I wrote it already. You need AFR gauge!!! idle jets work ( with progression hole ) until 3000-4000 rpm ( it depends on which size of choke ). At higher revs work only main jet. ( you can then take out idle jets - engine will still run ). Don't test dyno without sure you have the correct AFR full rev range
You need to find a grey-bearded carb wizard, that'll sort it. don't bother messing with the cam or anything else, at least until you've got the fuelling sorted! She's looking bloody awesome though, and sounds pretty good too!
Hey Matt. I’ve had a bit of experience with single carb mini with Delorto carb .. we ran on std cooper S cam Twin side draught 40’s With 32 mm chokes .50 as idler 135 main 170 air correctors Good luck 🤞
If it’s an inherrent design flaw of the dual carb to quad inlet then I see a few work arounds: The idle jets are probable still on the rich side. Since you won’t need much idle on a race car, keep it on the leaner side to help your plugs not foul. Go for a lesser heat number on your plugs to keep it burning fuel well. You don’t seem to be needing very racy plugs by the look of things so have the plugs be a bit hotter to keep burning off more soot and fuel. Look over the inlet manifold to see if you can lessen the flow a tiny bit to the outer cylinders so that the middle ones catch up (it is a balance after all!) A bit late now but when at the dyno with no emulsion tubes or main jets you can simulate a change of tune there by simple adjusting your float level - don’t be afraid of adjusting this level say 4mm up or down because it adjusts how early your main jet kicks in. In other words if your main jet kicks in too early now, you can get that super rich bog down that your dyno shows. Because the idle jet is still delivering the goods while your progression holes have open the gates to Mordor I mean main jets. When you lower the float level you delay the delivery of the main jet. When you increase the float level you activate the main jet earlier. At the dyno you could have adjusted the float level say 3-4mm (might give you 5-800rpm difference) to see the change of bog down on paper. You can do this on the road as well of course. Smaller main jets, ignition timing adjustment for earlier burn at idle, adjusting emulsion tubes or float level to remove enrichment bog down at 3500. You could possibly adjust your valves a tiny bit differently between the outer and inner cylinders to lessen the wetting of the outer plugs by blowing out a bit of the excess fuelmix with the exhaust valve. Or lessen the intake valve. Cheers
I’m not that far from you, the only place I have found to get minis rolling roaded is Southam mini & metro centre they are a bit of a trek up in Southam, Warwickshire but Colin’s your man and keeps loads of Weber bits
It's not the siamese ports per se that cause the outer cylinders to run rich on an A-Series, it's the inlet manifold and the inertia of the inlet charge and you cannot really avoid it - scatter cams help a little but in the old days folks looking to eek out the most power ran split webers to have a straight shot into the ports. This was expensive though as you had to cut up one carb, to allow them to fit, essentially destroying its future viability for anything other than use on an A-Series...
Frig Matt, that music she makes under load is amazing through that big Weber! A mate of mine runs a 1310 with bike itb set up efi and she runs super sweet I think he gets 100hp at the wheels. Have a great Chrissy and a happy new year
I recently had a rich mixture on one of my engines, it had been running ok before. I found the pressure relief spring in my filter king regulator had fallen out in to the bowl, something for the future.
If the dyno readout is right then it is ridiculously rich lower in the revs it will be washing the bores and wetting the plugs, it's down near 9:1 AFR somewhere, would sort that out first then see what is happening with the plugs etc
I would advise on fitting Misab plates between the carbs and manifold as the type you have can pop the o ring on a back fire . Sure Merlins will sell them at Coombe
Well Matt with the effort I'm sure you are going to put into it, you are going to solve this. Sometimes I think why all these problems and then I think oh yes it was supposed to be a hobby, so solving the problem should be too! Good luck
I have run race mini 1330cc engines on twin HIF 44 carbs making 105 hp and never had a problem with fuel fouling the outer plugs, but I was using a Metro electronic distributor, so I wonder if you have a spark problem as you look like you are running a wasted spark ignition which will do 1 and 4 and 2 and 3 together. Anyway, hope you have a amazing festive time and look forward to more videos and maybe catch you at a track day next year. I always go to Combe. Cheers Kim.
if it's wasted spark then Urch should try swapping the two coils out and see if the problem follows the coil. It might be an idea to run one heat range hotter on the outside cylinders to keep them from fouling at idle and low throttle running.
The firing order and the siamesed ports are probably causing the outside ports to run rich.... 1-3-4-2 has each outside cylinder firing directly after the corresponding inside, so the inertia of the flow set up by the inner cylinder contributes to the fuel then delivered to the outside. If that's the case then some port work might be able to even things out somewhat.
