S3 E28. Performance tuning and MPG tuning the 670cc predator powered Renault

[@markosluga5797]

This IS the only channel on KZbin with this kind of content.

[@sasabarisic8864]

It's amazing, i love it

[@Ekasmer549]

Aging wheels I like a lot too.

[@marekhlavackovi3677]

that is a fact

[@schrodingersmechanic7622]

Cars and cameras is like it's crazy cousin

[@devivoman]

Hartwick performance there is a kid trying to put a 2 stroke v8 from a boat into and old Datsun! Just clips of him working tho, not edited into episodes like this channel!

[@crissd8283]

Robot Cantina: I hate doing fuel economy tests! Proceeds to do 5 fuel economy tests in one video.

[@krashanb5767]

I wonder if some kind of a flow meter could be used to get instant fuel use reading. That would save a lot of time.

[@bossshoang]

​@@krashanb5767i would assume the number would not be reliable much, since the test is supposedly measured in distance to fuel ratio. Usually after a trip of driving (somewhat) normally. Instant read fuel consumption is not really telling much if at all

[@WarrenGarabrandt]

Since it's going to be well over 100 F (which in metric, is a different number) for the next week in KS, I don't expect we'll get any more fuel economy tests since there's no AC in that car. I guess he wanted to get all that testing out of way while he could.

[@martin-vv9lf]

@krashanb5767 He could put a weight cell under the fuel tank, check the odometer before and after, check the weight of the fuel tank before and after the economy test.

[@bfgoalie99]

@@martin-vv9lf its called a load cell, but that's a fairly good idea.

[@StevenIngram]

You know, its current acceleration makes it a perfectly acceptable "around town" driver that would beat the pants off most cars for gas mileage. I really like this little car. :)

[@pleasedontwatchthese9593]

I was wondering how close it was getting to the stock car too

[@gustiwidyanta5492]

​@@pleasedontwatchthese9593the stock 1.3 has about 47hp, but the 670s a tad lighter, so i bet it can match it, especially if Jimbo does some CVT magic

[@goosenotmaverick1156]

I'd cruise around in it for sure!

[@ronalddaub9740]

I like all of the work he's done to it and I love the car at one point I would call it good a cold air intake would have been better than ram Air at that one Point .

[@that1guy82]

​@@goosenotmaverick1156the 44 mpg he gets is all country highway driving, but i bet city is still 35+ mpg

[@c6unjourc6toujours]

The saturn turbo diesel is the most incredible car ever ! ❤

[@timothykeith1367]

I'd like to diesel swap a Geo Metro. I would have thought the D722 was too small, even as the Metro weighs 600 pounds less than the Saturn

[@Stevemax07]

I'm very jealous that you can spent your time working on these projects. Thanks for documenting the fun and sharing with us!

[@reverse_engineered]

Thanks for the recap of the progress so far. It's hard to believe you've been able to make such an improvement with relatively little modification. I totally understand wanting to tune the engine performance before tuning the transmission. The engine develops the power according to the load, while the transmission converts it to the appropriate torque for the current speed. The tuning of the transmission will greatly depend on the power curve of the engine, whereas getting power out of the engine is its own thing. And whatever you do, you don't want to change a bunch of things at once, otherwise you won't know what change made the difference.

[@robotcantina8957]

Exactly!

[@TheStuartstardust]

​@@robotcantina8957as you are not losing traction and the car is light, would it be allowed to use motorcycle tires? There should be more slim options and also aerodynamic ones - would that be cheaper and legal? No saying it is worth it, just wondering if it is an option 🤔🤓

[@lr0dy]

​@@TheStuartstardustYou can't mount moto tires on car rims - the beadlock is entirely different due to the lateral forces the tire must endure. They're also generally heavier than an equivalent-size car tire, because of all the reinforcement necessary.

[@TheStuartstardust]

@@lr0dy bead might be issue yes, but you can the other way around? BMW has a motorcycle with a sidecar which use car tyres, some others also. Also ryan f9/fortnine had an episode about tyres where he mounted car tyre on a motorcycle 🏍️

[@lr0dy]

@@TheStuartstardust The bead of a car tire is somewhat smaller than the bead of a bike tire, if I remember correctly, meaning a car tire can fit onto a bike rim. It's a stupid idea, but you can do it. The larger bike tire bead however will not seat onto a car rim.

