My (US, LHD) 1970 MGB

[1970mgb]

My friend lightbulbfun has been encouraging me to post this for a while. This is just a general information/ramble thread about my 1970 MGB.

 

I am an American, and my car is 100% a US spec model. It's a second car, but also a hobby for me. I also own an MGA, which we won't discuss now , but I've fallen in love with these fun little cars.

 

Mine is more-or-less a stock 1970 US model. The post-68 cars had several notable differences from UK market cars, and 1970 is a fun year to own because the US models had a bunch of one-year only things.

 

My car started life with a 1798cc 18GH "high compression"(8.8:1) B series engine, which is what the home market cars kept until at least close to the end(1973 US cars dropped to 8.0:1). I still have the original bottom end, but have made some changes to the engine. I also have a 4-speed non-OD gearbox, and have the original twin HS4 carbs with a cast iron "double y" exhaust manifold(1975 US market cars went to a single Z-S on a terrible combined intake-exhaust manifold designed to work with a catalytic converter). The US also got a heavily padded "pillow" dash in '68, along with dual circuit brakes and a few other "safety" items.

 

The engine in mine is a bit tired and I hope within the next year to rebuild it and up the performance a bit. I'll also fit an O/D gearbox at the time. For now, though, I'm just enjoying driving the car. It's cold and snowy here now, so it's only done ~100 miles since November, but I hope things clear up in the next few weeks so I can start piling some miles on it again. One thing for sure-the more I drive the car the happier it seems to be.

 

In any case, here are some general photos-the first the day I brought it home, then after installing a new top(I didn't do that myself). The below photos also show one US market 1970 only feature-let's see if anyone can spot it.

 

[1970mgb]

I mostly have the ignition and carburetors sorted. I run a rebuilt 25D with points, triggering a Winterburn CDI module. I need to send a set of carbs off to have bushings redone, and will likely have whoever does that(most likely Joe Curto in New York City, the best guy on this side of the pond for SU carbs) do a complete rebuild. In any case, though, here's friend and MG master John Twist messing with the distributor on my car a few years ago-this was at the 2016 All-Register MG meet in Louisville, KY

 

 

That aside, I've been no stranger to having to tackle the occasional minor or major technical problem. I ended up swapping the transmission about a year after buying it due to a bad speedometer drive gear and also likely a cracked 3rd/4th syncho, something which was a fun weekend engine out job(with a lot of might as wells). I'll write that up later. In the mean time, though, I'll share one of my first projects after buying the car in 2015-I jacked it up and found a cracked rear leaf spring. That led to a rear suspension rebuild, which was a bit of a "trial by fire" on a new to me car, but was fun and I learned a lot. It took me a few days, on and off, to do the suspension on one side and then a few hours on the other side. One of the keys was that after I fought with the front spring mounting bolt, someone finally advised that I just grab a Sawzall and cut it

 

I had to wait on replacement hardware from Moss, but once the right side was done I didn't even try getting the bolt out on the left side-I just cut it which made all the difference in the world in terms of how long the job took.

 

[1970mgb]

My final post for this evening-

 

I'm limping along until a complete engine rebuild(I have a lot of blow-by), but a few years ago a burnt exhaust valve caused me to expedite rebuilding the top end.

 

Although my engine is a factory "high compression" engine, it does have what's known as a "smog head"-it was designed to be used with a(long gone) smog pump that pumped air into the exhaust to theoretically help burn up any unburned HCs and CO, although its effect was questionable before catalytic converters came along. Since the pumps weren't overly reliable, they typically are only still installed in cars registered in states that actually check for those things(and even though '68 and later had them, I don't think any state checks emissions on cars that old). Still, though, the so-called "smog heads" are more prone to cracking. Thus, rather than rebuilding my existing head, I opted to just source another.

 

That presented me with another option. Stock "high compression" engines use shallow dish pistons with a combustion chamber volume of 42ccs. The low compression engines switched to deep dish pistons, but dropped the combustion chamber volume to 38cc. Thus, one can "mix and match" a late head with shallow dish pistons and get 9.5:1 without any extraordinary effort(but a noticeable performance increase). I have a friend who sells "reconditioned" heads, and I bought a ready-to-go 12H2923 head, crack checked, surfaced, and with new exhaust valves and hardened exhaust seats installed. The 12H2923 was one of two "small chamber" castings, and it's more desirable partially for its factory large diameter intake valves. For a street car they probably make zero difference, but they're nice bragging rights (this head casting was used 73-76, 77-80 got the infamous and notoriously crack prone CAM1106 casting).

