Am I expecting too much of my 1800 engine...?

Samblers Officially Full-On Dubber

236 posts · joined Apr 2005 · 30 Mar 2006, 2:35 pm

#469606

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... ???

Bizarre Moderator The artist formerly known as blue74l

12,789 posts · joined Aug 2002 · 30 Mar 2006, 3:48 pm

#469642

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

Futue te ipsum!!!

modulus Veteran Volks Folk

2,009 posts · joined Jul 2003 · 30 Mar 2006, 4:10 pm

#469647

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

Peter Hill
1975 Type 2 Double Cab
modulus.com.au

barls Administrator Causer of Chaos and Mayhem

9,476 posts · joined Jun 2004 · 30 Mar 2006, 4:13 pm

#469649

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

“We all pay for life with death, so everything in between should be free.” Bill Hicks
the chaos project - click me

Warrenm Wolfsburg Wizard

466 posts · joined Aug 2004 · 30 Mar 2006, 4:24 pm

#469652

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.

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Beetle Bugs and Dubs

76camper Fahrvergnugen

884 posts · joined Jan 2005 · 30 Mar 2006, 4:57 pm

#469661

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

http://www.bytevision.com.au/dee/kombi/index.htm

DoNkEy Wolfsburg Wizard

684 posts · joined Jul 2003 · 30 Mar 2006, 5:29 pm

#469667

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)

VWCOOL 23 Windows of Awesome

5,158 posts · joined Jun 2003 · 30 Mar 2006, 6:09 pm

#469681

The roof rack will cost you 2 litres per 100

Pay your debts, CxxT

Kombi Dad Slammed & Awesome Dubber

96 posts · joined Jun 2003 · 30 Mar 2006, 6:59 pm

#469698

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)

Gracey Wolfsburg Wizard

511 posts · joined Feb 2003 · 30 Mar 2006, 7:04 pm

#469701

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

helbus Administrator Mad fabricator, paint and body

7,386 posts · joined Sep 2002 · 30 Mar 2006, 8:42 pm

#469782

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.

EJ22 into Bay Microbus - Finished project build thread- click on this spot here for info

dubbill Officially Full-On Dubber

336 posts · joined Jul 2005 · 30 Mar 2006, 10:09 pm

#469836

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

Andy Andy\'s Adventures

2,820 posts · joined Nov 2002 · 31 Mar 2006, 12:45 am

#469879

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

Samblers wrote: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.

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... ???

aggri1 Insano Dub Head

824 posts · joined Dec 2003 · 31 Mar 2006, 7:10 am

#469909

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

56astro Custom Title Time!

1,772 posts · joined Aug 2002 · 31 Mar 2006, 7:29 am

#469918

Kombi Dad wrote:I cruise at about 90 to 100 kmh.

Another mobile road block. No wonder kombis get a bad wrap.

:P
:thumb

VW car, VW engine ...... keepin it "real"
35MPG on 101.3kPa

Warrenm Wolfsburg Wizard

466 posts · joined Aug 2004 · 31 Mar 2006, 11:23 am

#470010

DoNkEy wrote: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.

Adjustment is at carby end. Sometimes end fitting is worn.

When you basically shorten cable you will probably have to re adjust idling speed

Kombi Konnection
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Warrenm Wolfsburg Wizard

466 posts · joined Aug 2004 · 31 Mar 2006, 11:28 am

#470013

aggri1 wrote:I wouldn't be disappointed with 10litres/100km, for a vehicle shaped the way they are, and with ancient carburretted engine technology.

Cheers, Aurel

The Kombi shape is quite aeordynamic and is superior to a Beetle. Search of archives will show a number of post and tech data on this.

Kombi Konnection
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modulus Veteran Volks Folk

2,009 posts · joined Jul 2003 · 31 Mar 2006, 6:52 pm

#470133

Warrenm wrote:The Kombi shape is quite aeordynamic ....

Well, while it is true that the Kombi is, shall we say, less bad than the Beetle, it is a stretch to think of it as quite aerodynamic. The drag coefficient for the Bay is 0.42, better than the '70s Beetle (0.46) but worse than, e.g., a Volkswagen Sirocco (0.39) a Mercury Topaz (0.36) a Toyota Celica (0.34) etc. etc. Since the frontal area of a Kombi is largish, the total aero drag is 0.42 X 'largish', resulting in the other well-known scientific value, 'biggish'.

The aero drag goes up in proportion to speed squared, so the result is a quite low top speed for a 70 hp car.

I haven't got any figures fro a Kombi with a roof-rack, but in general this sort of fitting does alarming things to the drag co-efficient, already bad in the case of the Kombi.

I *think* the Kombi's aero (and consequently fuel economy on country trips) can probably be improved by:
- no pop-top
- no racks, ladders, bicycles, gym sets or gas bottles hanging off
- no front bull bar or external spare wheel
- lowering (to get the effective frontal area down)
- front chin spoiler (to minimise the amount of air flow under the bus) and
- keeping the windows closed.
These steps combined would result in a complete loss of the Kombiness of the Kombi, a sort of DeKombination, which can't be good.

hth

[ Edited on 31-3-06 by modulus ]

Peter Hill
1975 Type 2 Double Cab
modulus.com.au

Samblers Officially Full-On Dubber

236 posts · joined Apr 2005 · 3 Apr 2006, 5:01 pm

#471120

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

76camper Fahrvergnugen

884 posts · joined Jan 2005 · 3 Apr 2006, 7:06 pm

#471191

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)

http://www.bytevision.com.au/dee/kombi/index.htm

Samblers Officially Full-On Dubber

236 posts · joined Apr 2005 · 13 Apr 2006, 2:35 pm

#475399

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

🙁

76camper Fahrvergnugen

884 posts · joined Jan 2005 · 13 Apr 2006, 6:14 pm

#475503

🙁 😢

http://www.bytevision.com.au/dee/kombi/index.htm

Bizarre Moderator The artist formerly known as blue74l

12,789 posts · joined Aug 2002 · 14 Apr 2006, 9:38 am

#475743

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

🙁

Out of interest - how have you determined that??

Futue te ipsum!!!

Samblers Officially Full-On Dubber

236 posts · joined Apr 2005 · 19 Apr 2006, 11:19 am

#477752

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 ???