[@neutrodyne]

I used to drive a Renault R10 back when I was in High School (1974-75). I loved the front seats in it and it also got great gas mileage back then. When I came to driving it in the snow it was much better than than rear wheel drive cars of the time. It also had Michelin X radial tires on it. Radial tires were unheard of back then. My dad later replaced the back tires with a set of bias-ply tires. This made the car extremely unstable to drive as the rear of the car wanted to fishtail on every curve. It would be neat if you could find a person who still owned an original R10 and have a race between yours and the original car with the 4-cylinder engine. Thanks for posting these interesting videos.

[@robotcantina8957]

Thanks! I agree it would make an epic race between the 670 R10 and a stock R10. Sadly the only running R10's that I'm aware of are out of state.

[@cw7631]

That last 55 mph test was great! The car sounded like it stayed in the power band and kept pulling! I am enjoying this project! Very impressive gains!

[@TotesCray]

I usually finish my Saturday evening watching some carnage in an I Do Cars engine teardown, and then enjoy my morning coffee on Sunday catching up with what Jimbo and the crew have done with lawnmower powered classic French tourers. It's a nice contrast of things that don't work, and things that do even if they shouldn't. Love it! Heat this week is no joke, stay frosty, gentlemen!

[@robotcantina8957]

I do cars engine carnage on Saturday nights is always a treat.

[@th3R0b0t]

Ah, I See You're a Man of Culture As Well... 100% I do the same, plus I find out what I may or may not be ordering one of by watching Project Farm. Last week, I actually needed a plastic welder. His timing is impeccable.

[@Shiznit304]

I’m happy you’re going with a variable Venturi carb. My British cars have SU carburetters which are variable Venturi.

[@SoulTouchMusic93]

Dude, I love the fuel consumption figures. Please don't stop doing those! I want to do an in line hybrid of sorts and that helps me out a lot!

[@pancudowny]

With the "Ram-Air" system a friend built on my '85 S-10 pickup, it drew from the "clean" air seen by the lower front-end air dam. Also: The GM/Bosch TBI system (EFI) was able to compensate for the change in inlet air mass & temperature by constantly monitoring and adjusting the A/F-ratio in accordance to input from the numerous inputs it employed, as well as referencing the programmed fuel mapping "burned" into its PROM (Programmable Read-Only Memory) chip. The result: Avg. 25-mpg@77-mph cruising speed!😁

[@kensmith5694]

The pressure from the ram air system also needs to connect to the vent of the float bowl. The jets work on the pressure difference.

[@Xargsify]

Yep, gotta reference the venturi side to the bowl side. Motorcycles have been doing this with carbs since the 90s, and they all have fuel pumps that can exceed the ram-air intake pressure plus the bowl(s) vented to the intake...

[@kensmith5694]

@@Xargsify Yes cars and motor cycles do it but maybe a lawn mower didn't. It would explain the ram air thing and also the mixture being effected by other things that may be the same sort of effect. Done right, ram air may get them as much as 2 extra squirrel power.

[@-aid4084]

As always, this was a amazing and enjoyable video. I love the concept of slapping together a car and getting the most out of it. Makes me want to do it sometime.

[@TheShutterNinja]

Tune in next time when Jimbo powers a M1 Abrams tank with a 3.5cc 4 stroke Toyan engine! Joking aside, I love this channel and the thorough testing- it never ceases to amaze me with what you can get away with yet still be drivable.

[@christopherguez9927]

This is probably my favorite channel on KZbin. I stumbled upon it at the beginning of the Saturn build. I look forward to every video! Keep up the good work!

[@pancudowny]

An old trick I've seen done to help with the fuel's phase change is to heat the fuel before it enters the carburetor, done "quick & cheap" by running the fuel through a length of copper tubing wrapped around a "waste" heat source (heater hose or an under-hood exhaust part) placed in a point along the fuel line's delivery path AFTER the fuel pump or fuel filter.

[@HammerWrench]

I drive an Excursion, and after seeing all the fun with this car it makes me want to consider something tiny to tinker on.

[@that1guy82]

I wish i had more money. I'd love to f#ck around and find out stuff on my escort.

[@puebespuebes8589]

Tiny light car are superior

[@HammerWrench]

@@puebespuebes8589 now fitting in one is the next challenge!