 

 

The difference when installed was remarkable.

 

Unfortunately, about a year later I discovered the "wisdom" of not replacing the head studs when doing head work. I blew out the head gasket between cylinders 2 and 3, most likely due to a stretched stud. Aside from my lack of compression, I found some nice "milk" on the rockers when I pulled the rocker cover

 

 

The breech isn't overly obvious in this photo, but none the less was there

 

 

Fortunately, I didn't worry too much about the head. I took it in to work and had the machinist check it for flatness, then spent some time in the machine shop cleaning it up.

 

 

Including of course chasing all the threads in the head and block

 

 

I threw it back together with ARP studs-about $130 a set but worth every penny-and put it all back together

 

 

 

That's just a snapshot of a few projects on the car over the past 3 1/2 years. Now, I'm mostly just enjoying it, although as I mentioned I hope to fit a rebuilt bottom end and overdrive transmission some time this year.

 

The rebuilt will likely get a small overbore(20 over hopefully)-for wear and not displacement-along with of course crank grinding and a replacement of all the bits and pieces that wear out. I'll put it back together with a "street performance" cam-either a Delta D9 or APT VP-12-and enjoy probably somewhere in the ballpark of 110hp.

[MorrisItalSLX]

The below photos also show one US market 1970 only feature-let's see if anyone can spot it.

 

IMG_1990.jpgIMG_2655.jpgIMG_2964.jpgIMG_2971.jpg

 

Is it the strange mirror setup? I have seen a few US MGBs with one door mirror and one wing mirror, very weird.

[chadders]

I seem to remember some sort of survey from many years ago that concluded that wing mirrors were safer than door ones as you didn't have to spend so much time refocussing.

 

I know that all the old cars I had with wing mirrors rotted like **** around the mounts so maybe that was one of the reasons to change the mounting place.

[HillmanImp]

I've only just realised that I still call them wing mirrors even though they are very rarely mounted on the wing anymore.

[wuvvum]

Wobbler will be along shortly to drool over the triple wipers.

[mercrocker]

. The below photos also show one US market 1970 only feature-let's see if anyone can spot it.

 

IMG_1990.jpgIMG_2655.jpgIMG_2964.jpgIMG_2971.jpg

 

My money is on that split rear bumper....

 

Nice to see this at last.   Not many MGBs of this era seem to keep that facelift grille but I rather like them!    Very nice.....

[AlabamaShrimp]

What's it like driving such a small car with no roof in the land of bigger than ours cars?

 

That said stuff is getting bigger here I mean years ago I drove a convertible Seabring and when giant trucks go past they look like trains.

[1970mgb]

The wing/door set-up was used for several years in the late '60s and early '70s. I'm not exactly sure when they went to a full door/door set up. That actually took me a bit of getting use to, and it can be a pain to adjust the wing mirror, but it does work well.

The split rear bumper is indeed a North American 1970-only feature(although it was used on Midgets for several other years).

 

You can feel a bit overwhelmed in a car this size in the US. It's especially alarming when you look in your rear view and see a MINI(BMW) or Fiat 500(new one) behind you and realize how much higher they are than you. Dusk can really bug me in traffic from headlights shining right in the mirrors. Overall, though, you just have to look out for yourself and ASSUME that other cars aren't going to see you. I've made sure that if nothing else, my horns are nice and loud, and they get a work-out at times(such as when someone crosses 5 lanes on an otherwise empty road to pull in front of me and go 20mph on a 45mph road). Whenever possible, I just try to make sure there's as much space around me as possible and also try to constantly watch for an "escape route" if I need it.

[1970mgb]

One other thing on the three wipers, since someone commented on that:

 

Sometime or another in the late '60s, the US mandated either a certain swept area or a certain total percentage of the windshield(windscreen?) area-I forget which. Regardless, the GT, with its taller windshield and 13" wipers, complied without a problem. The only way the roadster could comply with two wipers(10" is the longest that will fit) was to make the windshield taller. Of course, that would require redesigning quite a bit of the car, but BL figured out that they could meet the required swept area by using 3 10" wipers.

