Chevy questions

[Petescj]

Ive pretty much decided to go with the Chevy 350 in my Limited now. The question now is what I should be looking for. I want a fuel injected 350 with plenty of grunt low in the rpm range. It needs to bolt directly to my SM465. Year ranges and specifics would be much appreciated. Im here enough I dont have time to search a bunch of Chevy forums. Heres an example of what I found on Craigslist:

Chevy350 fuel injected

 

[Scooter402]

You're definitely on the right path there. Literally any of the GM injected engines will bolt up to your Transmission . The issue comes in with the LQ4/9 truck engines (basically any "LS" type engine), as I believe there is some adaptation (i.e. crank spacers, possibly a special clutch? Not terribly sure there, as I have never participated in an LSx retrofit) to to either a torque converter or clutch.

I have heard about issues (again, never personally had any problem here) with the later model (95-98) vortec truck engines with the spider injection manifold, that they have a relatively crappy design on the spider injectors, and that their poppets get carbon deposits in them due to their design and proximity to the intake valve. There is a fix for them, though. The fix is putting a different spider injector unit with I believe a typical 4 pintle injector in them.

Engines like the one you have posted (Looks to me to be an LT1) is definitely a good choice. They can have issues with their Optispark distributors, especially if the water pump springs a leak, since the Optispark is driven off the water pump, which I think is driven by the camshaft.

Other torquey options would be a TPI 350, commonly found in corvettes. Be careful if you search for one of these, though, because the vast majority of TPI engines available are 305s from Camaros.

Another strong engine would be any of the TBI 350s from trucks. Especially if you put an EFI/RV cam in them, and possibly install headers. That would be the first thing I would do to any of the above, though...do a mild cam swap and headers. Always good for a little more grunt.

I could go on for days here, so I'll be glad to help any way I can. I guess the main choice to make is to decide if you want a TBI or MPFI engine. Then narrow it down from there. TBI leaves many fewer choices than MPFI, but there are potential advantages to them all.

 

[Old Dog]

The easiest & cheapest way would be The late 80's tbi it was obd1 so pretty simple to wire.
The early 90's (?) tuned port can be wired without to much trouble.
thisguyuknow has a post on doing tuned port on his 360. http://www.jeep-cj.com/forums/f2/junkyard-tuned-port-injection-amc-360-a-20171/
There's a lot of info out there about using the newer LS motors :drool: but that's going to cost more bucks.

 

[Petescj]

You're definitely on the right path there. Literally any of the GM injected engines will bolt up to your Transmission . The issue comes in with the LQ4/9 truck engines (basically any "LS" type engine), as I believe there is some adaptation (i.e. crank spacers, possibly a special clutch? Not terribly sure there, as I have never participated in an LSx retrofit) to to either a torque converter or clutch.

I have heard about issues (again, never personally had any problem here) with the later model (95-98) vortec truck engines with the spider injection manifold, that they have a relatively crappy design on the spider injectors, and that their poppets get carbon deposits in them due to their design and proximity to the intake valve. There is a fix for them, though. The fix is putting a different spider injector unit with I believe a typical 4 pintle injector in them.

Engines like the one you have posted (Looks to me to be an LT1) is definitely a good choice. They can have issues with their Optispark distributors, especially if the water pump springs a leak, since the Optispark is driven off the water pump, which I think is driven by the camshaft.

Other torquey options would be a TPI 350, commonly found in corvettes. Be careful if you search for one of these, though, because the vast majority of TPI engines available are 305s from Camaros.

Another strong engine would be any of the TBI 350s from trucks. Especially if you put an EFI/RV cam in them, and possibly install headers. That would be the first thing I would do to any of the above, though...do a mild cam swap and headers. Always good for a little more grunt.

I could go on for days here, so I'll be glad to help any way I can. I guess the main choice to make is to decide if you want a TBI or MPFI engine. Then narrow it down from there. TBI leaves many fewer choices than MPFI, but there are potential advantages to them all.

I believe I'll be picking your brain on this. We may have to set up a Saturday for me to stop by and talk Jeep/Chevy

The easiest & cheapest way would be The late 80's tbi it was obd1 so pretty simple to wire.
The early 90's (?) tuned port can be wired without to much trouble.
thisguyuknow has a post on doing tuned port on his 360. http://www.jeep-cj.com/forums/f2/junkyard-tuned-port-injection-amc-360-a-20171/
There's a lot of info out there about using the newer LS motors :drool: but that's going to cost more bucks.

