Journal: Mark's Mgbgt Adventure

The following is the machine work they performed: clean, magaflux, and resurface the head; install and 3-angle grind 8 hardened valve seats (intake and exhaust seat were all found to be in bad condition); install valve guides and umbrella type valve seals; clean, magaflux, and resurface the block; bore cylinders for 0.030 over pistons (pistons were already 0.020 over sized); line bore the main bearings; install camshaft journals; and confirm that the crank did not need turning.

Another winter project was the rebuilding of the HIF4 carburettors. The HIF4 carburettors use bushings on the throttle shafts, which can be removed and replaced easily with the use of a special little tool to pull the old ones out with and push the news in. Genuine SU rebuild kits come with throttle shaft bushings and the person I bought the rebuild kit from provided me with the tool for free.

Once I received my engine back from the machine shop the reassembly went smoothly. I think the most difficult part of the reassembly was getting the transmission’s input shaft to mesh with the clutch. I used flat-top pistons to increase the compression ratio and decided to use an original specification cam rather than a mild road cam. I had read in several sources that the original cam was a good, all around performing cam and since I have only driven a worn out B-engine I figured I wanted to get a feeling for what the engine and car performed like when new. Once the engine was pretty much assembled it received several coats of MG Maroon paint.

And so, one fatefully Thursday afternoon in June, the engine went back into the car. With the help of Judy, the engine and transmission slipped back into the car without scratching the newly painted engine compartment. The rest of Thursday and all of Friday was spent reconnecting the engine, installing the starter, a new exhaust system, putting on the rebuilt carburettors, and adding vital fluids. With the help of my son, Thomas, the clutch was bled and then we crossed our fingers as I tried the key. The engine started just like it always did. Other than one small plumbing problem on the carburettors everything went off without a hitch. We timed the engine and went for a drive around the block. What a great feeling to have rebuilt the engine myself and actually have it running again, with a little help from my friends of course.