Weber Jets

When I installed the new dizzy, it was recommended that I also change out the jets on the weber carb. The original jets are sized 140 and 135. Several folks who have installed recurved distributors have put in 150 primary and 155 secondary main jets. The air correction jets are left alone at 165 primary and 160 secondary.

The jets are tiny little brass screws with small holes in them. To replace the main jets you have to remove the air filter assembly and then remove the top of the carb. Removing the top is a little tricky because of the choke linkage. You can remove a small split pin that holds this in place.





After installing the new jets, I adjusted the timing and then the fuel mixture. I also altered the timing using the timing gun. With the vac on the carb plugged, I set the timing at around 14 BTDC. It doesn't ping (or knock) when I drive, so I assume this is good. Adjusting the idle took a little trial and error, and I may revisit it.

Prior to changing the jets I pulled the spark plugs. They were a little white, which can indicate a lean mixture, so the new jets were probably a good idea. The new plugs are gapped at 0.030.

National Motor Museum at Beaulieu

I took a trip to the UK recently and managed to pay a visit to the National Motor Museum at Beaulieu. This is a must see for any car enthusiast. The link to the museum's website is here:

I also took quite a few pictures which are hosted on the photobucket site here

Enjoy the pics!

New Distributor...

Distributors are pretty simple things really, they "distribute" the spark from the coil across the four spark plugs. You'd think that there wasn't much more to it, but it turns out that there is a whole dark art to distributors - and it lies in understanding "advance". The basic idea is that as the engine revs faster, you want to the spark to be a little earlier in the combustion cycle. But how? Well distributors have springs in them that cause the rate of advance to change as they spin faster. This can also be augmented by vacuum from the carb manifold. As the engine runs faster - there is more vac - and more advance. Great stuff!

What happens if your distributor is old and tired and has worn springs and perhaps the vac advance is not working too well? In this case the engine won't get the advanced ignition that it needs at higher rpms and the power will decline. The engine will feel "bogged down" at high rpms.

Ok, so back to my car... I have noticed that at 4000rpm the engine does bog, it basically doesn't really want to rev higher. This is despite the dual barrel weber where the second barrel kicks in at higher throttle. I think these symptoms are consistent with a worn distributor. So I ordered a new (rebuilt) one from Jeff at advance distributors.

Let me say something about Jeff. Here is a guy who knows distributors - the guy is an expert and frequently posts on mgexperience.net. He rebuilds and, very importantly, recurves distributors. Recurve???? This is the process of putting in new springs and advance mechanics to make sure that the advance works as it should and also that the advance works for your specific engine set up. When you order a distributor from Jeff, you have to give him full details about your engine, carb, exhaust and other mods, so that he can set the advance just right for your set up. Its really tailor made and better than the factory set up or any that you could get from a large retailer of parts.

Back to my car, again. I also ordered Pertronix electronic ignition and a higher power Flame Thrower coil. Electronic ignition removes the need for points and is virtually maintenance free and more reliable. The Pertronix set up also gives you more consistent sparks and more steady sparks.




Swapping out a distributor is not too hard. I removed the old one after noting the position of the rotor arm (very important). I put in the new coil, and put in the new distributor and wired it all up. The little mounting bracket is a little tricky as you have to loosen it enough to get the distributor out. I ended up removing the bracket - and loosening it. The main thing is to try and put the new one back in in roughly the same angle as the old one.

When the engine was fired up - it started and I adjusted the timing to 14 BTDC. I took it for a drive and WOW!!! First of all - no bogging down. The car would red line if I let it - and this is on the highway not when parked. Second the performance, particularly at higher revs was much better (this is consistent with the old unit having tired advance).

Setting the timing is pretty easy with a timing light. Mine is a dial back type that allows you to put in the amount of advance and then you adjust the timing so that the marks are a TDC. It makes it very easy. Jeff includes his recommended timing settings for the unit when he sends it to you, so it really takes out the guess work.

He has a great article written on timing. Here is the link...
Read this before you start messing with your timing.
http://www.mgexperience.net/journal/B-racer/1818

Anyhow, all in all, a nice upgrade that without a doubt bought me some extra HP. And as most folks know, HP is not cheap. In fact, with the new exhaust, carb, and distributor, I have probably bought all the cheap HP I can.

Jeff's website is here...http://www.advanceddistributors.com/

Brits and Battleship

I went to the Brits and Battleship car show in Wilmington NC on saturday. It was a 3 hour drive on the back roads from home, and turned out to be a really nice day out. The drive down was pretty cold, but the car ran well, although the temp guage never got above C. Makes me wonder if the thermostat is functioning - but that's another topic...

