Carb SBC vs TBI SBC vs Gen 3 LS reliability

[slow_c1500]

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.

I see. So in terms of ignition systems, are the vortec or LS engines more reliable?

 

[L31MaxExpress]

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 would not say that at all. Mine made peak power at about 4,700 rpm with stock heads and cam.

 

[FourEightZero]

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.

My newbie $0.02

The TBI was a good intro build for me. I would have been LOST without this forum and the oldtimers here.

I had modified enough of my 350 to require tuning and this could have put the project into "bitten off more than I can chew" territory for me.

A couple resources I can't recommend enough:
www.gearhead-efi.com - forum for tuning

.. and more specifically, Dave W from Old School EFI (he posts on the forum)

His help has been beyond excellent.

 

[slow_c1500]

After hearing all this I have narrowed it down to 3 options:

-Sell current vortec truck (after fixing) and buy a TBI truck

-Keep current vortec truck and LS swap it when the time comes

-Keep current vortec truck and just rebuild/replace with another vortec SBC when the time comes (easiest and least preferred option)

Idk if TBI swapping my vortec truck is possible, and if it is, it would be way too much work when I could just buy a TBI truck instead.

 

[Drunkcanuk]

Just a thought.
Why don't you go to a "treasure yard" and pull a vortec motor. Rebuild/refresh it at your leisure with the updated injection pieces, maybe a small "computer friendly" cam. And then r&r it in a day or so, on YOUR schedule not when the motor decides to crap out and then you are left scrambling.
A fresh motor with a small cam will feel way more powerful than a worn out one. You will feel it in your butt dyno.
That way your spreading the cost out over however long your finances dictate instead of a big hit all at once.

 

[0xDEADBEEF]

I see, however some early LS’s are drive by cable. Are failures with the individual coils very common on LS engines? I guess that’s something you trade for distributor failures on small blocks.

Not at all. I'm running 2 sets of random junkyard coils on my current 2 swaps.

 

[0xDEADBEEF]

I replaced aomething like 2 sets in the 3 years I ran them. Very common failures atleast on a van.

My distributor issues were caps and rotors, MSD fixed that for me, got 5 years out of the last one.

I've never had an LS coil go bad and I've owned a lot of LS/LT motors. I'd wager this board has probably changed 10,000 caps and rotors over the same time.

 

[L31MaxExpress]

I've never had an LS coil go bad and I've owned a lot of LS/LT motors. I'd wager this board has probably changed 10,000 caps and rotors over the same time.

I have an account at work that buys them often enough that we stock 8 of them. The Police Tahoes eat them too, but they rack up idle hours like crazy. So I was not really including them. They are also averaging 2 cam and lifter sets a month.

 

[0xDEADBEEF]

I have an account at work that buys them often enough that we stock 8 of them. The Police Tahoes eat them too, but they rack up idle hours like crazy. So I was not really including them. They are also averaging 2 cam and lifter sets a month.

How many caps and rotors do you stock?

 

[Scooterwrench]

They are also averaging 2 cam and lifter sets a month.

They are wiping out rollers that often?