Paul, I decided to post the E-Mail you sent to me. It's plenty obvious that you are talking to someone in a position to affect changes in the product design. It's pretty cool you were able to supply him with the Dupont link, and how willing he was to improve the pump!
This will become an excellent addition to the supplys available to those willing to cobble together there own alchy kit. Good job guy!!
Turbotim,
heres a couple of excerpts you may find interesting. The first explains a
bit of history, and the second comments some on the seal situation:
"Hello Paul,
Thanks for the link. We have been using Shurflo pumps for number of years
already mainly for high flow applications - truck racing and tractor pulling
is very popular in Europe - we supply them with shurflo pumps. I have no
problem recognising that their pump flows almost three times as much as
ours.
We developed the Aquamist water pump originally for the Ford's works rally
cars and they wanted a pump that weight less than 1 kg, Shurflo pump weighs
2.7kg and the Aquamist pump weighs 0.85 kg - in 1992, it weighs only 650g
!!- using aluminium winding instead of copper + few others lightening
tricks. The price for the pump was UKP 1200.00 each !!!.
We modified the pump for volume production in 1997 - bring the price down to
lees than 300.00 UKP - weighs slightly heavier. At the time - all private
rally teams wanted to use our pump instead of the shurflo, purely on slight
weight saving - means a lot for racers.
We did consider using the Shurflo pump for the aftermarket but most tuning
companies and the end users prefer to use our pump and willing to pay more -
perhaps it is just a matter of owning a piece of precision machined
component instead of a plastics moulded, high volume industrial pump - at
the time, flojet was another makers of diaphragm pump.
Round about the same time (1994) - Carroll Supercharger In New Jersey
marketed a water injection system based on the Shurflo pump. Rather
following the trend, we went ahead marketing our own pump despite the high
cost. We have come to learn that a few years later, we found out that we may
have achieved better sales in the UK than Carroll in the USA. We realised
that most of our customers liked the quality of our pump and don't mind
paying a bit more. It will be unlikely that we will stop making the present
pump and start using the shurflo for the aftermarket - we are current
supplying seven of our the eight works team of the WRC rally cars - we can't
really stop - accounts to 15-20% of our sales yearly.
It would be interest to found out the truth why people buy our system,
perhaps you can ask a few questions for me on varies boards. I really like
to know. There is just one little point on the aquamist pump's effect on the
water droplet size - the piston action creates a large spread of droplet
size - 30-80 microns on one single stroke. perhaps the range of droplet size
gives a better overall cooling coverage from the nozzle to the combustion
chamber - I am just guessing.
One other story from the history book - it was quite interesting to heard
from Carroll in the mid 90s, stating that their WI system pumps over a litre
of water into their customer's engine, I was stunned to learn that - we were
supplying Rolls Royce 's 6.7 litre Malsanne turbo and only pumping some
250cc/min of water to do the job of raising the boost pressure from 0.7 bar
to 1.2 bar !!!
Anyway, haven't really answered your questions.
Richard "
and
"Hello Paul,
Thanks very much for the link to Dupont.
A wealth of information there and I went through almost every link that
gives me the information on swelling - I may not have collated my thought
together yet - at present I am none the wiser after reading through the
articles.
The information we published and written on various emails regarding the
effect of alcohol was based on actual reports from our customers over the
years.
It has been found that de-natured alcohol (Ethanol) does contribute greatly
to the swelling of our valves. Ethanol has a very distinctive odour, easily
recognised by smell. Over the years we have been advising our customers to
avoid using windshield addictive that smells and diluted ethanol.
We also run tests at 0C, room temperature ~25C and 100C. We put all the
rubber components into a specimen bottom at concentrations between 25 to
100% at 25% increments. We used three alcohols - methanol, ethanol and
iso-propanyl.
The rubber parts are measured very three months - we used a range of gauges
to measure ID, OD and Depth. The test was consist with the advice given. We
started these tests in August last year.
Just to be absolute clear that our seals are made from viton and nitrile,
the two floating valves are made with NBR. Only three components are
critical to the operation of the pump: 1, 2 and 3 -marked by a red arrow.
Once the two valves and the o-ring seal are swollen, the pump can no longer
function properly especially number 3 - the all important floating valve,
responsible for priming and ejecting. The problem is reversible when clean
water is used to dilute the alcohol absorbed, providing the problem is
noticed early enough, normally pressure lost is the first sign. the o-ring
seal suffers from excessive wear - not too critical. None of these component
is expensive, the main cost of repair is the work to dis-assemble and
re-assembling the pump.
Some good news. We have decided to change the seals and valve material, it
has been good so far, we now have seals that run up to 75% of methanol, yet
to determine the result on iso-propanol and ethanol , I don't see that we
will have the new material in place for production and shipping until the
end of
this year. We still won't approve any user to run more than 50% due to the
prolong/accidental fume inhalation and fire hazard during dispensing and
mixing. We will put warning labels on all our systems before announcing that
our pump is compatible with alcohol. Finally, according to the Dupont
recommendation, all the rubber materials we used seemed to be OK for use
with any alcohol - somehow it didn't quite work in practice. Dupont also
have many types of Viton - we just don't have the time to try them all.
Anyway I will keep you informed of our progress. You must remember that our
system was originally designed for used with water only and only a small
amount of methanol is used in cold weather conditions. I see very little
point using alcohol as fuel enrichment from as single nozzle, in colder
weather, the droplet size will be large enough to cause uneven alcohol
distribution to the cylinders, leading to fuel starvation on the front
cylinders if the inlet manifold is the front entry type.
Regards
Richard "
Sorry for the length, but I sense that you find this stuff interesting!
Paul Elliott