I posted some pictures of the day on a photobucket site. They are here.

http://s242.photobucket.com/albums/ff32/gatorbrit/Brits%20and%20Battleship%20Nov%202007/?start=all

I also learned how accurate my speedometer is. My friend travelled down with me and brought his GPS. At 50mph on the speedo I am doing 48mph on the GPS.

Alternator

The alternator in my MGB is pretty much stock - a Lucas model that generates about 35 amps. The alternator is not the original, its been replaced at some point, but alternators don't last forever.  Recently, I have suspected that my alternator was on its way out.  The ignition light would stay on after the engine had started and then go out only once I started driving.  A steadily burning ignition light indicates that the car is drawing from the battery - and the alternator is not generating enough power to supply the car's needs.  

I have two voltmeters - the in dash meter which although it looks nice, is slow to register and not very precise and a plug in voltmeter that plugs into the cigarette lighter.  The plug in meter is digital and very precise.  
You can buy them at Walmart - they're really cheap and well worth getting. The voltmeter was reading for 12.3 V up to 13 V although occasionally it would hit above 13, but never over 13.5 V.  Most of the time we were in the sub 13 V range.  This is pretty good evidence that the alternator is not doing too well.  So I decided to replace it.

There are several choices for replacing an alternator.  The basic choice is a refurbished Lucas model.  This is the simplest solution, but not the best.  The basic Lucas model generates about 35amps - a charge rate that is pretty low compared to model alternators.   

The first commonly used alternative is from a 1980 Ford Fiesta.  This is in the 60 amp range and bolts on pretty easily by all accounts.  Finally, you can use a 1991 Saturn alternator that generates 96 amps and will power anything that you could ever want to run in your car!  The problem with the Saturn alternator is that it needs a different pulley and slight mods to the wiring.  But free enterprise is a wonderful thing and where there is demand, someone fills that demand and makes a buck and that's exactly what the owner of http://www.mgccars.com/ did.  I bought my new alternator from him - here's the link:  http://www.mgccars.com/96_amp_alternator_upgrade.htm.





The alternator arrived quickly and was nicely packaged with clear instructions.  
The alternator bolts on and there are just two wires to connect.  
I charged the battery and installed it this afternoon.  
When I started the car up, the voltmeter showed close to 14.5 V charging.  
When the lights were on and I taxed the system, the volts were still 14.3.

This is a great upgrade for your B and well worth doing. 

New pic of the car.

After I got it lowered I thought it was time to take a new picture...or two.
The new ride height is 15" rear (both sides) and 14.5" front right, 13.75" front left.  Still a bit of lean, but nothing to get bent out of shape about!

Swivel Axle

This summer I had the passenger's king pin replaced. I knew at the time that I needed to get the driver's side done but I decided to do it myself.
So what are we talking about here...?

31 is the king pin, and 21 is the swivel axle.
A picture of the new swivel axle is in this post...

http://1977mgb.blogspot.com/2007/09/swivel-axle-set.html

My swivel axle was badly worn - here is a pic of the lowering bushing, you can see how it is no longer centered.

Replacing the king pin on its own is tricky because there are brass bushings that run up the length of it that have to reamed and rebuilt. Although a king pin set is cheaper, unless you have a reamer and some shop skills, this is a hard job. Alternatively you can buy an entire swivel axle (they are usually sold in pairs) and just replace the whole unit. This is just a bolt on exercise and is easy to do.

1. Jack up the car and remove the wheel.
2. Remove the dust cap on the end of the axle #67
3. Remove the split pin and nut #71.
4. The wheel hub #68 will slide off and make sure you have some clean newspaper to catch the bits. You'll find a notched washer, a bearing race, some shims (very thin easy to loose in the grease), a spacer, another bearing race and a collar. Put these aside. Heres a pic.

5. Remove the brake caliper assembly and support it - don't let it dangle by the brake line unless you plan on replacing them!!! I used cable ties to attach it to the shock absorber.
6. Remove the steering lever- note that if you just remove this you shouldn't have to worry about getting the car realigned. If you take apart any other part of the steering you could mess it up. It'll look like this...

7. Undo the top and bottom bolts #42 and #32.
8. Remove the swivel axle and put a new one in.
9. You'll need to put new bushings and grease seals etc at the top and bottom bolts of the swivel.
10. Reassemble and don't forget the grease the swivel axle at the three grease nipples.
11. Reassemble the hub. I could tell you how to do this, but a video is worth a thousand words, so I refer you to John Twist of University Motors on YouTube.
http://www.youtube.com/watch?v=RJYIXZtnIiw

And thats it! You just swapped out your swivel axle.