What Fuel?

[Jonk179]

I tried Tesco 99 and got a fair bit of carb spit back. Went back to supermarket super unleaded and all is fine. Not sure why this happened but hey ho.

[B.RAD]

Ran my old Xflow for a year with additive fine

Have ran for the past 3 years without, done over 6k miles no problem enough lead in the old engine it seems.

Best to use it, you're right in that they're "probably" ok without lead additive, but if you really push on or do any kind of track work where the revs and temps get high, wear will take place surprisingly quickly. Voice of experience

[Lyonspride]

If it's running high compression ratios, you want super unleaded as an absolute minimum.

 

Remember these old engines don't have knock sensors and the ignition doesn't compensate for poor fuel quality and super unleaded doesn't contain as much bio-ethanol as regular unleaded as long as you avoid the supermarkets..... In fact just avoid the supermarkets completely.

 

 

I'm assuming the head (like mine) has been converted to run on UL fuel?

[Dommo]

I use V-Power, but that's only because the injectors were cleaned when I built it and I wanted to keep them as clean as possible. Ultimately it would run on any only tripe, or at least until a couple of weeks ago.

[TAFKARM]

Generally super doesn't contain any ethanol, there are locations that it does though - South west UK (Plymouth) and Notth East (Teeside)

Personally, (maybe I'm biased, but I've worked in various supply roles for one of the majors for the past 10 years, including a stint contracting for one of the hypers) I stay away from the supermarket stuff, remember Tesco's silica contamination in the South East a few years back?

Yes to some extent petrol is petrol, the difference between the super markets and the majors is in the additive giving a nice clean burn...

(Typing on phone sorry)

[stephenh]

If I had an older engine running on carbs and distributor, and it was quite highly tuned I'd be looking for the highest octane rating generally available, and I'd be avoiding supermarket stuff.

Interesting to read what RussH says, rather confirms what I always suspected.

[SootySport]

Yes, Russ knows about this sort of stuff.

 

Luckily I have an Esso station 100yds. away from me and they price their fuel within 1p. of Tesco prices.  Two days a week they reduce the price by 2p. a litre  which often puts it below Tesco's price,  it's a win win for me.     So the yellow bathtub gets 95 fuel thrown into her, tried the 97 but no different as far as I could tell.

[Lyonspride]

 tried the 97 but no different as far as I could tell.

 

Well, people say this a lot, but the truth is that octane rating has nothing at all to do with power. It's purely about how stable the fuel is under compression, with lower octane ratings having a tendency to pre-ignite, thus requiring a slight retardation of the ignition to prevent damage to the pistons.

 

Anyone who says it makes a difference is just experiencing a placebo effect. Admittedly the TV ads, the media and "word of mouth" don't really help people to understand the truth. I had it explained to me by one of the guys that founded Aldon Automotive, the guy that rebuilt my engine many years ago.

 

On a motor with a set ignition timing and no knock sensor (old crossflow for example), running high compression ratios will mean having to use high octane fuel and once the ignition timing is set around that fuel quality, switching to lower octane could cause severe damage.

[Kevin (Mr T)]

So now I have the little beauty, should I get it tuned to the fuel that I intend using, that's how I am reading a lot of this.

 

If so, can anyone recommend anywhere in the Chelmsford or surrounding area to have this done?

[Pistol Pete]

The best rolling road locally - the two Steve's at Track and Road (or maybe Road and Track - can never remember).

 

They can be a bit grumpy but know their stuff and also have the benefit of doing evening sessions - but be warned you may finish very late - my first session finished at half past midnight! And they will insist you test drive it when they have finished

[Kevin (Mr T)]

Thanks Pete, that would be Rainham if I have googled correctly? As a novice, I have no idea what it might cost, any guidance available?

[Pistol Pete]

Last year I had mine rolling roaded with carbs and ECU Ignition was £200, if you have clockwork ignition it may be slightly cheaper.

 

Yes, Rainham.

[Lyonspride]

I have no idea what it might cost, any guidance available?

 

It's near impossible to say, it depends how much work and what parts need changing around (jets etc).

 

If I had to guess, I would say budget for £300 and you'll defo come back with change.

 

Whether your running Delorto or Weber carbs, the parts for these are not cheap these days.

[Kevin (Mr T)]

That's better then I was anticipating, better get it booked

[dombanks]

I love fuel threads on any car forum ... Bar the good advice regarding tuning/carbs/correct unleaded conversions etc the jist is always avoid supermarkets their petrol is petrol but not proper petrol, [maybe it's akin to that rain you know the fine stuff that gets you "really wet"] but not if its the good stuff, apart from sainsburys thats no good tescos is ok ...shell can do no wrong, esso is fine (but mine is attached to a tesco???... Must be the good stuff) high octane only ... In my 1.3 fiesta .... But that's ok as I get at least 50% more power and at least 200 more miles to a tank,

Cracking we need more of these threads. makes me chuckle