Got a '75 1800cc manual kombi... currently doing some travelling around and so far have been pretty disapointed with the performance/ economy, and was wondering what other peoples experience with these engines has been?

Our previous kombi was a '73 1600... it sat on 100-110kph all day and would manage steep long hills if you attacked them with enough speed and still return 28 mpg. It ran great.

With our current kombi, we sit at around 90kph because anything more means driving at full throttle, hills are a chore (no top-end power) and we've got a miserable average 22.5 mpg over the last 11,000k's. Am I expecting too much?

OK, its loaded up for a 6 month trip and has roo-bars and a large-ish home-made roof rack, but we dont have THAT much stuff, and i'd be happy with the crappy economy if i thought it made up for it in performance, which it doesn't.

Interested to hear any comments

Sam

p.s. It has the standard twin-carbs, single vac dizzy timed at 28deg full advance with vac hose off, leccy ignition, good compression, 1-year old re-built carbs... ???

Your 1600 seems brilliant to me.

I have a 2L auto twin solex model, 82 vanagon.
heavier than a bay and i am not that much different than your current Kombi

So sonsidering yours is lighter and a manual i would have expected a "little" better, but not 28mpg

28 mpg is ~8.4 litres/100km - you won't be seeing that from an 1800.
22.5 mpg is ~ 10.4 litres/100 km, and that's about the best figure I've seen for a T IV engined Kombi, usually somewhere closer to 12 - 15 litres/100 km.

My (2 litre) double-cab gets somewhere 14 - 15 litres/100 km, but is never out of the city.

The good news is you're doing quite well, the bad news is you're unlikely to do much better. It sounds like you do a lot of country driving, so your best bet for improvement is to remove the roof-rack; they are very consumptive.

hth

22 mpg is about what im getting in chaos which has the 2L t4 motor in a bug

22mpg is good. However many Kombis seem not to have full "throttle".

Have someone push accelerator to floor-(not running:P) and then see if you can open linkage further.

im getting 13-14L/100km in my 2L type 4 dual carb around town. If i got 10.4 litres/100 km on the open road (soon find out) i would be happy. As for power up hill etc, i think you will find it will drop from 110 to 100 and stay there unless its a big ass hill. I have my timing set to 7.5 BTDC as recomended in the manual, i duno if 28 max advance is similar but incase you didnt know....

anyways i would be pretty happy with the performance and fuel consumption for a kombi, as modulus said remove the roof rack and see if it makes a difference. Good luck, hope this helps

According to my workshop manual my 2L kombi has a top speed of ~125. I have done that fast but it was a slight hill. I find that 110 is foot on the floor.

I also looked into this. With the foot to the floor the carbs don't open to full, my understanding is that this is intentional to limit the revs? Either way, i have noticed there is not enough movement in the accelerator pedal to accomidate the full range of the carbs.

Also its important to note that my carbs are lined up for a rebuild (when time permits)

The roof rack will cost you 2 litres per 100

My 2l fuel injected '82 camper gets about 18mpg when fully loaded for a long trip. Best I have seen is 21 mpg out on the Hay plains. I cruise at about 90 to 100 kmh. It will do in excess of 110 but I can't see the point. On hills it slows to about 80 ( eg. the hills on the Hume at the Wagga turnoff)

How long since it's had a proper tune up, including valve adjust, heads retentioned, spark plugs, air cleaner, oil change etc?

Our '75 when it had an 1800 got its average best of 298 litres over 2990 kms when we did a bit of a tour through NSW and eastern Vic. This included all driving through towns, Snowy Mountains etc, mostly 110kph on speedo (106-107 in reality) The odometer appeared to be accurate within 5%.

It worked out 10litre per 100km. We have no roofrack or poptop.

It held 110km up slight hills and never dropped under 75 up the biggest hills in the Snowy Mountains.

Reco carbies, distributor and well adjusted valves make a big difference. You can get full throttle out of the carbies if you have minimal wear and proper adjustment of the cable.

fill up with pulp(premium) it will give you better fuel economy more pwr and better longevity overall and as suggested do your rockers then if it were me id have leak down test done this is far more accurate than compression test and in the right hands is self diagnosing (eg rings hiss from breather inlet hiss at carby exhaust hiss through exhaust)
kombis are designed to carry aload and if hills are a noticable prob there is most probably something amiss
if you need the roof rack try and make it as aerodynamic as you can within reason

Economy does sound high for any bay kombi at those speeds, 1.6L, 1.8L or 2L. Are you sure their right? Also have you checked your speedo on both? Tyre sizes stock on both?
As for the speed you can maintain, all had different gearing, (1.6L had the lowest) which can make it pull well despite the smaller motor.
I don't have my manual handy, but type 4 motors have advance set at 7.5deg BTDC. Total advance (vac on) should be ~40deg. Check specs on timing if 28 max is correct., along with general state of tune as others have mentioned.
:thumb

I've got an 1800 as well, and I think your experience sounds very much like mine. I do about 85-90km/h most of the time (not full throttle), I figure the trip's part of the fun of having a kombi. She can do 100 just fine (pretty much foot to the floor, that just feels mean), but I reckon fuel consumption would be horrendous. I don't really know... I get between 10 and 11 litres/100km, mostly open country roads.

I wouldn't be disappointed with 10litres/100km, for a vehicle shaped the way they are, and with ancient carburretted engine technology.

My 1776 splitty with twin webers is worse...

Cheers, Aurel

WOW! So many replies, thanks guys

I guess that all makes me feel a bit better knowing that no-one else has really done much better.... although on a trip thru France, our old friends 1800 kombi got 25mpg average (and thats an Auto, with bars and poptop!), so it is possible if you drive like a Nun.

Unfortunately the bars, sunvisor, poptop and roofrack are all staying - we're about 5000km from home on the wrong side of Aus!

By the way, its been fully serviced/tuned by me to the best of my ability... valves, timing yada yada yada. I even did a compression check yesterday and its all good so i think i'll relax and be happy with my 22mpg and put the slow speed down to all the heavy crap that the wife keeps buying along the trip!

Cheers

Sam

i was thinking some sort of material could be formed around the pull bar with a spare tyre as picture above making the air flow over the front tyre a bit better and would probably reduce the wind resistance of the front (now curved rather than flatish)

Well, it turns out I wasn't expecting too much of our 1800 kombi engine - our camshafts Fooked, hence no power... rebuild time

Quote:

Originally posted by Samblers Well, it turns out I wasn't expecting too much of our 1800 kombi engine - our camshafts Fooked, hence no power... rebuild time

I took it to 3 different VW garages, In Adelaide and in Brisbane.

Wise old men with grey hairs and greasy hands stroked stubbly chins and explained "Camshafts rooted" on me starting the engine. Bugger.

Anyway, turns out they were wrong! We split the case and found that the camshaft was fine but the gears on the end of the crankshaft (the dissy one and the one which drives the cam) were loose... they should be a press fit.

I presume this explains why my timing mark rattled around and also might explain lack of power ???