Petrol additive for an old engine
 

I've been given an elderly (40-50 years) cultivator - 4 stroke Briggs
and Stratton single cylinder engine. Seems to be all OK and the
engine runs fine. However I believe I should be adding something to
the petrol to make it equivalent to that containing lead.

A local agricultural machinery company said this wasn't necessary, but
a decoke would be advisable.

What's the collective's opinion please ?

Thanks

Rob

Petrol additive for an old engine
 

In article .com,
robgraham wrote:
I've been given an elderly (40-50 years) cultivator - 4 stroke Briggs
and Stratton single cylinder engine. Seems to be all OK and the
engine runs fine. However I believe I should be adding something to
the petrol to make it equivalent to that containing lead.

A local agricultural machinery company said this wasn't necessary, but
a decoke would be advisable.

What's the collective's opinion please ?

It really depends what the exhaust valve seat consists of. If it's part of
a cast iron block or cylinder head you might well have problems, but even
then not always. If the material the seat is in is aluminium it will have
a steel insert which is almost certainly hard enough.

--
*I have plenty of talent and vision. I just don't care.

Dave Plowman London SW
To e-mail, change noise into sound.

Petrol additive for an old engine
 

robgraham wrote:
I've been given an elderly (40-50 years) cultivator - 4 stroke Briggs
and Stratton single cylinder engine. Seems to be all OK and the
engine runs fine. However I believe I should be adding something to
the petrol to make it equivalent to that containing lead.

A local agricultural machinery company said this wasn't necessary, but
a decoke would be advisable.

What's the collective's opinion please ?


I'm with the local company.
A 50 year old briggs and stratton probably runs best on a mixture of
poteen and medical ether anyway. :-)

Decoke and regrind the valves, pour in something vaguely petroleum based
and it will run.




Thanks

Rob

Petrol additive for an old engine
 

In message .com,
robgraham writes
I've been given an elderly (40-50 years) cultivator - 4 stroke Briggs
and Stratton single cylinder engine. Seems to be all OK and the
engine runs fine. However I believe I should be adding something to
the petrol to make it equivalent to that containing lead.

A local agricultural machinery company said this wasn't necessary, but
a decoke would be advisable.

What's the collective's opinion please ?

If in doubt, just buy some petrol additive - available from plenty of
outlets

--
geoff

Petrol additive for an old engine
 

In article ,
raden wrote:
In message .com,
robgraham writes
I've been given an elderly (40-50 years) cultivator - 4 stroke Briggs
and Stratton single cylinder engine. Seems to be all OK and the
engine runs fine. However I believe I should be adding something to
the petrol to make it equivalent to that containing lead.

A local agricultural machinery company said this wasn't necessary, but
a decoke would be advisable.

What's the collective's opinion please ?

If in doubt, just buy some petrol additive - available from plenty of
outlets

Trouble is, according to the classic car mags, the jury's out on whether
they actually work - unless they contain lead which most don't. An old
engine builds up a coating of lead and this can last for a long time after
the source is removed.

--
*Why is it that rain drops but snow falls?

Dave Plowman London SW
To e-mail, change noise into sound.

Petrol additive for an old engine
 

Dave Plowman (News) wrote:
In article ,
raden wrote:
In message .com,
robgraham writes
I've been given an elderly (40-50 years) cultivator - 4 stroke Briggs
and Stratton single cylinder engine. Seems to be all OK and the
engine runs fine. However I believe I should be adding something to
the petrol to make it equivalent to that containing lead.

A local agricultural machinery company said this wasn't necessary, but
a decoke would be advisable.

What's the collective's opinion please ?

If in doubt, just buy some petrol additive - available from plenty of
outlets

Trouble is, according to the classic car mags, the jury's out on whether
they actually work - unless they contain lead which most don't. An old
engine builds up a coating of lead and this can last for a long time after
the source is removed.

Not sure that a 50 year old agricultural engine would have run on leaded
petrol anyway.

Very low RPM, usually low compression as well..most of the reasons to
put lead in were to do with squeezing extra power out of engines by
raising CR and RPM limits.

Petrol additive for an old engine
 

In article ,
The Natural Philosopher wrote:
Trouble is, according to the classic car mags, the jury's out on
whether they actually work - unless they contain lead which most
don't. An old engine builds up a coating of lead and this can last for
a long time after the source is removed.

Not sure that a 50 year old agricultural engine would have run on leaded
petrol anyway.

All petrol had lead in it since roughly WW2 until the recent(ish) ban.

Very low RPM, usually low compression as well..most of the reasons to
put lead in were to do with squeezing extra power out of engines by
raising CR and RPM limits.

But had the added lubrication and cooling properties that allowed the use
of poor quality valve seat materials.

--
*If love is blind, why is lingerie so popular?

Dave Plowman London SW
To e-mail, change noise into sound.