[@puebespuebes8589]

@@HammerWrench ahah🤣 im french and i drive a voiture sans permis ( car whitout liscence ) I relate to your video dearly !! Small car ( for european standart ), no more than 70km/h downhill, no fuel gauge ! fwd cvt and no climate vent... In southern France ! So i drive slowly but surely windows opened and arm out and it fit everywhere !

[@HammerWrench]

@@puebespuebes8589 your description makes it like I can almost see it happening! I drive an 8000lb Excursion with a V10 engine in South Georgia, USA. It loves towing and the gas station. When my windows are down, it’s to hear that exhaust singing! Our sons are 6’4” and 6’5” tall, so they appreciate the legroom in the second row.

[@xzkt]

Thanks for producing such interesting content. I look forward to Sundays so I can watch your latest efforts. Phil

[@schzx14]

The ram air failed because you did not adjust the mixture to compensate. Gotta richen that mixture. But I agree to get the carb you’re going to use first. Once you pick a carb, the ram air can be a focus. Good job. Fun stuff.

[@PsRohrbaugh]

I don't mess with carburetors, but isn't the whole point of their venturi system to maintain a constant AFR across different airflows? Regardless, he's done EFI on these small engines before, and I'd like to see that here at some point.

[@schzx14]

@@PsRohrbaugh At atmospheric pressures (no artificial pressurization), you’re correct (generally speaking). But if you pressurize the air reaching the carb, via supercharger, turbocharger, ram air, etc), the vacuum signal at the Venturi is actually less. Therefore, with less vacuum signal, it picks up less fuel. So you get a double whammy of more air (due to forced air) as well as less fuel. Lean mixture ensues. Most forced air induction which incorporates carbs compensate for this by applying this extra pressurization to the bowl chamber of the carb which in turn forces more fuel. It’s likely though that jet and needle changes would also be warranted. Carbs are much more fun to tinker with than fuel injection. :-)

[@PsRohrbaugh]

@@schzx14 great explanation, thank you! >carbs are much more fun to tinker with than fuel injection Hey, to each their own! No problem with that! There are people who love messing with hit-and-miss engines, steam engines, and other things too. But for me, my brain understands a fuel map significantly better than the black magic of carbs! Especially if you want to casually add on forced induction, nitrous oxide, and similar.

[@schzx14]

@@PsRohrbaughI love all that stuff too. :-)

[@kingmarz3635]

Ram air has never worked and is a myth

[@radicaledwards3449]

5:26 Treee Fiddy! Dat got dam Loch Ness monster..

[@carlhartman9358]

So I love the straight edge across with fuel cell with the combi square for measuring the fuel level, but to increase the accuracy how about a little gnome in a boat acting as a float holding up a stick, fill the fuel cell up until the end of the stick reaches the same point on the combi square every time

[@robotcantina8957]

Hmmmm.... I reckon that's not a bad idea. I'll give it a shot.

[@webmasale]

Loving every bit of this series. And I 'm sure the Saturn will get a decent farewell.

[@Motosapien46]

I sure hope so! It's the car the brought me to this channel and it makes me sad they're going to dismantle it for other projects.

[@daniel33448]

If you are interested in what fuel costs in Germany. Conversion rate is $1.09 for 1€ Today here in Bavaria/Germany: Gas= 7,82$ Diesel= 7,08$ for 1Gallon I think twice about taking out my Corvette😊 . Thanks for the conversions to the metric system. Great Video👌👍.

[@robotcantina8957]

Thanks for the info!

[@Wagonman5900]

I like the "dare to be different" approach to the carburetor selection. And I hope the Saturn gets another motor. Try to find something really weird that nobody has heard of ever to put in it.

[@pancudowny]

Note to OP: Re: Cowl Induction. It's well-used in NASCAR as a way to create a "Ram-Air" effect with inlet air to the engine.😉

[@seriksson9721]

The basic rule of thumb when experimenting is to concentrate on one thing at a time, otherwise it's easy to get lost. You are talented and it's fun to follow the channel. Thank you

[@9233tv]

Thanks!

[@robotcantina8957]

Thank you so much!

[@PsRohrbaugh]

Curious if I'm shadow banned or just ignored... I donate $60 two hours before this, and still don't even have a like. Ah well.

[@alttabby3633]

Thanks Jimbo, I always enjoy checking in on the Cantina!

[@robotcantina8957]

Glad you enjoy it!

