Project 1974 MGB GT - The Mustard (Mit) Mobility Scooter - After nearly 7yrs, The End (for me)

[PhilA]

Bi-metallic strips, depending on use can work harden and stop functioning efficiently. That is rare and only usually in the case where it's a compensating spring taking repeat external load rather than the load it applies to itself, or if it's pushed past its elastic limit. In your case the application shouldn't cause any of these effects.

The coiled bi-metallic spring on my exhaust manifold works well still after nearly 70 years of heat cycling and flap operation.

If it's not fractured, yours should be fine.

 

Phil

[SiC]

3 hours ago, PhilA said:

If it's not fractured, yours should be fine.

This is pretty much exactly what I was thinking. Even if it wasn't fine and broken, it probably still be fine. Our climate here in the UK and the usual nice weather these cars are operated in nowadays, means that it's unlikely to even be moving that much anyway. It'll be ambient temperature + a small amount more for the most part and just building up a bit when heat soaked for a while. Relistically the temperature range will be 15-25c and maybe 15-35c if we have nice weather. 

I'm loathed to take the bottom back off unless I really need to as I'd need to replace the float seal - which I don't have a pair to hand. Also the part to replace isn't cheap and I don't reckon (or hope) it's at fault. If I still can't get a decent running idle and not missing at idle (i.e. not between 1500rpm and stalling - depending how it feels at that second) I may reinvestigate.

[1970mgb]

The thermal compensation on HIF carbs seems to be one of those parts that gets replaced just because-I'm not sure if I've ever heard of one actually going bad.

I have very little actual running experience with HIFs-most of my experience is with HS-4s. None the less, I wouldn't bother with replacing them.

[SiC]

Went up to try getting the MGB running this afternoon. Fusebox gave some grief. Realised that one position isn't actually wired in (one set of side lights), so I guess others have had trouble before here. One circuit actually stopped working after disturbing the box the other day. The one that did the always live, which caused some confusion when the interior lights didn't after connecting the battery. 

Anyway here is me waffling on attempting to start it. 

 

[LightBulbFun]

Woo Progress!

so how does she drive?  (you did drive her right?  )

[SiC]

She's back!

Absolutely filthy mind. So dirty I dare not wash the windscreen in fear of putting a whole heap of scratches on it by smearing the dust on/into it. Probably give her a quick wash tonight. 

Tomorrow I'll give a quick oil change and try getting those carbs off to replace the throttle discs. Then hopefully, if I get up early enough, I'll give a drive before it gets busy on the roads.

It's been so long it feels like a new car/project again. Mojo so far seems to be restored. Either that or good procrastination in getting the 1100 finished...

Apart from the idle, she didn't run too bad either.

[1970mgb]

A few thoughts:

1. MGB oil pumps don't get "weak," They generally work forever. I'll occasionally hear of racers shearing the drive, but that's because they're running at high RPMs with high oil pressures. In that case, though, it's a sudden and complete failure. I also wouldn't consider 50psi at cranking speed "bad." If you have 40psi at hot idle with fresh 20W-50, start eying a rebuild. Otherwise, you're fine. 55-60psi cold idle, as you show, is perfectly fine.

2. It's normal for an MG to need full choke at least initially to catch. If it will start cold on less than full choke, you're PROBABLY running too rich. Warm it up and check with the piston lift test.

 

 

[SiC]

Couldn't help myself not to get this started this evening. Weather is reasonable and it's not too cold. Cba to clean it tonight as not too much light. Easier to spanner by torch than clean by street light.

Carbs off.

I left the linkages attached. Doing this I'm hoping it will mean minimal fiddling required once back all together.

Carbs in bucket.

Carbs on bench.

Offending poppet valve.

Carbs are a bit moist inside. I think I might have been running a bit rich earlier. 

Probably running rich generally as the air leaking through the poppet valve meant that it would have to be set a bit richer maybe.

Time to get these flaps in.

[Dick Cheeseburger]

Great to see the GT liberated once again. Age is a funny thing, isn't it? When I was a youngster, there was an old fella who practically lived at the local chippy, and he drove one on a K plate, in the same shade. At the time, I thought the colour was bloody awful. Something seems to have happened now I'm older and wiser (in my forties) and I'd almost say the old thing looks pretty dapper in that period shade. Who'd have thunk it?! 