It's not the siamese ports that cause the outer cylinders to run rich, it's the inlet manifold and the inertia of the inlet charge and you cannot really avoid it, scatter cams help but the only real solution is split webers.
My take is that the two outer cylinders are suffering from some carbon buildup on the rings and the valves due to the rich state of the carb jetting. Tuning Webbers is challenging on those A-series motors. The good news is that if you can change the jets to get rid of most of that super rich dip, the carbon will burn off.
Hi Matt, At Piper Cams (some time ago now) we fully reworked an S engine 1310cc with a fully modded head , Weber and Cam that made 91 hp, so not so very different..
If it does less without the filter, it needs more main jet, depending on having velocity stacks still on. If you were drawing the air in against the bare straight edge of the carb body, that kills the dynamic CSA, as the edge creates a turbulence around it. There also should be a way to adjust part throttle and booster. If the carb opening is too small, the engine pulls enough vacuum to activate the booster on part throttle, fauling the plugs. Then there's the transition from carb to intake plenum. A step here destroys any kind of attempt for a tune. To keep the cam in, I would get a bigger carb with velocity stacks, blend that to the intake, make sure the intake is flush with the head openings, then start to tune the carb.
Really need to get the weber and ign map calibrated on a dyno, ideally Miglia specialist, if you keep driving it that rich your gonna wash the bores out before you’ve even started, guessing rings not been ran in?
Hi Matt. Watched your video when you set the corner weights on the mini with simple scales, thought I would do the same on my F2 Stock Car. Got the scales but do you have a link to the app you used? Thanks
Matt have you Tried The Tipton Garage as its close between ottery/sidmouth. They love the oldskool carb stuff and heard good thing they rolling road tune.Just a thought.👍🏻
What cc are you and what cam are you running, 649? 1.3 or 1.5 rockers make a surprisingly small difference if you are so don't waste your money changing them. What compression is this engine, 11:1 like migs or more? If its about there then you'll also find that there's a huge window where the ignition makes very little difference, you'll find from about 28 degrees to 36 makes no difference to the power, because the compression is relatively low. Migs always have that hideous rich area on WOT between 4 and 5k, you won't tune that out i'm afraid (I've running several of the race winning migs on our rollers, including Endaf's, many times)
Can you put different spark plugs on the outer 2 cylinders? I know very little about plugs, but it looks like these would have different requirements to the inner 2.
I am no expert on A series but I have seen similar issues in the past with these low to mid range flat spots on DCOEs when the owners have fitted way too big chokes. It might be worth trying smaller chokes to see how it behaves. I would also try a different manifold. Someone in the Mini Miglia paddock must know the best combo to use. I remember the late Peter Baldwin was the man to go to for Mini tuning. A real gent and a multiple Mini Miglia champion. Sadly a lot of the old school carb tuning is declining, mapping is all anyone seems to care about nowadays but carbs are still widely used and there are people out there who do them.
Many race minis use this manifold don't they? Unlikely to be the issue. Just changing idle jets was the main problem and limitation here I think. They don't do much after 1500RPM+ especially in an engine built this way. Choke+Main jets will have way more of an impact.
I would start by adding lambda ports on each exhaust manifold branch (less than £10 for 3), then buy or borrow a portable lambda reader, then you can do your own carb tuning under load without having to travel to a rolling road, particularly since the problem seems to be at the lower end of the rev range. To check the engine you could borrow a twin carb intake manifold and add a pair of HIF44s (which are quite cheap in good used condition, and easily resold) Then you will find out if the engine is OK, I suspect it is fine but that remains to be proved. My suspicion would be the Weber inlet manifold but maybe not.
Its not an over-spec issue, have tuned lots of weber equipped A series Mini's and Midgets with SW23 cams and 45's, its a tuning issue. To be fair the SW23 isn't meant for full throttle at low revs but they can be cleaner. If the comp gauge is accurate then the CR is too low for that cam, so thats not helping, particularly lower down. Mid to high 80's at the wheels is a long way off for the spec by around 15hp.
Does it have a scatter cam? Just thought if those might result in different compression readings on the outer cylinders due to the different timings. Just a thought. I guess your engine builder would know if that was the case.
I was just looking at the Vizard A series book and he says there isn't a lot of fuel bias because only one valve is open at a time, so the open cylinder takes what it wants. Re wet outer cylinders. If the mixture is correct then even with the two inner inlet ports blocked off (so all the mixtures goes to the outer) then the cylinders won't be wet because the mixture is correct. If the mixture is correct on the inner cylinders then it should be correct on the outer. I was going to suggest that the outer cylinders are not firing correctly, hence not burning the fuel. But we know the engine is making reasonable power so that is not true. So that brings us to the plugs, I presume they are all the same type ie you have not got cooler running plugs in the outer cylinders? Have you tried a set of new plugs in case the outer two are playing up?
