- Thread starter
- #161
Awesome! I'm sure that will save me some research. Thank you for sharing.
Builds '73 FJ40 rebuild - family wheeler (1 Viewer)
- Thread starter CreeperSleeper
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POTATO LAUNCHER
TLCA #6928
If you are using stock slave make sure you have the cast arm with two holes on the end. . The stamped piece does not allow enough stroke.
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- #163
Great reminder. Thank you! I *THINK* that is what I currently have from when the SM465 was mated to my F motor. I do need to dig that out of whatever box I put it in and double check.
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- #164
Wow, this just shows how little I have been working on this thing... :shaking: Big changes have happen in both my job and at home, so the 40 got placed on the back burner. That will change soon, though! I need wrench therapy. The engine is almost ready to be mated up to the rest of the drive train, so I will get some pics up soon.
I do have a questions that I have been pondering and I figured I would ask for some advice. The SBC I bought for my 40 came with the 1st generation, analog Holley Pro-Jection. Everyone knows that injection system is very hard to tune and kinda sucks, but it is fuel injection. My question is do I spend the extra money and time to get the Pro-Jection dialed in as best I can or do I sell it and buy a Truck Avenger carb (which I have had very good luck with in the past)?
Pros for Pro-Jection:
* Fuel injected (quick starts and no stalling)
* Fuel system would already be set up for TBI (for when I upgrade)
Cons for Pro-Jection:
* Need to put an O2 sensor in the exhaust
* Very hard to tune and set up right
* Fuel system will be expensive to plumb up (EFI lines, special pump, special filter, etc.)
* Wiring... Oh the wiring...
Pros for Truck Avenger:
* Very simple to set up and work on
* Very little wiring
* Less expensive fuel system with more parts availabity
Cons for Truck Avenger:
* Won't run as good on angles as FI
* Not as cool as FI
What do you guys think I should do? Huh As a reminder, this is a 1976 4-bolt main 350 with stock heads, Edelbrock Performer manifold, block hugger headers, and a big ol cam.
I do have a questions that I have been pondering and I figured I would ask for some advice. The SBC I bought for my 40 came with the 1st generation, analog Holley Pro-Jection. Everyone knows that injection system is very hard to tune and kinda sucks, but it is fuel injection. My question is do I spend the extra money and time to get the Pro-Jection dialed in as best I can or do I sell it and buy a Truck Avenger carb (which I have had very good luck with in the past)?
Pros for Pro-Jection:
* Fuel injected (quick starts and no stalling)
* Fuel system would already be set up for TBI (for when I upgrade)
Cons for Pro-Jection:
* Need to put an O2 sensor in the exhaust
* Very hard to tune and set up right
* Fuel system will be expensive to plumb up (EFI lines, special pump, special filter, etc.)
* Wiring... Oh the wiring...
Pros for Truck Avenger:
* Very simple to set up and work on
* Very little wiring
* Less expensive fuel system with more parts availabity
Cons for Truck Avenger:
* Won't run as good on angles as FI
* Not as cool as FI
What do you guys think I should do? Huh As a reminder, this is a 1976 4-bolt main 350 with stock heads, Edelbrock Performer manifold, block hugger headers, and a big ol cam.
Pro jection FI system is stupid easy to plumb. it's low(er) pressure than modern motors. O2 sensor in the exhaust? Is that necessary for the first gen projection? either way, that's a simple thing again. $20 at an exhaust shop.
Wiring is dirt simple as well. There are almost no sensors..
They never run perfectly, but does this rig ever have to pass emissions?
Wiring is dirt simple as well. There are almost no sensors..
They never run perfectly, but does this rig ever have to pass emissions?
buy a carb. I utterly loathe the pro-jection. I tried it on a couple different rigs and in both cases the system required constant tuning. It's not a closed-loop system. That means that you set the system up for the weather and altitude as you drive it.... you think texting a driving is bad? try tuning a pro-jection while you're driving. It really does take two people to make it run right.
