In a day and age where anything worth knowing is behind paywalls and subscriptions, AC Dodd is just casually gifting the world the most incredible information in easy to understand content through his years of experience. Thanks again for another fantastic video, once my car is back on 4 wheels, this carb won't know what's hit it. At least until I come and see you on a tuning session in the future!
Thanks AC i have spent most of the holidays going through your videos and I can’t tell you how educational they have been. Please keep them coming and a Happy New Year to everyone.
great summary AC many thanks. I have learned more from you than from any other site or shop manuals. We bought a new '67 MGBGT and the first winter (and winter in Saskatoon regularly has temps -20 to -30C) the car was stumbling on acceleration. Back to the dealership and the foreman's instructions to the mechanic were ' richen the carbs 3 flats '. The right thing to do ? John in Manitoba
No, the right thing to do is the tune the carbs properly, by optimising the fueling across the rev range, then adjusting the dampers/oil to give you the required fueling curves under all conditions. Adjusting the mixture 3 flats simply adds a ton of fuel at idle (potential bore wash) and also lots more at part throttle. It adds none on acceleration and full power. Classic advice from someone who understands little. If you add a wideband gauge to your car you will be able to see yourself what’s happening and then decide on how to improve it.
@@ACDodd thanks - I imagine the 'richen 3 flats' advice came straight from the MG factory types at Abingdon. Back then, there were no wide band gauges, which are essential to your approach, and no mention of needle profiling - just needle change. I had never heard of profiling until I started following you. The only other thing the BMC dealerships did was adjust damper oil type and level. And keep the dashpot and piston contact clean so the piston would not freeze in the bore.
Thanx AC Dodd .. learning a lot from your YT content . I’m theoretically modeling the SU HIF44 in supercharger context .. to make a decent step towards a HIF7 . Is it also possible to consult you , paid , to maybe solve some issues coming year in my 1950 cc SC HIF7 MGA ?
Hi AC, thank you for sharing the most common faults you experienced; Reg. no. 10: i had a bend flange on intakte manifold to the head, it costs me a lot of time to sort it out; Reg. no. 5, Fast Idle Setting: did i understood you correctly, 1800rpm? Isn‘t that a little bit high? Thank you for your feedback! br Niels
Hi Ac , are you likely to be anywhere in north wales soon . I have a brand new crate engined mini city not even done 5 miles from new with all brand new parts , still on the original points I would love to get it tuned up by yourself
You recommend ATF for the dashpot damper rather than straight 20 oil ( SU) , could you explain the benefit (s)... Thanks John EDIT Just watched " Part 4 Dampers & Oils " Thanks again John
Thanks for your video. I really appreciate you taking the time to put it together. Can you please tell me what AFR range you would be happy with? I have been working on a needle profile using an AFR gauge for 12 months in a HS6 fitted to a modified 1097 A series (80 thou over, Russell Engineering 266SS cam, larger valves and a little port work etc.). I can’t seem to get a cruise leaner than about 13:1. I was hoping to get it to cruise leaner but haven’t been able to get this without leaning out everywhere else. It feels like I am chasing a jackrabbit! Carb was a brand new unit when fitted to the new engine 1500 kms ago. Red damper spring fitted. I would appreciate your thoughts.
These are great, but the ‘for dummies’ examples would be gold. - checking the right amount of dashpot oil - checking for air leaks - adjusting throttle linkages The Gold Standard on checking can be what *everyone* points to. Especially on the forums!
I think the point here is that if you need a for dummies you need to get some sort of training, as adjusting a throttle cable is just about as basic as it gets. I get that you can see the benefit for video for the basics, but I would argue that those that have a very basic knowledge should not be fiddling without some sort of training.
AC, how accurate do you think vehicles were when they left the factory ie fuel curve across the whole rev range, did they have a reliable method of measuring (AFR, CO etc) as cars came off the production line?
Hi AC, have you ever seen a H4 twin carb set up on a Healey 4 cylinder car with no damper rods, no dashpot oil and really sooted up plugs? I think the car has been got at by some one who doesn't know what they were doing.