You can’t beat going to a specialist for getting the most out if these engines and also they know where the engine should be compared to others. Kad/ Swiftune dyno or Slark rolling road for example. I used Swiftune and the late legend Peter Baldwin and you know they will get every last bit out of the engine.
@@Kiwi-pp7rg I think the worst one was the really offset gooseneck / swan neck manifold that raised the carb enough to not have to cut the bulkhead for clearance, they were the worst but this one doesn't look too much better...
36mm chokes 4.5 aux vents, 45-50f8 Idle a bit weak but will not have plugs fouling in the paddock and your never under 4k rpm when racing, normally 5-9000 . F2 or F14 emulsion tubes 140-145 mains 160-170 airs You'll need 130+ bhp to be competitive. Fuel pressure needs to be 5psi, 200-225 needle valve, else it will run out of fuel under full load with only 2psi.
What cc is the engine? and what choke size do you have in the Weber, it looks like your main jet is to big for the choke size you run, they are closely related. if your engine is 1293cc a 38 choke should fit a top swiftune engine would run with 40mm chokes.
You really need to find somewhere with a stock of jets etc. I had my Mini set up by Airey Tuning in Cheriton more then a few years ago so somewhere like them might be able to help. I've got a big single SU on mine and with a 286 cam and high lift rockers it never ran very well under 2000rpm. Is the jet size info in David Vizards book any help with the setup you have ?
Lots of good comments already, but just to add our two pence, get it to a dyno who understands webers, theres been some mentioned already, that was a waste of time and potentially bad for your engine. Then once its been setup correctly get it booked onto the action day at blyton next year, its the uks only classic mini specific trackday. Itĺl be a good test for you get some seat time outside of a full on event. In fact to ensure a spot you need to be booking now, not waiting.!
Wouldn't the wet cylinder lose compression from the extra fuel thinning the oil on the outer cylinders, I would think jetting the carb with a smaller jet in the low to mid range would make a massive difference all though the rev range , good luck 🤞
Have a word with Mike Tarr at Ratt racing in Torquay and maybe take it down on his rolling road he’s specialised in and raced mini for years and builds the engines as well
Hello injoying watching u can use a electric fuel pump to test the float level ,just remove top of carb with float on ,fuel line connected and turn it upside so you can see then turn fuel pump on and lift the float to discover where the fuel flows when in operation it needs to flow max when the floats lowest and stop flow at top .and as for the compression test do it again with throttle fully open 😊 the power pump needs to be checked and use old main jets and drill the to size ,but quality drill bits this is accurate enough for testing im thinking looking at graph it made more torque low means lean ,but can't see from here ,my opinion is try different carb and try good old point system ignition to cancel out any errors, and good luck i used to run a mark 1 cortina with lotus engine i made 1.8 litres from 1.5 with Nissan crank so i know a little, been there 😅
You need to take it to someone who knows carbs. Seems you need to try different emulsions tubes. F16 is always a good starting point. Missab plates between carb and manifold.
Oh I forgot get a set of jet drills and tape mark them like a flag with their values in increments of 005 From 125-200 And the idle jet drills increments of 05 from .50 to .80 Buy a set of spare jets and solder them shut and drill to suit.. when you get it right buy the new jets you want.. job done ..!
I can see gaps where the carb meets the manifold and the washers have gaps in them too so they will leak in air thus causing issues with power and possibly causing fouling, have a look yourself.
@@Urchfab Yup, see my post elsewhere - splits were done precisely because of the inlet charge inertia, you just cannot avoid it due to the manifold geometry. Scatter cams help, but the ultimate is splits, but costly as you have to cut up one carb...
If your dyno man isn’t good with carbs, I’d be looking elsewhere. I’m no expert of carbs but I have had a couple of inline 4 bikes with carbs and still own one. There’s at least three carb experts in my area if I need one, surely there’s a carb man where you live?
There's no point in guessing with jetting, get it tuned properly Slark in Bristol or Alan Jeffrey (Enginetuner) in Plymouth would sort the jetting out.
Hi Matt looking at the video I thought I could see daylight between your carb and the gasket, it might be that way but just did not look seated, at 1:31 up where you talk about the idle needle, the spring washer under the carb attach nut did not look compressed either, sure the video may have been taken prior to testing etc. just thought I would give you my 2p 😌. Very nice build, wish I could have workshop like yours👍.
