land-speed
[Top] [All Lists]

New Cars

To: land-speed@autox.team.net
Subject: New Cars
From: ardunbill@webtv.net
Date: Fri, 23 Mar 2001 22:08:42 -0500 (EST)
In response to Dave's questions, I have a four-speed, but the fast idle
and defective clutch linkage I started out with last year resulted in
very difficult gear selection at rest, from clutch drag.  I expect the
hydraulic throwout bearing will improve matters.   

The air-leak I referred to is the one resulting from the amount of
daylight around the closed throttle plates in this early Hilborn
injector, despite the fact that the plates are installed right side up,
regardless of how they are adjusted, and after the hot-adjustment in the
book.  The plates are made so that at full throttle, there is perhaps
1/32" end play in the throttle shaft assy, apparently so they won't bind
in the bores, and this represents a permanent air leak, apparently
designed-in.  The plates and bores are not worn, and the throttle shaft
is just free to rotate, but probably some air does leak past it.  I
don't think Hilborn is concerned about that point unless it becomes
severely worn, it affects the idle speed issue, but nothing else.

I do have an advancer in the Vertex mag, so it starts at 20 degrees
which the engine likes, and advances to 44 degrees by about 2500 rpm,
which is correct for the "cartridge fire" Ardun heads which involve a
little inherent retard of the ignition.

The veterans tell me that richening the idle is the only real way to
slow your Hilborn down.  One respected Ardun Bonneville man said he can
get his down to 1000.  1200 - 1500 would probably be okay too if the
clutch releases fully and well as it should.  But some other experts
tell me their Hilborns are not like mine, and don't have these built-in
air leaks.  Maybe it's because mine are early ones.  I don't know.  I'm
not disturbed about it in any case, the instrument is made for
full-throttle running as priority 1 and at that, it's very, very good.  

I got the car to work last September at Maxton.  Now I'm trying to
develop it a little to be more manageable and not hurt itself.  Cheers
Bill 

///
///  land-speed@autox.team.net mailing list
///


<Prev in Thread] Current Thread [Next in Thread>