HE Injector Fuel lines

Hello everyone,
Does anyone know the original inside diameter of the fuel lines to the injectors on an efi engine.Mine are 10 yrs old and have to go.
I’m about to rebuild with SAE 30 R9 hoses but need to know I.d.’s.
Any info appreciated.

I think the I.D.'s for the fuel lines are not the same for pre-HE, HE and 6.0L V12s.
Paging @SD_Faircloth

If anyone here would know, that’s him.

What is the year and model of the V12 Jaguar that you are working on?


He apparently has an XKE, that has been converted to run on fuel injection. The real question is then - where did the rail and injectors came from (thread title has HE but that’s about it).
As I indicated earlier, I think it matters if we talk about pre-HE, HE or 6.0L setups.

I agree. We need to know what year and model the injectors and fuel rail were sourced from, and hopefully they are the same.


5/16" aka 7.9 mm. You would be wise to use Gates hose that is CARB compliant. SAE30R14T2.
FYI for all. The old pre-HE engines used a 7.5 mm ID hose. I would suggest that is because 45 years ago, that was the available size in Europe. Today it is difficult to find, as that size is not now made in the USA. The difference between 5/16" and 7.5mm (9/32") is 1/32", and not worthy of worry. I have used 5/16" (7.9mm) for years. The 6.0 liter engines do not use hose between the rail and injector. SD Faircloth www.jaguarfuelinjectorservice.com

I have an XKE that was re-engined with a 1989(I think) HE efi engine, by PO Peter Mitchell of Jaguar fame. He made several pertinent mods to the car, efi, outboard rear brakes, 4spmg with overdrive, large rad, large vented discs, 2.88 diff, slightly different exhaust system, modified out of tank twin pump fuel system, and lots of little things.
Hope this gives a good idea of the car.