That's how they're supposed to be to "soft mount" the carbs, reducing fuel frothing... The intermediate "gasket" has daylight as on either side there's a ruddy great big soft o-ring between the manifold the the "gasket" and the "gasket" and the carb. So the carb "floats" and not all the engine vibration is transmitted to the carb.
I am pleased it was not just me that saw / sees that - if you look at say 1.34, it looks as if the carbs are not tight against the manifold. All looks a bit lose. That is going to cause a problem.
@@edwardgurhy100 Thats totally normal, as usually you fit some rubber (big ring) between the mounts to isolate the carb, so the fuel there in doesn't get vibrated to uncontrollable levels.
I wouldn't run that much more without rectifying that overfueling Matt, as you will just borewash the engine and destroy the rings and bore finish. From thereon you will be looking at pulling it to bits again and honing the cylinders, (hopefully) and reringing it. Try and find someone with a rolling road knowledgeable about tuning Weber carbs and A series - try Slark Race Engineering. Happy Christmas!.
David Visard made a great video (Why cam companies cam timing cards are almost always wrong) showing how valve seat angle effects optimum cam timing. He found a lot of cam manufacturers timing recommendations are wrong because they don't take valve seat angle into account and he showed significant gains by tweaking them. The general gist was that 30 degree valve seat angles allow more flow as the valves start to open than 45 - 55 degree valve seat angles so cam timing base settings need to be advanced or retarded accordingly.
The dyno man is not up to the job for webers no good messing about with idle jets when it rich middle range,always do compresion checks on full throttle too get max air flow.
Compression checks were done with wot. As I said in the video, he doesn't stock any jets. It was supposed to be a quick swap of idle jets and a few power runs to see what it makes.
Sorry to hear your having so many problems with this motor. Stop messing around and give endaf a call at Owen's motorsport, he will give you the best advice available and no bullshit. This is WAY down on power,depending on the rolling road and weather conditions on the day this should be around 110-115 at the wheels...or if endaf is too far send it upto southam ... Be good to see you racing next year.
Fix one problem and another will come along trying to frustrate you. Always a joy to watch you Matt. Seasons Greetings
I wrote it already. You need AFR gauge!!! idle jets work ( with progression hole ) until 3000-4000 rpm ( it depends on which size of choke ). At higher revs work only main jet. ( you can then take out idle jets - engine will still run ). Don't test dyno without sure you have the correct AFR full rev range
p.s: th-cam.com/video/1pkFSA_rRFI/w-d-xo.html&ab_channel=SidneyCriticComedyHound
That driving position and gear stick position is absolutely wicked, looks like a lovely positive throw on it!! Great work!!
Looking and sound absolutely fantastic, what a build 👍 Be great to see some sponsor livery on board supporting you.
You need to find a grey-bearded carb wizard, that'll sort it. don't bother messing with the cam or anything else, at least until you've got the fuelling sorted!
She's looking bloody awesome though, and sounds pretty good too!
Hey Matt. I’ve had a bit of experience with single carb mini with Delorto carb .. we ran on std cooper S cam
Twin side draught 40’s
With 32 mm chokes
.50 as idler
135 main
170 air correctors
Good luck 🤞
What a lovely vehicle, I'm sure you'll get it spot on eventually.
If it’s an inherrent design flaw of the dual carb to quad inlet then I see a few work arounds:
The idle jets are probable still on the rich side. Since you won’t need much idle on a race car, keep it on the leaner side to help your plugs not foul.
Go for a lesser heat number on your plugs to keep it burning fuel well. You don’t seem to be needing very racy plugs by the look of things so have the plugs be a bit hotter to keep burning off more soot and fuel.
Look over the inlet manifold to see if you can lessen the flow a tiny bit to the outer cylinders so that the middle ones catch up (it is a balance after all!)
A bit late now but when at the dyno with no emulsion tubes or main jets you can simulate a change of tune there by simple adjusting your float level - don’t be afraid of adjusting this level say 4mm up or down because it adjusts how early your main jet kicks in. In other words if your main jet kicks in too early now, you can get that super rich bog down that your dyno shows. Because the idle jet is still delivering the goods while your progression holes have open the gates to Mordor I mean main jets.
When you lower the float level you delay the delivery of the main jet. When you increase the float level you activate the main jet earlier.
At the dyno you could have adjusted the float level say 3-4mm (might give you 5-800rpm difference) to see the change of bog down on paper. You can do this on the road as well of course.
Smaller main jets, ignition timing adjustment for earlier burn at idle, adjusting emulsion tubes or float level to remove enrichment bog down at 3500.
