331 MG Tech | Look INSIDE These MGB Gas Tanks!

John Twist takes the top off two MGB gas tanks and explains their form and function. John also explaining why it's a bad idea to use a torch to repair a used tank. Thanks for watching and Safety Fast!
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[@jaychambers2245]

Years ago had my MGB-GT into you. You are the best

[@garethgoodchild2643]

Very interesting John. I had no idea how the inside was arranged. Thanks for posting.

[@andrewwhenkel]

John it would never occur to me to question your abilities In fact When explaining my repairs I've done on my 1974 MGB I usually start by saying John Twist said....

[@joeabela4990]

Hi Sir l workes at Universty Motors in uk for 15 years l still like Mgb they are british icon keep it up nice to see you Joe Abela

[@fredgordon1788]

I have a 75MGB and I have done all the repairs from stop to bottom there is no one in my town that work on them love it got the book out and out had a MGA when I was in the AirFoce

[@paulsteele6120]

In Naval Architechture all tanks be they for water, fuel, sewage, cargo all have" longitudinal" divisions or indeed baffles. These are to split up the tank in lengthways divisions, the reason for that if you build a ship with no internal longitudinal the liquid in a cross seaway will build up a cross vessel wave which has the effect of lowering the GM (righting moment) and can in harsh circumstances can caused the phenomenon of the disappearing GM, this is when the roll is big enough that the vessel gets to (and beyond) the point of no return and capsizes. This may still happen on vessels with a whole load of slack tanks, so ships have been fitted with retractable stabilisers or counter acting "Flume Tanks" with sea water contained within the ship is allowed to go from one tank to another athwartships via a large pipe connecting the two tanks with a hurdle in the pipework above the upper surface of the tanks, so that once in a cross seaway the roll of the vessel sets up a counter balance i.e. as the vessel rolls over to Port or Starboard the majority of mass of the contained sea water is countering the roll its in the Starboard flume tank on a Port roll and counterclockwise on a Starboard roll i.e. it's 180 out of phase. It might not capsize a car going at speed around a round about, but if the tank was not 'press up' i.e. petrol is filling the tank up to and into the filler tube. It will cause the car to lift it's skirts and on such cars like Triumph Heralds and Spitfires with their cheapskate rear suspension may cause them to flip. Hope this helped.

[@upland1826]

John I'm a long time fan and have benefitted greatly from your wisdom and experience on my A, B and Sprite. During college I worked for Aero Tec Labs a maker of Fuel Cells for a variety of performance and competition cars; including a 1971 240Z that we ran in the 1972 Cannonball Baker. We also modified quite a few gas tanks over my time at ATL, in general, baffling was used to prevent fuel surge which would create too rapid a fuel transfer during hard cornering and significantly impact cornering stability. Nice to see MG took this into consideration. Stephen G.

[@coreysmith4583]

Awesome 😎👍 Thanks for such a great clip. Very helpful and informative. I'm just about to replace mine 😎👍

[@can-cruiser]

Thanks John, Great video and good seeing you online again. Glad you commented about "armchair mechanics" and "DIY'ers wannabes". It is a sad phenomenon showing up almost everywhere online and on forums. Those posers should listen to professionals of your expertise who kindly share their knowledge with others. But, instead, they chose to bash every bit of knowledge comes their way and the majority of them never actually leave their couches! Thanks again John. Looking forward to more videos.

[@blakeaasgaard9028]

Thank You Thank You Thank You for being you!!!

[@johngenova9870]

John’s knowledge and videos are a treasure. Thank you.

[@johnmurray3324]

Great to see you back

[@edwardlocke874]

Awesome stuff!

[@doctordjango]

Thanks for another enlightening video, John!

[@Tone76602]

Nice to see you back, keep up the good work.

[@MGB-learning]

Outstanding video and presentation. Welcome back!

[@yacineyassine5560]

I have gotten my 75 mgb ruuning thanks to your videos sir. You are a pro and you are awesome and you are a Nobel person

[@twistynobbly]

Very interesting.Thanks

[@chrisadams6595]

Love your videos John and respect the way you do stuff.!!!

