The 'E' Type Forum

I was wondering if my car was compatible with unleaded fuel , and whether the engine might need an expensive unleaded conversion , then , leafing through some old copies of Jag Driver magazine , I came across a letter from Mr. SR Jenkins , principle Engineer Power Train Development at Jaguar -

Quote " Since early `67 the valve seats of all Jag engines have been suitable for unleaded "
Is this still the current thinking ?

So , good news for me as mine is a late `67 early `68 car.

Hi
All ETypes have hardened seats by design, so can run on unleaded without any major changes. However, you may need to make timing/mixture changes to allow for the different grades of unleaded - 97, 98, 99 RON and E levels etc.

Mixture changes might be difficult as mine still has the Strombergs which are not tuneable apart from setting the idle speed.Timing - I`m reluctant to mess with it as it seems to perform ok ATM.

You may not need to make any changes - give it a go in standard tune. If you can get the best combination of high RON and low E, then you should be fine. I can get 99RON locally and all good.

max-it-out wrote: ↑

Fri Oct 04, 2019 1:18 pm

I was wondering if my car was compatible with unleaded fuel , and whether the engine might need an expensive unleaded conversion , then , leafing through some old copies of Jag Driver magazine , I came across a letter from Mr. SR Jenkins , principle Engineer Power Train Development at Jaguar -

Do you have a date for that Jaguar Driver magazine? I have checked all the Service and Part Bulletins up to 1973 and I can find no mention of a change in valve seats although the part numbers for the seats are different on the S2 cars.

Yes , its issue no.363 Oct 1990.

I was a member for quite a few years until I sold my Jag in `97 . Thinking about joining again but not sure which club to join - JDC JEC or some other ...any recommendations ?

Club choice is a personal thing. I find the JEC a bit oversized and remote. I'm a member of the E type club, but spend most of my time with the JDC. There, we have great tours, European as well as UK, and good days/weekends out. Very friendly. Also, everything is done at a cost basis, rather than making profit for the club.

Stromberg carbs are fuel mixture tuneable except for a few years around 1969/70. The sedans can be used for parts to change your carb bits to make them tunable.

Insert the two piece adjustment tool comprised of a tube that just fits into the top of the carb where the dampner drops in. The tube is thick and has a pin to locate an hold the piston to keep it from turning while adjusting. A long hex allen wrench slides into the tube and engages the hex at the top of the jet allowing you to screw the jet up or down therby changing the mixture.