Petrol additive for an old engine
 

Dave Plowman (News) wrote:
In article ,
The Natural Philosopher wrote:
Trouble is, according to the classic car mags, the jury's out on
whether they actually work - unless they contain lead which most
don't. An old engine builds up a coating of lead and this can last for
a long time after the source is removed.

Not sure that a 50 year old agricultural engine would have run on leaded
petrol anyway.

All petrol had lead in it since roughly WW2 until the recent(ish) ban.

Very low RPM, usually low compression as well..most of the reasons to
put lead in were to do with squeezing extra power out of engines by
raising CR and RPM limits.

But had the added lubrication and cooling properties that allowed the use
of poor quality valve seat materials.


The average lawnmower engine will have run the sort of cycles over 50
years that would barely get a car from here to Brighton. And generates
the sort of power that would disgrace even a BMC 1100.

It doesn't NEED to have advanced materials..and didn't then and doesn't now.

Petrol additive for an old engine
 

On 13 Mar, 23:15, "robgraham" wrote:
I've been given an elderly (40-50 years) cultivator - 4 stroke Briggs
and Stratton single cylinder engine. Seems to be all OK and the
engine runs fine. However I believe I should be adding something to
the petrol to make it equivalent to that containing lead.

A local agricultural machinery company said this wasn't necessary, but
a decoke would be advisable.

What's the collective's opinion please ?

Thanks

Rob

Thanks guys - the thought had crossed my mind that the duty cycle,etc
would be so low that an additive might well not be necessary.

Interestingly I have tried several what I thought were suitable
outlets and they looked at me rather blankly !

Re. then suggestions of a decoke, how do I get round the probable
problem of a gasket, etc ?

Thanks again

Rob

Petrol additive for an old engine
 

On Mar 15, 9:14 am, "robgraham" wrote:
On 13 Mar, 23:15, "robgraham" wrote:

I've been given an elderly (40-50 years) cultivator - 4 stroke Briggs
and Stratton single cylinder engine. Seems to be all OK and the
engine runs fine. However I believe I should be adding something to
the petrol to make it equivalent to that containing lead.

A local agricultural machinery company said this wasn't necessary, but
a decoke would be advisable.

What's the collective's opinion please ?

Thanks

Rob

Thanks guys - the thought had crossed my mind that the duty cycle,etc
would be so low that an additive might well not be necessary.

Interestingly I have tried several what I thought were suitable
outlets and they looked at me rather blankly !

Re. then suggestions of a decoke, how do I get round the probable
problem of a gasket, etc ?

Thanks again

Rob

Just adjust the valves, change the oil etc and use it. That's what
I'd do if it were me and it otherwise ran ok.

Petrol additive for an old engine
 

robgraham wrote:
On 13 Mar, 23:15, "robgraham" wrote:
I've been given an elderly (40-50 years) cultivator - 4 stroke Briggs
and Stratton single cylinder engine. Seems to be all OK and the
engine runs fine. However I believe I should be adding something to
the petrol to make it equivalent to that containing lead.

A local agricultural machinery company said this wasn't necessary, but
a decoke would be advisable.

What's the collective's opinion please ?

Thanks

Rob

Thanks guys - the thought had crossed my mind that the duty cycle,etc
would be so low that an additive might well not be necessary.

Interestingly I have tried several what I thought were suitable
outlets and they looked at me rather blankly !

Re. then suggestions of a decoke, how do I get round the probable
problem of a gasket, etc ?


Make one.

You can in extremis use lead sheet..copper sheet..I've even used
cornflake packets for water gaskets.

Thanks again

Rob

Petrol additive for an old engine
 

In message , "Dave Plowman (News)"
writes
Trouble is, according to the classic car mags, the jury's out on whether
they actually work - unless they contain lead which most don't. An old
engine builds up a coating of lead and this can last for a long time after
the source is removed.

You can still buy leaded fuel though. The places that sell it are few
and far between but they do exist.
--
Clint Sharp

Petrol additive for an old engine
 

Clint Sharp wrote
In message , "Dave Plowman (News)"
writes
Trouble is, according to the classic car mags, the jury's out on whether
they actually work - unless they contain lead which most don't. An old
engine builds up a coating of lead and this can last for a long time after
the source is removed.

You can still buy leaded fuel though. The places that sell it are few
and far between but they do exist.

http://www.leadedpetrol.co.uk/
--
Roger Hunt

Petrol additive for an old engine
 

On 18 Mar, 16:04, Roger Hunt wrote:
Clint Sharp wrote

In message , "Dave Plowman (News)"
writes
Trouble is, according to the classic car mags, the jury's out on whether
they actually work - unless they contain lead which most don't. An old
engine builds up a coating of lead and this can last for a long time after
the source is removed.