[@leneanderthalien]

the tinyest tires are 125/80R15 who are use on Citroën 2cv...But the best quality (Michelin) tires this size are very expansive (91€ for ONE tire in France).Carb pipes heater are relative similar to the VW on the 2cv flat twin air cooled engine...

[@GuHKSBASS]

We need more episodes of this, I know it's difficult. But really.. We need more Great job as always and keep it up

[@PsRohrbaugh]

If you want to play with the carburetor first that's fine, but I still want to see a predator pushed to the limits. We got close with the insight, but I really want to see what can happen with EFI & a good tune, turbo, ram air, and nitrous (either wet or dry / ECU compensated). I understand being careful with the diesel, but the predator engines are cheap enough to take a few risks. Anyway, another great episode!

[@subynut]

The carb on my parent's early 80's Ford LTD Station Wagon was a variable venturi carb, too. From what I remember, my father said it worked really well really liked it. His only complaint was at the time, it wasn't rebuildable. So, when it was time for a rebuild, he ended up having to replace it instead. Really neat design: Good power, good fuel economy, and minimal maintenance.

[@mikescudder4621]

Cool, i hadn't seen one of those constant velocity something carbs before, but it immediately reminded me of the legendary 'constant depression' SU carb. Cheers Jimbo!

[@thedarkknight1971]

09:38 - For the 'Ram Air' to work more effectively, you'd have to install some form of fuel injection system setup, driven by a seperate 'Stand alone' ECU with various sensors to monitor and adjust fueling to suit the increasing air flow the faster you drove. It CAN be done, but, it's not cheap as, well, you'd have to buy the gear, install it, and then book the car in for a coupla runs on a Dyno to tune it correctly & effectivly... So... Sadly a little too much for this kind of project. Though yeah, it would be intriguing how that route would go with regards to power & economy. 🤔 😎🇬🇧

[@TekedixXx]

Can't wait for that carburator upgrade, your dedication to the science is admirable. It's always easier on paper.

[@sylvieslug]

about jumped out of my chair w/ excitement when you mentioned you would be giving us at least one last video with the saturn. that little thing is one of the coolest cars on youtube IMO

[@Seth-mu3wo]

This channel is excellent and unique. You present the content so well. Can't wait to see what you do next my man.

[@josephpadula2283]

Just drove my 2002 ford focus wagon with 285k miles on it to the junkyard 150 miles away in 3rd gear on local roads . Tranny shot they gave me 175 dollars for it delivered . A guy picked me up at the junkyard in his 2000 Honda insight manual transmission car as a test drive . I bought it, had to, no way to get home! I seems to run fine and gets great Milage . When the engine goes who knows what I will put in it….

[@andie_pants]

I hope you share the experience with us! 😃

[@soundcode0246]

I love this guy. I think everyone who works on engines should watch this as its valuable information.

[@tallie185loco]

Man i really like all your vids, they're very technical and illustrative, thanks for taking the time to do what most of us wanted to but can't, appreciate it budd

[@TrilogyBPM]

Thanks for the sunday moneing entertainment jimbo! Coffee and robot cantina is my favorite way to start the day

[@mashidaho1298]

God i love your content. Never thought id be so ecstatic to see a french car with a harbor frieght motor shave 2 seconds on a 0-55 run. Youre doing great and im glad i subscribed

[@jackmanatee3162]

The "work" you've done on various cars has always looked so fun. If I was your neighbor I'd be over at your garage so often, you'd probably get a restraining order against me. Oh, and I love the shots of those blue skies and green vistas. 😃

[@BenKeeneOfficial]

In my experience with tuning cars, fuel ratio is only half of the equation. The perfect (stoichiometric) ratio is 14.7:1 at this ratio you get the most efficient burn. The other half of it is ignition timing you want the timing to be advanced to the point the motor creates the most power as possible then take a degree or so out for safety. The more power the motor makes the less throttle and fuel you need to supply to get the same results. Don’t know if you’ll read this or not but hope it gets to you and possibly help :) awesome project

[@2GSpyderTurbo]

This content strokes the best part of my ADD brain. Ive been watching for a long time and always look forward to your posts every week.