My thoughts too. I've advised the owner not to run the car without a complete carb rebuild back to stock replacing all the missing parts, new needles, rebushing etc. As a starting point.
Thank Dodd, great information, any advice on an AFR for twin carbs? I have a wideband gauge and dual HS4's on an MGB, is it still beneficial for me to tune with the AFR as long as I make the same changes to each carb and theyre balanced as the AFR measures the output of both of them?
Tune the same as a single. The point here is that both carbs need to be identical. If they are not the same tuning and the end result will be dissapointing
@@ACDodd Brilliant thank you so much. I picked up the AFR as a result of your videos. Final question if you don't mind! The Breather Tube on the carbs... my MGB doesn't have a crankcase breather on the rocker cover, when I got the car the carbs were connected together using both the breather tubes and some piping, is this correct? Or are they meant to be connected to the crankcase vent pip on the block? Thanks again and sorry for all the Qs!
AC - Bought a genuine Bosch 4.9 last week, and a £22.00 eBay cheapy. Both had same stamping, insulation; tip; plug tooling etc. Even down to the flashing on the plug. Possible I had a Bosch couterfeit, but doubt it. Same factory for sure.I'm buying £22.00 cheapies next.
@@johnsharonwhitaker9242 I've the cheapy on now. My Innovate gauge calibratesa 4.9 to 'free air' just the same. I've a narrowband on for my closed-loop LPG and it aligns. Will it last? No idea, for £22 - third of the price... I don't care! Can't be sure yet I strongly believe they are identical.
Hey AC, I have a bone stock 998 A+ and I'm interested in getting a bit more power out of my little engine, should I get a stage 1 kit or maybe change the head? Stage 1 here are around 350 / 400€ and I've seen a 12g202 that needs some work for 50€ (with new valves, etc goes to the 350€ mark) what should I get first?
Fit a stage one kit, and a modified head. You will also likely need a recurved dizzy and a good tune up to get the best from the engine. Power numbers will increase a little but a can change together with a head is how to get the best. If you don’t want to change the cam fit 1.3 rockers along with your modified head and a good tune will get the best out of a stock bottom end.
@ACDodd thanks for answering, been watching your videos for some time, I'm 19 last year got my dad's mini driving, the last time it was driving was in 2016. I'm from Portugal so getting parts is a bit complicated, still waiting for the stage 1 kits coming in stock so I guess I'll wait a bit more. Thanks again for all the help and videos, they're awesome!
Another Q AC. Some SU have a spring-clip to the damper piston. Sits inside the piston-tube. It appears to lock the damper in place. Why do we want this, why is it there?
Has anyone noticed that after Johns comment from Manitoba all subsequent replies to each comment seem to have the same content A small hiccup perhaps or am I seeing things
In a day and age where anything worth knowing is behind paywalls and subscriptions, AC Dodd is just casually gifting the world the most incredible information in easy to understand content through his years of experience. Thanks again for another fantastic video, once my car is back on 4 wheels, this carb won't know what's hit it. At least until I come and see you on a tuning session in the future!
Please like subscribe and share, many thanks
Thanks AC i have spent most of the holidays going through your videos and I can’t tell you how educational they have been. Please keep them coming and a Happy New Year to everyone.
AC decanting many years of knowledge and experience here. Many thanks for taking the time to share the information
Hey no problem.
No problem
Absolutely fabulous education & information. Thank you for taking the time to share!!
Thank you very much , ive really learnt a lot from this video.
great summary AC many thanks. I have learned more from you than from any other site or shop manuals. We bought a new '67 MGBGT and the first winter (and winter in Saskatoon regularly has temps -20 to -30C) the car was stumbling on acceleration. Back to the dealership and the foreman's instructions to the mechanic were ' richen the carbs 3 flats '. The right thing to do ? John in Manitoba
No, the right thing to do is the tune the carbs properly, by optimising the fueling across the rev range, then adjusting the dampers/oil to give you the required fueling curves under all conditions. Adjusting the mixture 3 flats simply adds a ton of fuel at idle (potential bore wash) and also lots more at part throttle. It adds none on acceleration and full power. Classic advice from someone who understands little. If you add a wideband gauge to your car you will be able to see yourself what’s happening and then decide on how to improve it.
