chevy 350 swap

[CherBear]

I had trouble with everything! Kidding... sorta. Michigan doesn't have any emission testing at this time. The only trouble I had was an O2 circuit (I run all four) problem which I fixed, and EVAP stuff which I am still working through. I am running single exhaust and a single cat so I am trying to figure out a way to program out one of the downstream O2 sensors and have the computer look for info from one. It stands to reason I will get slightly better fuel managment with one downstream O2 sensor making corrections. The EVAP stuff I don't think will be real bad I just haven't gotten around to it yet. Lots of info over here http://www.ls1tech.com/forums/conversions-hybrids-28/ A lot of 5.3L stuff comes up in there.

Have you tried wiring up the o2 circuit so that both receive input from the same sensor?
If im not mistaken the o2 sensor spits out a different voltage depending on the fuel/air mixture. So maybe you could just splice some wires together and hopefully it wouldn't change the voltage received by the engines computer.

Or you could always remove the CEL bulb :confused1

 

[Wow]

Otherwise you will just have some sloppy hill-billy install.

Most people prefer to go carb and sensorless for a conversion like this. There is nothing "sloppy hillbilly" about it.

 

[John D]

Most people prefer to go carb and sensorless for a conversion like this.

I would not agree with this at all. I think these days, with all the information available people tend to enjoy doing a fuel injected sensored conversion. I have done a few CJ swaps over the years with carburated engines and it seems like you are always tuning them. Not to mention stalling out constanly on steep climbs or off-camber climbs. My experience so far with computer controlled conversion is that once tuned it keeps itself tuned.

I think the people who shy away from a computer controlled conversion don't understand/are afraid of it. They should not be afraid of it, it does offer some challenges, but they can overcome them all. The Internet contains so much free information it just takes a little time to find it.

95% of my information came from here http://www.lt1swap.com/ This guy will tell you step-by-step how to build your harness. If you want him to do it, his price is unbeatable. I did my own and it wasn't too bad.

The other pieces of the puzzle came from http://www.ls1tech.com/forums/conversions-hybrids-28/ and http://www.hptuners.com/forum/

So I guess it's a federal offense then to put a V8 in an XJ, period. But then again, I don't care in the slightest...
(if someone calls the feds and says I took off my cat, I doubt they are going to come investigate)

No, it is perfectly legal to put a V8 into and XJ. The laws will vary from state to state, but there are minimum standards that must be met to be legal. A carburated, non-EGR, non-catted 1979 Chevy 350 would probably not pass in an '01 XJ because the '01 XJ had emmission standards that that engine would have difficuly reaching. On the other hand, if you used a Gen-III, catted and sensored 2005 5.3L your chances would likely go way up in reaching the standards. I know you probably don't care, I am putting this in here for the other people reading that are interested.

Have you tried wiring up the o2 circuit so that both receive input from the same sensor?
If im not mistaken the o2 sensor spits out a different voltage depending on the fuel/air mixture. So maybe you could just splice some wires together and hopefully it wouldn't change the voltage received by the engines computer.

Or you could always remove the CEL bulb :confused1

I will have to think about that. I know there's a solution, just have to find the right one. I like my light, best part of a computer controlled conversion it it tells you when its sick and almost tells you how to make it better.

 

[wolfpackjeeper]

John, there should be a way to tune one of the sensors out. What tuning software are you using? As long as you have an obd2 port you should be able to take it to any F-body shop and have them throw it on the dyno for a tune. Otherwise I hear LS1 edit is a great(expensive) program, and I was reading somewhere that Megatune will read and edit GM computers, however I am unsure on that.

 

[John D]

John, there should be a way to tune one of the sensors out. What tuning software are you using? As long as you have an obd2 port you should be able to take it to any F-body shop and have them throw it on the dyno for a tune. Otherwise I hear LS1 edit is a great(expensive) program, and I was reading somewhere that Megatune will read and edit GM computers, however I am unsure on that.