 

Because of that, all US market MGBs tourers from '68 or so until the end of production had 3 wipers.

 

I'll also mention that FINDING wipers here can be a nightmare. The previous owner never drove it in the rain, so never even paid attention to them. The day I bought the car, I got caught in a torrential downpour and found that out quickly . Initially, I went hunting for wiper blade refills, something that use to be common but that are all but impossible to find these days. I bought a set of 10" Bosch-branded wiper blades that claimed to fit, but there wasn't a chance. Finally, I found out that I could order refills from NAPA and pick them up in the store(funny enough, the NAPA store I used is attached to the regional warehouse and when I'm in the store they often "order" parts from the warehouse-on this occasion I ordered online and they called me a half hour later to say they were in) so was able to get functional wipers on the car. I should check them, as that was ~3 years ago and they're likely ready to be replaced again.

[PhilA]

NAPA no longer carry refills. Thankfully my local store never throws anything away either so they had some dusty boxes of refills on a shelf out back to sort out my Pontiac.

 

Stock up if you can find them.

 

Phil

[Uncle Jimmy]

Good work....carry on!

Btw, are you aware in the States of the infamous Leyland Sherpa?...

[mercrocker]

It's easy to forget what a challenge it can be driving something low and off-the-radar in the States!    When I used to go out in my brother-in-law's (proper) Mini over there it was pretty scary - eye level was about the lower wheel-nut level of the average Aalc0-wheeled Kenworth but the scariest stuff was 90mph Dually F350s with the driver trying not to spill his Tim Horton's rather than look for flying Minis.  

 

Long straight roads with dips that can hide an 18-wheeler unless it has an Aerodyne cab are another hazard I would imagine.... 

 

Having said all that, folk don't always appreciate what a massive success the MGB was in North America - there were still dozens of the things on the freeway when I used to go back over in the 1980s....

[1970mgb]

It's easy to forget what a challenge it can be driving something low and off-the-radar in the States!    When I used to go out in my brother-in-law's (proper) Mini over there it was pretty scary - eye level was about the lower wheel-nut level of the average Aalc0-wheeled Kenworth but the scariest stuff was 90mph Dually F350s with the driver trying not to spill his Tim Horton's rather than look for flying Minis.  

 

Long straight roads with dips that can hide an 18-wheeler unless it has an Aerodyne cab are another hazard I would imagine.... 

 

Having said all that, folk don't always appreciate what a massive success the MGB was in North America - there were still dozens of the things on the freeway when I used to go back over in the 1980s....

 

Yes, all sorts of LBCs do tend to sort of "disappear" on US roads, especially given things like ride height regulations that have been in place since the 1970s(which is why all 1974 1/2 MGBs worldwide got an extra inch of ride height and rubber bumpers). Even "compact" cars are big now, and the makers keep introducing newer "small" cars as their previous compacts put on weight. My grandfather had an '88 Camry that he drove until it died, and the current model Corolla dwarfs the Camrys of that generation.

 

MGBs are actually quite common here, although admittedly there are fewer of them than there once were. The number I always keep in mind was that BMC/BL built roughly 500,000 MGBs from 1962-1980, and roughly 450,000 of those made their way to North America. In a lot of ways, the US WAS the market for the MGB. There's quite a good cottage industry here in the US for a lot of MGB-specific parts where the replacements from the usual source(Moss Motors, etc) aren't quite up to snuff-the nylon webbing axle rebound straps I use are a good example of this. At the same time, though, we don't have the piles of B-series engine powered vehicles, and the MGB is basically it(we did get Oxfords in small numbers, and Marinas later, but that's basically it).

 

I'll also mention that I actually have a Marina manifold stuck in the garage earmarked for possible future use. The late single carb MGBs(1975 and later) fed the three exhaust ports into a line that then made a sharp u-bend to the catalytic converter. The Marina manifold is more or less bolt on for these late cars and lets you use either the Z-S 175 that came stock or an HS-6/HIF-6/HIF44 if you prefer, but gives you the "double Y" exhaust of the earlier MGBs. They're reportedly good for 10-20hp on these otherwise pathetic performing late cars.