Wht did yours come out of? The LS isnt in my future.

 

[Petescj]

This is a good running Chevy 350. 5.7 liter from a 1992 Buick road master with 94000 miles on it. It comes with all the accessories shown. I can load it in your truck. $600


Saved the pic and text from the ad

 

[Old Dog]

Pete, Mine is a crate motor from Jegs. I was going to run a carb and I figured it was almost as cheap as a rebuild.
The carb failed offroad so I went Howell tbi. Should have just looked for a good tbi truck motor to start with.

 

[tarry99]

Ive pretty much decided to go with the Chevy 350 in my Limited now. The question now is what I should be looking for. I want a fuel injected 350 with plenty of grunt low in the rpm range. It needs to bolt directly to my SM465. Year ranges and specifics would be much appreciated. Im here enough I dont have time to search a bunch of Chevy forums. Heres an example of what I found on Craigslist:

Chevy350 fuel injected

My Choice would be an Early 90's TPI tune ported 5.7 ( speed Density ) Corvette motor. It has one of the best platforms for a Jeep both on and off the road............250 Hp and 350 Ft lbs of table flat torque right off Idle............The factory tube headers are tight to the motor and fit right in between the rails of a Jeep. The conversion in the Jeep is about 500 + lbs lighter than in the Corvette where they have been known to get 25 Mpg with exceptional torque.........these motors have factory aluminum heads and were built that way during a time period that GM was having average fuel mile issue's with the Government. Not the fastest Corvette motor built but perfect for this application whereby most want something easy on fuel but still has a bunch of low rpm torque...........make sure you get a complete motor wiring harness ........although the factory ECM is not that important as there are aftermarket one's that are more easily tunable.

 

[Scooter402]

I believe I'll be picking your brain on this. We may have to set up a Saturday for me to stop by and talk Jeep/Chevy

No problem!

By the way, here's the Corvette TPI setup I mentioned earlier, as well as tarry99 had. This was in my CJ7 years ago, but on a 383 stroker. I'd do it again, but my heads won't directly allow it...I've got to cook up something a little different if/when I go back to EFI.

 

[Petescj]

Pete, Mine is a crate motor from Jegs. I was going to run a carb and I figured it was almost as cheap as a rebuild.
The carb failed offroad so I went Howell tbi. Should have just looked for a good tbi truck motor to start with.

Ahh I see. This is pretty much why I sarted this thread. Id like to get it right the first time. Not saying I will , Id just like to.

My Choice would be an Early 90's TPI tune ported 5.7 ( speed Density ) Corvette motor. It has one of the best platforms for a Jeep both on and off the road............250 Hp and 350 Ft lbs of table flat torque right off Idle............The factory tube headers are tight to the motor and fit right in between the rails of a Jeep. The conversion in the Jeep is about 500 + lbs lighter than in the Corvette where they have been known to get 25 Mpg with exceptional torque.........these motors have factory aluminum heads and were built that way during a time period that GM was having average fuel mile issue's with the Government. Not the fastest Corvette motor built but perfect for this application whereby most want something easy on fuel but still has a bunch of low rpm torque...........make sure you get a complete motor wiring harness ........although the factory ECM is not that important as there are aftermarket one's that are more easily tunable.

Thats the kind of torque Im talking about. That frees up my AMC20 for my Jeep trailer. Im not sure the 500 lbs will account for the slight aerodynamic differences between the Cj and the Corvette but if I got 20 mpg out of a V-8 Cj Id be more than happy. I just wonder about the availability and pricing of them.

No problem!

By the way, here's the Corvette TPI setup I mentioned earlier, as well as tarry99 had. This was in my CJ7 years ago, but on a 383 stroker. I'd do it again, but my heads won't directly allow it...I've got to cook up something a little different if/when I go back to EFI.

Mmmmm that looks good. This is something I definately have to look into. Im sure the TBI is easier and probably cheaper though. Im planning on grabbing a engine from my income tax check so I have some time to think.

 

[harleydragon]

I can see where fuel injection would be better for steep inclines and for fuel mileage.My driving includes mud and the street so I prefer carbs for several reasons.
I understand them better..
I can wire them in about 30 minutes for about 5 bucks..
they are simple and fairly inexpensive to build to any power level I want..

