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HS1 / Downton manifold .

Posted: Tue Mar 24, 2015 11:05 pm
by Orangerover
Just sent my twin HS1 ( 1-1/8 th ) to Burlen as the spindles had wear resulting in the idle being way to high.
They were running on a Calver 1218 (1098 +I00 thou ) probably a bit small to make use of the top end power but lots of torque low down compared to the correctly set up single 1.5 SU that I'm running while they are at Burlen.
Question is - can anyone give an educated guess as to what needles to use - old ones are probably worn so taking a number from them may not be reliable and were taken from a modified 850 engine.
Engine spec is -
1218
Sw5 type cam .
Calver 12g295 head.
3-1 small bore exhaust.
Want this to purr for Blyton !
Cheers.

Re: HS1 / Downton manifold .

Posted: Wed Mar 25, 2015 9:19 am
by Vegard
As you've got a "big" Cooper engine on the paper, I'd say fit twin Hs2s.
Why go to that sort of mods, and then strangle it that way?

I guess you won't find off the shelf needles.

Re: HS1 / Downton manifold .

Posted: Mon Mar 30, 2015 8:33 pm
by Orangerover
Vegard wrote:As you've got a "big" Cooper engine on the paper, I'd say fit twin Hs2s.
Why go to that sort of mods, and then strangle it that way?

I guess you won't find off the shelf needles.
Yes I could do that but Hs1s on a Downton manifold are so good looking .....
Going to start with hs2 needles from a 998 given that they will be in smaller carbs.
So based on not trading power for style I will stick with the hs1s as they feel great on the engine ie more torque than the 1.5 I currently have fitted.

Re: HS1 / Downton manifold .

Posted: Mon Mar 30, 2015 9:02 pm
by carbon
EB needles are listed for twin H1s on the '59 948cc Sprite as the rich needle option, these should be fairly easy to get hold of.

The Mini Cooper GY needle could also be a good starting point, will be slightly richer than the EB.

Other needles listed for twin H1s are much less common (BX1, M8, M6).

Re: HS1 / Downton manifold .

Posted: Fri Apr 03, 2015 8:51 am
by Orangerover
[quote][/quote]
Thanks - that's great advice -
Burlen called to say they had received the h1s and manifold -
£105 to fit bushes - £55 to strip carbs
£55 to assemble and about £120 for parts .
It tots up and I thought better of it and asked them to send them back with just the parts to fix .
Got a lathe and good pillar drill so I'll give it a go .

Re: HS1 / Downton manifold .

Posted: Fri Apr 03, 2015 2:38 pm
by surfblue63
Nielson

Thought I'd post a shot of those H1s in their engine bay so we can all see how good they look ;)

Image

Stuart

Re: HS1 / Downton manifold .

Posted: Fri Apr 03, 2015 5:22 pm
by 5portsrock
Good choice, definitely look good.
If your worried they dont breathe well enough you could always carryout a few mods to improve the airflow. Plenty of easy to carryout mods in the Vizard book.