• Hey Guest!
    British Car Forum has been supporting enthusiasts for over 25 years by providing a great place to share our love for British cars. You can support our efforts by upgrading your membership for less than the dues of most car clubs. There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Upgraded members don't see this banner, nor will you see the Google ads that appear on the site.)
Tips
Tips

Rich Needles - AUD1474 - Guidelines for use?

Share this page

S

SteveHall64Healey

Jedi Trainee
Offline
Does anyone know of any guidelines for the use of rich needles (AUD1474) versus the standard needles on the HD8 carburetors? I am wondering when to use the rush needles instead of the standard needles.

Thanks
Steve
 
I think they'd only be required in non-stock engines; i.e one with headers, higher compression or intake/carburettor mods. I've run STD needles in my BJ8 for over 140K miles with no issues (and up to 25MPG in the right circumstances). This with mostly 10% ethanol gas, but some think the richer needles work better with 'gasahol.' I think you'd need a dyno session to determine if they offer your car any advantage.
 
It was recommended by a shop won't name to install the richer needles due to ethanol. I have found no change except a noticeable drop in fuel consumption. I will put the originals back next time I fiddle with the carbs.
 
I ran the rich needles all last year - about 1500 miles. Although my experience is not the same as a dyno session, my perception is that there was a bit more power, particularly in the upper rev range. Mileage was definitely worse and the plugs were quite obviously affected with carbon build-up. This year, I went back to standard needles and after 150 miles the plugs are a textbook greyish-tan colour with no buildup. The engine was rebuilt two years ago with a DWR8 cam from Dennis Welch and I thought it could tolerate more fuel.
 
I have a DWR8 cam and HD8 SU's and use the standard needles. The plugs are textbook color. I tried the richer needles because of the addition of 10% ethanol on the advice of a shop owner and didn't notice any improvement.
 
I have a 184 cu in, DWR 8 engine with HD8 DMD manifold, 1.6 rockers, forged pistons and Kirk headers - running dual O2 meters.

I ran the rich needles for a while and they showed better power at higher rpms, however it wasn't really noticeable and mileage was lower. Plugs were always pretty dark but no fouling on a newish engine.
 
tahoe healey said:
It was recommended by a shop won't name to install the richer needles due to ethanol. I have found no change except a noticeable drop in fuel consumption. I will put the originals back next time I fiddle with the carbs.
Click to expand...

TH - The needle recommendation's something of a surprise given the altitude you live at.
 
The shop knew where I live as he comes up here a lot. That was my question but he insisted it would help. As I have stated, I notice no change. It has always run well up here and if I am going to be down at sea level for any length of time I tweak the jets 1/8 of a turn.
 
Back
Top