[1970mgb]

I hadn't driven the car in a few weeks(crazy busy at work, plus a lot of rain/snow/ice and with it salty roads that cause 1970s British steel to rust so fast you can hear it), and decided that this was a relatively warm evening that would be nice for a drive.

 

Unfortunately, it rewarded my neglect with being stubborn to start. I managed to run the battery down and had to use a jump pack and ether, but it finally came to life.

 

A few miles down the road, it started raining and unfortunately there was something on the windshield that decided it was going to make a smeary mess every time the wipers passed. Fortunately, I keep a can of glass cleaner in the car, so I hopped out in a light drizzle and gave the window a quick clean. All was well, and I kept on.

 

This was also a nice reminder to me that cars in 1970 didn't have ABS(forget even having power assist!) and also traction control-I managed to slide my way around one curve going 15mph...

 

In any case, though, about 25 miles into my 30 mile trip, I had a stereotypical BL/Lucas problem-the headlights, tail lights, and dash lights all went out. This happened to me about a year ago-I knew it wasn't a fuse issue since the headlights aren't fused and also the gauges(which were still working) run off the same fuse as the lights that had died(it's only mildly alarming that I know the wiring that well ) . Instead, it's a switch problem-when it last happened to me I opted to clean up and rebuild the old headlight switch since it's pretty widely agreed that the new replacements are junk. I also started hunting for a new old stock switch at the time-I found a few other switches, but not a headlight switch. It looks like I'm going to have to break down and buy a piece of Moss crap while I continue hunting for NOS.

 

The last time it happened, the high beams would still illuminate if I held back the "flash to pass" switch, so that's exactly what I did. I also flipped on the hazards to make the car a bit more visible, since I only had brake lights(and turn signals) at the rear otherwise. I drove the rest of the ~5 miles home like that.

 

Such is life with a BL product, and also my punishment for not driving it more.

[1970mgb]

A new old stock "Lucas-England" switch is on the way, and I have this to use in the mean time...

 

[busmansholiday]

I hadn't driven the car in a few weeks(crazy busy at work, plus a lot of rain/snow/ice and with it salty roads that cause 1970s British steel to rust so fast you can hear it), and decided that this was a relatively warm evening that would be nice for a drive.

 

Unfortunately, it rewarded my neglect with being stubborn to start. I managed to run the battery down and had to use a jump pack and ether, but it finally came to life.

 

A few miles down the road, it started raining and unfortunately there was something on the windshield that decided it was going to make a smeary mess every time the wipers passed. Fortunately, I keep a can of glass cleaner in the car, so I hopped out in a light drizzle and gave the window a quick clean. All was well, and I kept on.

 

This was also a nice reminder to me that cars in 1970 didn't have ABS(forget even having power assist!) and also traction control-I managed to slide my way around one curve going 15mph...

 

In any case, though, about 25 miles into my 30 mile trip, I had a stereotypical BL/Lucas problem-the headlights, tail lights, and dash lights all went out. This happened to me about a year ago-I knew it wasn't a fuse issue since the headlights aren't fused and also the gauges(which were still working) run off the same fuse as the lights that had died(it's only mildly alarming that I know the wiring that well ) . Instead, it's a switch problem-when it last happened to me I opted to clean up and rebuild the old headlight switch since it's pretty widely agreed that the new replacements are junk. I also started hunting for a new old stock switch at the time-I found a few other switches, but not a headlight switch. It looks like I'm going to have to break down and buy a piece of Moss crap while I continue hunting for NOS.

 

The last time it happened, the high beams would still illuminate if I held back the "flash to pass" switch, so that's exactly what I did. I also flipped on the hazards to make the car a bit more visible, since I only had brake lights(and turn signals) at the rear otherwise. I drove the rest of the ~5 miles home like that.

 

Such is life with a BL product, and also my punishment for not driving it more.

I had an electrical fault like that many years ago on my Rapier. After hours of searching it turned out to be a broken wire on the feed to the switch. Depending which bump in the road you hit altered whether the lights were on or off.

