[Healeys] Burlen SU experience

[Bob Spidell]

Interesting.

Another SU Burlen data point: the Burlen-supplied fuel pumps use an O-ring to 
seal against the banjo (there's a reset cut in the pump port for the O-ring). 
Though this seems to work OK, I'd prefer a good ol' fiber washer--crush issues 
notwithstanding--to the O-ring.


Bob


Freese, Ken wrote:
> I got new HD8's in 2001 and as I recall they were fine out of the box. I
> no longer remember my initial setup mixture adjustment techniques, but
> after last year's engine rebuild I couldn't seem to get an idle via the
> slow run screw. A good overall mixture was achieved on the engine dyno,
> though, using oxygen sensors. A few months ago, I wanted to get back to
> basics which is having the jet flush with the bridge and then richening
> the screw 2.5 turns. I could not get the jet up high enough to be flush
> (instead was .035 down). Thus I asked this list about what depth below
> flush corresponds to 2.5 turns. I think I got one response but I dug up
> an old HD8 and 2.5 turns corresponds to .060 depth which also
> corresponds to a 1:1 lever ratio with a screw pitch of 40 threads per
> inch.
> Yesterday I found out the two reasons I couldn't get the jet flush and
> they are unique to these new reproduction carburetors, not withstanding
> using "SU tooling".
> 1. The Burlen jets are very short. They are 1.145 long. The old SU and
> Moss supplied jets are 1.177. That is quite a bit.
> 
> 2. The lever that holds the mixture screw is not shaped properly. It
> interferes with another part of the casting so that the mixture screw
> lever doesn't get full travel in the lean direction.
> 
> Another area of difference to the original HD8 SU's is the use of metal
> throttle shaft bushings and push on rubber seals instead of Teflon
> sleeves. After 10 to 15 thousand miles, there is way too much slop in
> these bushings, requiring attention. One bushing has quite a large burr
> on it and the adjacent rubber seal has lots of cracks that the three
> don't. That seal won't last much longer. The bushings are of a split
> design, so I guess they have to leak a little bit.
> 
> Conclusion: might as well get your old HD8's rebuilt.
> 
> Ken Freese
> 65 BJ8



-- 
*******************************************************************
Bob Spidell           San Jose, CA            bspidell at comcast.net

*******************************************************************