I am using HP Tuners. My original plan was to do all my own tuning, but the learning curve is beyond my available time. I found a place in Texas that will do a tune for my needs including removing one O2 sensor and collecting all the nessessary data off the single. They include a transmission tune and are claiming 30 rear wheel HP on 93 Octane and 1-4 mpg for 300 bucks. That is likely the way I will go.

 

[FlexdXJ]

I would not agree with this at all. I think these days, with all the information available people tend to enjoy doing a fuel injected sensored conversion. I have done a few CJ swaps over the years with carburated engines and it seems like you are always tuning them. Not to mention stalling out constanly on steep climbs or off-camber climbs. My experience so far with computer controlled conversion is that once tuned it keeps itself tuned.

I think the people who shy away from a computer controlled conversion don't understand/are afraid of it. They should not be afraid of it, it does offer some challenges, but they can overcome them all. The Internet contains so much free information it just takes a little time to find it.

95% of my information came from here http://www.lt1swap.com/ This guy will tell you step-by-step how to build your harness. If you want him to do it, his price is unbeatable. I did my own and it wasn't too bad.

The other pieces of the puzzle came from http://www.ls1tech.com/forums/conversions-hybrids-28/ and http://www.hptuners.com/forum/

THANK YOU! I hate the fact of people putting a dinosaur technology(yeah I said it) in a computer controlled vehicle. If this were an 84-86 XJ in question I would say carb it but anything newer than that needs to be computer controlled IMO. ProjectTK don't even bother to quote this because you bought yours and We all know it! I don't know the first thing about doing a conversion but I am not going to lie and say i did it!

 

[shelbyluvv]

I have, for example, a 1979 Chevy truck with the 350, and a RIDICULOUS emissions system. , even though I don't have a cat. (from the factory)

I thought cats were mandatory in 79? I know Dodge got away with it in 78 with the LRT because of a snafu in the law and some creative play. But, the following year (79) the laws were changed and the LRT was required to have cats.

Why would this Chevy be any different? What kind of truck is it? C/K 10 or 20?

 

[wolfpackjeeper]

John, are they gonna do a few dyno pulls for that price? If so its a pretty good deal, especially on a custom install. If not, and they are just going to install their homebrew setup(like a handheld tuner does), then I would try to find somewhere else.

Getting my SS camaro dyno tuned was one of the best mods I ever did, it really woke it up.

 

[John D]

John, are they gonna do a few dyno pulls for that price? If so its a pretty good deal, especially on a custom install. If not, and they are just going to install their homebrew setup(like a handheld tuner does), then I would try to find somewhere else.

Getting my SS camaro dyno tuned was one of the best mods I ever did, it really woke it up.

Yeah, they were just gonna email me the tune for that price. What did you have to pay for your "dyno tune"?

I never really considered doing it that way. I don't know why, I have read plenty about it. I guess when I decided I would buy a tune it was a time/convenience issue. Maybe I will try to find someone locally to go to.

 

[wolfpackjeeper]

I only paid $250 for a dyno tune. Then pull it once to get a baseline, then apply a general tune, pull it again, then fine tune it, then pull it a final time to make sure it looks good.

$300 for a tune emailed to you is a bit high in my opinion, but I may be way off base. If you look around at a few more shops you can probably come up with a better price. Ill shoot the place that tuned my camaro an email to see what they would run you for one emailed if you want.

 

[John D]

I only paid $250 for a dyno tune. Then pull it once to get a baseline, then apply a general tune, pull it again, then fine tune it, then pull it a final time to make sure it looks good.

$300 for a tune emailed to you is a bit high in my opinion, but I may be way off base. If you look around at a few more shops you can probably come up with a better price. Ill shoot the place that tuned my camaro an email to see what they would run you for one emailed if you want.

Yes please... 2005 5.3L/4L60E, LS1 intake and injectors, headers and single 3" exhaust. I will need one of the downstream O2 sensors removed and computer looking for only one. Would also like a minor trans tune included.

 

[Wow]

I thought cats were mandatory in 79? I know Dodge got away with it in 78 with the LRT because of a snafu in the law and some creative play. But, the following year (79) the laws were changed and the LRT was required to have cats.

Why would this Chevy be any different? What kind of truck is it? C/K 10 or 20?