You could possibly adjust your valves a tiny bit differently between the outer and inner cylinders to lessen the wetting of the outer plugs by blowing out a bit of the excess fuelmix with the exhaust valve. Or lessen the intake valve.
Cheers
I’m not that far from you, the only place I have found to get minis rolling roaded is Southam mini & metro centre they are a bit of a trek up in Southam, Warwickshire but Colin’s your man and keeps loads of Weber bits
It's not the siamese ports per se that cause the outer cylinders to run rich on an A-Series, it's the inlet manifold and the inertia of the inlet charge and you cannot really avoid it - scatter cams help a little but in the old days folks looking to eek out the most power ran split webers to have a straight shot into the ports. This was expensive though as you had to cut up one carb, to allow them to fit, essentially destroying its future viability for anything other than use on an A-Series...
You are correct ❤
Frig Matt, that music she makes under load is amazing through that big Weber! A mate of mine runs a 1310 with bike itb set up efi and she runs super sweet I think he gets 100hp at the wheels. Have a great Chrissy and a happy new year
I recently had a rich mixture on one of my engines, it had been running ok before. I found the pressure relief spring in my filter king regulator had fallen out in to the bowl, something for the future.
The lower compression must be caused by cylinder wash due to over fueling
If the dyno readout is right then it is ridiculously rich lower in the revs it will be washing the bores and wetting the plugs, it's down near 9:1 AFR somewhere, would sort that out first then see what is happening with the plugs etc
Just remembered, I had twin DCOE on my tuned Ford Mexico……..those were the days. Plus supper Oscar rallie spot lights
I would advise on fitting Misab plates between the carbs and manifold as the type you have can pop the o ring on a back fire . Sure Merlins will sell them at Coombe
Well Matt with the effort I'm sure you are going to put into it, you are going to solve this. Sometimes I think why all these problems and then I think oh yes it was supposed to be a hobby, so solving the problem should be too! Good luck
I have run race mini 1330cc engines on twin HIF 44 carbs making 105 hp and never had a problem with fuel fouling the outer plugs, but I was using a Metro electronic distributor, so I wonder if you have a spark problem as you look like you are running a wasted spark ignition which will do 1 and 4 and 2 and 3 together. Anyway, hope you have a amazing festive time and look forward to more videos and maybe catch you at a track day next year. I always go to Combe. Cheers Kim.
spark plugs may be too cold
if it's wasted spark then Urch should try swapping the two coils out and see if the problem follows the coil. It might be an idea to run one heat range hotter on the outside cylinders to keep them from fouling at idle and low throttle running.
Siamese heads do love an SU, summet to do with fuel atomisation apparently.
Very interesting video hopefully you get this tuned right next year
Happy Christmas Matt and family. Split webers could solve the problem and more direct to port flow, but expensive.
The firing order and the siamesed ports are probably causing the outside ports to run rich.... 1-3-4-2 has each outside cylinder firing directly after the corresponding inside, so the inertia of the flow set up by the inner cylinder contributes to the fuel then delivered to the outside. If that's the case then some port work might be able to even things out somewhat.
It's not the siamese ports that cause the outer cylinders to run rich, it's the inlet manifold and the inertia of the inlet charge and you cannot really avoid it, scatter cams help but the only real solution is split webers.
@@Farlig69 Just read this and in the day I think David Vizard had great success with split Webers but do the rules allow this maybe not?
My take is that the two outer cylinders are suffering from some carbon buildup on the rings and the valves due to the rich state of the carb jetting. Tuning Webbers is challenging on those A-series motors. The good news is that if you can change the jets to get rid of most of that super rich dip, the carbon will burn off.
Hi Matt, At Piper Cams (some time ago now) we fully reworked an S engine 1310cc with a fully modded head , Weber and Cam that made 91 hp, so not so very different..
If it does less without the filter, it needs more main jet, depending on having velocity stacks still on. If you were drawing the air in against the bare straight edge of the carb body, that kills the dynamic CSA, as the edge creates a turbulence around it. There also should be a way to adjust part throttle and booster. If the carb opening is too small, the engine pulls enough vacuum to activate the booster on part throttle, fauling the plugs. Then there's the transition from carb to intake plenum. A step here destroys any kind of attempt for a tune.
To keep the cam in, I would get a bigger carb with velocity stacks, blend that to the intake, make sure the intake is flush with the head openings, then start to tune the carb.
Really need to get the weber and ign map calibrated on a dyno, ideally Miglia specialist, if you keep driving it that rich your gonna wash the bores out before you’ve even started, guessing rings not been ran in?
Its been run in on an engine dyno prior to fitting. I wont be driving it until it been back on the rollers again.