[@stuntvist]

The reason VW probably found the exhaust thingy to improve power is because you don't want your fuel to vaporize before getting into the combustion chamber; if possible while still getting good atomisation. It's one of the reasons direct injection is better for fuel efficiency and why it lends itself well to higher compression engines. Latent heat of vaporization is a pretty powerful thing when it comes down to engine performance and even though petrol/gasoline is almost laughably weak at pulling heat from the air around it to do so, it still makes a massive difference for engines. It's also why you can make more power on E85 even though the specific energy of E85 is far lower than petrol/gasoline, the simple fact that ethanol pulls much more heat out of the air to vaporize cools down the combustion chamber enough to provide an actual performance benefit over petrol/gasoline, even though absolutely everything else about E85 should make your car less powerful. Also ram air intakes need to be very carefully designed to get a decent amount of more air forced into the intake. On modern cars it's easier (and less aerodynamically problematic) to use intake manifold resonaces to achieve a similar amount of extra manifold pressure. Even then you'll be looking at maybe 15% more air which is speed dependent and a nuisance to manage on a car without some sort of system to monitor and adjust the AFR constantly, like say, an EFI system. You could also go the old plane route and add a lever or dial in the interior to let you adjust AFR on the fly, which could make it work. Probably doable somehow with some cables and whatnot going through the firewall and looking like a tripwire inside the car lol. The carb spacer is also a bad idea on principle alone. You want as short of a distance between the throttle and intake valve as possible to reduce the distance of vacuum between the two to reduce pumping losses. It's why things like ITB's exist. They won't make any more power than a good intake plenum, usually, but they improve throttle response for that reason. There's a reason BMW dumped a whole lot of money and time into developing valvetronic. Having the intake valves be the throttle bodies themselves does a whole lot for throttle response.

[@RadioReprised]

Once the CVK is on route the Ram Air straight up the window to the roof and jet for it!

[@StillFunBrewing]

This is the most interesting experimental engineering channel out there imo. It’s crap like this, that I want to work with daily.

[@4saken404]

I drive an air cooled VW and I swear I don't think my carburetor is any bigger that the ones you've been using. So now you got me thinking...

[@neilredelinghuys3263]

i must say I appreciate the amount of effort you put in. and also the metric conversions, they help me out alot!😊

[@PsRohrbaugh]

It may be acceptable in metric, but in America it's said "a lot" as two separate words 😊

[@neilredelinghuys3263]

@@PsRohrbaugh lol, yes we also do not say aluminium the right way 😜

[@giggiddy]

​@@PsRohrbaughgee, wonder why people dislike us Americans. I know you're attempting to be funny, but not everyone gets the humor and immediately places a comment like that into the arrogant American bucket.

[@ronalddaub9740]

Yes grease works. good,, I said cold air intake.. but you went for cold air plus ram. but I just said cold air.. hope it works good I love that car.

[@Ahto42]

Garage 54 did a test when they did heat up the fuel to its boiling point and did get almost 2/3 the mileage as with the ambient temp fuel. Sure, the test subject was fuel injected. Our old moskvitch 412 had also problems when it was below freezing. It also had a pipe connected from the exhaust manifold to the air filter. On summer, many drivers(my Dad also) disconnected the pipe to get better performance and mileage. But in autumn, if you forgot to connect the pipe back, then you where sitting beside the road waiting to the carb to heatsoak a bit and drive forward few km/miles if you did nod had the pipe with you.

[@ArcticMayhem]

On the ram air idea, there is a difference in pressure between the fuel in the float bowl and the air in the intake pipe. If you connect the float bowl vent to the intake, I'll bet the mixture will be more stable. Rotax used to use this trick to their advantage in the 90s to tune their carbureted snowmobiles for higher altitudes. It was called a H.A.C. or high altitude compensator. Early versions used some kind of mechanical vacuum regulator, but later versions used a solenoid to regulate the negative pressure on the float bowl.

[@Orbacron]

Yes, the grease keeps the gasket from ripping when disassembling again. Also keeps threads from corroding longterm. This episode is very satisfying, and the performance is great

[@3rdpig]

Good video! Recently Uncle Tony did a similar fix on his slant six drag car, he found that routing some exhaust heat to the intake manifold both improved his time and made the engine run smoother.

[@benholroyd5221]

It's air cooled, so perhaps routing the cooling air? Plus your get fan assistance for free.

[@lr0dy]

Not surprising - heating the intake runner prevents fuel condensation, particularly if the runner isn't straight. A downdraught carb has less of an issue with it.