[@Gordini62]

Very Good video!!!!!!

[@BareRoseGarage]

The baffles are to keep fuel on the pickup tube as you take corners, break hard, or change pitch on the car with only about a 1/4 tank of fuel left. Also they help your fuel system from "pulsing" air. Not so much a big deal with carbureted/mechanical fuel pumps, more of an electric fuel pump/injection nightmare. If you change to an electric fuel pump its always a good idea to use a baffle tank, esp if your pump has to have a "prime" to work. Good vid, glad I stumbled onto it.

[@TornadoCAN99]

Yes, baffles to keep fuel around the pick during hard/long duration cornering, esp when fuel level is low. This is common in motorcycle tanks (also helps reduce slosh-caused balance issues) and the reason we now see open-cell foam used in the race car fuel cells.

[@phillippowell3847]

Hi John (UK) here I well remember my boss at EMI asking me to put a new tank in his MGB at his home on the drive way ,when I got it raised up I found I could put my fingers through the metal of the tank top and it was full !! i did the job after a lot of expletives and buying lots of containers . Long story short.

[@tourettestrickenshan]

So many new uploads! Is this real life? Please let this never end, and THANK YOU!

[@tourettestrickenshan]

1956 MGA owner here, glacier blue and loved tremendously! Dying to see another in your shop!

[@craigmonteforte1478]

thanks for the Video, i found it very interesting ,in 1980 i bought a running in good shape 1979 MGB the car had a Trailer Hitch Welded underneath the fuelTank and the old owner used it to Pulll a light Sailing Catamaran boat inFlorida ! i knew that because the car had matching dents on both rear Quaters where he Jacknifed the Trailer and Boat into the Car ? at one point over the 14 years of my Ownership i needed to drop the FuelTank and that entire Trailer Hitch had to be removed my Vehicle was equipped with the Overdrive but it used to slip a lot like it had a bad Clutch , it wasn’t the Clutch and eventually i swapped out the Tranny to a straight 4 Speed Gearbox out of another Car it solved the Slipping issue but gave me horrible FuelMileage becuse at that time highway speeds were usually around 60MPH and with the gearing you had to keep the RPMs up pretty high i kept the numbers matching Overdrive and Tranny but the car was sold and eventually wound up being stolen and never recovered ? ironically i was contacted and questioned about the Theft ? Imlived over 25 years inMaryland and i’m pretty sure i met. you at University Motors years ago looking for parts as you were one of the Employees of the Old British Leyland Dealership inRockville MD that all went out on your own in that area and i got to know all of you as i’ve owned the B , a 53 TD , 55 TF 1500 , 64 Spridget , and Tinkered around with some Triumph Cars and Bikes my realPassion is the Prewar TDs and Fs unfortunately due to Health Related issues i don’t have anything but the knowledge and Memories

[@RobatRobot]

Hi John. Thanks for all your videos and credit to those behind the camera who help us see you. Over here in the UK we never had the emissions laws but I was researching the options to see what could be retrofitted. I noticed some diagrams list a vapour separator behind the taillight in the trunk. Is that something you would like to mention?

[@parrotraiser6541]

Without the baffles, spirited cornering would leave the fuel pump sucking air well before the tank was empty.

[@gostowski]

Thanks for putting this video up. Rockets have baffles in their propellant tanks to keep the propellants near the pickup connections. I am thinking MG is doing something similar to keep the in-tank pickup surrounded by gas when the fuel level is lower or as Paul said, to keep the mass of the fuel from messing up the CG of the car.

[@markdavis2475]

Nice episode thanks. I considered refurbing my tank, but a closer look showed the seams were splitting, also it's more time!! I'm just waiting for the delivery of my Moss extended range tank. According to their promo info, it's baffled and better quality than the original, it's cheaper too! Fingers crossed!

[@timbutton4990]

Thank you for making these video's John and it's good to see that you're keeping well. Some folk are not just armchair critic's, there are people making KZbin vid's on MGB's over here in the U.K who really shouldn't be. For example running flexible fuel pipe designed for the engine bay and using it to couple to the external fitting of the tank with a jubilee clip. Instead of bending bundy pipe to shape fitting a threaded fitting and flaring the end! The reasons for not fitting fuel hose with a jubilee clip in the wheel arch should be obvious I would have thought, but hey ho. Then the clown faces the camera and tells everybody that his bodge is perfectly O.K!