 

[SiC]

Throttle discs now on. Buggered putting some of the new screws in. They have a split section at the end, the idea being it makes them less likely to rattle out. Unfortunately I was over zealous splitting them and snapped the ends off. I used some of the original screws, split them and also locktite for good measure. 

Old poppet valve discs

 

2 hours ago, Dick Longbridge said:

Great to see the GT liberated once again. Age is a funny thing, isn't it? When I was a youngster, there was an old fella who practically lived at the local chippy, and he drove one on a K plate, in the same shade. At the time, I thought the colour was bloody awful. Something seems to have happened now I'm older and wiser (in my forties) and I'd almost say the old thing looks pretty dapper in that period shade. Who'd have thunk it?! 

 

I'm not entirely convinced this is actually Harvest Gold! It might have been when it left the factory, but when ever it got resprayed (you can tell it has been at some point) I wonder if a slightly different colour was chosen. Either that or it has faded.

I bought a Harvest Gold touch up paint pot from Moss and the colour looks a lot darker. I have painted a small offcut of fresh metal and tomorrow I'll give it a compare against the car and see how well it matches. Also bought a can of Sandglow from Halfords that I used to paint the 1100 cooling fan. I will also use that as a reference to see if that is closer. 

I suspect it may be neither and is somewhere in between. Hopefully it will be some sort of standard colour as it could do with a respray on some small sections like the front offside wing. Also removing that wing, for when I get around to welding the bits under it, will mean the lead shot join at the top will need repainting too.

[1970mgb]

I'd have to check the book to see what colors were offered in what years, but are you sure it's not "Pale Primrose"?

Admittedly the ones I've seen in person are a bit yellow-white than yours, but that's another good yellowish color you see on these cars.

[SiC]

Definitely not Pale Primrose! That's much more of a faded yellow type of colour. This is darker than that. 

As it has had a respray, there is no guarantee it is a colour that is correct to its year. Also no guarantee that it's actually a BL colour. 

V5 says Gold. I do wonder what a heritage certificate would say too. If anything. 

I'll have a look later on my test piece to see how it matches. Bits that have been touched up by a previous owner are very visible and I guess the used a Harvest Gold paint. However it's clearly different but still pretty close.

Maybe it's just simply that the person painting it got the paint mix slightly wrong. It's Cellulose paint and as the first owner (who relistically would be the only one who would have) reportedly owned a garage, may have resprayed it himself. Or got it done somewhere at mates rates. 

I have no history with the car unfortunately, so don't have anything to check against. It got all thrown away by the second owner and maybe if the first owner was a garage owner, he may not have kept the history either. The third owner only had it a couple of months before selling on. I'm its fourth owner.

Looking at dates, it's coming up to 2 years in my tenure in 2 months time!

[Joey spud]

Back in the day when S.U carbs were still cutting edge tecnology it was a common modification / bodge to remove the spring etc from the poppet valve and just solder its disc securely to the butterfly flap.

I did it on my old Range Rover and instantly cured its erratic idle.

Also saw this honey out and about at the Strood branch of Aldi back in February.

[SiC]

22 minutes ago, Joey spud said:

Back in the day when S.U carbs were still cutting edge tecnology it was a common modification / bodge to solder the poppet disc to the butterfly flap.

I did it on my old Range Rover and instantly cured its erratic idle.

Also saw this honey out and about at the Strood branch of Aldi back in February.

If that had my plate on, I'd never know the difference between that and mine! Literally identical. Looks so utterly different to modern cars it's staggering. Both style and size.

I'm hoping she'll be more behaved with these new discs. I'll be happy if the idle is stable enough that it won't vary between stall and fast idle, depending on how she feels! If it wasn't for the fact that I have a Moss branch about 200 metres from the bus stop I catch to get home from work, I'd probably have soldered them up. They were £10.50 each but that included all the gaskets (2 lots in each pack too) and screws too. I put hylomar gasket sealer on the last set, so will need replacing anyway.