Hi Matt. Watched your video when you set the corner weights on the mini with simple scales, thought I would do the same on my F2 Stock Car. Got the scales but do you have a link to the app you used? Thanks
Put Robrobinette corner balance calculator into google, You'll find it.
Merry Christmas and new year from nz.
Matt have you Tried The Tipton Garage as its close between ottery/sidmouth. They love the oldskool carb stuff and heard good thing they rolling road tune.Just a thought.👍🏻
What cc are you and what cam are you running, 649? 1.3 or 1.5 rockers make a surprisingly small difference if you are so don't waste your money changing them. What compression is this engine, 11:1 like migs or more? If its about there then you'll also find that there's a huge window where the ignition makes very little difference, you'll find from about 28 degrees to 36 makes no difference to the power, because the compression is relatively low. Migs always have that hideous rich area on WOT between 4 and 5k, you won't tune that out i'm afraid (I've running several of the race winning migs on our rollers, including Endaf's, many times)
It's a 1293 11.3:1 compression, 1.5 roller rockers, sw23 cam. Have you ever had issues with wetting 1 and 4 at idle? Cheers
@@Urchfab no its no an issue usually
Happy Christmas mate to you and your family 👍👍... L. A. G....
Can you put different spark plugs on the outer 2 cylinders? I know very little about plugs, but it looks like these would have different requirements to the inner 2.
I am no expert on A series but I have seen similar issues in the past with these low to mid range flat spots on DCOEs when the owners have fitted way too big chokes. It might be worth trying smaller chokes to see how it behaves. I would also try a different manifold. Someone in the Mini Miglia paddock must know the best combo to use. I remember the late Peter Baldwin was the man to go to for Mini tuning. A real gent and a multiple Mini Miglia champion. Sadly a lot of the old school carb tuning is declining, mapping is all anyone seems to care about nowadays but carbs are still widely used and there are people out there who do them.
Many race minis use this manifold don't they? Unlikely to be the issue. Just changing idle jets was the main problem and limitation here I think. They don't do much after 1500RPM+ especially in an engine built this way. Choke+Main jets will have way more of an impact.
A lot of the migs do seem to run a much shorter manifold so its probably worth looking at.
Miglias will run a maniflow tubular manifold I think 3 3/4” length (or around this size depending on engine characteristics)
@@Urchfab Yep maniflow 5" was the dog's back in the day...
I would start by adding lambda ports on each exhaust manifold branch (less than £10 for 3), then buy or borrow a portable lambda reader, then you can do your own carb tuning under load without having to travel to a rolling road, particularly since the problem seems to be at the lower end of the rev range. To check the engine you could borrow a twin carb intake manifold and add a pair of HIF44s (which are quite cheap in good used condition, and easily resold) Then you will find out if the engine is OK, I suspect it is fine but that remains to be proved. My suspicion would be the Weber inlet manifold but maybe not.
Its not an over-spec issue, have tuned lots of weber equipped A series Mini's and Midgets with SW23 cams and 45's, its a tuning issue.
To be fair the SW23 isn't meant for full throttle at low revs but they can be cleaner.
If the comp gauge is accurate then the CR is too low for that cam, so thats not helping, particularly lower down.
Mid to high 80's at the wheels is a long way off for the spec by around 15hp.
That sound so good !!
Does it have a scatter cam? Just thought if those might result in different compression readings on the outer cylinders due to the different timings. Just a thought. I guess your engine builder would know if that was the case.
I was just looking at the Vizard A series book and he says there isn't a lot of fuel bias because only one valve is open at a time, so the open cylinder takes what it wants.
Re wet outer cylinders. If the mixture is correct then even with the two inner inlet ports blocked off (so all the mixtures goes to the outer) then the cylinders won't be wet because the mixture is correct. If the mixture is correct on the inner cylinders then it should be correct on the outer.
I was going to suggest that the outer cylinders are not firing correctly, hence not burning the fuel. But we know the engine is making reasonable power so that is not true.
So that brings us to the plugs, I presume they are all the same type ie you have not got cooler running plugs in the outer cylinders? Have you tried a set of new plugs in case the outer two are playing up?
You can’t beat going to a specialist for getting the most out if these engines and also they know where the engine should be compared to others. Kad/ Swiftune dyno or Slark rolling road for example. I used Swiftune and the late legend Peter Baldwin and you know they will get every last bit out of the engine.
Is that goose neck inlet manifold anygood and on the siamese split on the head knife edge or rounded
Looks like a POS to me, the best ever inlet manifold for the A, least in days of old was the steel maniflow...