[@J0K3-R]

Waking up on a Sunday morning never felt so good 👍

[@peterbrown6224]

Well done to Performance 670, it made your life much easier. That said, $3.50 a gallon is only about $1 per litre, you get no sympathy from me :-) It's great to see this quirky French car back on the road.

[@espenschjelderup426]

That is about half the price of gas on a cheap day where I live.

[@Steevo69]

We Americans drive a lot more, our states are the size of most west EU countries and it’s nothing new for someone to drive a few states every couple weeks. I live in Montana and it’s hundreds of miles sometimes for a single school event. Like Paris to Milan, Berlin to Warsaw, Dresden to Vienna for the short trips

[@PsRohrbaugh]

When Trump was in office gas was under $2 a gallon, so, it's basically doubled.

[@peterbrown6224]

@@Steevo69 I'm from Australia, and I understand completely. Our petrol is more or less the same. It's just tax.

[@Steevo69]

@peterbrown6224 Taxation is theft. Unless I agreed to it they are taking my money, the fruit of my labor, food out of my mouth by government force. I'm done funding wars my children might die in, my family hurt and died for, for people that ungrateful and unworthy. Let them stand and die for their rights as my family has and will on our own ground

[@herbertgearing1702]

Thank you for your time and effort, this is quickly becoming my favorite weekly show.

[@jdholbrook33]

Worked on air cooled engines for many years as a Porsche tech up in Dallas. Almost every carburated motor I worked on had down draft mikuni or weber. Individual runner for each cylinder, not very long runner either. How about a set of regular mikuni carbs on short manifolds for each cylinder? Those long, bendy manifolds are not helping peak power for sure. Call me crazy but I always enjoyed syncing up the carbs. 3 barrel down draft weber on each side. Great fun.

[@davidlampe4153]

We love the channel and the projects you are working on. Love Love Love the Saturn car wonderful design and execution of the Diesel engine happy some parts will get a second life. Thanks

[@RPS13DRlFT]

Your videos have become a sunday tradition for me, keep up the good work!

[@chilternsroamer872]

I had variable venturi carbs (with diaphragms) when I owned a 1980 R80/7 BMW motorcycle. One carb each side (one for each cylinder). Yeah, they were pretty good.

[@rjung_ch]

Hey Jimbo, back for more like all the others here. Just a great Sunday vid, thanks man! 👍💪✌

[@Cookie-Dough-Dynamo]

Uncle Tony just learned about heating the intake on his slant 6 race car. It was causing stutter while doing 1/4 mile passes. Drove him nuts.

[@noname-sd5dt]

I love this stuff. Look forward to seeing how these projects go. Reminds me of the days my mates and i spent in sheds with outboards, motorbikes and cars. You probavly already know but with ram air you need to pressure reference your fuel bowls. Tap a hose fitting in there to a plenum shared with the ram air.

[@B0RN2RACE100]

You could the breather from the bowl into the ram intake tube and it would balance out the pressure rise on the intake vs the bowl and it would maintain your AFR. Theoretically

[@oddojaggins]

The 0-30 time is finally acceptable! I'm gonna miss the diesel saturn but I'm glad the power train will live on. Every episode I learn something and there's usually one good laugh to be had, best Channel on KZbin

[@Ariccio123]

The discussion about warm air intake reminds me of the "thermac"/thermal air cleaner/exhaust manifold heat shroud on a ton of GM cars from the late 60s and 70s. There was a vacuum modulating thermostat and a vacuum operated solenoid connected to a door on the air cleaner. The air cleaner had a normal under hood or front grille intake, and *also* an intake that connected to a flexible hose and shroud around the exhaust manifold. You can find some excellent 1960s service training videos from Chevy that explain this system in detail - it would blend the air intakes to target a 125°F intake temperature in all conditions. If I remember from the original EPA documents, this system reduced cold start carbon monoxide by *ninety* percent! That's a huge improvement on top of driveability and efficiency improvements.

[@Ariccio123]

Ah! Found it! kzbin.info/www/bejne/fHXYYZRvjcSkeNU

[@ThePaulv12]

As usual I enjoyed this vid very much. There's only so many Gen II 426-572 Hemi vids on KZbin and I'm Hemied out! For those interested, the Keihin carb, like all carbs, load senses on the principal of there being an inverse relationship between manifold vacuum and Venturi vacuum. Where it is different over conventional carbs is it has a variable Venturi as opposed to the more usual fixed Venturi.

