SLROC Forum

when I WAS RUNNING a disco 4.0 i was getting 19 mpg  a 3.9 rangie auto was 22 mpg and a 3.9 manual before the exhaust was changed to a sports system was 22 mpg  after it was changed i danced on the throttle and get less mileage

I Wish 

I need to spend some time on it, its running fine when cold jst wont idle properly when hot, I know its gettin a good spark as it tries to idle at 250 rpm so if the spark was bad it would not idle and just cut out.
I dont drive about at 55 also its only 16 miles to work, ill get a better idea on mpg when i take it to inverness next week.
Is there anybody in scotland (Fife ish) that is S**t hot with V8's???

I am sure they could set your timing advanced correctly to suit running LPG & have it running fine when on petrol..
www.wellsidemotors.co.uk

george

i played about with my 3.9 the base idle is critical the co2 is critical timing dizzy and leads also cap and rotar arm are critical  you have to start with the easy bits then move on to the more complicated bits  the vacume diaghprame in the dizzy could also be fubared i have had several split  your air meter could also be jiggered not alowing you to adjust the co2  the worst mpg i ever got was 10 mpg with a carbed 3.5 on the school run that one only returned 18 mpg just with one tankfull  normally it was 16 mpg it is complicated and time consuming  the first time once you have done it a lot you will be telling others how to do it
the last 25 years of v8 owner ship has been expencive but not a waste of time

SimonBBC makes better ignition Parts that Lr now. The so called genuine rotor arms are riveted pattern ones rather than moulded. I got cap leads and rotor arm for 48 quid delivered and they are excellent. Drew when last did it have new plugs?

Hi steve.

Serviced it last weekend, oil, filter and plugs, air filter is a K&N.
The leads I got from you are great and still on.
I ordered a new temp sender (the injection one) that was supposed to be an origional "Lucas" item, when i tried to tighten it up the plastic outer with the molded nut spun on the brass bulb so a 2 min job turned into an hour, I have never come across so much junk being sold as oe parts untill i started with Land Rovers, i have even found some britpart parts to be useless and have stopped using Paddocks as their customer service is the pits. (rant over).

In the 80s I ran, messed with, overhauled/rebuilt and lived with several V8 Sd1's for the best part of 10 years, being young and daft back then I used to go everywhere flat out, I won an autotest in one and even did night navigation rally's with the Raf in a standard one with a cage fitted and never once had problems with the ignition side of any v8, or overheating, or cracked blocks and in all that time I only had to change 1 cam due to wear and that was caused by low oil pressure.
My Disco has a crank pully that is 22degs out at tdc, has a new (not oe) mafm, new distributor, cap n rotor n leads and has never run the way I want it to run, I have to get to the bottom of it tho as i will be putin an auto in it asap.
I need to look at the distributor as the vac advance doesnt when you suck on the pipe (neither does the old one tho) and follow up on the other advice ive recieved in this thread.
I have to say that although the lpg stsyem I fitted is basic, im chuffed with it.
Asda is down to 69.7 for lpg.

keep the good advice cumin folks.

cheers.

Drew.

Who do you guys recomend for good quality v8 ign. parts

Drew.

I would suggest that you try it on an Airfilter that will let it breath better to see how it performs.

I know all the K&N claims and for dusty conditions and wet they are worth it,
i find they strangle an engine & may have something to do with your poor fuel economy.

Easy enough to put the K&N back on if you find no improvement with a filter suitable for the LPG.

george

Thanks George.

Im a bit glad of the K&N as about a week after fitting the lpg i had a backfire thru the inlet and im sure it would have blown the standard airbox to pieces, i have been told that there is a higher risk of inlet backfires when using aftermarket filters.
The standard air filter when new is very good, the problem lies in the air box which is quite restrictive, just take a look at the air inlet on the airbox and compair it with the size of the hoses around the mafm, that said, the reducer is very restrictive and the engine seems ok when on petrol but i dont go much above 3000rpm.

Drew.

How can a k&n strangle an engine? It's less restrictive than standard!

Drew google SimonBBC for ign parts, get the genuine lucas cap
With red rotor arm and the powermax leads. All are excellent quality and well priced.

Backfires are caused by lean running lpg, did you adjus the mixture after fitting the
K&n as the increased air flow will lean out the mixture considerably.

...or go 300 Tdi.   

Steve,
Its not the cost of buying K&N filters that stops me using them, its previous experience of a few.

In my experience of having first used K&N Airfilters when i was a young boy racer & later having bought vehicles fitted with K&N filters they are not more free flowing than a nice clean standard filter or an actual 'Free Flowing Filter.

There can be advantages in a K&N cone possibly, but thats not certain to be the same when you put a new K&N panel filter into an airbox.
In fact i can put a Jimny on the Analyser and change between filters & clearly see how it is breathing.
(i have a K&N filter sitting almost new now, removed from a Jimny so that it could run properly)
I usually use Pipercross filters & when not worriyng about water & not with LPG i gat MANN filters for not much money.

They are nice and strong & re-usable over a length of time, many years infact.
Which comes to the point of K&N filters,
properly cleaned and re-dressed they can be used again and again.

Still does not lead to them being 'free flowing,
but if your experience with them is positive, thats great.

george

Steve, thanks for the info, been onto their ebay shop so will keep you posted.

Genem, no thanks, id rather have a petrol.

Graeme, Its a cone filter im using, i tried a pannel filter in the BMW and apart from more induction noise any other gains were marginal. The filter im using is rated upto 400 bhp and was on my BMW, I will be refitting the standard filter box and filter so i can have a base line to start with.

cheers.

Drew.

Interesting stuff George, I have only ever experienced k&n with a suitably freer flowing exhaust, it does make a much bigger improvement I understand. An engine is just a pump after all!

I found a problem with the RPI engine & the big pan filter on top,
even though it was a Strengthened filter against Blow Backs, it was 'too open and exposed' to getting more air in with a gust on windy days.

On the motorway say coming through Fife and the big side gusts of wind, it was not the vehicle getting effected by sidewinds it was how the engine was running.
Blasts of air into the Defender Engine compartment could be felt in how the engine was performing.

Not a major problem but i was aware of the ambient air temp on the Gas mix between seasons and in windy conditions with a very open filter rather than one enclosed in an airbox and getting a more controlled Air Intake Temperture and flow.

Obviously the Ambient Temp changes, just not the unexcpected blast of air.
(it was a very basic system tho and no MAF or the likes)

george