HIF fuel pipe conundrum

[Mr Spigot]

I am in the process of fitting an HIF carburettor but have a conundrum with the fuel inlet pipe. It has a captive securing nut which was presumably originally to fit a mating fuel pipe to - see photo. I have no idea what car it originally came off. I had intended to try and cut the nut off so that I can fit a pipe over the 'olive' and secure with jubilee clips. However, it occurred to me that it might be easier to take the 'olive' off the pipe so I can the slip the nut off.
My question is, is the 'olive' a compression fit over the brass tube, as in domestic plumbing, or is it cast into the pipe? If the former, I should be able to file a flat across it and then prise it off to release the nut. If the latter, I am back to either cutting the nut off, or trying to find a pipe adaptor fitting to secure the new inlet tube to.

Any advice welcome!

[daveejhitchins]

The olive is a compression fit - just like copper plumbing olives.

Dave H.

[Mr Spigot]

Many thanks. Just what I needed to know! Mission accomplished! Now to fit it and connect it all up!

[oliver90owner]

Double post?

[oliver90owner]

I would recommend against fitting fuel pipes on parallel connectors with a jubilee clip.

While it was not a jubilee-clipped pipe, In 1977 I suffered a fuel pipe disconnection from a carburettor body, while travelling at very high speed on a motorway. At over 3000 strokes per minute, the fuel pump dispensed a huge amount of fuel before the engine stopped (after immediate switch off). We were lucky there was no fire/explosion!

[Mr Spigot]

The standard pipe fittings on the fuel pump outlet are held by jubilee/hose clips so I would be surprised if they were not safe if properly fitted. I have used jubilee/hose clips for over 40 years without any problems. High speed use/racing may require something else. What alternatives would you suggest?

[oliver90owner]

The standard pipe fittings on the fuel pump outlet are held by jubilee/hose clips so I would be surprised if they were not safe if properly fitted. I have used jubilee/hose clips for over 40 years without any problems. High speed use/racing may require something else. What alternatives would you suggest?

Most sensible fuel pipes (which do not use olives or a suitable means of leak prevention) have an expanded part such that a jubilee clip will clamp the pipe beyond that expanded part - thereby preventing the pipe ever slipping off while the jubilee clip is sufficiently tightened.

My suggestion would be the same as you have recently removed from that pipe, with a proper serrated nipple affixed, to enable safe connection to a flexible pipe.

I have related the risk. It is up to you whether you take heed. A car is not like a lowly lawnmower or garden cultivator, where you can remove yourself to a safe distance in the case of a fuel leak/fire. There is proper fitting and bodging. I would place your choice in the latter category.

[svenedin]

The standard pipe fittings on the fuel pump outlet are held by jubilee/hose clips so I would be surprised if they were not safe if properly fitted. I have used jubilee/hose clips for over 40 years without any problems. High speed use/racing may require something else. What alternatives would you suggest?

Most sensible fuel pipes (which do not use olives or a suitable means of leak prevention) have an expanded part such that a jubilee clip will clamp the pipe beyond that expanded part - thereby preventing the pipe ever slipping off while the jubilee clip is sufficiently tightened.

My suggestion would be the same as you have recently removed from that pipe, with a proper serrated nipple affixed, to enable safe connection to a flexible pipe.

I have related the risk. It is up to you whether you take heed. A car is not like a lowly lawnmower or garden cultivator, where you can remove yourself to a safe distance in the case of a fuel leak/fire. There is proper fitting and bodging. I would place your choice in the latter category.

What you say makes sense but the fact is, the standard HS2 carburettor on a Minor has a parallel fuel pipe spigot and the flexible pipe is secured with a jubilee clip. I can't disagree that it could be done better but the standard SU fuel pump is a low pressure pump after all.

Stephen