Inline Fuel Converters & Additives

[Neil MG]

I always felt that my car ran smoother after a good wash and clean out! Makes about as much sense as any of these in line systems or pellets in the boot!

IMHO placebo effect at best.

Now when I hear of the potential to improve performance and economy I like to see corresponding test figures. There are often ways to improve on 50 year old technology.

Recently there was a lot of discussion on an MGA forum about the benefit of using a shallow stub stack to eliminate the sharp entry into the carb. inside the shallow filters. Several members had reported distinct improvements in feel, so I received a pair and went to the dyno. Sure enough there was almost 4% power increase and 3% in torque. The improved throttle response was noticeably evident on driving too. So my point? A rounded stub stack design was introduced as standard together with a better filter design on the MGB. In other words the manufacturer recognised the improvement and introduced it in production. If anyone believes that the manufacturers would not take advantage of any proven fuel saving technology.... well need I say more.

BTW if anyone is tempted to use those small pancake "sports" filters, be warned they may significantly reduce performance compared to the standard set up!

[simmitc]

When unleaded first came out, Practical Classics ran some on-road tests using a standard vehicle with various additives and in-line / in-tank devices. Plain unleaded = valve seat recession. Various liquid additives worked, and matched the FBHVC endorsed products. The in-line / in-tank products were a complete failure. The manufacturers have always refused to release independent research. There is a clear conclusion.

[linearaudio]

Next spring I am determined to give the Broquet a go. Having been anorackish enough to record my fuel consumption tank to tank over the last 3 years, I can then make my own comparison, which will be either laughed at or of the "told you so" category! Not doing it this time of year as the consumption can get a bit erratic in the snow/ ice/ associated traffic!

[bmcecosse]

The round -edged stub-stack eliminates (or at least mitigates) the vena-contracta at the carb entrance. Well know improvement, and well worth doing on any carb if you want to run at full throttle. You can achieve it by simply taking a half-round file to the carb entrance - and yes -pancake filters are worse than useless......
Looking forward to the results LA!

[Neil MG]

... You can achieve it by simply taking a half-round file to the carb entrance ...

If you don't mind butchering both carburettor and filter housing...

[Bazzalucas]

Doggone it! Now I have to discard my pancake filters! Whatever next? I KNEW I should spent the extra money and got the waffle filters...or the bacon and egg ones...is anyone else hungry?

[bmcecosse]

You're not 'butchering' the parts - you will be improving them - making them as they should have been in the first place. And most importantly - not spending money!

[Alec]

Hello BMCE,

"making them as they should have been in the first place",

I'm not sure if my memory is failing but didn't some BL filter housing bases have a smooth radius, later Mini or 1100 ?

Alec

[bmcecosse]

Yes indeed they did - just not the earlier ones.

[rayofleamington]

Perhaps when 'science' can't see the wood for the trees, it should learn to accept that it has only limited means of analysis... ...Meanwhile, we should trust our instincts a little more too.

Placebo affects need blind testing to convince everyone they don't work.
The rest of us might trust the data from easily repeatable, 'properly engineered test program' as proof.

Having been anorackish enough to record my fuel consumption tank to tank over the last 3 years, I can then make my own comparison, which will be either laughed at or of the "told you so" category!

My mpg (also measured tank to tank over many years ) varies by more than 10% (varies up to 21% on my current car, although at the lowest it had a mechanical problem, so really only 16%).
What I found on one car was that I got a discrepancy on mpg between different fuel stations. That was unexplained until I though more about the fuel station itself. One forecourt sloping to one side, opposite in the other, and one caused a 2L air lock in the tank and the other didn't The numbers looked like I got better mpg when fuelling up at station A prior to B. Actually I was only getting more range.
what makes me wonder is how people judge the claimed mpg differences when variation depending on driving aggression, journey type and weather conditions can affect the result more than the claimed difference.

[bmcecosse]

I was going to suggest that when LA carries out his experiment - he should NOT work out the MPG as the test goes along - simply record miles and litres. Knowing the result could influence the driving style - ie drive slightly more carefully to get better MPG to 'make' it work - or vice versa of course.

[linearaudio]

Perhaps I need someone to fit/drop one of the things into my tank, at some time not known to me, so that I don't feel tempted to improve the consumption figures by prior knowledge of the "experiment" starting!!
Throughout the entire warm season, my fuel consumption on the mixed mileage I do has been within 1mpg tank-to-tank, so I am happy with the predictability of my base line!

[bmcecosse]

And - what was that MPG ?? The usual 40/45 mpg folk usually claim on here ?? Me - I'm lucky to get 30 maybe 35 on a good day.....but I don't have an MG cam in that engine.

[linearaudio]

OK!! If you really want, I can post the dodgy quality scrap of paper with last seasons figures, but....
38.4 to 40.1mpg with the 940 head and MG cam. Sudden sustained jump to 41.3 to 42.4mpg when I swapped the Moggy rad for a Metro one and so lost the mechanical fan.
I drive like her like the rest of the Essex looneys, and cruise at 70+ on the dual carraigeways, also carry quite a load of tools etc in the back for my call-out work, also often have 1 or 2 passengers.
Season before last had been ranging around 35-37mpg with the old 4.55 diff (now 3.9). Other than a slight extra sting-in-the-tail and greater desire to accelerate beyond the danger point of 6000, the MG cam made no noteable change to the consumption.
I am looking forward to some improved mpg results this winter with the vastly quicker warm-up of the Metro rad. Still need to block part of it off as she still runs cold! I would be the first to admit that winter figures are a bit scattered, depending on snow/slow traffic/detours down icy lanes etc!

[bmcecosse]

Very interesting indeed - + 2 mpg for ditching the fan !

[faversham999]

Over the Last year and 3000 miles I have averaged 32MPG with my standard 1961 2 door 948cc

[bmcecosse]

Slow driving there!

[rayofleamington]

I am looking forward to some improved mpg results this winter with the vastly quicker warm-up of the Metro rad. Still need to block part of it off as she still runs cold!

The rad shouldn't affect the warm up!?
The purpose of the rad is to receive hot water and return cold water - until the engine is warm the thermostat should be closed and not sending water to the rad.
Best system I know of is to remove the heater tap and replace with a permanently open stub pipe (like Marina version) and remove the bypass hose from water pump and close off the mating connection in the head. This gives optimum water flow to the interior heater and no flow anywhere else until engine is warm enough to open the thermostat.

[bmcecosse]

Couldn't agree more - my last Mini engine was rigged like that - and on the coldest day there would be warm air from the heater before I left the village - 1/4 mile slow driving at most!