A/C add on/tech question
Posted: Tue Jan 25, 2005 2:52 am
I have copied an e-mail I sent to Vintage Air. A supplier of after market
A/C - heater - defroster units. The following correspondence outlines my
concerns involving such an undertaking. Are there any engineers on the list that
could help me better understand this problem. Suggest any texts? I have no
experience with this. I only know it can be a potentially serious problem. I
understand car companies do exotic tests to determine correct damping and
ancillaries effects on the crankshaft. It is certainly beyond my capabilities. I
knew that when I sold my business and took some time off I would get my self in
trouble!
I am thinking of updating my 1969 Lotus Elan +2 by installing your A/C-
heater -defrost 05000 series. The car is now the subject of a complete "body off"
restoration. An ideal time to undertake such a project.
I have yet to determine whether or not the unit will fit in the place of the
original Smiths Heater Unit.
My initial concern is with damping torsional vibrations in the crankshaft
and accessory drives. My concern is knowing before hand that these forces are
understood and designed for. The Lotus twin cam engine does not utilize a
damped crankshaft pulley. The addition of the compressor mass and required double
crankshaft pulley could cause vibrations and/or crankshaft seal or
crankshaft failure. The block used for the Lotus twin cam is the Ford "Kent" engine
with a Lotus twin cam head. The water pump and engine front cover is also
unique to the Lotus variant.
It may be possible to use a crankshaft pulley from a Ford Cortina or Pinto
or Capri that was supplied with factory A/C. I will ask several engine experts
about the similarities of the Lotus and Ford Kent engines and crankshaft
pulleys.
I am concerned that even though the system works and may be vibration free
uncertain harmonics could cause premature crankshaft or ancillary failure.
What are your thoughts on this?
Thank you.
Robert Seligman
A/C - heater - defroster units. The following correspondence outlines my
concerns involving such an undertaking. Are there any engineers on the list that
could help me better understand this problem. Suggest any texts? I have no
experience with this. I only know it can be a potentially serious problem. I
understand car companies do exotic tests to determine correct damping and
ancillaries effects on the crankshaft. It is certainly beyond my capabilities. I
knew that when I sold my business and took some time off I would get my self in
trouble!
I am thinking of updating my 1969 Lotus Elan +2 by installing your A/C-
heater -defrost 05000 series. The car is now the subject of a complete "body off"
restoration. An ideal time to undertake such a project.
I have yet to determine whether or not the unit will fit in the place of the
original Smiths Heater Unit.
My initial concern is with damping torsional vibrations in the crankshaft
and accessory drives. My concern is knowing before hand that these forces are
understood and designed for. The Lotus twin cam engine does not utilize a
damped crankshaft pulley. The addition of the compressor mass and required double
crankshaft pulley could cause vibrations and/or crankshaft seal or
crankshaft failure. The block used for the Lotus twin cam is the Ford "Kent" engine
with a Lotus twin cam head. The water pump and engine front cover is also
unique to the Lotus variant.
It may be possible to use a crankshaft pulley from a Ford Cortina or Pinto
or Capri that was supplied with factory A/C. I will ask several engine experts
about the similarities of the Lotus and Ford Kent engines and crankshaft
pulleys.
I am concerned that even though the system works and may be vibration free
uncertain harmonics could cause premature crankshaft or ancillary failure.
What are your thoughts on this?
Thank you.
Robert Seligman