Carbs and Reliability

[autofrank]

Has anyone else noticed that using 2- or 4- barrel carbs reduces the life of the engine? Is this a bug or intended by the devs? I don't see why the life would be reduced, but I'm not an expert on carburetors.

[Daffyflyer]

Yes, they're somewhat less reliable than single barrel carbs simply due to being more complex with more possible parts to wear or fail. Same with multiple throttle EFI etc.

[autofrank]

Yes, they're somewhat less reliable than single barrel carbs simply due to being more complex with more possible parts to wear or fail. Same with multiple throttle EFI etc.

That makes sense, though wouldn't they become more reliable over time? Would you really lose up to 10k MTBF going from 1bbl to 4bbl? Also, now that I think about it there's a post about engine families. Will MTBF in the future be improved over time by sticking with the same family of platform / engine?

[Jakgoe]

No idea about carb reliability outside the game... I'll leave that to someone who knows what they are saying.

If you stick with a certain feature through the years, for example OHV, you will get a quality boost for that. I'm sure it will work the same way for carbs.

[gt1cooper]

I wish there was a way to make big single carbs, like the 1150CFM on my Mustang. I've had triple deuces and 4x2's and the only problem was having to clean the jets more often (as the ports are smaller with more smaller carbs). As for reliability, I cannot speak for in house, but 4x2's often share 4x1 components, and you are not putting more stress on them; however, I obviously am only speaking from my experience, but I have had many cars over my ~40 years of car ownership.

[JayZee88]

The only efi car I had was a 1997 supercharged riviera. The 12 others were mostly stock 50s GM cars so ille chime in. Single carbs rarely break down given you use the correct fuel and ignition parts. My carberated cars were no less reliable then my riviera. Efi does regulate fuel/air ratio much better and if you don't have your ignition system in good order or your carb tuned well they can be hard to start at low temps. I should know I drive classics daily. As far as reliability a modern efi isn't that much more reliable then a post war carbed motor. I can't speak for international cars, but US domestic cars that's my experience. Mechanical injection has always been unreliable and less efficient then carbureted cars. Dual or tri power set ups are a lot more finnicky and require constant adjustment as all the carbs MUST be adjusted the same. So mechanical fuel injection is least reliable, then multi carb set ups, then single carbs, then most reliable would be efi.

[JeffreyCor]

I've found the opposite, having EFI being vastly more reliable than carbs. I've had experience with 2 carb cars and 3 EFI, both the carb ones have had multiple carb problems over the time of ownership. In contrast, the only problem with the EFI on any of the 3 is 1 of them needed the fuel pressure regulator replaced once which was part of the fuel filter in that model so a very simple job.

[JayZee88]

My rule of thumb when buying vintage cars is a complete tune up. Rebuild the carb, ignition, fuel, and charging system. Modern fuel plays havoc with older style gaskets, not to mention who knows when they had their last tune up. Here in Nebraska its almost impossible to find non ethanol gas. Replacement (newer) fuel pumps and carb kits come with ethanol resistant gaskets. My 54,3 57s, 58, 72 Chevys, 55 Packard, 56 pontiac, 2 58s, and 4 59 Buicks have all had that same tune up. When points set right, and carb adjusted to specs never had a fuel problem, or rough winter starts.

There are several things owners of vintage cars tend to not realize.
Lead in gas to protect valve seats for example. Most guys put hardened valve seats in to combat that when rebuilding older motors just to find out they ruined the heads. Some motors CANT have hard valve seats and/or don't need them due to high Nickle content in some heads. Buick nailheads are a great example of this.

Then there is ZDP in motor oils. Modern oils have a fraction of what they used to. ZDP is critical in our flat tappet valve trains to keep the lifters from flattening the cams. Most older car owners have no idea that without the zdp they could tap valves, wear out the cam, or worse! That's why I buy ZDDP for every oil change and full synthetic oils. You will be supprised how well our baby's love synthetic oils! Runs cooler, more power, more efficient who can complain bout that?

[USDMFTW]

Efi when it was first released was worthless junk, injectors and the likes always failing, carbs to my knowledge were generally reliable because they were simplier with less parts. Ive had more issues out of EFI cars over carbs.