I tried keeping the linkage as undisturbed as possible, so hopefully won't need too much of a retune today either. Set flow rates and idle speeds, then double check mixture. Maybe a slight tweak on the mixture maybe needed as the discs no longer leak?

[SiC]

This car is such a bloody time thief. You go to fix something and then you find something else urgently needing sorting. 

Got the carbs back on. Put new gaskets and hylomar on the engine side of the carb.

Buttoned it all up and swore a lot at the inaccessible manifold studs. Started up and retweaked the idle. I did fiddle with the mixture but tbh I either got it to the same or just worse! Probably close enough now. 

Replaced the cork gasket on the rocker cover. Old one isn't actually that old but I think I way overtightened it previously.

Also stuck a new cap on. Wasn't too expensive and gives me a chance to pull the original one apart to give it a good clean.

Then went to investigate the fusebox. Top two fuses are supposed to be for the lights on each side. However it looks like someone had problems with the top circuit and connected both light sides to the one. After sanding down the fuses and contacts the top one appeared to work again.

Anyone got any suggestions on what cleans up these contacts well? I could carry on using abrasives but I seem to remember some household chemical is excellent at cleaning these sort of things up.

Decided to give a Sparkrite ignition amplifier ago. Already stripped this one down and fixed it to get it just about acceptable electronically. In doing this I found several issues with the ignition system.

Firstly was shit quality modern parts again. Another bbclassic poor quality special here. Never heard of the cap posts turning around like this before. Luckily I already had bought a decent quality cap with brass terminals from Moss the other day.

Secondly was the coil power wire had split. This is infused 12v too, so not ideal. I was pretty hacked off at this point so I decided to run a fresh wire directly to the coil and fusebox, then zip tied it to the loom. I'll sort it out properly eventually.

Fired all back up and she ran ok. Still a bit lumpy and checking the plugs they're pretty black. Yeah I know she needs a good run to clean them. To give a headstart I cleaned them down with a brass brush. 

Might actually just get a chance to wash down the filth, dust and dirt car tonight...

At least the evenings are lighter now, so if I don't get a chance for a run tonight, I should get several chances during the week.

[schonker]

Don't bother washing it drive it!

[busmansholiday]

New fuse box best way, or just keep cleaning it with abrasive paper.

As for the oil pressure readings, as I've said before, stick some gaffa tape over the gauge so you cannot see it.  The chances of a B series going bang are pretty slim.

[GBJ]

When you were turning it over with the coil disconnected you were filling the cylinders with fuel. You flooded it.

That's why it wouldn't start.

 

 

[1970mgb]

The Burlen/SU branded gaskets have a sealant impregnated in them that will activate the first time they are heat cycled. They are not supposed to be used with any gasket sealant at all. I prefer the plain rubber ones, but I still avoid the use of sealant and instead put a thin coat of grease on them.

[LightBulbFun]

2 hours ago, SiC said:

This car is such a bloody time thief. You go to fix something and then you find something else urgently needing sorting. 

Got the carbs back on. Put new gaskets and hylomar on the engine side of the carb.

Buttoned it all up and swore a lot at the inaccessible manifold studs. Started up and retweaked the idle. I did fiddle with the mixture but tbh I either got it to the same or just worse! Probably close enough now. 

Replaced the cork gasket on the rocker cover. Old one isn't actually that old but I think I way overtightened it previously.

Also stuck a new cap on. Wasn't too expensive and gives me a chance to pull the original one apart to give it a good clean.

Then went to investigate the fusebox. Top two fuses are supposed to be for the lights on each side. However it looks like someone had problems with the top circuit and connected both light sides to the one. After sanding down the fuses and contacts the top one appeared to work again.

Anyone got any suggestions on what cleans up these contacts well? I could carry on using abrasives but I seem to remember some household chemical is excellent at cleaning these sort of things up.

Decided to give a Sparkrite ignition amplifier ago. Already stripped this one down and fixed it to get it just about acceptable electronically. In doing this I found several issues with the ignition system.

Firstly was shit quality modern parts again. Another bbclassic poor quality special here. Never heard of the cap posts turning around like this before. Luckily I already had bought a decent quality cap with brass terminals from Moss the other day.

