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Wed Jan 28, 2015 8:14 pm

I know the dual port vs single port question has been asked here more than its fair share. But I am really wondering if the low end torque of the single port makes it a better engine for mountain passes? Any feedback would be greatly appreciated.

Wed Jan 28, 2015 8:16 pm

depends on which gear you're in

Wed Jan 28, 2015 8:24 pm

Brian wrote: depends on which gear you're in

9 mph in first gear, 17 in second
downhill on ice is the problem

Aloha
tp

Wed Jan 28, 2015 8:41 pm

Carver Dude wrote: mountain passes?.
Mountain passes at what speed, what load and under what conditions? As you've probably noticed from the replies already your question is pretty open ended.

Wed Jan 28, 2015 8:58 pm

Shed pounds from the bus. It's cheaper. Any difference between Sp and Dp in these low HP engines would be marginal.

Wed Jan 28, 2015 10:48 pm

Two VW buses head up a steep grade racing to see who gets to the top first. Regardless who wins it will be dark and the party over by the time they get there. When you've driven a VW bus for awhile you just accept that hills are a challenge and don't think about it.

If it means that much, get a late bay with a 2L motor and spend your time worrying about valve seats instead of who goes faster up a hill. The late bay will be first up the hill (as long as the valve seat holds.)

Wed Jan 28, 2015 10:55 pm

busdaddy wrote: Carver Dude wrote: mountain passes?.
Mountain passes at what speed, what load and under what conditions? As you've probably noticed from the replies already your question is pretty open ended.

I think a 2180 single port would have more torque than a 1600 dual port.

Wed Jan 28, 2015 11:11 pm

TomWesty wrote: Shed pounds from the bus. It's cheaper. Any difference between Sp and Dp in these low HP engines would be marginal.

Yep... narrow tires, small battery, empty interior, no amp or subwoofers, skinny girlfriend... :roll:

But the single port will probably run a bit cooler and return better fuel mileage, if you're running close to stock engine specifications, i.e. a stock 1970 1600 SP vs. a stock 1971 DP. With those specs, the DP will have a little more 'wind-it-out' power, but the SP will have a bit better low-RPM torque. Seriously, the difference wouldn't even be noticed by most drivers, since it's relatively small and both vehicles are considered way SLOW!

If not considering engines in mostly stock factory configurations, the characteristics can be all over the board. Relax, treat your engine right, be willing to pull over for vehicles behind you, and enjoy the journey!

Thu Jan 29, 2015 12:27 am

WestyPop wrote: TomWesty wrote: Shed pounds from the bus. It's cheaper. Any difference between Sp and Dp in these low HP engines would be marginal.

Yep... narrow tires, small battery, empty interior, no amp or subwoofers, skinny girlfriend... :roll:

It always fascinates me to observe the length people will go to while trying to shave weight off their car. Then take seats out, dashboards out, and spare tires out, but they don't bother to clean the seventy pounds of dirt and mud off the underside… :lol:

I personally don't think dual ports are all they're cracked up to be. VW only used it on the bus for one year before abandoning the design on these cars. (It continued on in the bug, though never exceeding 1584cc.) I think they realized the limit of the bored-out forty horse base they were working with. It intrigues me how they redesigned the head to flow more in without provisions for increasing flow out. I also think the increase in cold fuel/air charge into the cylinder increased the thermal difference between intake and exhaust valves, thus putting more strain on the metallurgy of the head/seats/valves assembly.

Just my dual cents…
Robbie

Thu Jan 29, 2015 12:49 am

asiab3 wrote: It always fascinates me to observe the length people will go to while trying to shave weight off their car.

Gassers used to drill out the frame to remove as much metal as they could. Wonder if that's illegal now.

Thu Jan 29, 2015 6:15 am

My question has nothing to do with speed or how light I can make my bus.... It has everything to do with the fact that I live in a valley sorounded by 14,000 foot peaks. If I want to take my bus out of the valley I have some pretty good hills to climb... Just want to make sure the engine I go with is the best for the job.

Thu Jan 29, 2015 7:32 am

Take along a box of apples and a 5 disc CD changer and you won't notoce the difference. :roll: :lol: :lol: :lol:

Thu Jan 29, 2015 7:40 am

Carver Dude wrote: My question has nothing to do with speed or how light I can make my bus.... It has everything to do with the fact that I live in a valley sorounded by 14,000 foot peaks. If I want to take my bus out of the valley I have some pretty good hills to climb... Just want to make sure the engine I go with is the best for the job.

They will be equally as slow. You'll be running 3rd year all the way on most "hills" at altitude. You want to go faster, bore and stroke it. I went from 45-50 mph on 3rd all the way home to 60+ in 4th with my 2109cc. Even getting better milage with the larger engine. Good luck.

Thu Jan 29, 2015 8:35 am

I have heard that it is getting difficult or impossible to find usable, uncracked single port cores.
Yes/No?

Thu Jan 29, 2015 8:42 am

Carver Dude wrote: My question has nothing to do with speed or how light I can make my bus.... It has everything to do with the fact that I live in a valley sorounded by 14,000 foot peaks. If I want to take my bus out of the valley I have some pretty good hills to climb... Just want to make sure the engine I go with is the best for the job.
The dual port makes better power at highway speed but tails off on long hills if your speed/RPM drops, the singleport has a better low and midrange power curve and usually keeps pulling longer in that situation.

Thu Jan 29, 2015 8:50 am

FWIW i am of the notion that the superior "low end torque" of the single port engine is because of the smaller carb venturi :wink:

someone told me one time that they had put a Karmann Ghia engine in their bus and it "hauled ass" now.
seemed like a lot of trouble to get a bigger main jet to me :lol:

Thu Jan 29, 2015 10:16 am

Living in northern New Mexico I have to contend with mountain grades. Even just getting up to Los Alamos is a 2000-ft climb from the Rio Grande to the Plateau, and it is a great test track to see how buses do on long grades.

So, I currently have two data points:

1. A 1979 Transporter, good 2.0-L engine, with a single carburetor on it.

2. A 1975 Single Cab, good 1.8-L engine, with dual Weber IDF 40s.

The SC, while much stinkier and less efficient, roars up the hill with no issues. The Transporter struggles (and I'm sure would do much better of FI, but that is another story.)

Not sure if that helps at all.

Thu Jan 29, 2015 10:42 am

borninabus wrote: FWIW i am of the notion that the superior "low end torque" of the single port engine is because of the smaller carb venturi :wink:

someone told me one time that they had put a Karmann Ghia engine in their bus and it "hauled ass" now.
seemed like a lot of trouble to get a bigger main jet to me :lol:
That's similar to all those people who tell me they "had one just like it but with a Porsche motor" :P

The smaller venturi likely helps, I think VW went DP to get the highway speeds up a little, no science here but my "ass dyno" can tell the difference when driving both on the same day up the same hill :lol:

Thu Jan 29, 2015 10:57 am

busdaddy wrote: ... That's similar to all those people who tell me they "had one just like it but with a Porsche motor" :P

The part I wanted was the same, but different.

Aloha
tp

Thu Jan 29, 2015 11:58 am

I still think the OP is wasting their time if he/she is debating which VW bus to buy to get there faster. Single port, dual port, etc etc are all slow climbing mountains. It also overheats the oil. Coming down in winter the heat exchangers blow cold air too.