If you want EFI (and I can't think of a reason why you wouldn't), get the Howell EFI wiring harness and a GM computer. Costs about $500 for all of it and you can use the Holley TBI.
If you want EFI (and I can't think of a reason why you wouldn't), get the Howell EFI wiring harness and a GM computer. Costs about $500 for all of it and you can use the Holley TBI.
- Thread starter
- #167
@Mace, the rig will never have to go through emissions. It is on special interest plates. As for the O2 sensor, I don't think it is required but it makes it a lot easier to tune and keep in tune. But you think the analog Pro-Jection would be better than a Truck Avenger?
@SuperBuickGuy, I want EFI. I just don't know if I want THIS FI! I don't have a ton of $$ to throw at this thing, so cost is a big part of it, too. I don't have an extra $500 to modify the Holley TBI.
@SuperBuickGuy, I want EFI. I just don't know if I want THIS FI! I don't have a ton of $$ to throw at this thing, so cost is a big part of it, too. I don't have an extra $500 to modify the Holley TBI.
$250 for a carb, $80 for a fuel pump.... you're already most of the way there. Yet that was the point, carb or modify the efi; don't use the Pro-jection.
also, you don't have to buy the wiring harness - you can modify a harness from either 87 up v8 Caprice (or similar) or 87-95 Chevy truck and do it all old-school, junkyard style... the money part simply saves time and testing.
also, you don't have to buy the wiring harness - you can modify a harness from either 87 up v8 Caprice (or similar) or 87-95 Chevy truck and do it all old-school, junkyard style... the money part simply saves time and testing.
- Thread starter
- #169
Right, but if I go with the carb I can sell the Projection to make some money back. I could sell the Projection and make a junkyard TBI, but I don't know if I'm smart enough to do that! LOL
Lets see,
Pick up the motor and leave the projection on. Doesn't ever really run right, but it'll run upside down. You have to wire it and plumb the fuel system for a TBI system. Later you decide to replace the Projection system with either a Junkyard TBI system or simply throw away the Projection computer and run a MEgasquirt controller on the holley TBI unit. Done..
Or, $500 (ish) for a truck avenger, buy a different fuel pump and watch it stumble on hills. It'll never really run right cause you won't put the effort into it because it'll go fuel injection one day anyway.. Then, when you want to do a TBI unit, you have to modify the fuel system and buy another fuel pump.
Truck avenger will never run at angles as well as a TBI unit will. The 2D projection will be finicky.. but it's a step towards your ultimate goal. The carb is a step backwards..
Pick up the motor and leave the projection on. Doesn't ever really run right, but it'll run upside down. You have to wire it and plumb the fuel system for a TBI system. Later you decide to replace the Projection system with either a Junkyard TBI system or simply throw away the Projection computer and run a MEgasquirt controller on the holley TBI unit. Done..
Or, $500 (ish) for a truck avenger, buy a different fuel pump and watch it stumble on hills. It'll never really run right cause you won't put the effort into it because it'll go fuel injection one day anyway.. Then, when you want to do a TBI unit, you have to modify the fuel system and buy another fuel pump.
Truck avenger will never run at angles as well as a TBI unit will. The 2D projection will be finicky.. but it's a step towards your ultimate goal. The carb is a step backwards..
- Thread starter
- #171
That is a very good point, Mace. Originally my thought was to someday replace this motor with an LS, so I would be changing everything anyway. However, for how slow I'm going on this thing that may never happen! I think the amount of money I'm going to spend will be a wash for either choice. It just comes down to which "never runs quite right" is a better option... I never thought about swapping just the injection later on down the road.
Tons of good info on the Projection system.
Calling out Holley tbi guru's need help please [Archive] - International Full Size Jeep Association
Calling out Holley tbi guru's need help please [Archive] - International Full Size Jeep Association
Have you considered propane? I am kicking the idea around of swapping my 40 to full time propane and my j55 to dual fuel. It is just hard for me to pull the trigger right now since gas prices are so low.
