SU HD8 Carburettor - Rebuild & Restoration

I will show you how to disassemble, clean, polish, and rebuild a SU HD8 Carb from my Jaguar XJ6 project, but these carbs were used in MGs, Triumphs, Minis, and lots of other british cars. They're surprisingly simple, with very few parts, and easy to rebuild, I'll show you how!
Links:
#suhd8 #carburettor #jaguar

[@jimstocks]

The small lift pi on the side has 2 functions to see if the dashpot is not seized & during manual tuning lifting the dashpot while the engine is running a slight rise in rpm denotes correct mixture as opposed to using a gas analizer & using the large screw on the side of the carb body this ensures correct co for emission control & the dashpot is actually lifted off the main jet by 2 holes in the dashpot facing the butterfly vacuum formed between the butterfly & the holes acts on the top of the piston in the bell creating a variable Venturi over the main jet accompanied by the lift of the variable size of the needle that’s about as simple as I can tell it

[@Waldvogel45]

I believe that around 8. min 19 secs
the mystery part is just a standard SU feature, i.e a lift pin which is used to test the piston free rise and fall in case of doubt. On a non -running engine you can raise a normally free dashpot piston with this gizmo, and if all is well , on releasing the pin the piston drops freely with a nice metallic clic as it falls under its internal spring pressure dropping quickly onto the jet bridge. Baically it's a test in case of a a suspected jammed piston..

[@kennethtalbott2233]

nice one. think i'm gunno do mine on the 420G

[@donniebelcher7214]

Great job, Rob! Becareful going back and forth round rods. You want to light go with the circumference of the choke rod or even the butterfly shaft. Love the videos

[@recyclememalznz1450]

Excellent as usual your channel iv very underrated

[@addvancedgarage]

Thanks!

[@williamwright7262]

Mind the copper crush washers, they can cause problems. I got a Mini. Uropeians love crush washers.

[@dunmail7744]

2.07 Best not to bend that spring under the dashpot!

[@zx10danny1]

Rob, do you have an ultrasonic cleaner? Most of those carbs including all the small metal parts need to go into it. If you want that to run like factory, all that goop needs to get cleaned off. Also, if didn’t look like you cleaned the main jet needle. It is really important to clean that, without removing any metal or changing the shape. The fuel runs up along that needle into the Venturi of the carb. And any grit or grime left on that will effect your fuel metering.
I really like the garage content! You’re doing a great job jumping right in and going for it. Please keep it coming. 😊

[@addvancedgarage]

I do not. I just sprayed off the needle w carb cleaner and hoped for the best. I have replacement needles that came with the kit, but the old ones don't really show any wear, not sure if I should be replacing them or not?

[@zx10danny1]

@@addvancedgarage I would vote on the side of putting the new needles in. There’s nothing to wear. It really shouldn’t touch the jet and only have fuel passing over it. But and residue could harden into varnish changing the size and shape of the needles. But you saw it, not me. I trust your judgment.

[@davoco.2775]

You still doing anything with that jaaaaagg?

[@justinneo4406]

11:30 big screw

[@tomlipscomb2211]

18mm 😂 probably 5/32 furlong whitforth or some such made up size.

[@addvancedgarage]

Yeah I just kept using metric and standard on this project so far, never know what's going to fit. lol.