Fuel consumption with new manifold

[malcolm]

As per my other post, I have a new stainless steel "Long" manifold now on my series 2 2+2. So now my pipes are 6 into 2 all the way to the first silencer. Previously, as with all 2+2s, they were 6 into 2, then into one for a short way, then back to 2 for the first silencer. Why? Obviously more backpressure. Anyway, my consumptiuon ocver the last 3,000 miles has always been spot on 22 mpg. Consistent. Came back from Goodwood to Andover Sunday, then filled up, and stayed at a friends house. Drove home to Chelmsford this morning. An easy drive, so I expected good consumption, but was amazed when I refilled back home and found I'd done 27mpg! Great result, even though the purpose of the new pipes was merely to enhance the look under the bonnet.

[PeterCrespin]

That has to be with a five speed or 4-speed + 2.88 diff, right?

Has to be gentle driving of a well set up car too. Well done, I think?

The reason the 2+2 pipes siamese briefly is to get round the big square sump on the auto box. Since the 2+2 primaries are also longer than SWB models they used the same down pipe config on all 6-cyl 2+2s regardless of transmission type.

Pete

[malcolm]

Thanks for the info Pete. But no, mine is a standard 4 speed, no overdrive, and has the 3.07 diff. My handbook says the 3.07 diff should give 70mph in top at 2850 revs, and that's what I get exactly as checked with a handheld sat nav (TomTom) Drove at a steady 70 to 75 on the motorway most of the time, with a brief excess (daren't talk of speeds on forums as police have used them and videos to convict?) here and there to see if performance in top was crisper. It was. Bit of a hold up at the Dartford tunnel too which wouldn't have helped, but only for a short time. So very pleased with the consumption. I balanced the carbs myself with an SU flowmeter, and tuned using Garston colortune but setting richer than Garston say.
Oil consumption not quite as good, with 380 miles per pint over 3000 miles, but no smoke and engine sweet as a nut, so should I worry?

[Mark Gordon]

I'm surprised that the police have used a comment made on the internet to convict someone of speeding. Wouldn't they have to have physical evidence such as location, date and time, speed you're accused of reaching? I would think that if charged with an unobserved offense, the only defense necessary would be, "I admit it Your Honor, I was just shooting my mouth off to some friends and, no, I would NEVER exceed the legal posted speed, Your Honor, Sir!"

[Heuer]

They only go after people who post video's of themselves driving at excessive speeds. I had to remind someone on J-L about that a few years ago - pressing on in a D-Type replica through the English countryside with the speedo visible Not sure if that is why he quickly emigrated to America!

[malcolm]

Oh, OK, then my "brief excess" was a quick visit to 100 mph just to see how it went.
Think you're right; it's where people post videos showing a bike's speedo etc where they convict.

[Heuer]

Gotcha! This is a Police entrapment operation and you, my friend, are well and truly nicked!

[malcolm]

Damn! Fell for it! Fair cop guv

[Peter Harrison]

Hi All, I monitor my MPG and spark plug colour to be more sure that the optimal set-up has not drifted. I get 22-27mpg largely depending on use of the right foot and the balance of short/long runs. My lowest was <20 and my highest was 29.2! Mine is a series 2/4.2, 3.07 diff, factory manifolds etc. I also get 50mpg from my new 1.2L Mini One which is IDENTICAL to the E-type - per cylinder. Regards, Peterh