Secondly was the coil power wire had split. This is infused 12v too, so not ideal. I was pretty hacked off at this point so I decided to run a fresh wire directly to the coil and fusebox, then zip tied it to the loom. I'll sort it out properly eventually.

Fired all back up and she ran ok. Still a bit lumpy and checking the plugs they're pretty black. Yeah I know she needs a good run to clean them. To give a headstart I cleaned them down with a brass brush. 

Might actually just get a chance to wash down the filth, dust and dirt car tonight...

At least the evenings are lighter now, so if I don't get a chance for a run tonight, I should get several chances during the week.

I dont get it, you had it running in the video, what stopped you going for a nice drive then?  

and are you going to actually drive it now?

[BorniteIdentity]

The idle on the mini is up and down because of a sticky throttle. I enjoy a bit of Riverdance™️ at traffic lights so just laugh it off. 

I think we used a file, sanding disc and brick cleaner on my fuse box - although a new one us cheap. 

Whatever you do just keep using it! 

[SiC]

2 hours ago, 1970mgb said:

The Burlen/SU branded gaskets have a sealant impregnated in them that will activate the first time they are heat cycled. They are not supposed to be used with any gasket sealant at all. I prefer the plain rubber ones, but I still avoid the use of sealant and instead put a thin coat of grease on them.

TIL. Never heard this anywhere else and I wish I knew they were. Would have saved me a lot of time.

I did notice they are squishy and thick. Just thought it was to give plenty of give to absorb any imperfections. 

Can't imagine a thin layer of hylomar will do any harm though tbh. Just be more of a bastard to remove. Which I'm hoping won't have to be done for a good while. 

[SiC]

4 hours ago, schonker said:

Don't bother washing it drive it!

I could barely see out through the dirt! Had to resist all the urge to use the wipers and washer jet. Not just because it would likely scratch the windscreen but more that it'd just smear rather than clean. I've yet to find a quality source of wiper blades that will fit. I don't know of any Bosch or similar blades that come with the required fittings anymore.

Got her all washed tonight though. Was tempted to go for a spin but knackered from working on the car and the headlights are hopeless in the dark. Joys of sealed beams and knackered + dirty contacts. Another thing on the list to sort but low priority.

Hoping I'll get time to take her out tomorrow. I started a new job last week though and I'm still learning the ropes. So depends if I don't leave too late and/or take stuff home to read & learn.

4 hours ago, busmansholiday said:

New fuse box best way, or just keep cleaning it with abrasive paper.

As for the oil pressure readings, as I've said before, stick some gaffa tape over the gauge so you cannot see it.  The chances of a B series going bang are pretty slim.

I've had this long enough now that I've mentally written this off this car financially. Not scrap of course but if something big did go bang like the engine, I'd just dispose of it and let someone else sort it. Or I'd stuff it back into the garage and wait till I found a cheap replacement unit... 

Helps that I now have the tools and know how if I did need to pull the engine or transmission.

2 hours ago, BorniteIdentity said:

The idle on the mini is up and down because of a sticky throttle. I enjoy a bit of Riverdance™️ at traffic lights so just laugh it off. 

I think we used a file, sanding disc and brick cleaner on my fuse box - although a new one us cheap. 

Whatever you do just keep using it! 

The repo fuseboxes look like they are made of plastic and don't have the loveliness of bakelite. So I still would like to get it cleaned up and go back to the original, but throwing a replacement in will be a lot quicker short term. They aren't terribly expensive either. Like a tenner or something I think. Also helps that it's really easy for me to take a bus stop early on the way to/way back from work and indulge in a bit of retail therapy.

[1970mgb]

1 hour ago, SiC said:

I've had this long enough now that I've mentally written this off this car financially. Not scrap of course but if something big did go bang like the engine, I'd just dispose of it and let someone else sort it. Or I'd stuff it back into the garage and wait till I found a cheap replacement unit... 

Helps that I now have the tools and know how if I did need to pull the engine or transmission.

At least on this side of the pond, good running engines are a dime a dozen. That's probably exaggerating a bit, but I'd venture to guess that if I needed one I could get a good running lump for well under $1K with a few phone calls-of course a fresh rebuild would cost 3-4x that, but they're still not terrible.

