Better economy

Larosto · Post by **Larosto** » Sun Apr 22, 2007 6:43 pm

Hi,

perhaps this can help anyone: I was looking to optimise fuel consumption, so I adjusted the distributor as discribed in the handbook, and renewed the contact breaker points. After that, I overhauled the carbs, (CD 175)- that means new needles, jets, diaphragms etc. Then I adjusted the carbs. Fuel consumption was about 18-19 ltrs per 100 km. That didn`t please me realy, `cause I`ve got a book about Land Rovers, which says that the Stage One can do 100 km with 16 ltrs if you drive normaly.
So I looked again at all parts which influence the fuel consumption, and I noticed that there was a problem with the intake temperature control system.
The temperature sensor in the air filter didn`t work, that means, the car gets hot air for the whole time. In normal case, it should only get hot air, if it is cold. But when the engine is hot, the flap should be closed, so that the engine gets cold air, that means air with more oxigene (O), which results in better burn.
For a test, I simply disconnected the tube from the vacuum capsule and closed it. Now, the engine always gets cold air. After the next test, the car did 100 km with just under 16 liters. I drove normaly, no racing speed, but not as a snale, but using the overdrive regulary. I drove in town traffic a little bit, motorway a bit, and the biggest part overland.
I think, that the air intake temperature control is sometimes neglected, but it strongly influences fuel consumption. Perhaps you should control it.

regards

Horst

Raggylad · Post by **Raggylad** » Sun Apr 22, 2007 11:18 pm

The Haynes Manual on early Range Rovers covers this and gives good directions on how to service this valve.

Nick

stirlsilver · Post by **stirlsilver** » Wed Apr 25, 2007 4:19 pm

I highly recommend changing the distributor over to an electronic version, no contacts to worry about and you can use a transistor coil which gives you oodles more spark. And as a result you can open up your plug gaps.

steven 90 · Post by **steven 90** » Sun Apr 29, 2007 2:32 pm

I never get below 25 liters

(30 liters on mud tyres).
I am now rebuilding my engine hoping this wil help.
Curently i have a holly carbu and a sprint-gas mixer from rpi.
With the new valves and head gaskets i hope it will drop a bit.

stirlsilver · Post by **stirlsilver** » Tue May 01, 2007 1:29 am

One thing that can help steven is changing the cam. If you want to go with a slight improvement put in the 3.9L cam shaft, it will give you a little more power. Or you could always research into some other after market cams, there is some more suited to LPG.
Stirling

steven 90 · Post by **steven 90** » Sun May 06, 2007 8:01 pm

stirlsilver wrote:One thing that can help steven is changing the cam. If you want to go with a slight improvement put in the 3.9L cam shaft, it will give you a little more power. Or you could always research into some other after market cams, there is some more suited to LPG.
Stirling

I have a 3.9 cam placed inside,before the 3.9 cam i was running with 33 liters/100 km.

I have just completed my rebuild,i have placed :
New valves and seats grinded
New valve springs
Heads checked (had a water fit).
New piston rings
New big end bearings.
And if the stupid hose from the thermostat bypass didn't leak i would have done a proper testdrive...
So i am hoping to get 22 liters/100 km.

gary_in_nz · Post by **gary_in_nz** » Mon May 07, 2007 4:41 am

hi, thats what i worked mine out to be about, 22l/100kms, and the only mod i have to my motor is, an electronic dizzy from a v8 ford, and removed the restrictors from the manifold.

i'm running old cross ply track gripper tyres 7.50 16LT (noisy as on the road, brillant off road,hopefully soon to get some radials, once i take her off the road for a bit, but thats another story), and at least 2/3 of my driving would be around town, going to and from work.

i get 230 to 240 odd kms to a 50 litre tank of 95 octane. I use a lead additive (Contains 200ml/litre kerosene and 800ml/litre alkyl phosphate) since the fuel in NZ has no lead, to help the valve seats out since the motor was designed to run on leaded gas, this only costs the same as a litre of 95 here, about NZD $1.58.

My rover 3.5L has done 48,000kms since a complete rebuild by specialist rover team, called Summit Engineering (Rotorua).

Please tell me how you get on with the rebuilt motor and what economy are you getting from it.

Cheers, Gary

steven 90 · Post by **steven 90** » Mon May 07, 2007 4:05 pm

Restrictors from the manifold

Do you mean the ones in the inlet ??.

I am hopping to serious test my engine sometime next week,will post it

gary_in_nz · Post by **gary_in_nz** » Tue May 08, 2007 5:04 am

yeah the ones between the carb and manifold, sorry to cause any confusion

Mik · Post by **Mik** » Tue May 08, 2007 6:08 pm

After Glencoyne have rebuilt my engine (3.9 cam, brand new SU's etc) and fitted high ratio gears, I use approx 12l/100 km when cruising around 90 km/h - pushing the load pedal of course affects this otherwise nice figure

Larosto · Post by **Larosto** » Tue May 08, 2007 8:17 pm

Hi,
you should have a look at your steering chain. If it is to long, your timing will be wrong, so the engine won`t run smoothy on low rpm. Fuel consumption will get worse, and power decreases. I renewed chain, cam, rocker shafts etc. Have a look at www.v8engines.com . There are good tips and good illustrations. The parts for rebuilding the engine are payeable. I bought the most of them at www.limora.com in Germany.

regards

Horst

steven 90 · Post by **steven 90** » Tue May 08, 2007 8:21 pm

Larosto wrote:Hi,
you should have a look at your steering chain. If it is to long, your timing will be wrong, so the engine won`t run smoothy on low rpm. Fuel consumption will get worse, and power decreases. I renewed chain, cam, rocker shafts etc. Have a look at www.v8engines.com . There are good tips and good illustrations. The parts for rebuilding the engine are payeable. I bought the most of them at www.limora.com in Germany.

regards

Horst

I have called several times with chris from rpi is a great guy and very funny to speak with

steven 90 · Post by **steven 90** » Thu May 17, 2007 6:55 am

I am testdriving it now,have done about 150 km.Power is serious increased and the full consumption has dropt.It is still early to say exactly.
It runs smoother only starting on lpg is still poor.(dont have a petrol tank anymore).

Steven

steven 90 · Post by **steven 90** » Sun May 20, 2007 7:46 am

24.3 liters /100 km and dropping will keep you posted...

S

steven 90 · Post by **steven 90** » Fri May 25, 2007 9:32 pm

22 liters/100 km tested for 200 km with 80 km highway.

S

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