This is my MGB GT for track use, and didn't start after a four months storage since the last race...In this video I walk through the defects and troubleshooting. This is not set in scene......
Nice vid showing your thinking and progressive testing. Well done! And, of course, it's always the last thing we check right? LOL... I was also thinking while listening to you that it's quite remarkable how good your technical English is. It's one thing to speak fluently with day to day conversation if you're not a native speaker, but another one entirely to be proficient with technical terms that most people in the UK or US would not even know. Impressive! And where did that part go while the car was stored?
My first car was a MGB-GT. It's where I first started paying with building cars and repairing them. I replaced the floors and boot corners. It' didn't sound like yours though! I now have an MGB with a partial Sebring look, just the front and rear valances and not the flared wheel wells. I recently got my Riley 9 engine running and it was very rough. It wasn't until I made a tubular exhaust manifold for it I worked out why. One cylinder wasn't firing, I could clearly see the lack of heat on the headers. It was a valve not fully closing which a compression test then a visual check with the rocker box open confirmed.
Nice to hear and they are great cars... I build and had a sebring not that long ago a V8 3.6 , look for project orange on my channel... but the 1950cc former (1800cc) is so much more fun to race and easy/cheap to repair versus the v8
Great Video! It was nice to see you methodically go through the different systems, and the process of elimination to land on the DCOE carb. I Love my 69 MGB GT which has a stage two "Fast Road" . I considered a DCOE Weber but elected to install rebuilt HS4 SU carbs. Truthfully the DCOE's and all the jetting etc are like black arts to me. Thanks for sharing this very informational Video.
I expect that you'll find the center carbon electrode of the distributor cap laying down in the bottom of the distributor body. Also, when you do your fine tuning of the ignition, check the timing at idle, then observe it while increasing the engine speed. It should vary with speed. The centrifugal advance weights in the bottom of the distributor can get stuck giving you static timing (since you have no vacuum advance).
thanks and indeed, I always use static and dynamic adjustments. The bobweights have been adjusted ( springs) to alter the advance curve.... But will change it out to a 123 programmable distributor soon. The reason is that the current EI is not accurate enough due to the fact that the blocking blades in the distributor ( optcoupler) are not accurate and cause an offset for the ignition pulse on the different cylinders.
@@D3Sshooter I had the pertronix2 on my red car, and have accuspark on this 67, but do hear good things about that 123. I believe that's what Dave Wilkes runs. don't you have one on the mini?
@@D3Sshooter I think you'll like the 1-2-3. When my brother and I put one on his distributor machine, there was zero timing wobble. The Luminition setup that you have is the same as the one that I have on my Mini and it works very well. You shouldn't have any timing variation from the chopper wheel, but the distributor shaft runs in a bushing in the distributor body. That bushing wears out and you get wobble in the distributor shaft. David Vizard, in his book "How to Modify Your Mini", has diagrams for replacing the bushing with a needle bearing. This modification removes all of the wobble in the timing, but a 1-2-3 is a MUCH better idea.
Jim, I did but did cut it out of the video as it was to long... Note that on a race car , you tend to go Wide open all the time ( 5000 RPM), so at idle the plugs will spoil quickly if running to long... That engine is prepared for racing...
Just had my Mg BGT 2 days ago having long crank on start, and wanted to cut out on 1st and 2nd gear. standard engine with Hs4 SU carbs. Finally saw fuel leak coming from overflow pipe from front fuel pot. Had to rig a plastic bottle to catch the amount of fuel overflowing. Turned out the amount of grit/rust particles coming from the fuel tank was blocking the fuel pipe from bottom of fuel pot tube to carb jet. Cleaned up fuel pot and checked needle and spring inside Carb Pot. Car started first crank. Going to add an in line filter and eventually new fuel tank. Checked timing last night, out by 5 degree got that fixed, need to do valve gap at the weekend. Thanks again for a very informative video.
