Saturday, January 26, 2008

Book Review: MGB and MGB GT problems and how to fix them

MGB and MGB GT problems and how to fix them by Roger Williams tackles some of the more common MGB problems. It is written for the amateur mechanic and is very readable. Each chapter tackles a particular issue, for example, chapter 1 is titled "engine will not start from cold". The chapters are then nicely broken down into sub paragraphs that deal with the various aspects of the problem. Throughout there are excellent photo graphs. This is a great book. I have used it for dealing with specific problems, and also to give me some background information before I tackled some general maintenance problem. This is a great book, and a must have. I give it 9/10.

Book Review: How to power tune MGB

How to Power tune MGB 4 cylinder engines for road and track by Peter Burgess is an interesting book, but I think it is of limited use for most amateur wrenchers who are just mucking around with their daily driver. Most of the modifications involve pretty drastic work to the cylinder head or fuel system and are really the only suitable for someone with a pretty high skill level and also some experience in machine shop work.

Having said all this, the book is still very interesting and provides a lot of information about how the potential of the engine can be realized. I enjoyed reading it, but I don't think that I'll be doing much from it any time soon.

So, I give it 6/10. For a shade tree mechanic, you can probably skip this one if you are looking for books that will help you work on the car.

Book Review: MGB Electrical Systems

MGB Electrical Systems by Rick Astley is a fantastic book - a must have book for any amateur working on an MGB. The book is beautifully illustrated with lots of high quality pictures of components and very clear and well labeled circuit diagrams. The book is very well written and very readable.

The book is much more than a fix it manual. The first 7 chapters provides a lot of really useful introductory stuff. For example there are sections on tools and wire handling, electrical theory, fuses etc. The subsequent chapters each focus on a particular electrical system, for example, chapter 10 looks at the starting system. In each chapter, Astley outlines how the system works and what the major components are. He then outlines potential problems and diagnostics as well as solutions. The best way to approach any of the chapters is to read them from beginning to end before you start work and then have the book at hand as you go to work.

I give this one a 10/10.

Fixing a seat

The hinge on the back of the drivers seat broke, basically making the seat useless. Rust was the problem, although the car is pretty much rust free, so I don't know if the seat was original or not. After some searching, I found a pair of seats on ebay. The vinyl on the seats was torn, but I wanted the frame. I basically used my seat cover and foam on the squab frame (the back of the seat) of the seat I bought on ebay. The "new" seat works great, and is pretty much as good as new.

Of course now I have to get sell the extra seat that I bought!

Temperature and Thermostats

The car has always run pretty cool. In fact I don't think the temp gauge has ever made it more than 1/4 of the way to N, and that is the middle of the NC summer. Normally the temp gauge won't get above C. I checked the temperature sender and it was working fine. You can test it by just making a circuit with it and the temp gauge should go to H. The sender seemed fine. I pulled the thermostat, it was rated 180 F. It also worked OK when I dropped it in a pot of boiling water. I also have another one that I ordered from VB. This one is rated so 195 so I decided to experiment. First of all, the new one also worked fine. One difference was that the 180 F thermostat opened much wider than the 195, so it would provide much more rapid cooling.

OK, so I went ahead and swapped out the thermostats, and went for a long drive. First of all the temp gauge moved!! Very quickly it moved to the left of N, and pretty much stayed there all the time.

So what???
Well a few things...
First, the car reaches operating temperature much more quickly. This means that I can put the choke in more quickly. This will save gas, reduce emissions, and result in less running rich which can coke up the engine.

Second, the car is now running at a higher temp, and within reason, a hotter engine is a happier engine in that it will run more efficiently, and in fact generate more power.

The results were quite dramatic, the car drove much better and performance was better as well. Its amazing what a $5 part can do.

I am running a 195 thermostat, which I might need to replace in the summer with a lower temp rated one, but I think that the old one was opening too much and letter too much coolant flow through the engine.

For an excellent discussion of thermostats, see this site..
http://www.mgcarz.com/thermostats.html

The key point here is that a fully functioning thermostat doesn't prevent the car from overheating. As the car gets hotter the thermostat will be wide open and the radiator is working flat out. The thermostat does provide a minimum operating temp, unless of course it is sticking open, in which case the min temp is going to be too low.

Monday, January 14, 2008

Compression Test

I did my first compression test on Sunday. The correct procedure is subject to a lot of debate but I did what I had seen others do. First, the car was cold. I removed the plugs and wires and tested the first cylinder first. I turned the engine over 10 times and recorded the value on the meter.

The results from the front to back were: 145, 140 140 145. The engine currently has about 116k on it. These numbers are pretty good. The nice folks over at MGExp suggested that these are well in line with where they should be. As a reference point a brand new rebuild should be around 150-160.

The important thing is that there is little variation between the cylinders. I could have done a wet test (putting oil in) to see if any variation was due to rings or valves, but given that these numbers were good, I decided not to worry about it.

Finally the front plug was a little sooty. I may be running too rich - remember I just put in bigger jets in the weber. So perhaps the next size down would be better. On the other hand, I haven't done much distance driving and most of the trips of late have been on cooler days with more choke, so that might be part of the issue.

Thursday, January 10, 2008

Brighter brake lights

My brake lights are really not that bright, so I decided to refurbish them a little. It was an easy project. I removed the lenses and put them in the dishwasher. The reflectors got a good cleaning and then were sprayed with a shiny silver paint. The end result is a big difference.

But what if this is not enough - what can you do to make them even brighter?

First of all, I also plan to install a third brake light on the luggage rack, so although this doesn't make them brighter, it will improve overall visibility. For the brake lights themselves, you might be tempted to put in halogen bulbs - but I have heard that these can melt the lenses. Also the extra current draw would shorten the life of the brake switch. LEDs are a possibility, but these have the drawback that they are directional, and therefore the reflectors will have no effect. Super bright LEDs are available, but they are pricey. Upgrading to more powerful incandescent bulbs will also strain the electrics, but you can get around this by installing a relay to handle the brakes.

For now, I'll stick with what I've done, and install the third brake light.

Steering Wheel


Just a picture of the new "Tourist Trophy" steering wheel that I got for xmas. A huge improvement over the old rubbery one.