So with the car on the road now, the sun shining as if it's about to go red giant, and a car show beckoning along
with it's many other attractions, mostly Texas burger shape, it's time for the first fill of "gogo juice".

So what should I use?

Since the 4* that the 907 drank in huge quantities back in 1976 is now a distant memory I'm not sure what to use.

Since I had 8p a litre left on the Tesco Clubcard I've just bought 35L of "Momentum 99"
No idea if that's a wise move or not.

Additives (lead replacement) seem to cost an arm and a leg as do octane boosters. Depending what report you read
it's all snake oil anyway.

As an aside I have an electronic dizzy fitted with no vac advance and the timing set a degree or two below what's
recommended for the original fuel.



What do we think ?


Looking forward to reading the replies.

Cheers,
Paul G

For the annual mileage our cars tend to do I would just use normal fuels and keep an eye on the valve clearances . Not so easy for some.

PS where's the car show?

99 to 100 was 5* so 99 should be fine, you could probably run on 95 without issue, 93 with retarded ignition should be fine
I run valve protector with octain boost and I bottle will do about 20 tankfuls

Put some castrol R in and smell the roses baby!!

So, OK to set timing to old 4 star setting if using 99oct ?

Paul G



@ Coozer

I'll put some R on the birthday list.

[Edited on 2/7/15 by 907]

If your running a standard engine yes
And also no
Unleaded fuel also contains more ethanol than leaded and the flame front is slower so I would start with where you are and try advancing a couple of degrees if all runs well with no pinking you can go to the original 4 degrees
That said if you have a manual distributor you will be reducing maximum advance at revs above 3000rpm or so

With 98 dB in my left ear and that damn ticking from the SU fuel pump in the other I don't think I'll hear any pinking.


I have a Powerspark non-vac electronic dizzy fitted with timing as, or as near as I can get to, what Lotus recommends. (in red)


Lotus 907 timing settings



Description



I had some stuff to deliver yesterday for a '55 Porsche so I took the Suttol.
It was the chap that "loaned" me Uncle Ron's book all those years ago so quite apt that a test run should call in and see him.

Engine seems to run well, possibly a little hesitant on the throttle, maybe richen mixture or increase accelerator pump setting?

Adjusted front shocks to give more ker-lunk and less bong-yong-yong (techy term).
The wheels will now run over cats eyes with hardly any noticeable suspension movement, although it was hard to find two cats
willing to lay down so I could test both wheels at once.


So for now I'll stick with "Momentum 99" and see how things pan out.


Cheers
Paul G

Edit to delete ref to car / flying show.

Cancelled due to, quote, "world events".

[Edited on 2/7/15 by 907]