't be tweaking manually). I think you run the same distributor on both in this case since you have it and only have the sniper do fuel. So that won't change. I think you will pick up MPG with the sniper and the cold engine performance will likely be better but if that's not a concern no worries. It also costs money to do it.
You already spent the money so if you are really on the fence, maybe trying what you have already is the right move.
yellow rose
Overnight Sensation
Then don’t read it. A bunch of babies populate this place. That was a fact.
You and I are both old enough to remember the Cadillac V8-6-4. Remember it? Was that “technology”? No, it was ****. Some will say it lead to VVT like some use now, but it didn’t.it was produced because CAFE standards force the OE’s to do anything they could to try and get in line with a useless standard.
So not all “technology” is good, and not all of it even serves a purpose were it not for outside forces.
I’ll say it again...the EFI guys by FAR are the worst at sniveling about “technology” and all that. It gets old.
Hell, it wasn’t that long ago that KTM (the motorcycle company) was getting all the print media to pump up their “Formula One” technology they were using in their valve train. It was a finger follower and that’s about where the F1 analogy ended.
I ran into the editor of one of the rags at the Washougal Nationals and we were talking between moto’s. So I asked him how close the KTM valve train resembled F1 and he said honestly he didn’t know. That’s what KTM was telling everyone.
It goes on and on and will continue as long as people love to believe the lie.
yellow rose
Overnight Sensation
goldduster318
Overzealous Car Modifier
For the OP's sake and everyone else's, I don't want to turn this back in the wrong direction, but "You have to spend more time making a fuel system" and "It also costs money to do it" along with the time for wiring it are drawbacks. It's unfortunate the level to which you have to jump down everyone's throat if they disagree with you. I mean I even agree with almost everything in your post back there. If you just cut out the bloviating I think you can get to a fair answer for the person who asked the question. We know what technology you don't like, it's all on display here for everyone to read and decide how much they believe it.
There are dyno tests that I would say even accurately represent what most people are able or willing to do with a carb and they're +/- a few hp depending on which one even with a sniper vs a carb. The OP wants to enjoy his car not squeeze every last amount of ET out of it. It may never see a dyno. He just wants to get it running well and even I suggested that maybe starting with what he already purchased might be the right move. For example this one is particularly relevant for the original poster:
https://www.hotrod.com/articles/test-holleys-new-sniper-efi/
yellow rose
Overnight Sensation
I didn’t “jump down your throat”. I pointed out that you love to point out all the deficiencies of a carb, but you fail to ever address EFI issues.
And I don’t bloviate. That’s what you say when you disagree with what I’ve said.
Post 290 is the correct answer, and yet you are still crying about it.
goldduster318
Overzealous Car Modifier
I said that post was correct except for the last line because if anyone was actually honest that's just bitching and name calling. Then a few posts later you go right back to calling everyone a baby and going on a rant about something nobody asked about, or all the previous rants about CAFE. That's the bloviating.
The deficiencies of EFI is the difficulty in installation (Sniper is a lot easier than an MPFI due to being a contained unit), cost, and then if someone isn't too savvy with a computer or tuning in general to get the last bit of it out. There's effort there. Nearly none of us tune a carb fresh out of a box on a daily basis. This is why it's my belief that this is going to be simpler for the average person once the installation is done due to the auto tune and the setup wizard to get it "close" and then take it from there. Even some of us could help with what to change in the tune to get the last out of it thanks to the tune and datalogs being available. Maybe someone gets a better ET or a better dyno print out with a carb, cool if that's the most important thing for you. Just want to have an honest conversation about things given that most of us didn't spend our lives reworking carbs, especially the last 7-10 years the EFI stuff changed a lot and took it from being very difficult to being within reach for a lot of people. I suspect we go forward a few more and the difficulty will continue to drop. The sniper is a good value for someone that hasn't purchased anything yet. But the OP has a carb so he might make the best move by starting with that.
Again I did both carb and EFI on the same engine and that's my experience. Was barely any help on this board at the time about the carb because the average person never gets that deep into it. Literally people were just telling me to buy another off the shelf carb which is the one they have. That frustrates a lot of people. What I did learn and with that I could apply to the EFI the first day and then move from there to take out the things I didn't like with my carb. At the time I had never tuned an EFI system and I didn't even drive the car for 2 hrs working on it to get to to the level of the carb i had spent literal entire days tuning. It may be more difficult for others, I don't know. No regrets, but I spent a good deal of money to do it. Some people don't want that and I get it. If you want to pick apart my tuning advice today about the carb or distributor because you know better, go for it. I'm perfectly happy to admit if I did something wrong there and someone can learn from it. My opinion is that if money isn't an issue the EFI can be a good upgrade for someone's car they just like to drive. There are also others that it made a big difference for them.
I remember it very well. Total POS. I don't like any of that cylinder cancelling crap.
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