100A engine and non leaded petrol
 

Dear readers,

I am in the proces of restoring my 401/3. It did not run for the last 30 years, so I do not have an idea of what I have to do to make the 100A engine ready for running on non-leaded petrol. I would like to have some advise:

1. Is it possible to run the engine on non-leaded petrol with certain additives?
2. If so which additives give the best result?
3. Or should I adjust the engine in order to make it ready for non leaded petrol
4. Is so what adjustments are advisable.

Thank you in advance for reacting to this message.

PeterK
Holland

100A engine and non leaded petrol
 

Peter

I doubt you'll need to do anything, it should run okay on 95 Octane unleaded with the standard settings. However if you need guidance or are doing any rebuild work then Hurley Engine Services of Bath in the UK are the best people to speak to. They do all the boring and machining for Spencer Lane-Jones, Tony Byford and TT Workshops and they couldn't be more helpful. Speak to Paul on 01225 336812.

Ashley

100A engine and non leaded petrol
 

Ashley/
:

Great information for Peter. However, I have been lucky enough to buy
two Bristols ( both 406s) with 50,000 miles on the clock, and laid up
forever. As Bristol engines leak a bit of oil, the engines and
gearboxes were in super condition for their wear, and no corrosion
around there ( don't mention the rest). So no great relining, boring
nor all that. But all heads Loctited as a matter of course. Also
truing, if warped.

I'd suggest getting a professional, on hoist assessment, and I'd be
surprised if the bill for mechanicals is more than the quote for body
and cosmetics, but maybe you're not there yet!

Best. Sean

100A engine and non leaded petrol
 

Hello Peter K -

This has been a popular and mostly ill-informed topic on US car
forums for more than 10 years. I suggest an initial question should
be: Why was "lead" added to gasoline?

A good and concise answer can be found on
http://en.wikipedia.org/wiki/Gasoline under "Lead".

Current gasoline sold in the US matches the octane ratings of most
50s and 60s available gasoline, except the highest 95+
octanes. Ignition advance can be adjusted on most engines to avoid
detonation. I've never had any problems with my Imperial (Chrysler)
440 with a nominal 10.5/1 compression ratio.

The second feature of using lead was valve-seat "lubrication",
delaying seat recession, usually caused by high RPM use over
prolonged periods. This varies because of valve seat material and
design on any engine series/family. Many owners with
high-performance engines in the US specify hardened valve seats
during a rebuild, if that was not the original standard. Verified
reports of recession, however, are fairly rare.

Sorry I don't know much specific about Bristol engines, but the above
factors should apply to all gas/petrol engines.

Bob

100A engine and non leaded petrol
 

Dear Ashley, thank you for your reaction. As I am living in Holland the
Hurley option seems complicated. But I am glad with that suggestion as
well as your suggestion of the 'pressure test'

Regards

Peter Kwakkelstein

100A engine and non leaded petrol
 

Bob, thank you for taking the trouble to answer my questions. Your
experience sounds quite reassuring.

P

100A engine and non leaded petrol
 

Hallo Peter,
I lost contact with you in the nineties. My 403 came back on the road in
1995 completely rebuild.
I had my 100A engine reconditioned by Gerrit Meijerink in Enschede. I can
give you their adress details.
They installed new valveguides in the head, new valves and hardened
seatings for unleaded fuel.
And afterwards they pressurised the head several times .
All other work to the engineblock was also marvelous . I have done since
1995 some 40.000 KM's
without engine trouble.
Please contact me off-line on 020-6413921 or jpkoopmans@xs4all.nl

All the best ,
Jaap Koopmans, Netherlands