More questions, aircooledness, gearbox ratios, t25 slowness

[z3i]

Hello, im back again after 2 months. After the cylinder head went bang on my 2l CU Aircooled bus, Ive managed to source another one, have it rebuilt, bolt it all on, find out its the wrong one, take it all off, have a massive argument with the guy that sold it to me, get nowhere. Buy another used genuine head, have that rebuild and finally get it on. My girlfriend also spent £750 on a complete new exhaust with heat exchangers and all those other bits we never had. Bolted it all back together and it runs like a dream, runs exceptionally well! I also found out why my oil pressure was so low..... So some absolute idiot fitted a dipstick that was too long!! I drained the oil and filled it with the correct amount 3.5L it was about twice the height of the maximum mark on the dipstick!!! i really couldn't believe it!! so the bus had been driven around with about 1.75L of oil in it!! grr, im surprised the engine is even alive! but runs great now, phew

Anyway, onto the latest. So me and my girlfriend gutted the van, tore out the hideous, poorly constructed 'devon' interior (my god what a shower of s***!! ive never seen such terrible workmanship!! anyway so its a bare shell inside now ready for us to build up (around the rust) but we drove it 60 miles last night from mine to hers and the engine was nice, pulls very well didn't miss a beat. However..... although you can quite easily push the bus to 65mph probably more, it sounds so straining on the engine!! i haven't got a tachometer, but it seems happy at about 45mph!! any more and it sound so revvy, like its got a dam rally cross gearbox on it! 1st gear is like 5mph! its terrible on fuel, absolutely terrible! we want to tour Europe in it, but this is never going to happen with it doing £20 for 60 miles!! How we will get anywhere doing 45mph!! 45MPH!!!! we have a single twin choke weber on it, i plan to fit original carbs when i get some more money (it came with the weber) which may help, I've been told to maybe fit bigger wheels and tyres, but feel this wont help much. I looked at other gearboxes. but not getting very far with that, maybe a diesel box on a 2l Aircooled? are there any other gearboxes with higher ratios? my friend said about fitting a brickwerks 4.14 final drive, but they are £650! and only for diesels?
I feel the van should be alot better on fuel as its a bare shell

anyway, a little disheartened with how much money and effort weve spent on it, yet its no where near a level to tour Europe

many thanks
Taylor

[tforturton]

You can read all sorts of threads on here about fuel consumption, but the truth of the matter is that the petrol versions of these vans are not particularly fuel-efficient. They're heavy, square, under-powered, and use old-school technology (the air cooled engine design dates back to the thirties...), so you're probably expecting too much from them, in the way of mph and mpg. Even the best stock van is probably happiest at 60mph, and your van should do that fairly happily.
Diesels are more fuel efficient, but you already have a petrol, and a petrol/diesel engine swap is a big and expensive job, so unless you're going to sell up and buy another bus, you're stuck with it. You could improve mpg by fitting lpg, at a cost of about £1200, and that will halve the fuel bills. But you can buy a lot of fuel with £1200. Is it worth it?
You have to realise these are old vans, and were never built to crusie at the sort of speeds you're dreaming off.

[bigherb]

I looked at other gearboxes. but not getting very far with that, maybe a diesel box on a 2l Aircooled? are there any other gearboxes with higher ratios?

Short answer No.
The 2 ltr DK box is one of the highest geared box's around 19 mph per 1000 rpm in 4th gear on standard tyres, which is around 80 mph at 4000 rpm.
Check you have actually got a 2ltr box and not a 1.6lt DH box which is around 16.5 mph per 1000 rpm.

You can get good cheap rev counters to tell you what the engine is actually doing.
http://forum.club8090.co.uk/viewtopic.p ... r#p8130010" onclick="window.open(this.href);return false;

[CovKid]

I've been a massive fan of the VW lump for over 30 years (owned 10 to date) but even I concede its had its day when you compare it to the efficiency of modern engines. However, there is a rub. To get that level of efficiency requires far more electronics and with that comes even greater costs in terms of servicing and parts. My runaround car (Smart) does about 220 miles on a full tank (£17 worth) and great though that is, it doesn't beat the ride comfort or the sheer fun of driving a T25 and changing as clutch means removing the entire subframe on the Smart. No way would I do long distance in the Smart either. It serves its purpose brilliantly during the week but I can't sleep in it, spend weekends away in it or enjoy fixing it. The camper does a very different job and MPG and power aside, it does it very well. Its also going up in value every year.

You could improve power, mostly at the cost of MPG but its really about looking at its purpose in a different way I think. Either that or swap the engine out but the stock Aircooled body places limits on that.

