TBI vs Vortec

[L31MaxExpress]

I bought LD K2500 ECSB with the NV3500 with 9800 mi on it in 1992. The NV3500 was a absolute POS, replaced once under warranty, again at 150k, and when I sold it at 285k the trans was in the process of fragging 5th gear....again. I really liked that truck—the rest of it was almost flawless and gorgeous.

With apologies to the Mopar 318 and FOMOCO 1st gen 302, the 5.7 TBI motors may be the longest lived cast iron gas V8 ever devised by humankind. It’s no secret, it’s a low RPM motor. The TBI’s outlast the 5.7 Votecs, and the 5.7 Vortecs outlast the 3rd gen 4.8/5.3/6.0’s which operate at even higher RPM’s.

Stoplight to stoplight my 5.3 beats my 5.7’s, but running up the mountain passes the 5.7’s have a wider power band, don’t hunt and peck through the trans as much, and pull the hill at lower RPM’s.

Also, that 91 TBI got better fuel mileage than the 5.7’s and as good as my 5.3.

Problem is, the TBI’s don’t have the power needed to negotiate Mtn highways at altitude here in Colorado.

When the Express van was stock never had a stock 5.3 get around me until I was running about 70+! My old TBI G20 with headers and an edelbrock intake manifold would hold a 5.3 off up to about 60 too. Acceleration from a stop with all the 5.7s torque was never a problem, they just get asthma on the top end in factory form.

 

[L31MaxExpress]

I bought LD K2500 ECSB with the NV3500 with 9800 mi on it in 1992. The NV3500 was a absolute POS, replaced once under warranty, again at 150k, and when I sold it at 285k the trans was in the process of fragging 5th gear....again. I really liked that truck—the rest of it was almost flawless and gorgeous.

With apologies to the Mopar 318 and FOMOCO 1st gen 302, the 5.7 TBI motors may be the longest lived cast iron gas V8 ever devised by humankind. It’s no secret, it’s a low RPM motor. The TBI’s outlast the 5.7 Votecs, and the 5.7 Vortecs outlast the 3rd gen 4.8/5.3/6.0’s which operate at even higher RPM’s.

Stoplight to stoplight my 5.3 beats my 5.7’s, but running up the mountain passes the 5.7’s have a wider power band, don’t hunt and peck through the trans as much, and pull the hill at lower RPM’s.

Also, that 91 TBI got better fuel mileage than the 5.7’s and as good as my 5.3.

Problem is, the TBI’s don’t have the power needed to negotiate Mtn highways at altitude here in Colorado.

350 is durable but I think the TBI version of the 366 tall deck is the most durable cast iron V8. That extra compression ring and the fact many of them run on propane or natural gas probably helps alot along with the 4,000 rpm governor.

 

[udidwht]

454 TBI with 4L80E here in my Fleetwood Southwind Storm 28ft. I've owned it since Sept 2014 and it has been very reliable. I've replaced many items due to age rather than waiting for them to fail such as TPS, MAP, PCV, IAC. Idle Cont Solenoid, Purge valve, O2 sensor (single wire), Pick up coil, Ignition coil, Cap & rotor, alternator, radiator hoses & T-stat etc....

The engine is very simple and I consistently get 8-10 mpg @~ 60mph. I'm now at 68,205 on the OD was at 45,*** when I bought it. Just replaced the spark plugs and put on new ceramic truck 8.5mm wires.

 

[stutaeng]

With apologies to the Mopar 318 and FOMOCO 1st gen 302, the 5.7 TBI motors may be the longest lived cast iron gas V8 ever devised by humankind. It’s no secret, it’s a low RPM motor. The TBI’s outlast the 5.7 Votecs, and the 5.7 Vortecs outlast the 3rd gen 4.8/5.3/6.0’s which operate at even higher RPM’s.

I'm not bashing the TBI. I agree with you about them being pretty durable. But I think it's a little more complicated than simply low rpm = longer life.

I've never heard them living any longer than Vortec engines, and certainly not longer than the LS engine platform. But I'm no engine expert. And I'm sure the LS engines have different bearing material than the former 2 engine generations.

 

[kenh]

350 is durable but I think the TBI version of the 366 tall deck is the most durable cast iron V8. That extra compression ring and the fact many of them run on propane or natural gas probably helps alot along with the 4,000 rpm governor.

Back in the early to mid 70's the local school district had school busses with the 350 small block in them. Seemed to replace at least one engine a year and they only ran 5 busses. Finally they got one of the 366 big blocks. End of engine issues.

 

[DerekTheGreat]

350 is durable but I think the TBI version of the 366 tall deck is the most durable cast iron V8. That extra compression ring and the fact many of them run on propane or natural gas probably helps alot along with the 4,000 rpm governor.

What year ranges were these available? Happy to have any pics? I'd be curious to learn the specs too. I only thought those were available with carburetors.

 

[L31MaxExpress]

What year ranges were these available? Happy to have any pics? I'd be curious to learn the specs too. I only thought those were available with carburetors.

From about 91-97 the 366 and 427 were TBI.

 

[Schurkey]

There used to be plenty of 366s around here in farm trucks. Decently durable, but no power.

The common wisdom was that they couldn't make enough snort to hurt themselves. A 427 could.

You want durable? Drop a properly-build IHC 345 long-block into your truck, with feedback fuel injection on top.

 

[L31MaxExpress]

There used to be plenty of 366s around here in farm trucks. Decently durable, but no power.

The common wisdom was that they couldn't make enough snort to hurt themselves. A 427 could.

You want durable? Drop a properly-build IHC 345 long-block into your truck, with feedback fuel injection on top.

304, 345 and 392 were all durable. For the longest I have wanted to adapt a 4L80E behind a 392 in a late 60s TravelAll and put TBI on it.

 

[alpinecrick]

In the 60's here in my neck of the woods IH trucks--both medium duty and light duty--were very popular. We had pair of 1966/67 two ton livestock/grain trucks with the (I think) 345's in them. They were indeed quite durable trucks. Parts for them, when you could find them, were breathtakingly expensive. An alternator for my buddy's 1971 half ton with a 345 was 4x more expensive than one for my 71' K10.