In the past year I replaced the headers on both my CJ7 /350's with mid 60's style corvette ramhorm manifolds w/2 1/2" outlet.they solved any clearance problems,blown gaskets,burnt plug wires and tremendously reduced the temp under the hood.Since I don't run at full throttle I have noticed no difference in power.Another plus is you can find them,new on ebay for about $125

 

[Petescj]

I can see where fuel injection would be better for steep inclines and for fuel mileage.My driving includes mud and the street so I prefer carbs for several reasons.
I understand them better..
I can wire them in about 30 minutes for about 5 bucks..
they are simple and fairly inexpensive to build to any power level I want..

In the past year I replaced the headers on both my CJ7 /350's with mid 60's style corvette ramhorm manifolds w/2 1/2" outlet.they solved any clearance problems,blown gaskets,burnt plug wires and tremendously reduced the temp under the hood.Since I don't run at full throttle I have noticed no difference in power.Another plus is you can find them,new on ebay for about $125

I see where your coming from. Im just not much of a mud runner. I want the fuel injection for my long term plans down the road. This Cj is going to be with me quite awhile and once my kids are out Im planning some long distance trips.

 

[Petescj]

I didnt think Id be able to find a Corvette engine like the one stated by Scooter and Tarry but low and behold...

Parting Out 1991 C4 Corvette Coupe

Hopefully I can find something similar around Income Tax time.

 

[Scooter402]

Nice...they're not impossible to find, I'm sure a little digging would produce some good results. With mine, I was doing an EFI swap on an existing engine, and most of the TPI units/manifolds/whatever was off of 305 engines. I believe all the manifolds and runners are the same parts, but the ECMs and injectors are different. I'm pretty sure the throttle bodies are the same too, with 305 vs 350. But like stated earlier -- I would get a MAP sensor/speed density unit vs. one with a MAF. They're more easily tuneable, and they look cleaner upon installation.

 

[Petescj]

I would get a MAP sensor/speed density unit vs. one with a MAF. They're more easily tuneable, and they look cleaner upon installation.

I was gonna google the difference but I figure I'll just ask so others can learn from my stupidity. MAP / MAF? When I started this train of thought I was thinking TBI cause it would be easiest for me to wrap my small brain around. School is in session.

 

[Scooter402]

In a nutshell:

The MAP TPI is a speed density system, which references the MAP sensor (Manifold Absolute Pressure) and a VSS (vehicle speed sensor). The TPI system I had posted a pic of that was in my CJ is a MAP setup. The sensor is bolted to the firewall with a vacuum hose running to it. They are more easily tuneable, can make greater changes to the ECM when you do cam swaps, head swaps, etc. It bases its tuning off of manifold vacuum at idle and under load.

This is a MAF system:


The plastic tube is the MAF (Mass Air Flow sensor). It has a heated filament that measures air flow. These can be temperamental in dusty environments (a.k.a pretty much near any Jeep I know of ). They aren't as kind to changes in intake air volume/velocity, as they base fuel timing maps off of the MAF sensor. So cylinder head swaps, displacement changes, cam swaps, etc. etc. are a little more tricky with this. Not to mention you have to find a spot in tight engine compartments to plumb in the MAF sensor a particular distance from the throttle body. These unfortunately can't be plumbed in just anywhere they fit. I don't recall directly whether or not the MAF system references a VSS.

Another difference, if I remember correctly, is the cold start enrichment circuit. The MAP system uses intake air temp and manifold pressure to richen the fuel on cold starts. The MAF system actually has a "9th" injector in the lower plenum.

All in all, I believe the MAP (speed density) system is much easier and cleaner upon install.

I do have a TPI swap guide somewhere amongst all my piles of , if I can find it. I just moved, so it might take me a minute to find it. If you would like, if you decide you want to move forward with the TPI swap, I'll be more than happy to slap a stamp on it and drop it in the mailbox. I also probably have a select few EFI parts laying around, should anyone need them. Off the top of my head, I do have an extra set of fuel rails and a working VSS that adapts to the speedometer drive cable.

 

[Old Dog]

I was gonna google the difference but I figure I'll just ask so others can learn from my stupidity. MAP / MAF? When I started this train of thought I was thinking TBI cause it would be easiest for me to wrap my small brain around. School is in session.

That's why I went tbi, it's the easiest. I'm old and haven't kept up with all the newer stuff. ( I know it's 20 years old now )
I have a O2 sensor
coolant sensor
Throttle position sensor
MAP sensor
No vss or other stuff like that.
My HEI is not run by the computer.
It's been one of the best up-grades I've done. Would tpi be better? I'm not sure it would make a lot of difference on the trails I run. I know it will stay running at 90* either up, down or to the side..