It's a 1 ton. 9000# GVW.

All those freaking out about carbs really need to take your uneducated attitude to california where it belongs. If you want to go electric that's fine, but most people who swap 350s into things they never came in, choose carburetors, and that doesn't mean they're less efficient. This is a fact. People put 350s in everything from motorcycles to airplanes. They've even come up with conversion kits for the Gen III chevy engines that never came with carbs or distributors from the factory - now you can buy a carb intake and distributor to put on it.

You can absolutely bet, no matter how many sensors and cats you have, that 350 conversion would be illegal in california, PERIOD. Even a brand new, never used, manufactured in 2010 5.3L aluminum engine would not pass a CA inspection. I seriously doubt you'd get by the federal emissions laws either, if anybody checked. That's why all the fancy V8s you see for sale at Jegs and such say "for off road use only", even if they are FI.

 

[John D]

It's a 1 ton. 9000# GVW.

All those freaking out about carbs really need to take your uneducated attitude to california where it belongs. If you want to go electric that's fine, but most people who swap 350s into things they never came in, choose carburetors, and that doesn't mean they're less efficient. This is a fact. People put 350s in everything from motorcycles to airplanes. They've even come up with conversion kits for the Gen III chevy engines that never came with carbs or distributors from the factory - now you can buy a carb intake and distributor to put on it.

You can absolutely bet, no matter how many sensors and cats you have, that 350 conversion would be illegal in california, PERIOD. Even a brand new, never used, manufactured in 2010 5.3L aluminum engine would not pass a CA inspection. I seriously doubt you'd get by the federal emissions laws either, if anybody checked. That's why all the fancy V8s you see for sale at Jegs and such say "for off road use only", even if they are FI.

Talk about uneducated... they do all sorts of emission legal/tested swaps in California every day. Have you ever looked at a hotrod magazine? They do one almost every month, IN California. Have you ever read a 4X4 magazine? They are quite common in there too. There are laws and standards that if followed correctly can and will pass all emission tests. The reason the motors and aftermarket parts at Jegs and other places state "for offroad use only" is for liability reasons. They can't be sure what you're going to use it for. For all they know you may try to take one of their carburated 350's and put it into an XJ and they are quite sure it would not pass emissions.

I think this is what you are talking about http://www.streetrodderweb.com/tech/0910sr_ls1_carb_swap/index.html minus the distibutor, not sure what would drive your distributor on your idea. Anyway, reading through the article you can almost hear the writer's cynicism while explaining that someone could take a nice LS1 out of a salvage and then convert to a carb so they wouldn't have to deal with the difficulties that come from a newer technology motor -funny.

You my friend seem to be the only one freaking out about the carbs. But what do I know? I am uneducated...

 

[Wow]

You my friend seem to be the only one freaking out about the carbs. But what do I know? I am uneducated...

Like I said, if you want to go electric, that's fine. But to say a carb is "backyard hillbilly" as somebody else did is complete bullshit. Do you know how much time and R&D money went into developing a gen III carb intake/distributor and other complete stand alone non emissions equipment? They would not have done that if there wasn't a market for it. Kind of like how performance parts are extremely rare for an XJ as compared to a Chevy.

A properly tuned carbureted engine, with a modern carb, intake, exhaust, and fuel, can burn just as clean and get just as good of mileage as any FI engine. They both have their ups and downs. After I remove the emissions equipment and update the intake/exhaust from my 1979 350, I can guarantee you the engine will get better mileage, and run cleaner than it did, with that stupid 70s smog pump design and leaded fuel.

With the right setup, you could easily pass a sniffer test without so much as a cat. Usually it's the irrelivant inspection part that gets you.

 

[John D]

Like I said, if you want to go electric, that's fine.

You keep saying this, but I really don't understand it.

Do you know how much time and R&D money went into developing a gen III carb intake/distributor and other complete stand alone non emissions equipment? They would not have done that if there wasn't a market for it.

Actually businesses start everyday that have spent tons of money on R&D and fail because of a variety of reasons, but one reason that comes around a lot is underestimating the market they are trying to tap.

