Carb SBC vs TBI SBC vs Gen 3 LS reliability

[L31MaxExpress]

I guess I can see your point about the vortec being simpler now, especially considering the ignition system.

The vortec really only has 4 failure points: cap, rotor, ignition coil, ICM.

The LS has 8 individual coils, so theoretically more failure points.

I will also admit that my coils were off running engines that I pulled, sold, etc and not new ones. 8 x D585 GM coils gets $$$$, compared to an hour switching one out for another used one laying around.

 

[slow_c1500]

You also mentioned that the vortec has less wiring and connections than the LS, what else do the LS engines have that the L31 doesn’t, aside from coil packs?

 

[L31MaxExpress]

You also mentioned that the vortec has less wiring and connections than the LS, what else do the LS engines have that the L31 doesn’t, aside from coil packs?

Coils, DBW, 1 less knock sensor, less emissions stuff pertaining to the charcoal canister.

 

[alpinecrick]

Meh, I vote TBI but, that's just me

With apologies to the Mopar 318, but none to the LS motors, the TBI motors may be the longest lived cast iron V8's ever devised by humankind......

Donning my flameproof suit........
It's simple, the TBI's operate at lower RPM's. Less RPMs for every mile driven translates into less wear. LS motors have higher HP potential, lower emissions potential, all in a slightly smaller package, albeit at higher RPM's than the TBI or 1st Gen Vortec.

The Vortec V-8's fall somewhere in-between.

The SBC have 45 years of R&D, and the Vortecs are the culmination of that. Particularly reliability. I"m old enough to remember when any engine was "wore out" when it crossed over 100k.

I know I'll catch flak, but.....all things being equal, the Gen 3 LS motors do NOT last longer than the TBI's or the Vortecs--notably dependent on level of maintenance and how it's driven.

I've owned all three of these engines, and I've owned 2 of them when relatively new and I know the provenence of ALL four of my pickups noted in my sig and am/was the second owner of all four. They all were fairly well maintained and driven fairly sane. Importantly "well maintained" also means keeping the truck relatively clean beyond the interior and the shiny side. It also means keeping the chassis and engine bay clean. I see photos on here all the time of filthy engine bays and rusty trucks. Plastic and rubber doesn't like to be covered in grease and road grime. Road salt and mag chloride love to rust metal.

My 96 and 97 ECSB's have no rust in the corners of the x-cab. Why? Because I and the previous owners washed the underside of the truck often. Even though I own pressure washers I still hit the carwash (especially during the winter) often. I almost always spend more time (and money) washing underneath and the engine bay than I do the paint.

 

[L31MaxExpress]

The Vortecs achilles heel is the intake gaskets. Use a composite paper gasket and they are solid.

 

[haroldwca]

I'll throw in on this. My vote is TBI for its simplicity. If you can trouble shoot a carbed 350, it's a short learning curve to handle the TBI 5.7. And the actual throttle body injection unit that gives us the initials "TBI" is far simpler to work on than a Q-jet. It IS plug and play. Checking injector function is as simple as pulling the connector, touching a 9V battery to the contacts, and listen for the click. Other than the fuel pressure regulator, there is nothing else to go wrong. (OK, it does have a TPS and a IAC solenoid, but the diagnostic for each is straightforward.) A standard type distributor and a separate coil complete the ignition system. Yes, the fuel pump is in the tank (that's one point in favor of a carb), but that's the extent of the drawbacks. No, it doesn't come with 300+ HP out of the box, and you probably won't be getting 22 mpg, but from a diagnostic standpoint it's the way to go. And for disclosure, I was a die-hard Q-jet fan in a world of EFI until I bought my '88 Silverado as a flip. I enjoyed driving it so much, I sold my 1985 Silverado and made the '88 my daily driver.

 

[slow_c1500]

With apologies to the Mopar 318, but none to the LS motors, the TBI motors may be the longest lived cast iron V8's ever devised by humankind......

Donning my flameproof suit........
It's simple, the TBI's operate at lower RPM's. Less RPMs for every mile driven translates into less wear. LS motors have higher HP potential, lower emissions potential, all in a slightly smaller package, albeit at higher RPM's than the TBI or 1st Gen Vortec.

The Vortec V-8's fall somewhere in-between.

The SBC have 45 years of R&D, and the Vortecs are the culmination of that. Particularly reliability. I"m old enough to remember when any engine was "wore out" when it crossed over 100k.

I know I'll catch flak, but.....all things being equal, the Gen 3 LS motors do NOT last longer than the TBI's or the Vortecs--notably dependent on level of maintenance and how it's driven.

I've owned all three of these engines, and I've owned 2 of them when relatively new and I know the provenence of ALL four of my pickups noted in my sig and am/was the second owner of all four. They all were fairly well maintained and driven fairly sane. Importantly "well maintained" also means keeping the truck relatively clean beyond the interior and the shiny side. It also means keeping the chassis and engine bay clean. I see photos on here all the time of filthy engine bays and rusty trucks. Plastic and rubber doesn't like to be covered in grease and road grime. Road salt and mag chloride love to rust metal.

My 96 and 97 ECSB's have no rust in the corners of the x-cab. Why? Because I and the previous owners washed the underside of the truck often. Even though I own pressure washers I still hit the carwash (especially during the winter) often. I almost always spend more time (and money) washing underneath and the engine bay than I do the paint.

I’ve never driven a TBI before so I was unaware that they operate at lower rpm. The reduced wear from the lower rpm’s would be a huge benefit for me. The TBI has always seemed appealing to me due to its minimal electronics and the exhaust sounding like the gates of heaven opening. But now I am seriously considering trading my vortec OBS for one with a TBI.

 

[alpinecrick]

I’ve never driven a TBI before so I was unaware that they operate at lower rpm. The reduced wear from the lower rpm’s would be a huge benefit for me. The TBI has always seemed appealing to me due to its minimal electronics and the exhaust sounding like the gates of heaven opening. But now I am seriously considering trading my vortec OBS for one with a TBI.

The swirl port heads on the TBI's were designed to make their power and torque down low. On the flip side the motor plumb ran out of breath by 4k rpm's..........

 

[Schurkey]

The vortec really only has 4 failure points: cap, rotor, ignition coil, ICM.

Plastic distributor housing--bushings wear out. And lots of reported problems with the gear at the bottom of the distributor. The rotor, coil, and module have no excessive reports of failure. The caps are a problem.

There's a million brands of replacement (aluminum) distributors, one of them apparently made in the USA.

 

[slow_c1500]

The swirl port heads on the TBI's were designed to make their power and torque down low. On the flip side the motor plumb ran out of breath by 4k rpm's..........

I’m not gonna be building a race truck or anything, it would just be a daily driver so I wouldn’t need to worry too much about performance in the higher rpm’s.