@@Farlig69 I seem to recall that those cast alloy goose necks don't flow any good
@@Kiwi-pp7rg I think the worst one was the really offset gooseneck / swan neck manifold that raised the carb enough to not have to cut the bulkhead for clearance, they were the worst but this one doesn't look too much better...
Will you exhaust wrap the headers, being right under the intake?
36mm chokes 4.5 aux vents, 45-50f8 Idle a bit weak but will not have plugs fouling in the paddock and your never under 4k rpm when racing, normally 5-9000 .
F2 or F14 emulsion tubes 140-145 mains 160-170 airs
You'll need 130+ bhp to be competitive.
Fuel pressure needs to be 5psi, 200-225 needle valve, else it will run out of fuel under full load with only 2psi.
So what im getting at is I think there is a flow issue? I had the same set up and no issues except my inlet was tubular and flowed extremely well
What cc is the engine? and what choke size do you have in the Weber, it looks like your main jet is to big for the choke size you run, they are closely related. if your engine is 1293cc a 38 choke should fit a top swiftune engine would run with 40mm chokes.
Reminds me of my youth, DCO’s make such great sounds………………..close your eyes and you’d think you were on the RAC rally
imho put a balance pipe in the inletmanifold.
I’d swap a hiff44 onto it and see what it does 🤷♂️ merry Christmas Matt 👍
Has it got to be carb'd..?? What about TB's..??
Can only be one TB unless you go complex like the MPIs are.
Obviously you knew what I meant 🤦 why has everyone got to contradict everyone....
@@grenphelps7455 very difficult to TB an A... spilt webers are the ultimate, but if you really want TB then you need and Arden 8 port
it might not work, but it's worth a try. try running hoter plugs on the 2 outer cylinders ?
How about hotter plugs in the outer cylinders?
You really need to find somewhere with a stock of jets etc. I had my Mini set up by Airey Tuning in Cheriton more then a few years ago so somewhere like them might be able to help. I've got a big single SU on mine and with a 286 cam and high lift rockers it never ran very well under 2000rpm. Is the jet size info in David Vizards book any help with the setup you have ?
There are recommendations in the book but there's so many variables. I will get it ironed out soon. Cheers
You'll have bore wash on the outer 2 cylinders. Petrol washing away oil from the rings.
Merry xmas all, I'd try 36mm chokes, the 38's maybe a bit too big.
Not at all, I ran 48/38 on a 1293 full race no issues, Matt needs to get his Vizard book out...
Lots of good comments already, but just to add our two pence, get it to a dyno who understands webers, theres been some mentioned already, that was a waste of time and potentially bad for your engine. Then once its been setup correctly get it booked onto the action day at blyton next year, its the uks only classic mini specific trackday. Itĺl be a good test for you get some seat time outside of a full on event. In fact to ensure a spot you need to be booking now, not waiting.!
See you on the next one, Matt.
Valve leak ?
What chocks do you have,
Wouldn't the wet cylinder lose compression from the extra fuel thinning the oil on the outer cylinders, I would think jetting the carb with a smaller jet in the low to mid range would make a massive difference all though the rev range , good luck 🤞
Have a word with Mike Tarr at Ratt racing in Torquay and maybe take it down on his rolling road he’s specialised in and raced mini for years and builds the engines as well
Malc at TTP performance Bromsgrove is ya man to set that up best in the business 😊
I agree, all of my A series builds go to malc at TTP, he's a great guy and very knowledgeable.
@pauljeffries my little bro he's the best at wot he dose
Go for split Webers. That will cure the richer mixture going to the outer two cylinders.
Hello injoying watching u can use a electric fuel pump to test the float level ,just remove top of carb with float on ,fuel line connected and turn it upside so you can see then turn fuel pump on and lift the float to discover where the fuel flows when in operation it needs to flow max when the floats lowest and stop flow at top .and as for the compression test do it again with throttle fully open 😊 the power pump needs to be checked and use old main jets and drill the to size ,but quality drill bits this is accurate enough for testing im thinking looking at graph it made more torque low means lean ,but can't see from here ,my opinion is try different carb and try good old point system ignition to cancel out any errors, and good luck i used to run a mark 1 cortina with lotus engine i made 1.8 litres from 1.5 with Nissan crank so i know a little, been there 😅
Did you say 2 or 3 PSI ??
Either should work fine if the needle+floats are fine.
I've tried 2, 2.5 and 3
Had a 1275 Midget in a Moggie 1000 and it did the same with 1 and 4 cylinders
You need to take it to someone who knows carbs. Seems you need to try different emulsions tubes. F16 is always a good starting point. Missab plates between carb and manifold.