[@nodrug2]

Another enjoyable and informative video, this channel is my first choice for Sunday mornings. I'm looking forward to seeing how the Renault goes with the new carb. Although totally impractical or just impossible, I'm not a mechanic or engineer so what do I know but I'd love to see an old Weber dual throated carb somehow installed on this engine. Keep up the interesting insane videos.

[@hubertcornett7]

I just love that old car. You still find some of them in Denmark.

[@althejazzman]

I appreciate how you've made the digital speedo easy to read on camera without needing a second camera. I don't think you mentioned how you did this.

[@daveself6386]

You have to have the carb vents in the ram air tube to keep the float chamber pressure the same as the ram air.

[@roberthoffman4713]

This was another great video. I am looking forward to more on both this and the saturn. I like diesel engines so the saturn really peaks my interest.

[@thedarkknight1971]

07:12 - Hahaha yeah, I suffered 'Carb Icing' once. Many years a go I had a 1991 VW Polo Classic 1.3 Litre (2 door saloon). I had removed the large circular metal air filter & housing (the design that had a 'Summer/Winter' flap that would allow heat to be directed up through to the air filter housing for warm air to stop the carb feezing in winter), and had installed a home made sponge air filter... ALL WAS FINE in the summer months (could hear the induction roar sound nicely too 😏😉), but, one time during a cold November night driving home from a girlfirends place, the car suddenly coughed and died miles from home. I though "FAAAAK! How am I gonna get home!?" Anyhew, checked under the bonnet, nothing seemed out of place, tried starting the car again and, hey presto! She started! And so, gingerly drove her home expecting a total breakdown... Well, this happened a few times, and after some research I was starting to get a few ideas (fueling? Blockage? Carb Icing?) until one night, torch and screwdriver at hand, I was ready for it. Yup, she died, so I quickly pulled over, popped the bonnet (hood - for you guys lol), unscrewed my DIY air filter, and yup! There it was... FROZEN FUEL in the top of the carb! Hahaha. Being a biker too I felt such a dope as I SHOULD have recognised this from the start! hahaha. So, I swapped back to the original filter & housing for winter, then back to the DIY foam one for Summer. Ohhh what a numpty eh? Hahaha 😉 Sadly, I miss that car 😟, it's one of a few that I SHOULD have kept... 😎🇬🇧

[@98grand5point9]

Driving around on a 100 degree day in my girlfriends Austin America the engine suddenly died. I got out and opened the hood to find that the carb(constant velocity) was a large block of ice. I chipped some away and as soon as it was mostly thawed I discovered that the heater band that was wrapped around the top had the wire broken off. I thought it only worked to warm it up during cold weather. Apparently that particular carb was very efficient at vaporizing the fuel. No wonder it got a solid 35mpg all of the time. Hooked the wire back and away we went !

[@robotcantina8957]

LOL, I had the same problem with my Triumph Spitfire every spring.

[@Dis-Emboweled]

I'm excited to see the Return of Saturn! The new carb for the Renault will be interesting to see! Great video again Jimbo!

[@GIGABACHI]

Jimbo, I appreciate you take your time to do these fuel economy tests. As always, tip of the Hat to the Robot Cantina Team for all your efforts and mad science-ing. 👌🙂👍 P.S: The cold air induction it's always a blessing on ANY engine operating in warm climates. The whole ram air debacle: YUP, YOU NAILED IT ! It's the same as trying to run a blow thru turbo or supercharged system with a regular carb off an N/A engine.

[@wesleypollard3058]

I love this channel and this kind of experimentation! I look forward to each one of these videos, and I recon I ain't the only one. Looks like we are still in Kansas Toto. click click.

[@szabcsababcsa]

A tip for the ram air intake, if you connect the breather tube of the carb into the intake, you compensate for the extra pressure, it will still lean out, but a lot less.

[@PsRohrbaugh]

If the ram air changes AFR that much, it'd probably do really well with fuel injection (and maybe in conjunction with a turbo)....

[@nigeltrigger4499]

Could you chop the bottom of the funnel off so that it is level with the fuel when the tank is full. You could then just keep poring in measured amounts of fuel until the fuel level reaches the bottom of the funnel (instead of having to take the funnel out, align the file and set square, then put the funnel back in, add more fuel, repeat).