@@ACDodd thanks - I imagine the 'richen 3 flats' advice came straight from the MG factory types at Abingdon. Back then, there were no wide band gauges, which are essential to your approach, and no mention of needle profiling - just needle change. I had never heard of profiling until I started following you. The only other thing the BMC dealerships did was adjust damper oil type and level. And keep the dashpot and piston contact clean so the piston would not freeze in the bore.
@ and there lies the problem of precision, by polishing you can get perfection.
Thanks
Thankyou that’s very generous of you
Happy New Year. Thank you for another informative video. You provide food for thought.
Thanks a lot from Spain.
Great video
Thanx AC Dodd .. learning a lot from your YT content . I’m theoretically modeling the SU HIF44 in supercharger context .. to make a decent step towards a HIF7 . Is it also possible to consult you , paid , to maybe solve some issues coming year in my 1950 cc SC HIF7 MGA ?
Happy to help if possible
Thanks AC: have you done a video about working with AFR gauges?
No.
He only gives out so much information out the rest he wants payment for!
Hi AC, thank you for sharing the most common faults you experienced;
Reg. no. 10: i had a bend flange on intakte manifold to the head, it costs me a lot of time to sort it out;
Reg. no. 5, Fast Idle Setting: did i understood you correctly, 1800rpm? Isn‘t that a little bit high?
Thank you for your feedback!
br Niels
Not high, it’s done when warm, the final setting should be set specific to your engine, as it varies.
AC should be knighted for his content. 5⭐️
Please send a recommendation to the palace!
Hi Ac , are you likely to be anywhere in north wales soon . I have a brand new crate engined mini city not even done 5 miles from new with all brand new parts , still on the original points I would love to get it tuned up by yourself
Send me a message on fb messenger with your postcode and I can look at a price
@ done 👍
Would be great to show video with AFR guage fitted and how it works.
You recommend ATF for the dashpot damper rather than straight 20 oil ( SU) , could you explain the benefit (s)... Thanks John EDIT Just watched " Part 4 Dampers & Oils " Thanks again John
Yes it’s thinner than 20w oil, usually 10w or 15w. The SU 20w oil is a starting point only
Thanks for your video. I really appreciate you taking the time to put it together. Can you please tell me what AFR range you would be happy with? I have been working on a needle profile using an AFR gauge for 12 months in a HS6 fitted to a modified 1097 A series (80 thou over, Russell Engineering 266SS cam, larger valves and a little port work etc.). I can’t seem to get a cruise leaner than about 13:1. I was hoping to get it to cruise leaner but haven’t been able to get this without leaning out everywhere else. It feels like I am chasing a jackrabbit! Carb was a brand new unit when fitted to the new engine 1500 kms ago. Red damper spring fitted. I would appreciate your thoughts.
13:1 at cruise is much too rich. More like 14.5:1 is ideal.
Thanks for confirming what I thought. Looks like I need to find a way to see the needle position at different settings.
I had issues with the enrichment system(choke) causing similar issues I replace the O-rings and it helped quite a bit
Great video!
What lube to lubricate linkages? I put some lithium grease before.
and is the SU oil ok for the dashpots? Thats what I use.
You need to watch my other videos on how it works, there is no one oil for all applications. Engine oil for the linkages is fine
Hi A.C & Happy New Year.! What lubricant should we be using on our Carb Linkages.? 3in1.?
Engine oil
Thanks AC. Love this. Some SU have a 'spring wrap-round' on the float needle. Pulls needle open? Is it necessary? Which have these?
I have also seen this, I have not noticed it as necessary
These are great, but the ‘for dummies’ examples would be gold.
- checking the right amount of dashpot oil
- checking for air leaks
- adjusting throttle linkages
The Gold Standard on checking can be what *everyone* points to. Especially on the forums!
I think the point here is that if you need a for dummies you need to get some sort of training, as adjusting a throttle cable is just about as basic as it gets. I get that you can see the benefit for video for the basics, but I would argue that those that have a very basic knowledge should not be fiddling without some sort of training.
@@ACDoddsign me up!