Great content oh how to trouble shoot - God Speed on drilling down an getting it "dialed in" .
Oh I forgot get a set of jet drills and tape mark them like a flag with their values in increments of 005 From 125-200 And the idle jet drills increments of 05 from .50 to .80
Buy a set of spare jets and solder them shut and drill to suit.. when you get it right buy the new jets you want..
job done ..!
why take it to someone that doesn't have weber parts?? Ben in Dudley to setup your webers
I can see gaps where the carb meets the manifold and the washers have gaps in them too so they will leak in air thus causing issues with power and possibly causing fouling, have a look yourself.
Maby thats why the split-Weber setup was done…?
Because of the enerti of the misture goes toward the outher cylinders. Manifolddesign….
Hmm, I don't know why that's done but it would make sense.
@@Urchfab Yup, see my post elsewhere - splits were done precisely because of the inlet charge inertia, you just cannot avoid it due to the manifold geometry. Scatter cams help, but the ultimate is splits, but costly as you have to cut up one carb...
If your dyno man isn’t good with carbs, I’d be looking elsewhere. I’m no expert of carbs but I have had a couple of inline 4 bikes with carbs and still own one. There’s at least three carb experts in my area if I need one, surely there’s a carb man where you live?
_"If your dyno man isn’t good with carbs, I’d be looking elsewhere"_ BINGO!
There's no point in guessing with jetting, get it tuned properly Slark in Bristol or Alan Jeffrey (Enginetuner) in Plymouth would sort the jetting out.
sind die federn bei den muttern brücke vergaser auf block
Hi Matt looking at the video I thought I could see daylight between your carb and the gasket, it might be that way but just did not look seated, at 1:31 up where you talk about the idle needle, the spring washer under the carb attach nut did not look compressed either, sure the video may have been taken prior to testing etc. just thought I would give you my 2p 😌. Very nice build, wish I could have workshop like yours👍.
That's how they're supposed to be to "soft mount" the carbs, reducing fuel frothing... The intermediate "gasket" has daylight as on either side there's a ruddy great big soft o-ring between the manifold the the "gasket" and the "gasket" and the carb. So the carb "floats" and not all the engine vibration is transmitted to the carb.
It looks like the carbs are not tight to the manifold.
I am pleased it was not just me that saw / sees that - if you look at say 1.34, it looks as if the carbs are not tight against the manifold. All looks a bit lose. That is going to cause a problem.
@@edwardgurhy100 Thats totally normal, as usually you fit some rubber (big ring) between the mounts to isolate the carb, so the fuel there in doesn't get vibrated to uncontrollable levels.
If you watch on a bigger screen you can see the black gaskets. It isn't loose.
I wouldn't run that much more without rectifying that overfueling Matt, as you will just borewash the engine and destroy the rings and bore finish.
From thereon you will be looking at pulling it to bits again and honing the cylinders, (hopefully) and reringing it.
Try and find someone with a rolling road knowledgeable about tuning Weber carbs and A series - try Slark Race Engineering.
Happy Christmas!.
David Visard made a great video (Why cam companies cam timing cards are almost always wrong) showing how valve seat angle effects optimum cam timing. He found a lot of cam manufacturers timing recommendations are wrong because they don't take valve seat angle into account and he showed significant gains by tweaking them. The general gist was that 30 degree valve seat angles allow more flow as the valves start to open than 45 - 55 degree valve seat angles so cam timing base settings need to be advanced or retarded accordingly.
I do have his book on the mini engine. its not possible to swing the cam timing with the engine in the car unfortunately.
The dyno man is not up to the job for webers no good messing about with idle jets when it rich middle range,always do compresion checks on full throttle too get max air flow.
Compression checks were done with wot. As I said in the video, he doesn't stock any jets. It was supposed to be a quick swap of idle jets and a few power runs to see what it makes.
@Urchfab i wasnt critising just trying to help i know you will get it right.
If you believe the carburetor is affecting the compression remove it and test engine without carburetor
HONDA TURBO K24 SWAP TIME! 600H.P.! You can bloody run with the big dogs.😂 "MERRY CHRISTMAS, ERCHMAN!"
Why not drop AC Dodd a line. He may be able to offer some advice.
Maybe a combined video between the two of you.
Spanish Webers :-/
the honda likes a long cold air intake 1000mm
Sorry to hear your having so many problems with this motor.
Stop messing around and give endaf a call at Owen's motorsport, he will give you the best advice available and no bullshit.
This is WAY down on power,depending on the rolling road and weather conditions on the day this should be around 110-115 at the wheels...or if endaf is too far send it upto southam ...
Be good to see you racing next year.