Hello Steve very good video. My old Honda used to run very badly. Then i checked everything like you did. Then I tried an additive for the injection system and the problem was gone after a long, fast ride :)) A video about additives for engine, transmission and cooling would be a good thing. I'm sure a lot of people will find that interesting. Great video Steve. 👍👍👍
Back when I used to run Webers and Dellortos on old Corollas I learned to disconnect the fuel pump and run the engine until the bowls were dry if I was going to leave the car sitting for several months.
@@D3Sshooter we calculated about the same with my short block/head combo but after putting camera inside, it looks like it was never run after being rebuilt. So hopefully my 172-178 # will come up after some driving. How do you do your break in on rebuild? and you have 4 idle air adjust screws? Or what are the other 2 for?
I’m wanting to build an engine for my 66 MGB and wondered what camshaft to choose. It will be a road car but I still want to get more performance out of the engine. Any suggestions?
First you need to decide how far you want to go, what is the purpose of the car , daily driver, fast road, ralley, race... Note that the comfort factor and ease of driving gets worse from daily driver to race... The faster camshafts increase the HP's but becomes more aggressive with a power curve that shifts to mid to high RPM. With the 720 Camshaft the high torque sits around 5000 RPM . As on the track we tend to run at around 5000 and shift around that RPM... not useable for a dialy or fast road purpose. I would start with a mild cam, free flow exchaust, stage I or II cylinder head and a DCOE 45 carb. That will bring you to the 90 HP range and still driveable on the public road.
@@D3Sshooter I’m looking to something between a daily driver and fast road car. Probably closer to the fast road. I’ve already gotten a big valve head with shallow bowls that will increase the compression ratio. I’d rather stick with my SUs though. There’s just something special about the dual carbs I don’t want to give up. Is there a particular manufacturer of the cam and exhaust you’d recommend?
Had to laugh when I saw your video. My first car was a 1963 MGB Roadster, which when I bought I knew nothing about cars. In 1972 I drove it to work for the first time. I was worried about it being stolen in London so I took the rotor arm out. I came back to the car at lunch time and refitted the rotor arm but it would not start. Desperate, I asked a new older and it turned out wiser colleague for help. When arriving at the car he asked me for a precise account of what I had done. After I told him he simply said look under the car! I did and guess what, there was the distributor cap centre electrode pin. I refitted it and the car started immediately. Whew what a relief and never to be forgotten. Later on my 2nd car a 1971 MGB Roadster I worked on the engine for many years but every time I refitted the distributor cap I double checked the centre electrode had not fallen out. . .
I also like the MGB-GT. Allways liked the look. The MGC-GT (3L 6 cylinder) was also fun. The Weber DCOE and the original SUs are may favorite ways to get the fuel air/mixture into the engine. That was a very good introduction to troubleshooting an MGB starting and running problem. I like your HT tester. I have had carbon tracking problems before and that would have been a handy tool for troubleshooting that problem. I made my own tool after I had three bad distributor rotors in a row on a VW bug. All were brand new Bosch brand rotors also! A handy tool for figuring out mixture problems (especially on multi carburetor or multibarrel carburetor engines) is the Gunson Colortune. They are sparkplugs with windows and you can actually see the fuel burning in the cylinder. Great video Steve. Thanks for posting.
I can see you have been in that alley too. I had a V8 3.6 sebering last year, but sold it. That one had so many issues with the amplifier module ...I even moved to the side with a larger cooling surface..
@@D3Sshooter I never worked on the original MGB-GT-V8 as they are very rare in the US where I live. Worked on plenty of conversions most of which were poorly done. Wasn't the amplifier on the original V8 merely a GM HEI module? They are very common here and inexpensive to replace. One thing about Webber DCOEs. (You probably already know this but for others reading this.) Never look directly at the back of the carburetor you have just taken off the car and blip the throttle... or if you do, you will only do it once because you will get two thin streams of gasoline directly in each eye.
22:03 Hmmm...I wonder which word was withheld? LOL I do sense self censoring at this moment of a piece falling at the moment of carburetor removal. Great video!
