Pontiac V8 + LS1 EFI. Feasible?
04-10-2016, 10:46 PM
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Pontiac V8 + LS1 EFI. Feasible? A few disclaimers, first:
One, yes, I know, you could just put an LS into (whatever. Anything. Everything)
Two, yeah, I know, Pontiac V8's have a lot less support than Chevy stuff. Chevy stuff would be easier - and I should probably just put an LS in it.
Three, yeah, I know, carbs can do everything that EFI can do and make you more attractive to sexual partners at the same time.
Those out of the way, here's what I'm thinking:
Sequential fuel injection with coil-near-plug ignition offers a lot of drivability, reliability, economy and power improvements over anything I'm likely to accomplish via carb. Honestly, I'm 32 and haven't yet bothered to learn how to tune a carb. Now, why not buy an LS engine and put it in? Well, the engine (fully dressed) would run me $700. Add an oil pan to make it fit, conversion mounts for the engine, possibly an intake & accessory drive change, either a new trans & drive shaft or an adapter to go from LS to BOP... it's adding up quickly, isn't it?
So, the compromise: put modern management onto an old Poncho.
The Generation III LS motors need just a handful of things to run with factory style injection. Well, ok, maybe a few more than a handful.
Crank signal - where's the crankshaft?
Cam signal - where's the cam?
Coolant temp - how hot is "hot", anyway?
Idle air controller - keeps it running "goldilocks" RPM
Throttle position sensor - how fast do you want to go?
Intake air temp - cold air burns better
Mass airflow sensor - more air more power
Manifold absolute pressure sensor - this one does stuff, too.
I think that's all of them. I've also got a pissed off toddler in the house so I could be wrong. I could be wrong even when he's in a good mood, though, so maybe I shouldn't blame the kid.
Update: it was probably a poopy diaper. Everything's cool now.
Back to EFI.
Knock sensors are optional but included from factory. I'd ditch them, probably.
So, the IAC + TPS can be taken care of on a universal 4-barrel style throttle body. Coolant temp is just an adapter fitting away from using a factory LS unit. Factory MAP, I'm sure, can be made to work. I think it has the IAT integrated into it, though I don't recall. Maybe machine a flat spot on a Pontiac EFI intake drill two holes, tap one - worst case scenario. MAF is external and, really, a good speed density tune works really well. Hell, Chrysler doesn't run MAF sensors at all.
Firing order can be changed with wiring. Let the computer think whatever it's going to think, but let the Pontiac cam decide the firing order & change wires so they fire according to the cam.
This leaves the crank & cam signals to work out.
Gen III LS cam signal is a hi / lo signal. The sensor picks up the presence or absence of a machined half-moon rib of steel as it spins past, riding the camshaft or (in later engines) the cam timing sprocket. I think what'd work here is to run an LS2 (timing cover mounted, shorter than LS1) cam sensor mounted in a modified distributor cap, with a half-moon machined into a steel disc mounted to the distributor shaft.
The crank signal is potentially a bit trickier. Gen III uses a 24 tooth reluctor. This works out to a tooth every 15 degrees but I actually don't think they are evenly spaced.
So.
I don't know the diameter of the reluctor, either outer or inner. It may be feasible to attach this to the back of the Pontiac harmonic dampener, then mount the crank sensor as if it was any other crank trigger ignition sensor.
I suppose one could also scan or draw a 24x reluctor in CAD, scale it down (or up) to fit on the back of a Pontiac dampener, and then attach it as above.
If the LS computer can be programmed to live with other reluctor tooth counts, then that opens up some options as well.
So... technically speaking, am I missing anything here? It seems like the hardest part is getting a crank signal fed to the ECM. After that... off the shelf junk should do the job.
Right?
One, yes, I know, you could just put an LS into (whatever. Anything. Everything)
Two, yeah, I know, Pontiac V8's have a lot less support than Chevy stuff. Chevy stuff would be easier - and I should probably just put an LS in it.
Three, yeah, I know, carbs can do everything that EFI can do and make you more attractive to sexual partners at the same time.