[@mmassimini1]

The baffles I know are used to minimize sloshing around in the tank. Water trucks used this for handling purposes, and with gasoline, I believe it keeps fuel to the pickup instead of sloshing side to side while cornering. In regards to welding on a gas tank, you are correct that it should not be done, unless done by a professional. The metal is porous and has gets into it. The professional welders fill the tanks with an inert gas. And I reiterate, this should only be done by professionals familiar with welding fuel tanks. I hope this explains it some.

[@jennifernicholas523]

The baffles stop the fuel running to the outside of the tank on long bends and starving the engine of fuel.

[@majorscope]

Hi John. Good to watch your videos again. We sure missed them. When i replaced my Healey tank with an alloy one and it stopped going uphill i was told that was because they don't fit baffles like the old tanks. We weld motorcycle tanks by feeding inert gas into them. No explosions so far!!.

[@RandomGuyDan]

A home trick is to run hose from your car's exhaust to the tank to fill it with CO2 while you're welding.

[@Cell1000bc]

Where’d the throttle blip on the intro go? Loved that.

[@MorroccoM13]

Hi John. Thanks for all your great videos and tips. I might have to replace my gas sending unit. Should I used gasket cement on the gasket? I have a can of aviation gasket cement that I've used in the past on gasoline sealing.

[@CHRoNo-ky6yz]

Thx John, that was really informative. A quick question, at about 1/2 a tank my car "runs" out of fuel. It only take 15liters or so to get it going again (it still has half a tank). The only thing I can think of is the the filter has fallen off, have you ever experienced anything like this before?

[@joemcghee8383]

pay no attention to the negative comments, I know a good mechanic when I see one I've been doing it for forty years, and I wouldn't watch your videos, if I didn't think you were up there with the best ,I m sure you realise in the classic car world there's lots of part time / hobby mechanics, and you know what they say about a little knowing 😉

[@donthuis]

I still refer to your guidelines and KZbin video's of old on MG Experience. Maybe some of the more popular ones can be remade in a better videoquality? By now almost any digital camera is defeated on imagequality by a smartphone. I just stopped using my digital camera in favor of a recent smartphone either offering 4k or highly stabilised HD video..

[@chrisadams6595]

My Dad told me the story of a guy he knew who threw an empty 5 gallon drum on a bonfire (it had been empty for years) . The resulting explosion killed him.

[@albertfroggett2281]

Hi John..great videos !! Did you put an electric rad fan on your daughters car ?

[@emrodsky4379]

How many gallons does the 1980 MGB Tank hold?

[@the_retired_mechanic]

John my car is a 1972 mgb roadster here in England. We didn't have the same emissions laws over here in that time. So would I have the earlier tank with the baffles??

[@sic-]

My 1974 BGT tank on my UKDM car was like the earlier tank in this video. Had enough rust holes on the top that I didn't even need to cut it open to see inside! Only difference is that I didn't have the pickup screen. Neither was there any evidence of it ever having one.

[@davelinkson1]

That's what I'm thinking also TRM, having the same year B in England..

[@johnwren3976]

Maybe its baffled for weight distribution while driving?

[@NerdofNorthStar]

With an MGA would a tank replacement just be easier than sending it out to be slushed?

[@netpackrat]

Yes, and you'll eliminate any worries about modern fuel additives degrading the slushing compound and plugging up your fuel system. Just be aware that not all MGA replacement tanks are created equal. The Moss tanks are good, others not so much.

[@integr8er66]

You can certainly weld gas tanks, there are two good methods, one is fill it with water and weld it up, the other is put a vacuum hose in the filler and take the the sending unit out to allow air in and this will purge any vapor and keep it from exploding. You are correct though that it can explode violently if you do it wrong.

[@dpforth]

You could easily wind up with an explosion in your vacuum cleaner when the fuel vapour meets the arcing from the motor brushes.

[@michaelannen4168]

Baffling