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MG Midget and Sprite Technical - Best position of fuel line

As I've got my engine out I have some option to put things to right that I would not normally undertake. In this instance I'm interested in the best route for the fuel line (1275 midget).

A few years ago a 'Midget racer' told me he did not like my (standard?) layout of fuel line entering the engine bay on the right-hand side but then crossing to run down the inside of the left chassis rail. He argued this was too close to the exhaust manifold. With the engine in and the car running well, I left well alone. However, with the engine out it would be easy to re-route the fuel line but is it worth the effort (I've had no problems to date)?

P.S. You can tell I lost my job six weeks ago and have some time on my hands to do something constructive!!!

Chris
Chris H (1970 Midget 1275)

I doubt if there's really much point is there? I mean, the car came out of the factory like that and I'm willing to bet it's never once burst into flames. In fact, I don't think the pipe comes within 3 inches of the exhaust does it?
looking at the front of mine, I supose you could take it vertically up the front edge of the passenger footwell panel then down the diagonal chassis outrigger but it's pretty pointless.

graeme
graeme jackson

I've never had a problem with the standard routing, even on the racer.
Dave O'Neill 2

We suffered very badly with fuel problems, the fuel was literally boiling in the glass filter in the engine bay on tick over.

Our routing is now from the tank into the boot where we have mounted 2 Facet Red Top pumps.

From the boot it then passes back into the real "cave" and is p-clipped along the original threaded studs until it turns 90 degrees and passes through the bulkhead and into the cockpit.

If you look into the cockpit in this photo you will see where both the fuel line and brake line come through thte bulkhead. I still get cold sweats at the thought I made the entire line from the engine bay to the boot in one run :S



PeterJMoore

Being done like that will prevent the copper or kunifer from perishing very quickly due to being away from the elements. We also made sure it was clear of our seats and anything else that could rub or hurt it.

It then bends up the bulkhead and across the underside of the lip behind the dash

My apologies, the wiring wasnt finished at this stage is is not neat or tidy.

Again, to prevent rubbing or shorting, the pipe was covered with heat shrink (doubled up in thickness) and p-clipped to prevent vibration and subsequent cracking.





PeterJMoore

It is then turned 90 degrees upwards (and contoured around the lip) and out the hole in the bulkhead to the engine bay.

This brings it right in line with the edge of the battery try and as such an ideal place to mount it securely.

You can see in the photo below where it appears in the engine bay to the right of the battery.

We have now cut it a little shorter as the fuel filter and regulator are mounted outboard of the hole and meant that a neat wee bit of braided line was required to join the two.



PeterJMoore

Pete the problem you had was self-inflicted; if left as designed, without the glass bowl filter, I sugggest you would not have had a problem to fix.
David Smith

We require a regulator

As such it is mounted as close to the carbs as we can within reason.

It wasnt the filter that was causing the problem, just the fact the fuel line was passing too close to the gearbox, engine and manifold en route to the bulkhead so it was boiling by the time it reached the filter.

The original design would have lasted about 5 minutes in one of the farmyards we get to throw the cars through - one good stone or ledge and your fuel line is gone.

Have also recently seen lines run in the tunnel get caught up in the prop (not sure on specifics)

There is good reason why we have run everything the way we have. All modifications to the car have been done to eliminate problems encountered in the past.

At the end of the day we have to produce an incredibly reliable, easily maintained and highly competitive car, and due to this reason almost everything bad has been considered when we were putting the car back together, everything has its place and is designed to cause minimum/no impact to other areas/items and even remain safe in the event of an accident.

We dont throw cars together, everything must go through extensive planning prior to going on to the building/fabricating stage

PeterJMoore

If it were me I'd spec the pump to match the demand of the carb & engine spec, so that no extra points of failure (regulator and after market filter) required. Saves time, money and weight too :-)
David Smith

peter. I can understand that the changes you've made were neccessary from a competition point of view. However, Chris doesn't mention anything other than a standard roadgoing car so i'm still convinced the original fuel line routing is more than adequate.
graeme jackson

David - Getting the pumps spec'd would be fine if we didnt have to alter the pressures during rolling road tuning, so kind of eliminates the ability to fine tune the fuel system every time - which makes it expensive if you have to redo the pumps every time.

Graeme - I kinda agree, but he asked for suggestions and I gave him mine.

We are of the understanding that the best road cars are in fact competition cars with carpet. The development that goes into the wee cars is all in aid of improving them as a driving car, so what better to base your road car on than a competition car.

It was only a suggestion, whether Chris wants to go with it or not is his decision and I for one am not going to push him down a route he doesnt need to go. The one thing I will add is that it is the safest way to route a fuel line (just look at all rally cars) and it keeps everything away from heat sources and the elements.

Pete
PeterJMoore

This thread was discussed between 26/10/2010 and 27/10/2010

MG Midget and Sprite Technical index

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