Those out of the way, here's what I'm thinking:
Sequential fuel injection with coil-near-plug ignition offers a lot of drivability, reliability, economy and power improvements over anything I'm likely to accomplish via carb. Honestly, I'm 32 and haven't yet bothered to learn how to tune a carb. Now, why not buy an LS engine and put it in? Well, the engine (fully dressed) would run me $700. Add an oil pan to make it fit, conversion mounts for the engine, possibly an intake & accessory drive change, either a new trans & drive shaft or an adapter to go from LS to BOP... it's adding up quickly, isn't it?
So, the compromise: put modern management onto an old Poncho.
The Generation III LS motors need just a handful of things to run with factory style injection. Well, ok, maybe a few more than a handful.
Crank signal - where's the crankshaft?
Cam signal - where's the cam?
Coolant temp - how hot is "hot", anyway?
Idle air controller - keeps it running "goldilocks" RPM
Throttle position sensor - how fast do you want to go?
Intake air temp - cold air burns better
Mass airflow sensor - more air more power
Manifold absolute pressure sensor - this one does stuff, too.
I think that's all of them. I've also got a pissed off toddler in the house so I could be wrong. I could be wrong even when he's in a good mood, though, so maybe I shouldn't blame the kid.
Update: it was probably a poopy diaper. Everything's cool now.
Back to EFI.
Knock sensors are optional but included from factory. I'd ditch them, probably.
So, the IAC + TPS can be taken care of on a universal 4-barrel style throttle body. Coolant temp is just an adapter fitting away from using a factory LS unit. Factory MAP, I'm sure, can be made to work. I think it has the IAT integrated into it, though I don't recall. Maybe machine a flat spot on a Pontiac EFI intake drill two holes, tap one - worst case scenario. MAF is external and, really, a good speed density tune works really well. Hell, Chrysler doesn't run MAF sensors at all.
Firing order can be changed with wiring. Let the computer think whatever it's going to think, but let the Pontiac cam decide the firing order & change wires so they fire according to the cam.
This leaves the crank & cam signals to work out.
Gen III LS cam signal is a hi / lo signal. The sensor picks up the presence or absence of a machined half-moon rib of steel as it spins past, riding the camshaft or (in later engines) the cam timing sprocket. I think what'd work here is to run an LS2 (timing cover mounted, shorter than LS1) cam sensor mounted in a modified distributor cap, with a half-moon machined into a steel disc mounted to the distributor shaft.
The crank signal is potentially a bit trickier. Gen III uses a 24 tooth reluctor. This works out to a tooth every 15 degrees but I actually don't think they are evenly spaced.
So.
I don't know the diameter of the reluctor, either outer or inner. It may be feasible to attach this to the back of the Pontiac harmonic dampener, then mount the crank sensor as if it was any other crank trigger ignition sensor.
I suppose one could also scan or draw a 24x reluctor in CAD, scale it down (or up) to fit on the back of a Pontiac dampener, and then attach it as above.
If the LS computer can be programmed to live with other reluctor tooth counts, then that opens up some options as well.
So... technically speaking, am I missing anything here? It seems like the hardest part is getting a crank signal fed to the ECM. After that... off the shelf junk should do the job.
Right?
04-19-2016, 11:00 PM
#3
With a lot of time, this is feasible IMO. I don't think in the end you will beat a 5.3 dropout with harness, ECM, accessories $$-wise. And then if you consider your time worth anything at all.. At $3 an hour I think you will spend so much time on this that you will be double the price.
It would have cool/unique factor but the 5.3 will make a crap-ton more power all over the place and do it more efficiently. I love doing things that are "bad ideas" by general consensus. But I can't bring myself to spend more time/money for less performance in the name of uniqueness. Then why the heck are we resto-modding in the first place?
If you don't want an LS engine, it would be wiser I think to just get yourself a 4-barrel replacement TBI or even TPI all-in-one retrofit system. Some are about a thousand bucks right? That's nothing compared to what you are about to spend $20 at a time.
It would have cool/unique factor but the 5.3 will make a crap-ton more power all over the place and do it more efficiently. I love doing things that are "bad ideas" by general consensus. But I can't bring myself to spend more time/money for less performance in the name of uniqueness. Then why the heck are we resto-modding in the first place?
If you don't want an LS engine, it would be wiser I think to just get yourself a 4-barrel replacement TBI or even TPI all-in-one retrofit system. Some are about a thousand bucks right? That's nothing compared to what you are about to spend $20 at a time.
