For my upcoming slant six build, I would like to build a "very" reliable slant six. As we know, slant sixes by nature are reliable. But what can we do to make it super reliable?

For starters, let presume that the bottom end of the motor and the head has just been rebuilt and is in great shape. Also, let's assume that the electrical wiring is correct. So for reliability we turn our attention to the peripheral items such as:

1. Ignition System - What is the simplest and most reliable ignition system? Best distributor?

2. Fuel Delivery System - What is the simplest and most reliable fuel delivery system?

3. Other weak links such as distributor gear and oil pump drive system.

4. Vacuum Leaks - What can I do to help prevent and guard against vacuum leaks.

One reason that I note "simplest" is because with more complexity you have more things to break. For example, fuel injection may be more reliable in general, but if the ECU dies, you are dead in the water. Whereas with a carburetor it may run less than ideal and need more tuning, but there are much less things to break.

Please provide your best tips for reliability in these and any other areas for the slant six.

Thanks, Craig

Attention to the details is probably the biggest thing.. are you taking your slant 6 truck overlanding?

Points ignition for ease of repair and troubleshooting... HEI for better performance and most likely no troubles ether.

Mechanical fuel pump. Maybe add a fuel return to your fuel filter set up to reduce hot soak issues. Also do the fuel line modification that SSD has in the FAQ engine section.

Distributor gear that is not 40 years old, and reusing the original oil pump in your rebuild.

Vacuum leaks? What vehicle are you installing this slant in? Care and attention to details will go a long way here...

Thanks Jase for the input. The vehicle is a 1984 Dodge D100 /6 4 Speed.

The reason I noted vacuum leaks was that on a previous build I used a cheap rubber cap to seal off an unused vacuum port on the carb (that ended up cracking and leaking) and it took me a while to figure out what was wrong. Like you say - attention to detail and hopefully I have learned that lesson.

For this use, I'd probably go with a HEI wired to a stock type Mopar distributor, and a Carter BBD carb. But make sure to get a good quality source for both. Parts store rebuilt carbs tend to be worse than what you'd get if a teenager rebuilt a previously unmolested carb in Dad's basement... and I am speaking from firsthand experience at comparing the two.

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Matt Cramer
1966 Dodge Dart turbo / EFI project

Very dependable set up and fine to run 12.78 in the quarter!!

But go ahead and spend a couple extra dollars and get the genuine GM HEI module.

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

This came up (not any car brand or engine specific) 15 years ago when I took the Fury on power tour at one of the gas stops
It was said that for such a trip that a car with a mechanical fuel pump, carb, and some kind of electronic ignition was best for such a trip. Fuel pump (back then) was only $18 and 2 bolts to replace "if it should be necessary" in some parking lot several states away instead of dropping a tank while laying on your back in some unfamiliar area, while also being much cheaper and (again back then) more likely easier to come up with when you're who knows where...

"ultimate dependability" was on my mind when I built my last /6 (beyond their legendary reputation for that to begin with) which was why I went with new but very old stock parts within... And parts within like an NOS OEM Mopar performance double roller timing chain setup, (this box was quite dusty) and scouting ebay for old versions of well known name brand parts that were made before "Chinesium" was even a thought.

Carry spares of likely-to-fail parts, and tools to replace them. That way you'll never need to.
See HEI upgrade (and note the small size of the HEI module; makes it easy to carry a spare)
There is more than one correct answer to this. What's your budget for putting together a fuel system? How far from stock are you willing to deviate? What regulations (emissions tests?) apply to your vehicle where you live now…and where you're likely to live in future?
Neither of these is a weak link.
Don't create them in the first place, and use high-quality fittings and hose.
This is a few different kinds of wrong. For one thing, a fuel injection system is much simpler than a carburetor. EFI has fewer parts, and the parts are much less complex; there's a lot less to break. ECUs mostly don't die, but if you're consumed with fear of the extremely unlikely, well…carry a spare ECU.

Carburetors, on the other hand, are full of finicky parts just waiting to break or fail or otherwise stop your car. Combine the difficult availability of good carburetors at this late date; the near-extinction of apposite repair knowledge in today's world, and the carburetor-hostile formulation of modern gasoline, and then consider that one of the big reasons why gas stations have food marts instead of service bays now is that fuel injection doesn't crap out like carburetors did, and…well…kinda…time to rethink the idea that a carburetor is more reliable. It isn't.

On the other-other hand, there's no off-the-shelf/drop-on Slant-6 fuel injection system, so you'd have to be prepared to do some amount of roll-your-owning. If not, then the right answer for your particular case might be to very carefully choose a carburetor and live with it.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

The closest thing to a drop on, off the shelf "EFI system" for the slant, is a Holley Sniper setup for a BBD replacement. They are catering to the Jeep crowd with this setup. This would require a Super Six intake. How dependable this setup is, depends on who is installing it.

Cost for FI, is not cheap. Scraigallen can do a bolt on 2 barrel setuup for a fraction of the cost to do a fuel injection set up.

I will say that in all the years I have been driving and of all the people I know; I don't know of a single time that someone was left sitting because of a carburetor issue. I'm sure it has happened but not to everyone that runs a carb. My 2 cents.

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

Thanks everyone for all of the help.

Regarding the fuel injection vs. carb - I keep going back and forth on this one. Is Holley Sniper EFI the best option?

I looked into Mega Squirt and it just seemed to complex to me.

Thoughts on the Holley Sniper EFI vs their throttle body EFI competitors?

Thanks!

wjajr has had great success with his FITech EFI setup. Search his name. I would try to have a long talk with him, if you can. Personally, I would not trust Holley to make something simple, functional, and reliable, unless it's for a common Chevy or Ford engine, but that's my bias.

IMHO, Megasquirt is for advanced builders and electronics semi-experts. It would be very easy to cobble together something that would be unreliable, for a Slant 6. They have plug-n-play stuff, but only for really common cars like Miatas and Mustangs.

Reliability has several quite different aspects to it, which I will discuss in a future post...

Lou

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Home of Slant6-powered fun machines since 1988

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

This seems timely....

https://diyautotune.us11.list-manage.co ... 9e17c9fd11

I'm staying carbureted for the foreseeable future on my /6 (my version of the K.I.S.S. principle)
But over the years I've read about v6 fiero or S10 adapted to a /6 as well as 4.0 jeep computers and wiring being adapted over the years to various/6s..... Basically scrounge the boneyard, get a complete wiring harness, throttle body, the injector "showerheads", and all the sensors you possibly can pirate from your vehicle if choice and weed out all the wiring not absolutely essential to the running of the system and away you go