[@tiporari]

Ram air needs a throttle butterfly to moderate the intake Velocity. Tuning the opening and timing used to be done with nonlinear linkages. You can use a constant Velocity carburetor with slides instead of throttle blades. These don't suffer from pressure increase upsetting the venturi. In all cases, calibrating the AFR is necessary. In the early 80s GM Rochester introduced PWM controlled jets for closed loop operation with a simple 02, MAP, temp, and other sensors plus a basic ECM. Thunderhead289s AFR cheater would probably help a lot for these experiments. That would allow you to get nearer to the volumetric efficiency limit of the engine and experimental accessories. Fun stuff!

[@kf7tkj]

Im looking forward to seeing how the CVK carb works!

[@WellbeWelloff]

Tuned in a little late, but I certainly can't wait to see what the diesel engine goes into. I really enjoy these videos, and appreciate the work you put it.

[@joshuaanothereraseddad]

Thanks for another fun video y'all! It's quite fascinating watching all the experimenting. Many folk today have absolutely no clue how challenging it can be to tune a carb. Let alone an I4 sportbike. I am so grateful I grew up during the end of the analog days and into the digital days. Being able to tune a carb and yet use a laptop to adjust A/F mixtures is knowledge not too many have.

[@XGamesJ6]

The V4 engine on my Honda bike has Keihin carbs, and I love em! I knew exactly what you were after when you introduced it

[@9233tv]

I’ll say it again, that car brings back soooo many memories of oma, and learning so much about a car in general. Was also reminded about the spare tire storage behind front plate while you had the info posted over the front of the car. If I had the cash, I’d buy it when you’re done. Memories 🥰😢 thanks for providing them.

[@Catfish4000]

I have some points to make: * Using a shared plenum between carb barrels is not a good idea on an uneven-firing engine. One cylinder robs the other due to intake pulses being closer together in one part of the cycle than the other. * The "richer" readings you were getting with the carb shrouded might be due to more complete combustion from better atomisation. More oxygen is being used up, less comes out the exhaust, O2 sensor shows richer. * The long intake tube might be providing a tuned induction effect, which the carb may not be calibrated for.

[@GrantOakes]

Your channel is one reason why I LOVE Sunday mornings!

[@toddtonis]

BMW used these CV carbs on their Airhead boxer engine bikes from the 70's and 80's. The carbs were made by BING. I have two on my bike and the carbs are fiddly, but work well when they are dialed in. Throttle response is slower by my experience to traditional carbs.

[@alistairshanks5099]

All cars before the introduction of electronic fuel injection ran inlet manifold heating to aid atomization. In most cars, exhaust gases were used to heat the intake manifold but in some vehicles with inline engines and crossflow head coolant water was used. This system was also used in conjunction with a warm air diverter for the air cleaner to stop ice particles from forming in the carburetor venturi area and blocking the main fuel jet. The warm air induction tapered off as the engine reached operating temp because engine efficiency does improve with colder and therefore denser intake air. The more volume that enters the cylinder the higher the compression is and the more force generated by combustion, e.g. more power. As the engine is running more efficiently then fuel economy is generally better unless you let the extra power go to your head and push the foot down harder than normal. The new carburetor is a modern adaptation of the famous British SU units seen on so many British cars when performance was wanted and in the case of Jaguar they had up to three of them for a six-cylinder 3.8 and 4.2-liter engines.

[@Hungry_Hunter]

This is some fascinating testing in the real world very well explained and carried out.

[@ChrisB...]

When I built my first 4-stroke motorized bike I added an aftermarket "free flow" air filter because it looked cool. It ran like absolute crap until one day I decided to put the stock air filter back on. It has run like a swiss watch since that day. DERP on me.

[@robotcantina8957]

Parts that look cool vs parts that actually work..... I'm glad you sorted it out. lol

[@mrsockyman]

Didn't know the cv carb was for atomisation, well explained! 👏

[@IndridCool54]

This is the absolute best way to start off a Sunday morning! 👍🏼

[@TotoGeenen]

Tuned out for a while because I've been busy in life. But coming back to a RobotCantina video is like coming home. Love the content mate!

[@LukeSchiralli]

You sir are living the dream! Love your channel. Hi from Australia 🇦🇺

[@fabiotiburzi]

The billet intake has a sharp edge on the carburator side, you can see it at 13:35. Moreover, i suggest you to 3d print an adapter that will make a smoother transition into the intake manifold so that the splitting of the flux between the cylinders is more homogeneous