Superb 👍…As Mini(etc) owners, I’m guessing we know 70% of this…but the 30% you teach us , is both fascinating and of course critical to running and tuning….thankyou 👍
Amazing video! As a mini owner who tries to keep my car running, I find this content very useful and informative. Thank you so much for sharing this knowledge.
Glad you like them, please like and subscribe to my channel, this is your way of easily supporting me as this grows, and will enable me to add more content.
That’s just to point of this series it’s to explain how it works and help people make the right decisions when it comes to what they need to get their cars to run right
I do like your clearly explained videos. I've been in this game for a long time,but it does no harm to listen to the whys and wherefores . By the whey, I've throne away more than enough perfectly good wax jets in the past!
Nice one Constant depression carburettors are beautiful things And you mentioned the importance of the crankcase ventilation👍 it is positively dangerous to disconnect it Carbon monoxide isn't friendly
Thanks AC. Good as ever Subcribed. In my application, swapping from an HS6 with level float-bowl to HIF44, where you can't level the float-chamber, carb is to be tilted at 25-30 degress. Do we have to worry re: float height?
Great video! If I’m understanding well, the momentary enrichment of fuel when opening the throttle happens because the RPMs go up faster than the piston goes up (because of the delay effect caused by the damper), thus the air velocity momentarily increases because the open cross section in the carb body is still small (piston still down) causing a higher Venturi effect in the jet-needle?
The enrichment would also happen in constant RPM situations(Or even with (non-extreme) RPM drops) too, the enrichment happens because the piston lags behind the airflow increase from opening the throttle.
a good thing to show would be the different jets available for each carb. fixed jets come in rebuild kits, so do you piecemeal a rebuild kit? And do you use the waxstat jets for all HS carbs?
Great video, one of the most confusing things learning when a piston flys up (thin oil etc) it leans, which I'll admit was not what I used to think due to thinking the needle was pulling out and therefore must be enriching. As a side request you once did a videos with a weight (lay shaft I think) to show approximately the drop speed on a carb, would you be able to show that test on this hs4 please?
Thank you AC for this new episode on explaining SU carbs👍👍 I’m a little bit confused on why ported vacuum gives better emissions on idle. I already read a lot about this but don’t see the benefit. My 1275 is fitted with a 123 dizzy and the recommendation is to run this dizzy with ported vacuum. I’m a little bit unsure. What are your thoughts on this Thank you 🙏
when engine idle - set AFR 14.6 ( lambda 1 ) - very good emission, for higher revs you have correction by vacuum and for HIGH revs mechanical correction by ignition system ( distributor )
Does the float chamber need to be mounted with a rubber mount between it and the carb body ? I was always under the impression that if they were mounted solidly then vibration could cause problems with the fuel supply.
@ That’s interesting, never knew that. Both my cars are twin carbs and it’s 30+ years since I have owned a mini so don’t recall how the float chamber was mounted.
Great video AC, and happy birthday too.... Question.... why did the factory opt for manifold vacuum signal over behind throttle blade? Or is this just your performance improvement to only bring in vacuum advance quickly as throttle is opened....??
Superb 👍…As Mini(etc) owners, I’m guessing we know 70% of this…but the 30% you teach us , is both fascinating and of course critical to running and tuning….thankyou 👍
I would guess on average most are below 30%!
@@ACDodd Agreed, the less they know the confident they get!
The best video I’ve seen explaining the workings of a carburettor 👍🏻
There is more parts yet!
Amazing video!
As a mini owner who tries to keep my car running, I find this content very useful and informative. Thank you so much for sharing this knowledge.
Glad you like them, please like and subscribe to my channel, this is your way of easily supporting me as this grows, and will enable me to add more content.
Never understood how the piston was pulled up. Now I do!!! Good video. Thanks
That’s just to point of this series it’s to explain how it works and help people make the right decisions when it comes to what they need to get their cars to run right
Your knowledge of these su carbs are amazing great video
Another brilliant video - your sharing of knowledge and experience is greatly appreciated.
I do like your clearly explained videos. I've been in this game for a long time,but it does no harm to listen to the whys and wherefores . By the whey, I've throne away more than enough perfectly good wax jets in the past!
Extremely interesting video, AC. The SU is an ingenious contraption and a beautiful piece of engineering. Thanks for a great video👍
Im enjoying my home tutoring 😁 So interesting. Thanks AC
Clear and concise quality information.....👍
Excellent, thanks!