You know I have no problem helping you through the issues of running EFI... I go to Portland often enough to visit the parents (Oregon City) that it wouldn't be a big deal...
I'd avoid propane, though, because it's such a pain to get the tank filled, gets worse fuel economy, makes less power, and takes what little space you have for the tank....
If I were running a rock buggy or a dedicated trail rig - propane is pretty cool; but one of its major benefits - the decreased wear and tear on a motor - simply doesn't make any fiscal sense in something that might do 10,000 miles over the course of its existence... even if it doubled the life-expectancy of the motor (60%, meaning you get 160,000 miles out of a motor that would get 100,000 miles on unleaded) doesn't help you when it costs less than $500 to completely go through a SBC...
I'd avoid propane, though, because it's such a pain to get the tank filled, gets worse fuel economy, makes less power, and takes what little space you have for the tank....
If I were running a rock buggy or a dedicated trail rig - propane is pretty cool; but one of its major benefits - the decreased wear and tear on a motor - simply doesn't make any fiscal sense in something that might do 10,000 miles over the course of its existence... even if it doubled the life-expectancy of the motor (60%, meaning you get 160,000 miles out of a motor that would get 100,000 miles on unleaded) doesn't help you when it costs less than $500 to completely go through a SBC...
It also allows greater angles and if dual fuel it is makes sense to run a smaller propane tank and use gas to get to the trail and switch to propane while on the trail. It sounds like his SBC may have a fair amount of compression so a timing controller to advance a few degrees could restore some of the power loss. Also carb/ propane is easy to work on and could possible be more reliable. That said if you have the coin FI is the way to go.
I had a 75 Chevy pickup that was an old utility truck when I lived in Reno that was propane powered. Prior to EFI, it was the snizzle.... now it's just a drizzle. It is so cheap to do EFI anymore that even carbs are pretty expensive comparatively speaking. The best part of EFI is it becomes such a selling point that even if you have 4x the money (I say it costs $250 to put a carb on) that you'll get it all back when you sell it and it will net you at least a 5% and up to a 20% gain in fuel economy... even at cheap gas that's not bad.
And I'll say it again, the schematics and the donor rigs are so plentiful that there isn't a better time to jump into the EFI pool.
And I'll say it again, the schematics and the donor rigs are so plentiful that there isn't a better time to jump into the EFI pool.
Propane is a cheap and functional fuel system. If you can deal with the tank concerns (weekend worth of wheeling on a couple forklift tanks) it works great. If You optimize the motor for propane there is no power loss. It's cheap, functional, and cool. But does have limitations.
Again, bolt on the projection, and go wheeling till you want it better..
Again, bolt on the projection, and go wheeling till you want it better..
optimize the motor for propane? do tell, how will you do that for less then the $500 difference between carb and EFI? a propane system costs at least $1600 by the time it's bought and installed. Then you have to "optimize the motor."
As I'm sure the story is next to those $300 axles you've mentioned to me before, I just can't wait to hear how you manage to "optimize" propane when it has 1/3 less energy per unit of fuel... is pixie dust involved?
OP - whatever you do, don't use the holley pro-jection; it's a trail of tears an optimized carb is much better. heck, and you don't have to trust some random guy on the internet - my dad lives fairly close to you - you can go ask him what happened with mine, he was there for the install and removal.
As I'm sure the story is next to those $300 axles you've mentioned to me before, I just can't wait to hear how you manage to "optimize" propane when it has 1/3 less energy per unit of fuel... is pixie dust involved?
OP - whatever you do, don't use the holley pro-jection; it's a trail of tears an optimized carb is much better. heck, and you don't have to trust some random guy on the internet - my dad lives fairly close to you - you can go ask him what happened with mine, he was there for the install and removal.
I think he is referring to higher compression and advancing the timing for propane. Also a factor is the price of propane when gas prices are high. It is usually as much as a dollar cheaper per gallon. Not right now though. Gas is cheap and I love it.