[1970mgb]

Unfortunately the switch is done "good and proper" this time around...but I have a "made in England" one coming from Canada. It's not strictly NOS, but is coming from someone who parts out MGBs-this particular switch is brand new and was installed in a never-completed project. It's fairly new(1990 production) but at least WAS in fact made in England and not China.

 

 

[PiperCub]

That split rear bumper looks more like a RWA (1972-74) Midget one (with square no. plate). Not seen that on any B's over here.

 

Plus those side markers fitted for the US market look awful. (On any small car not just MG's). 

[1970mgb]

That split rear bumper looks more like a RWA (1972-74) Midget one (with square no. plate). Not seen that on any B's over here.

 

Plus those side markers fitted for the US market look awful. (On any small car not just MG's). 

 

It was 1970 only in NA, and AFAIK not used anywhere else(on the B at least).

 

It DOES make the car distinctive, but more than a few 1970s with collision-damaged or badly pitted bumpers have been redone with a more conventional one-piece rear. Of course, that involves a fair few changes too as the license plate mounting needs to be moved up higher on the back of the car. Of course, that particular size of license plate is pretty well standard for North America.

 

I'll also mention the fact that my state normally issues a new license plate every few years(the current design is getting a bit stale, but the previous one was widely hated and was redesigned after ~2 years rather than the more normal ~8 year cycle, so I suspect it will be 2022 or so before we get a new design). I use an "historic motor vehicle" plate, which in theory(although not practice) is supposed to restrict the use of the car, but also saves annual road taxes. Also, my state allows any vehicle that has been issued HMV tags to display any other tag as long as it's more than 25 years old as long as you carry the "real" HMV tag in the car with you-the tag I display on the car is an Ebay purchase . I have another from 1970 that has my home county on it, and I need to get it cleaned up and repainted to be legible so that I can put it on the car.

[LightBulbFun]

I have to say its a shame no British Bs got the split rear bumper

 

as I think it would work/look really well with a British Square plate

[1970mgb]

Made it home from work last night with the lights jumpered....it will probably take a week or better for the switch I ordered to get here from Canada.

 

[chadders]

Who did you get the switch from as I could do with a few bits for my 74 and,as you say the quality of a lot of the parts on the market is crap, although not as bad as VW T2 ones in my experience.

[Magnificent Rustbucket]

It's a lovely little thing, the MG. They seem to look 'right' in the US - more than they do here, at least to my eyes.

[1970mgb]

Who did you get the switch from as I could do with a few bits for my 74 and,as you say the quality of a lot of the parts on the market is crap, although not as bad as VW T2 ones in my experience.

 

I bought it from Anthony Henderson, who posts on the MG Experience forum under the name MGBAnthony. Unfortunately, I don't know of a better way to contact him.

 

There are a lot of rusty and crusty MGBs up in Canada, where he lives, and he provides a valuable service in salvaging good bits and pieces off of cars that are otherwise past economical restoration.

[1970mgb]

I hadn't touched the car in a week and a half or so, so decided tonight was a good night to give it some attention.

 

First, I dropped in the "new" headlight switch.

 

 

I'm not wild about the chrome bezel on it, since all the other switches are black(or once were) but at least it's NOS Lucas and hopefully will last.

 

Even so, though, I need to bump up the relay project, as the switch was getting uncomfortably warm.

 

I then decided to take it out for a drive. At ~35ºF, it was quite a bit less reluctant to start than at sub-freezing temperatures. With the choke out, it "caught" but died during the first crank cycle, ran a few seconds the second time, and then stayed running(more or less) the third time. I think I still have some of the SAE 50 I dumped in last summer in the sump, and I'm sure that's not helping, but I'm also thinking I MIGHT need a new battery-cranking is a bit less than enthusiastic even when hot.

 

I was down around a quarter tank, so decided that the first trip was to a gas station. It took 9.7 gallons to fill it up(12 gallon tank), although I was a bit embarrassed when I pulled out my log book and saw that the last time I'd filled it up(10.2 gallons) was in early November. Still, though, drop Sta-Bil in every tank for a reason, and this one was no exception.