 

[tarry99]

In a nutshell:

The MAP TPI is a speed density system, which references the MAP sensor (Manifold Absolute Pressure) and a VSS (vehicle speed sensor). The TPI system I had posted a pic of that was in my CJ is a MAP setup. The sensor is bolted to the firewall with a vacuum hose running to it. They are more easily tuneable, can make greater changes to the ECM when you do cam swaps, head swaps, etc. It bases its tuning off of manifold vacuum at idle and under load.

This is a MAF system:


The plastic tube is the MAF (Mass Air Flow sensor). It has a heated filament that measures air flow. These can be temperamental in dusty environments (a.k.a pretty much near any Jeep I know of ). They aren't as kind to changes in intake air volume/velocity, as they base fuel timing maps off of the MAF sensor. So cylinder head swaps, displacement changes, cam swaps, etc. etc. are a little more tricky with this. Not to mention you have to find a spot in tight engine compartments to plumb in the MAF sensor a particular distance from the throttle body. These unfortunately can't be plumbed in just anywhere they fit. I don't recall directly whether or not the MAF system references a VSS.

Another difference, if I remember correctly, is the cold start enrichment circuit. The MAP system uses intake air temp and manifold pressure to richen the fuel on cold starts. The MAF system actually has a "9th" injector in the lower plenum.

All in all, I believe the MAP (speed density) system is much easier and cleaner upon install.

I do have a TPI swap guide somewhere amongst all my piles of , if I can find it. I just moved, so it might take me a minute to find it. If you would like, if you decide you want to move forward with the TPI swap, I'll be more than happy to slap a stamp on it and drop it in the mailbox. I also probably have a select few EFI parts laying around, should anyone need them. Off the top of my head, I do have an extra set of fuel rails and a working VSS that adapts to the speedometer drive cable.

Scooter......all good points.........and correct me if I'm wrong but for the layperson here including myself ..........Not all 5.7 TPI systems are " Speed Density" some years were built using the Speed Density logs while other years used the direct MAF system built into the air intake track.........not to be confused as they are separate and distinct systems.............
The big difference between the two is that the speed Density system use's predetermined values embedded in the computer data base to make fuel adjustments while the MAF system gets it's information in real time via a sensor mounted inside the air intake track in front of the motor..........both work almost the same.......and the discussion about which is best will go on forever..........but because you need a long air intake track to have the MAF sensor mounted in they are not a good donor motor for a swap in a Jeep or street rod.......simply because of the lack of room needed upfront.
1990 and 91 Corvette motor's were Speed Density........years before and after used the MAF system........so you need to make sure what your buying.

And I would love to see that book / guide your talking about. Thanks

 

[Petescj]

I think Im leaning back toward the T.B.I.

 

[Petescj]

I re read a few posts now. Are we saying that the 90 / 91 Corvette is the one I want? If so Id try and work something out to grab the one I posted earlier.

 

[Scooter402]

Scooter......all good points.........and correct me if I'm wrong but for the layperson here including myself ..........Not all 5.7 TPI systems are " Speed Density" some years were built using the Speed Density logs while other years used the direct MAF system built into the air intake track.........not to be confused as they are separate and distinct systems.............
The big difference between the two is that the speed Density system use's predetermined values embedded in the computer data base to make fuel adjustments while the MAF system gets it's information in real time via a sensor mounted inside the air intake track in front of the motor..........both work almost the same.......and the discussion about which is best will go on forever..........but because you need a long air intake track to have the MAF sensor mounted in they are not a good donor motor for a swap in a Jeep or street rod.......simply because of the lack of room needed upfront.
1990 and 91 Corvette motor's were Speed Density........years before and after used the MAF system........so you need to make sure what your buying.

And I would love to see that book / guide your talking about. Thanks

Tarry,

All good points. I am nearly a decade removed from my research/work with these EFI systems, so my memory could be getting garbled... I was going purely off of memory when posting above. I'll have to take a look through my TPI manual to confirm or deny anything I had posted. I do know that you are correct with few years being Speed Density (MAP) systems. I also agree that the MAF was not speed density. The street rod/jeep/whatever else swap comment is exactly why I went with the MAP system.

On a side note, I did locate my TPI book. I'll see if it will be too much of a pain to scan/e-mail or photocopy, or just mail it to you. At any rate, I could scan a couple factual pages and post them up here if there is any interest.