Kind of like how performance parts are extremely rare for an XJ as compared to a Chevy.

What are you trying to compare here?

 

[FlexdXJ]

All those freaking out about carbs really need to take your uneducated attitude to california where it belongs.

Ok, First of carbs are finicky and need lots of adjustment compared to FI where the computer compensates for everything. This in turn makes for better fuel atomization which leads to less fuel consumption all while making MORE power! Most V6's now make way more horsepower than any carbed 350 every made from the factory. So you sir are the uneducated one! In older vehicles I find nothing wrong with putting a carbed engine in it but not on any car I'll build! I like driving my project not letting it sit!

 

[JJacobs]

Like I said, if you want to go electric, that's fine. But to say a carb is "backyard hillbilly" as somebody else did is complete bullshit. Do you know how much time and R&D money went into developing a gen III carb intake/distributor and other complete stand alone non emissions equipment? They would not have done that if there wasn't a market for it. Kind of like how performance parts are extremely rare for an XJ as compared to a Chevy.

A properly tuned carbureted engine, with a modern carb, intake, exhaust, and fuel, can burn just as clean and get just as good of mileage as any FI engine. They both have their ups and downs. After I remove the emissions equipment and update the intake/exhaust from my 1979 350, I can guarantee you the engine will get better mileage, and run cleaner than it did, with that stupid 70s smog pump design and leaded fuel.

With the right setup, you could easily pass a sniffer test without so much as a cat. Usually it's the irrelivant inspection part that gets you.

:bs: on that whole post.

 

[Wow]

You keep saying this, but I really don't understand it.

I'm not telling you you shouldn't be using FI, nobody should be telling me I shouldn't use a carb.

Ok, First of carbs are finicky and need lots of adjustment compared to FI where the computer compensates for everything.

LOL! My XJ has been parked for 3 months because the sensors will not allow it to start. If it had a carb all I'd need is a can of starting fluid. There is way more to go wrong on a computer controlled vehicle than an all mechanical one.

Most V6's now make way more horsepower than any carbed 350 every made from the factory.

Not talking about any factory engine. Yes, my POS 1979 350 came with 175hp from the factory. That's the HO truck version. With a MODERN CARB, MODERN INTAKE, and MODERN EXHAUST, like I already said 40 times, will nearly double the HP, increase gas mileage, and reduce emissions.

I will not continue to argue about carbs with people who do not understand them. I would not expect to find much carburetor knowledge on this board, considering XJs have been FI nearly forever and most of you aren't old enough to drink yet...

 

[wolfpackjeeper]

I know about carbs, and I have been drinking legally for a few years now, and I am one of the younger people on this board. I am not telling you not to use a carb, I don't care. But The subject was brought up in regards to what you would swap in given the chance. That being said:

I seriously doubt that just adding a modern card, intake, and exhaust will Double the HP. That would put you above the numbers I got on my LS1 with long tubes, intake, lid, filter, and mild tune.

There is nothing magical about carbs. If there were they would still be in widespread use today. FI will always be cleaner, and more efficient. It is for sure more flexible.

 

[John D]

Where I live if you have a pre OBD-II computer, they just put the sniffer in your tailpipe. You can pass with a carbed V8 as long as it's running efficiently enough to pass and you have a cat installed, which isn't hard these days. They don't check under the hood, they only use a mirror to look for the cat. I recently got an address outside the emissions boundry here and my first project is to remove all the emissions crap from my vehicles.

An all aluminum 330+hp 5.3L engine would be SO sweet in an XJ...

(import one of those 4 cylinder "Super Cherokees" from China and drop a 5.3L in it.....oh my god that would be cool)

This was your first post into this thread.

After that I offered an argument that emissions are a good thing and since then you continue to throw out baseless untrue statements.

You have been wrong on everything you have posted in this thread, please stop. People are going to search and discover this thread. Some of them will be just learning and will not be able to know the difference between what is true and what is not. The information you continue to offer could confuse them and possibly cost them money doing the wrong things.

I know your feelings are hurt, but you are wrong. Just suck it up and go.
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