 

As a side note, blue marine-grade Sta-Bil 360 is great stuff. I actually lucked into buying a bunch of 8 oz bottles of it for $1.25 each(I went into a gas station and saw it, then cleaned them out), as the marine grade version normally runs ~$30 for a 16 oz. bottle. Even at normal price it's worth it, as 1 oz. of 360 treats 10 gallons of gas vs. 3 gallons for the regular "red" kind(and it's usually $6-8 per 8 oz). I also added the requisite dose of Marvel Mystery Oil to the tank. I was advised a while back by one of the carburetor guys that it can help keep the needle valves operating correctly-whether it's true or not, I don't know, but it's cheap enough that I figure it won't hurt. Plus, I like the nice minty smell

 

I went out for a nice little drive after that that ended up being an hour long, but covered some favorite roads and even saw some deer(not exactly the most pleasant thing to see at night, as they can be rather destructive). I ended up doing about 30 miles, mostly just tooling along the back roads.

 

 

[1970mgb]

Today was quite a nice day, with temperatures flirting with 70ºF and clear skies.

 

I was tempted to drive the MG to work, but some very important commitments right after work made me second guess that.

I did take advantage of the nice evening, though, to both take the car out for a drive and run some errands.

 

The first stop was the self-serve car wash down the road to give the car a much needed bath

 

 

I'm going to have to figure out what I can safely use on the vinyl, as there are some spots on it that aren't coming off with soap and water. Also, the car needs a good wax and the chrome would benefit from a bit of polish, but at least now it's a lot more presentable.

 

I'm due for an oil change in my daily(a Lincoln MKZ), so I decided to head to Wal-Mart to pick up oil. The Wal-Mart I usually visit is across the river in Indiana. It use to be a quick interstate trip, but the interstate now involves a $2 toll so I instead take a downtown surface street bridge. That routes me around the tolled bridge, and then puts me back on the interstate. That still gave me a few miles at 70mph+ to "blow dry" the car from the car wash. I actually hadn't had it up that fast in a while, and it really could use a longer trip at speed for a good old fashioned "Italian Tune Up."

 

The MKZ gets full synthetic at a 10K mile drain interval. I've been a faithful Mobil1 user for years, but it's up to $29 for a 5 quart jug at regular price. Wal-Mart usually has at least one full synthetic on sale at any given time, and today it was Valvoline Max Life at $22/5qt. I've never used that before, nor have I traditionally been a Valvoline guy. Still, though, VR-1 dino oil in the MG has treated me well, and I tend to think of all the major name brands as being equivalent. So, with that in mind, I came home with 10 quarts of Valvoline(the car takes 7, and the cost difference between a second 5 qt. jug and two single quarts is usually small enough that I buy two and save the leftover for top-ups and the next oil change).

 

I came back across the river, went to the grocery store, and then drove one of my favorite routes to round out the evening. All told, we put a nice round 25 miles on the car, and had a good outing on a nice evening. Unfortunately, rain tomorrow will keep it parked...

 

As a side note, I'm normally picky about using Shell V-Power premium, which is 93 Octane(US gas is specified as R+M/2, which is usually equivalent to a RON 5-7 points higher). Absent Shell brand, I usually get premium, which is 92 or 93 octane. I mentioned that I had bumped the C/R up to 9.5:1. Usually, an MG engine is okay with mid grade(89) at that C/R(8.8:1, which is stock high compression, will run fine on regular 87), but I run the timing a bit advanced to get more low-end torque and consequently benefit from slightly higher octane.

 

I don't know what I was thinking on my last fill up, but opted for 89 instead of premium. I didn't notice any knocking, but got a few seconds of dieseling every time I shut the car off this evening-perhaps I'll toss in an octane booster, or alternatively visit the airport for some 100LL and top the tank up with that.

 

Since dieseling just doesn't happen on modern cars, a few seconds of lumpy running after shutting off the key usually gets a few stares in parking lots . In times of worse tune, I've seen a solid 10+ seconds of dieseling, so at least a second or two isn't too bad.

[Sudsprint]

I think it's time you introduced us to the MGA.

[Uncle Jimmy]

The dieselling is pre-ignition caused by some carbon build up in one or more of the combustion chambers I guess; maybe running a bit rich, that and more hard driving should see to it.