This is surreal, I just had the exact same problems a week ago on my own car. Button was MIA from the inside of the cap and made a huge mess of the cap and rotor by sparking across the gap- amazingly it did just about run though! Tomorrow morning I'm cleaning out my Webers to hopefully get rid of some idle stumbles.
That was a good find troubleshooting the dizzy cap, it would have stumped me for a while. One thing that I found was the rotor arm lengths can very a lot, I found 2 in my batch that were 1mm and 1.4mm shorter than the rest. That's a long way for a spark to jump as well as jumping the sparkplug electrodes.
What do you think if you put an air filter on the carburetor? There are other options for that ignition. Check the Ukrainian engine control system SECU-3. In the carburetor version, only a few sensors and a waste spark coil are needed.😉
How strange, I've had the exact same issue with a distributor cap on my Mini before when it was running an old Lucas 25D points distributor, I could never figure out why or what happened but the spring-loaded stack had just completely disappeared! I wonder if it's a quality issue with the caps that are being made these days. Since fitting a programmable CSI electronic distributor (along with a rebuilt engine I should add!) I've had far fewer problems, you won't regret upgrading to the 123 ignition system on your MG, they are fantastic.
What are your thoughts on keeping carb's functioning with potential increases of ethanol in the future? Ever since ethanol was increased to around 10% my Dellorto DRLA's have been regularly playing up. They have developed an intermittent blocked idle/progression circuit and no amount of ultrasonic cleaning has resolved it. Main circuits still run perfectly and I have ruled out everything else you covered in this video. I'm guessing that the factory plug that separates the main/idle gallery has come loose and is moving around causing the blockage.
we have had alcohol here for 15+ yrs. Just make sure every line up to date for alky and always have fresh fuel. That stuff sucks up water and goes BAD in under a month. Fuel up at airport if your racing.
Best to try to find ethanol free gasoline... Luckily, Shell here in Canada has none added to the high octane. It can also be tested quite easily at home for ethanol content.
@@TheEnemySU37 Best you can do in the UK is the high octane which is up to 5%. I was using this but having moved to a remote location only the regular fuel is easily available and this is up to 10%.
@@djambrosia that is a shame. Would be interesting to find out it's octane rating after removing the ethanol. My Spitfire has a distaste for lower octane than 91RON.
Going to guess timing Hard to start Doesnt run good As long as fuel is in good shape Seems like youd be sacrificing some power to parasitic load of the double valve springs
Dad gave me his 71 BGT a few years ago and iv been in the process of restoring it. Having a similar issue with running rough and also have a Webber dcoe, and I think I know what I need to do now, same result if I pull #3 or 4 plug. Sometimes you need to listen to somebody talk about the same issues you have, and it helps bring you (me) to the correct conclusion. Anybody with a MGB or MGBGT is awesome in my book and I hope to some day build up another BGT like yours for the track. Now I'm extra motivated. Thank you!
Thanks, yes... But as you know after a race , one typical parks the car without an inspection ,,and when hot during the race not all issue pop up. Often its afterwards... so i always start from scratch
1950ccm, Stage 3 Head, Hot Cam, Roller Rockers but only one DCOE? With that configuration only one carb is a restriction. You should convert to two 45 DCOEs. 165hp with one carb is hard to belive for me. Also because you have only 101 hp wheelpower.
Converting to two 45s would be difficult. That engine only has two inlet ports. Intakes 1&2 share one port and 3&4 share the other. It's the same design as a Mini, just larger. Converting to fuel injection is very difficult due to the head design too (and would probably not be allowed without switching to a different class).
@@andreichichak5242 Didn't know that the head design is that restrictive. On a 4 cylinder engine with 4 inlet ports it makes a big difference if you use one or two carbs. But in this case it seems everything is tuned to the max. For the Mini engine there was a crossflow head. Maybee for the bigger engine too? But if, probably not homologated.
@@D3Sshooter As I just read there is just one inlet port for every two cylinders. So two double-Webers won't make sense. The power figures for me look odd. 64 Hp between wheelpower and calculated engine power is a lot. Anyway, I wish you a lot of fun on the track.
