Genuine AC built Cobra for replica money

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Roger King
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Re: Genuine AC built Cobra for replica money

Post by Roger King »

This'll be us then:

https://www.youtube.com/watch?v=Xsr_k1wKSWI

(I'm sure that's better than the original, can remember the release of both - or maybe I'm confused)
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peterc
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Re: Genuine AC built Cobra for replica money

Post by peterc »

Clive,
My Rover is 4.6 and circa 275bhp.
MPG varies between 17-23 mpg obviously depending on road type and acceleration.
Theoretically with 9 galls available out of 10.5 and maybe 22mpg on a motorway would give almost the 200 miles. But a few decent accelerations reduces this to 17mpg thus only 150 miles. Besides the fuel gauge is not very linear so I tend to be on the cautious side. I have thought of talking to Spyida on their fuel gauge calibration device.
Longer term I might review of the space in the boot and what size the tank could expand to. Not sure whether I could justify the expense of a custom made tank.
Peter C
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clive
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Re: Genuine AC built Cobra for replica money

Post by clive »

I don't think it matters too much what capacity our tanks are, within reason, as we seldom travel vast distances away from petrol stations. Occasionally if I'm travelling North through the Highlands I'll carry a spare can of fuel in the boot just in case as petrol stations can be few and far between, but so far I've never needed it. I am quite paranoid about running out of fuel and so far, in over 40 years of driving, never have, but when the needle falls below 1/4 I'm on the lookout for a pit stop.
Cheers, Clive.

(If I'm not here I'm in my workshop or on the golf course!)
Paul Blore
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Re: Genuine AC built Cobra for replica money

Post by Paul Blore »

Roger King wrote:Cobra, Mini, MC and Mustang never get anything except Shell Nitro plus v max whatever they call it now. Partly because my rolling road guy always tells me to use it, but mostly because there's a good chance it contains less of the demon ethanol.
If I put standard unleaded in the Mustang (such as in Sicily, where there is nothing else available, or get caught short over here) it pinks like perky.
Really? I only ever put standard Unleaded on the Cobra and Ferrari and neither misbehave.

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Post by catsx11 »

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Last edited by catsx11 on Wed Aug 23, 2017 4:23 pm, edited 1 time in total.
Paul Blore
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Re: Genuine AC built Cobra for replica money

Post by Paul Blore »

I don't believe a carb can be setup for higher octane fuel, because the requirements are no different to normal fuel. I won't comment on the relative ethanol levels because I don't know, but the main difference with higher octane fuels is the increased anti-knock properties to prevent pinking. But I'd be surprised if any of our engines run compression ratios that would generally be considered high enough to dictate Super Unleaded fuels.
However, the combustion chamber shapes on our engines are generally pretty poor, with poor spark plug locations. This means that the fuel has to be ignited sooner to ensure that it is all burning as the piston passes TDC. It is probably this, more than anything else that is causing any pinking.

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Post by catsx11 »

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Last edited by catsx11 on Wed Aug 23, 2017 4:23 pm, edited 1 time in total.
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Roger King
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Re: Genuine AC built Cobra for replica money

Post by Roger King »

A long article, but a very interesting one which gives a basic octane/CR table under the 'octane and power' paragraph.

http://www.carbibles.com/fuel_engine_bible_pg3.html

Some very interesting stuff further on regarding ethanol and politics, which the public don't get to hear very often.

Anyhoo, my Mustang runs 9.5:1 CR (and 351Ws are very prone to knocking), the Cobra and Mini both run 10:1. And I have figures to prove that all give a better mpg return on superunleaded over 5-figure mileages.
The M Coupé's BMW handbook states that the S54B32 M3 engine should be fuelled with 98 RON - 12.5:1 CR and a much more modern design.

Can anybody see the original topic from here? I can't...

sorry, another edit - and yes, there are no jet changes for octane rating but ignition timing would be advanced. This is done for you in your modern Eurobox. Like so many other things are - don't get me started
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Re: Genuine AC built Cobra for replica money

Post by COX5012 »

My engine has a compression ratio of 11.2:1 which I guess is quite a high compression and the engine builder states " must use 97 octane or better". Not sure where you can buy higher octane than 97 Ron?
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Roger King
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Re: Genuine AC built Cobra for replica money

Post by Roger King »

COX5012 wrote:My engine has a compression ratio of 11.2:1 which I guess is quite a high compression and the engine builder states " must use 97 octane or better". Not sure where you can buy higher octane than 97 Ron?
Just stick Shell V-max Nitro whatever in it, it'll be fine.
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