04-19-2016, 11:19 PM
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I...
I think I'm over it. If I was retired and well-off, maybe. As is, I don't have time & money for one-offing projects just to be one-off.
Even my old man, who inspired this by having put Cadillac MPFI on a Pontiac 455 in the early 90's, said "Sure, you could do that. Or just stuff an LS in it. I only did that EFI because they hadn't invented the LS yet"
I might put a four barrel intake & carb on it. Cammed 5.3 + swap parts go on the wish list.
I think I'm over it. If I was retired and well-off, maybe. As is, I don't have time & money for one-offing projects just to be one-off.
Even my old man, who inspired this by having put Cadillac MPFI on a Pontiac 455 in the early 90's, said "Sure, you could do that. Or just stuff an LS in it. I only did that EFI because they hadn't invented the LS yet"
I might put a four barrel intake & carb on it. Cammed 5.3 + swap parts go on the wish list.
04-20-2016, 12:03 AM
#5
I...
I think I'm over it. If I was retired and well-off, maybe. As is, I don't have time & money for one-offing projects just to be one-off.
Even my old man, who inspired this by having put Cadillac MPFI on a Pontiac 455 in the early 90's, said "Sure, you could do that. Or just stuff an LS in it. I only did that EFI because they hadn't invented the LS yet"
I might put a four barrel intake & carb on it. Cammed 5.3 + swap parts go on the wish list.
I think I'm over it. If I was retired and well-off, maybe. As is, I don't have time & money for one-offing projects just to be one-off.
Even my old man, who inspired this by having put Cadillac MPFI on a Pontiac 455 in the early 90's, said "Sure, you could do that. Or just stuff an LS in it. I only did that EFI because they hadn't invented the LS yet"
I might put a four barrel intake & carb on it. Cammed 5.3 + swap parts go on the wish list.
04-20-2016, 02:01 AM
#6
Just food for thought here. A couple of months ago I attended the Autorama car show in Dallas, TX. Saw a lot of really neat vehicles. Saw the Count, from Count's Customs play on stage with his band.
Back on topic, one of the really neat cars that I saw was a 427 Cobra replica. I *think* that it was a Mark V, which is one of the better known Cobra manufacturers. As I was looking this vehicle over, I discovered that this Cobra was powered by an aluminum Butler Pontiac V8. And it looked great in there. Knowing it was a Butler engine, there is no doubt that this car was a rocket.
The LS series engines are decades ahead, design wise, from the Pontiac V8. And, earlier in this thread, someone made the comment that there are more aftermarket parts and support for LS series engines. Absolutely true, no one could deny that statement. With that statement out of the way, there is more aftermarket support for Pontiac V8 engines currently than I have ever seen. Multiple vendors producing aluminum heads, blocks, forged cranks, etc. Your biggest problem is deciding which one you're going to give your hard earned money to.
If the vehicle in question coulda/woulda/shoulda have had a Pontiac V8, by all means, build one and stick it in there and enjoy that low end Pontiac torque. If an LS series engine makes more sense, you are sure in the right place to study other people's builds and ask questions.
Maybe a better question is, "This engine you are building and planning an EFI system for, what is it?"
Back on topic, one of the really neat cars that I saw was a 427 Cobra replica. I *think* that it was a Mark V, which is one of the better known Cobra manufacturers. As I was looking this vehicle over, I discovered that this Cobra was powered by an aluminum Butler Pontiac V8. And it looked great in there. Knowing it was a Butler engine, there is no doubt that this car was a rocket.
The LS series engines are decades ahead, design wise, from the Pontiac V8. And, earlier in this thread, someone made the comment that there are more aftermarket parts and support for LS series engines. Absolutely true, no one could deny that statement. With that statement out of the way, there is more aftermarket support for Pontiac V8 engines currently than I have ever seen. Multiple vendors producing aluminum heads, blocks, forged cranks, etc. Your biggest problem is deciding which one you're going to give your hard earned money to.
If the vehicle in question coulda/woulda/shoulda have had a Pontiac V8, by all means, build one and stick it in there and enjoy that low end Pontiac torque. If an LS series engine makes more sense, you are sure in the right place to study other people's builds and ask questions.
Maybe a better question is, "This engine you are building and planning an EFI system for, what is it?"