Excellent, thanks
Nice one Constant depression carburettors are beautiful things And you mentioned the importance of the crankcase ventilation👍 it is positively dangerous to disconnect it Carbon monoxide isn't friendly
I would not say it was dangerous but it’s most definitely not healthy for you.
Great informative video AC.. Learning all time . When you move the vacuum tube. Which process to you use to plug the old hole ..
Thred the hole and plug it.
Great video thanks
Thank you very much Sir🙏
Great video 👍I’d love you to explain how the Hif choke works? Thanks.
the same rule applies
@@flapjck1 it’s not the same though, it doesn’t lower the jet as it does with the HS2/4… So what does it do?
@@mcmotors100 The adjustment mechanism is different. The principle of operation is the same
Great video!
Are there HIF carbs with ported vacuum from factory? Mine is already ported vacuum.
Yes a few were made like this but the vast majority are manifold vacuum.
@ACDodd ok thanks. As my Mini is from 1992, maybe this change was implemented quite late in the production of carbs.
@@ptirom44it was, your 92 car has emission limits hence the factory adjusted the carb to ported vacuum for the same reason I do.
Thanks AC. Good as ever Subcribed. In my application, swapping from an HS6 with level float-bowl to HIF44, where you can't level the float-chamber, carb is to be tilted at 25-30 degress. Do we have to worry re: float height?
Should all be good nothing to worry about.
@@ACDodd Thanks AC.
Great video! If I’m understanding well, the momentary enrichment of fuel when opening the throttle happens because the RPMs go up faster than the piston goes up (because of the delay effect caused by the damper), thus the air velocity momentarily increases because the open cross section in the carb body is still small (piston still down) causing a higher Venturi effect in the jet-needle?
Yes
The enrichment would also happen in constant RPM situations(Or even with (non-extreme) RPM drops) too, the enrichment happens because the piston lags behind the airflow increase from opening the throttle.
a good thing to show would be the different jets available for each carb. fixed jets come in rebuild kits, so do you piecemeal a rebuild kit? And do you use the waxstat jets for all HS carbs?
No both jet types are available in rebuild kits, as are the exact rebuild kits I use for the carbs I rebuild, CRK121A for the HS4 carbs
Great video, one of the most confusing things learning when a piston flys up (thin oil etc) it leans, which I'll admit was not what I used to think due to thinking the needle was pulling out and therefore must be enriching. As a side request you once did a videos with a weight (lay shaft I think) to show approximately the drop speed on a carb, would you be able to show that test on this hs4 please?
Use the same test. It’s only starting point, and still maybe miles out for your actual car.
Will connecting a crankcase breather to the carb affect the mixture in the engine?
No, because the carb is calibrated with it fitted.
Thank you AC for this new episode on explaining SU carbs👍👍
I’m a little bit confused on
why ported vacuum gives better emissions on idle.
I already read a lot about this
but don’t see the benefit.
My 1275 is fitted with a 123 dizzy
and the recommendation is to run this dizzy with ported vacuum.
I’m a little bit unsure.
What are your thoughts on this
Thank you 🙏
when engine idle - set AFR 14.6 ( lambda 1 ) - very good emission, for higher revs you have correction by vacuum and for HIGH revs mechanical correction by ignition system ( distributor )
Nothing to be confused about too much vacuum advance at idle causes incomplete combustion, and therefore higher HC emissions.
@@ACDodd thank you
got it now 👍👍
Thank you for the presentation; do you use the wax jets on twin HS2's as well?
That’s a good question, and no is the answer
Does the float chamber need to be mounted with a rubber mount between it and the carb body ? I was always under the impression that if they were mounted solidly then vibration could cause problems with the fuel supply.
Only rubber mounted on the twin carb models, can’t say I have ever seen an issue on the single carb applications using a solid mount.
@ That’s interesting, never knew that. Both my cars are twin carbs and it’s 30+ years since I have owned a mini so don’t recall how the float chamber was mounted.
Great video AC, and happy birthday too.... Question.... why did the factory opt for manifold vacuum signal over behind throttle blade? Or is this just your performance improvement to only bring in vacuum advance quickly as throttle is opened....??
I will cover this at the begining of the next video.
You do do some pretty units. Is that some satin clean on the body?
No.
@@ACDodd I was kidding. 🤟 Are you using a tumbling media for body cleaning?
@ no tumbling
Hey teacher, how long till the next lesson? And i wish my pistons in the bell housing were that strong
Filming part 2 today.
Do you prefer hs or hif as a general rule?
HIF is a better carb full stop.
@ACDodd Thanks. From what I read a lot of people seem to want to swap from HIF to HS, at least on MGBs.