You can still buy leaded fuel though. The places that sell it are few
and far between but they do exist.

http://www.leadedpetrol.co.uk/
--
Roger Hunt

Quote from this website :-

"That means you can advance the timing and raise the compression ratio
or turbo boost higher with leaded petrol than is possible with
unleaded or LRP, without detonation. That equals more power from your
engine. If you are involved in racing where seconds count, that could
be the edge you are looking for."

I'm driving a 50 year old single cylinder cultivator !! Do I need to
add anything more ?

Rob

Petrol additive for an old engine
 

robgraham wrote
On 18 Mar, 16:04, Roger Hunt wrote:
Clint Sharp wrote

In message , "Dave Plowman (News)"
writes
Trouble is, according to the classic car mags, the jury's out on whether
they actually work - unless they contain lead which most don't. An old
engine builds up a coating of lead and this can last for a long time after
the source is removed.

You can still buy leaded fuel though. The places that sell it are few
and far between but they do exist.

http://www.leadedpetrol.co.uk/

Quote from this website :-

"That means you can advance the timing and raise the compression ratio
or turbo boost higher with leaded petrol than is possible with
unleaded or LRP, without detonation. That equals more power from your
engine. If you are involved in racing where seconds count, that could
be the edge you are looking for."

I'm driving a 50 year old single cylinder cultivator !! Do I need to
add anything more ?

Open up the ports, skim the head, stick a Bonnie piston in there and run
it on Nitro.
(I have an Allen scythe and it is terrifying to use ...)
--
Roger Hunt

Petrol additive for an old engine
 

In message , Roger Hunt
writes
Open up the ports, skim the head, stick a Bonnie piston in there and run
it on Nitro.
Port the head, knife edge the valves and reprofile them for max flow,
add a second injector into the airflow and bring it in at WOT. Don't
forget the anti-reversal notches in the port if necessary. Depending on
space in the head, a second spark plug can yield a worthwhile boost in
power at higher revs but you need space. Of course, you've already
lightened and balanced the crank, baffled the sump to prevent oil surge
when cornering if you've not dry sumped the beast yet. Water injection
is handy for stopping detonation at higher boost pressures. BTW, don't
forget the natty little LEDs mounted on the bonnet that show you
*really* know how to tune an engine.
(I have an Allen scythe and it is terrifying to use ...)
Bugger, I'm in the wrong group again.
--
Clint Sharp

Petrol additive for an old engine
 

robgraham wrote:
On 18 Mar, 16:04, Roger Hunt wrote:
Clint Sharp wrote

In message , "Dave Plowman (News)"
writes
Trouble is, according to the classic car mags, the jury's out on whether
they actually work - unless they contain lead which most don't. An old
engine builds up a coating of lead and this can last for a long time after
the source is removed.
You can still buy leaded fuel though. The places that sell it are few
and far between but they do exist.
http://www.leadedpetrol.co.uk/
--
Roger Hunt

Quote from this website :-

"That means you can advance the timing and raise the compression ratio
or turbo boost higher with leaded petrol than is possible with
unleaded or LRP, without detonation. That equals more power from your
engine. If you are involved in racing where seconds count, that could
be the edge you are looking for."

I'm driving a 50 year old single cylinder cultivator !! Do I need to
add anything more ?

No. Run it on unleaded like everyine else does..and maybe retime it
slightly.

Those old engines run seriously rich anyway, which is anti-knocking in
its own right,. they run low comp, and if the exhaust valve eats burn in
another 50 years, there will still be enough metal in them to grind again.


Rob

Petrol additive for an old engine
 

Roger Hunt wrote:
robgraham wrote
On 18 Mar, 16:04, Roger Hunt wrote:
Clint Sharp wrote

In message , "Dave Plowman (News)"
writes
Trouble is, according to the classic car mags, the jury's out on whether
they actually work - unless they contain lead which most don't. An old
engine builds up a coating of lead and this can last for a long time after
the source is removed.
You can still buy leaded fuel though. The places that sell it are few
and far between but they do exist.
http://www.leadedpetrol.co.uk/
Quote from this website :-

"That means you can advance the timing and raise the compression ratio
or turbo boost higher with leaded petrol than is possible with
unleaded or LRP, without detonation. That equals more power from your
engine. If you are involved in racing where seconds count, that could
be the edge you are looking for."

I'm driving a 50 year old single cylinder cultivator !! Do I need to
add anything more ?

Open up the ports, skim the head, stick a Bonnie piston in there and run
it on Nitro.
(I have an Allen scythe and it is terrifying to use ...)

Bloody animal!

Petrol additive for an old engine
 

In message . com,
robgraham writes
"That means you can advance the timing and raise the compression ratio
or turbo boost higher with leaded petrol than is possible with unleaded
or LRP, without detonation. That equals more power from your engine. If
you are involved in racing where seconds count, that could be the edge
you are looking for."

I'm driving a 50 year old single cylinder cultivator !! Do I need to
add anything more ?

Yes. A nitrous oxide injector at the air manifold. :)

--
Clive Mitchell
http://www.bigclive.com