[Mocki]

What herb said ^^^^
And that Webber isn't doing you any favours at all with power or mpg .
The CU runs best with twin carbs , dells or standard solex

[Mr Bean]

I agree with CovKid.
Apart from a brief love affair with an early beetle which I completely rebuilt and sprayed silver then in Roots Electr9ic blue because it looked like a deflated Barrage Balloon in silver, I am a late entrant to VW in the form of a 1988 Leisure Drive High top 2.1 water boxer which again have almost completely rebuilt - £500 to buy plus circa £3K to rebuild and re-fit.
I am a realist however and also run a Y reg focus for town and long same day journeys. I use the camper for towing boats to rallies, touring holidays and overnighting on visits to relations etc. In my mind running two some might call "Bangers" is no more expensive than running one say fairly up market camper from new. I have no real idea how much petrol they use and am not really that interested as I the Focus owes me nothing and will be replaced by a similar "Banger" should it blow an engine or gearbox and the camper saves me hundreds if not thousands of pounds in accommodation and releases me from the hassle of seeking digs or getting put up in other peoples houses no matter how accommodating they might be. In other words I have complete freedom. If one should break down I can use the other while I fix it.
I do realize that I have to have two or three thousand pounds set aside for a complete Focus replacement and at least similar amount for a serious problem on the camper. But then once a new vehicle runs out of warranty you are in the same boat. But the real driver is the hobby and comradeship element of a more or less classic vehicle type of which in my opinion the T25 certainly is. I generally pass two or three miscellaneous T25's per hundred miles on motorways when cruising at between 60 and 70MPH. But I admit it takes a lot of reading the road and anticipation to prevent from being bogged down on hills and by dodgers in.
I have to say that the Club 80-90 forum has been unbelievably helpful particularly in the early days.
CS

[rivage5]

Hi there - just done a 950 mile round trip up to Scotland in our Devon (taking in Volksfling - first time there - great show) and on to the top end of Mull, over some very big mountain roads. Had realy good weather and had a fantasic holiday in our van which is a 2.0 Aircooled auto ...... so as you might imagine the mpg is mid teens at best - fortunately he runs on LPG, so even paying top prices for LPG in the highlands (having paid nearly 70p/litre up there, I recon we averaged over the entire trip around the mid twenty's - would have been better if I had a bigger LPG tank and could fill up at 48p/litre more often. At 48p/litre it works aout at about 30mpg irespective of how I drive.

Friends who drag caravans up and down the countryside say they only get mid 20's when towing, so I can put up with wafting along (auto) in our VW cammper being waved at by fellow VW drivers with an enthusiastic wave rather than being waved at with some other kind of odd hand gesture.

Two weeks after coming back I am still grinning from the trip.

He runs standard twin solex carbs and a three speed auto by the way. We would all love better fuel economy and more power ...... but I really can't complain for the amount of total investment.

Hope you find a solution.

[CovKid]

The Aircooled T25s were very much a case of 'testing the water' as far as VW were concerned, appearing as they did for the first three years of production with suitcase engines (as some like to call them). Then when they figured there might be a good market for them, they basically took the standard VW lump and forced water around it. The T25 was very much the last of what most die-hard dubbers see as the finale. After that the engine was moved to the front to get greater commercial sales and the rest is history.

I've owned both types over the years (air & water models) and apart from a DOKA I converted to take a bored-out beetle lump in 1995 (the headroom is there on that model), I have gone to great lengths to avoid Aircooled T25s due to the complexities involved in converting them to accept watercooled engines. Horses for courses I suppose as wasserboxers bring their own problems, but the cost of heat exchangers and a rapidly dwindling partsbase for Aircooled models convinced me to stick with the watercooled body. Fitting one with a bug lump was a step in the right direction since the US market still has a great following for earlier Aircooled engines so spares are not a problem. It was fabulous to drive and easy to fix. I just felt the suitcase engine was an unhelpful, even bizarre diversion and ultimately was a no-go for VW themselves. Its a great collectors item all the same, and fairly reliable.

That said, an Aircooled CAN be adapted to take a rad and that then offers far more choice of engines. If I was buying a T25 now, my first criteria would be does it have a watercooled lump and how much rot is there under the shiney paint. With that as a starting base anything is possible. Mileage is pretty much irrelevant. You can force more fuel into the Aircooled lump and make it breathe better, but it is what it is. Just enjoy it and don't waste hundreds of pounds trying to get more ooomf out of it. The gains won't really justify the expense.

[Ralf85]

I get about the same mpg from my 1.9 water cooled as I did from my old T2 air cooled about 24mph at a steady 55/60mph on the motorway. You won't get any better pulling a heavy van. The difference is the ability of the more powerful water cooled van is that it can go up most hills faster in 4th/3rd gear instead of dropping down to 2nd.

[CovKid]

Said this a few times over the years but the T25 needed a 2.5 or 3.0 engine. It was always underpowered as stock. I always felt that had they developed a bigger engine, MPG would have if anything, risen.

[faggie]

if you upjet the standard carbs and remove the chokes the fuel consumption actually goes up managed 26/ 28 on a run even m ore if you up the cc to 2400cc and even more with a b igger motor as you don't need to drive it as hard you should be able to go loads faster than 45mph if you have the correct dk gearbox

[multisi]

So what gearbox is fitted to that thirsty beast ? Have a look for the code .

[kevtherev]

What herb said ^^^^
And that Webber isn't doing you any favours at all with power or mpg .
The CU runs best with twin carbs , dells or standard solex

X2.

[dapple]

HI,my old air cooled t25 could do 70mph and a bit more but never had more than 17 mpg had twin Webbers very thirsty

[z3i]

Hi guys. Thank you for all your replies
We've been getting around 16mpg maybe less. Just worked it out

Just checked my gearbox and it's got a definite DH stamped on it? So this is the one from the 1.6 Aircooled?

Would a different box make a big difference? Our engine is definitely the 2l CU as I can see that stamped on it clearly

What box do you recommend? Would refurbed twin carbs and another box help me considerably? Many thanks