Look up Motolearn;
motolearn.bigcartel.com/what-can-motolearn-offer-you
@ many thanks. Have enquired!
Hi A.C & Happy New Year.! Great video as always.. One question. What Oil should we be using on our Carb Linkages.? 3in1.?
AC, how accurate do you think vehicles were when they left the factory ie fuel curve across the whole rev range, did they have a reliable method of measuring (AFR, CO etc) as cars came off the production line?
I don’t think they were that great, the tolerances needed to get that are simply too tight for mass production.
Hi AC, have you ever seen a H4 twin carb set up on a Healey 4 cylinder car with no damper rods, no dashpot oil and really sooted up plugs? I think the car has been got at by some one who doesn't know what they were doing.
I can’t say I have seen a Healey like that but I have seen many other vehicles destroyed by so called professionals!
My thoughts too. I've advised the owner not to run the car without a complete carb rebuild back to stock replacing all the missing parts, new needles, rebushing etc. As a starting point.
Thank Dodd, great information, any advice on an AFR for twin carbs? I have a wideband gauge and dual HS4's on an MGB, is it still beneficial for me to tune with the AFR as long as I make the same changes to each carb and theyre balanced as the AFR measures the output of both of them?
Tune the same as a single. The point here is that both carbs need to be identical. If they are not the same tuning and the end result will be dissapointing
@@ACDodd Brilliant thank you so much. I picked up the AFR as a result of your videos. Final question if you don't mind! The Breather Tube on the carbs... my MGB doesn't have a crankcase breather on the rocker cover, when I got the car the carbs were connected together using both the breather tubes and some piping, is this correct? Or are they meant to be connected to the crankcase vent pip on the block? Thanks again and sorry for all the Qs!
Later cars used the vent pipes. No harm in making the mods to make this work like a later vehicle
thanks sollywelch. We also have a B with HS4s. Where did you mount the gauge sender ? I notice AC shoves his up the tailpipe. John in Manitoba
@@johnsharonwhitaker9242follow the instructions in the gauge kit very closely.
AC, is there an afr gauge you recommend? If not, which one do you use?
Aem or innovate but get one that uses a genuine Bosch sensor
@ACDodd Great, thanks for the reply.
AC - Bought a genuine Bosch 4.9 last week, and a £22.00 eBay cheapy. Both had same stamping, insulation; tip; plug tooling etc. Even down to the flashing on the plug. Possible I had a Bosch couterfeit, but doubt it. Same factory for sure.I'm buying £22.00 cheapies next.
@@somebloke5565 most useful observation. do they read the same ? I am in the market. John in Manitoba
@@johnsharonwhitaker9242 I've the cheapy on now. My Innovate gauge calibratesa 4.9 to 'free air' just the same. I've a narrowband on for my closed-loop LPG and it aligns. Will it last? No idea, for £22 - third of the price... I don't care! Can't be sure yet I strongly believe they are identical.
Hey AC, I have a bone stock 998 A+ and I'm interested in getting a bit more power out of my little engine, should I get a stage 1 kit or maybe change the head? Stage 1 here are around 350 / 400€ and I've seen a 12g202 that needs some work for 50€ (with new valves, etc goes to the 350€ mark) what should I get first?
Fit a stage one kit, and a modified head. You will also likely need a recurved dizzy and a good tune up to get the best from the engine. Power numbers will increase a little but a can change together with a head is how to get the best. If you don’t want to change the cam fit 1.3 rockers along with your modified head and a good tune will get the best out of a stock bottom end.
@ACDodd thanks for answering, been watching your videos for some time, I'm 19 last year got my dad's mini driving, the last time it was driving was in 2016.
I'm from Portugal so getting parts is a bit complicated, still waiting for the stage 1 kits coming in stock so I guess I'll wait a bit more.
Thanks again for all the help and videos, they're awesome!
Another Q AC. Some SU have a spring-clip to the damper piston. Sits inside the piston-tube. It appears to lock the damper in place. Why do we want this, why is it there?
Again I have yet to understand why these were needed.
Has anyone noticed that after Johns comment from Manitoba all subsequent replies to each comment seem to have the same content
A small hiccup perhaps or am I seeing things