>Question is: Is there anything special that needs to be done to the L20b
>engine when desmoging it? Does timing need to be chaned etc? I'm planning
>on putting new carbs on it (webers, mikunis?) and an exhaust header. I'm
>hoping I don't need any of the smog stuff as I don't even know if all the
>components work! The engine also looks like a mess with all that extra
>stuff.
Matt,
There's not really anything special about desmogging an L-20b or any
other L-motor. Unless you plan on keeping the motor buzzing around 5K
plus all the time, I'd strongly suggest going with a set of 38mm SU's and
(if it'll fit) an early non-smog L-16 exhaust manifold. The slightly
later manifolds with smog pump fitting are okay, you just have to plug up
the holes. I think they're 14mm by 1.50. Tom Walter has made plugs for
the roadster manifolds but I don't know if they're the same size. A nice
middle of the road Schneider or Isky cam (260 to 270 degrees/under '500
lift) in a 1 1/2 inch port head would be excellent for daily use in an
L-20b with the 38 SU's. The 46mm SU's are really too big for a daily
driver and would require a lot of fiddling to get the jetting even close.
As far as I know none of the L-series Weber/Mikuni manifolds have coolant
passages. Some folks might argue with this, but having coolant running
through the intake improves cold weather driveabililty a lot. Bottom
line, I'd suggest leaving the Weber/Mikunis for warm weather and racing.
Marc Sayer posted a comparison of Weber/SU flow sometime ago that was
VERY enlightening. The 38mm SU's with M66 needles is an excellent place
to start.
You really don't need a header for performance unless you are racing.
However you might need a custom built one for clearance. In my (510)
experience good equal length tubing headers tend to take up more room
under the hood than the cast iron manifold. Speaking of clearance, you
will almost certainly need custom motor mounts and you'll probably need
to modify the front crossmember to get the motor low enough to fit under
a stock hood. You may need a custom oil pan, too, but you might be able
to use an OEM pan, probably with some mods. There are all sorts of
L-series pans. Just make sure you match and/or modify the oil pickup to
whatever pan you use.
If the L-20 didn't come with one, get a late model breakerless
distributor, preferably one with the electronics attached. Get out Jason
Gray's distributor info site at <http://home.att.net/~jason510/>. This
should keep you busy for a while.
HIH, Ron
________________
Ronnie Day
rday@home.com
Dallas/Ft. Worth
'71 510 2-dr (Prepared class autocrosser)
'73 510 2-dr (Street Toy)
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