Economy 3.9 vs 4.2

It is actually 8" longer. I get 13 mpg on gas as opposed to 16 on petrol when I was running on petrol.

HTH

Tony

So sounds like the added momentum overides the effect of the extra drag.

Lee D

On or around Fri, 10 Oct 2003 12:19:50 +0100, "Lee_D"

enlightened us thusly:

the word on 3.9 vs 3.5 is that the 3.9 give more go with similar or better economy. Dunno so much about 3.9 vs 4.2, but similar may apply there too.

I think this applies much more to the comparison between 3.5 carb and

3.9 than to 3.5 EFI vs 3.9. AFAIUI the 4.2 was a fairly hasty rebore of the 3.9 (let's face it, the whole LSE concept was a hasty bridge between the too small Classic and the forthcoming P38).

I would expect the 4.2 to be a bit worse than a 3.9, but not by much and mostly due to the extra weight of the LSE.

FWIW my Disco returns 18mpg fairly consistently (last news was actually 14mpg, but that's with roofrack, Northumberland hills and a very bad misfire).

Thankfully the misfire is gone, because now it won't start. Ignition amp is prime suspect...

Tim Hobbs

'58 Series 2 '77 101FC Ambulance '95 Discovery V8i

On or around Fri, 10 Oct 2003 15:57:38 +0100, Tim Hobbs enlightened us thusly:

look on the bright side, replacing the amp might cure the misfire too.

the 110 appears to be doing something slightly over 12 mpg, which is nice as before it was only doing about 11.

Just fitted some of Champion's triple-silicone leads. They're not magnecor, of course, but they're also about a third of the price. Similar construction, AFAIK too. Does sound a bit smoother.

Warren was stumped, but having waited several hours for a wheel bearing to arrive hadn't had much chance to test it, so only had about

45 minutes (after hours) to fiddle with it. Autologic says it's all OK, the ignition test thingummy says all is OK, but the engine is crap and the oscilloscope shows spikes on all cylinders alongside a very healthy main trace.

It's booked back on Monday for various bits swapping out (the great thing about Warren is that he will swap things with his comprehensive collection of bits to test them, but doesn't insist on starting with the most expensive part or charging for the ones that didn't make a difference, a la most main dealers). He suggested that the ignition amp was shagged, but says that mostly they work or they don't.

It seems his prophesy may be right - not sure how I'm going to get the damned thing to Sheffield for him to fix it!

Tim Hobbs

'58 Series 2 '77 101FC Ambulance '95 Discovery V8i

Bloody hell - you're right again (well nearly).

I replaced the ignition amp and the coil to no effect. I had a good spark from the king lead but sod all from the 8 HT's. Today I've replaced the rotor arm. The one that came off is clean and visibly identical to the one I've put on. But now it's fixed!

Just goes to show that

a) you can't always tell by looking at the thing b) a 1.50 component can be quite important!

Thanks Lee. I can get the bugger off the drive now and get the 101 out!

Tim Hobbs

'58 Series 2 '77 101FC Ambulance '95 Discovery V8i

Yeah BABY!!!! But will Your Mrs forgive me? :-) And to think I only looked as someone mentioned my favorite number (4.2) :-)

Glad to be of come service, may be worth taking a peek at the carbon bush which sits on the centre of the Dizzy, they have been known in the past to disintegrate and an even smaller item could bring it to a halt then.

Lee D

On or around Sat, 25 Oct 2003 21:07:34 +0100, "Lee_D" enlightened us thusly:

I don't think the 110 will get a 4.2. I might one day go to a 3.9 in it, if I think I can afford the insurance.