It doesn't hurt things any that you're dealing with a basically indestructible tractor engine. There's honestly not a lot that can go wrong. In the US, post-68 heads are bad about cracking, but home market cars don't have the smog ports on the head that cause issues. Even at that, most people don't discover a cracked head until they pull it for another reason and the machine shop finds it when they go to install hardened seats. Cams can wipe a lobe every once in a while(although you see that more often on the XPAG/XPEG engines), but a cam is ~$300.

I've heard of more than one broken crank in MGAs, but then the 1500/1588/1622 crank(especially the 1622) is a fair bit smaller than any B crank. Even 3-main MGB cranks are a fair bit stronger(if it didn't involve a trip to excavate the storage building I'd show them side-by-side). I've never heard of a broken 5-main crank(or 1798 3-main for that matter) outside the racetrack.

[SiC]

22 hours ago, 1970mgb said:

At least on this side of the pond, good running engines are a dime a dozen. That's probably exaggerating a bit, but I'd venture to guess that if I needed one I could get a good running lump for well under $1K with a few phone calls-of course a fresh rebuild would cost 3-4x that, but they're still not terrible.

Unknown but turning engines can be picked up for £200-400 here in the UK. Ivor Searle in basic spec looking at around £1550 - tuned more. Oselli is £2.2k+, again tuned more. I reckon my local engine builder here in Bristol would be a lot less, providing too much didn't need changing.

[SiC]

Took this for a little spin earlier. Not too far - only up to the garage to put a bucket on the Boxsters roof to stop the hood being damaged by the leak in the garage roof.

I think she's running stinking rich at the moment. Idle drops down if idling and revving up makes some impressive clouds. Also I can pretty much start it when stone cold with a little bit of throttle and no choke. I gave the lift pins a poke and that also confirmed it's a bit rich. Of course short journeys aren't helping here either. I've turned her down a bit but I think she'll need a bit more. 

Did an essential job tonight - fitted a new radio. Had this on the garage shelf for months/year. The old Radiomobile unit looked nice but unfortunately none of the buttons worked and thus couldn't be tuned in! 

Had to tidy up some of the wiring as the crimped connections failed when pulling apart. I find if crimps are not made by a proper ratchet crimper or high quality crimper, they simply do not hold properly.

New unit was a £13 eBay cheapy. Plan is to fit a switch into that blank I removed, so it's possible to turn off the radio completely if I know the car isn't going to be used for a while. Irritatingly whoever fitted the last radio cut the hole much bigger and to a non standard size. So the radio cage doesn't fit snugly.

Got a new fusebox to go in tomorrow. That shouldn't take more than a couple of minutes. Then I'll go for another drive and hopefully allow me to get this carb tuned in a bit better.

[LightBulbFun]

congrats for driving it

see we told you she would not immediately burst into flames and piss on your chips!

[busmansholiday]

You need to send the knackered radio to PhilA, he'll have it fixed in no time.

[mrbenn]

Radio looks good!

Apologies if I've missed it but have you ever had the carbs set up/tuned "professionally"? Not that I'm suggesting you haven't done it correctly, just wondering if it was worth throwing the problem at someone else.

[SiC]

3 hours ago, busmansholiday said:

You need to send the knackered radio to PhilA, he'll have it fixed in no time.

I've had a quick look previously and I suspect that one of the lines to the front is broken. Tempted to fix as it's a bit retro, but it's nothing special and it's cheap + easy to buy a working one. 

2 hours ago, mrbenn said:

Radio looks good!

Apologies if I've missed it but have you ever had the carbs set up/tuned "professionally"? Not that I'm suggesting you haven't done it correctly, just wondering if it was worth throwing the problem at someone else.

No I'm definitely considering it. There is a classic friendly garage literally around the corner I will probably give it to. I wanted to put a few more miles on it first to give it a bit of a shake down + blow out the cobwebs, but it may make sense to just let them sort it first. Then once it's had a few good runs, maybe send it back for some tweaking. 

I did get it pretty close before (going by the plugs) but it's all been adjusted since with new throttle discs and the linkages disturbed. I think I'll get a Gunson Colortune and give it one more go first to get it a bit closer.