Engine Rebuild - Len and Kelly's 63 MGB

by Bob Forward

Recently Kelly and Len Bykowy decided to rebuild their 1963 MGB engine as it was using some oil. The engine ran well and was not noisy so they were unsure what would be found inside.

The engine was removed for inspection, this is when I joined in so I could help with the diagnostic process. I must say that this sadly is another case of very poor workmanship by some one unknown, this is what was found.

First we checked the piston crown for signs of oil consumption after the cylinder head was removed. It was plain to see that the piston rings were not doing their job. Also at this time we proceeded to remove the con rod caps to check on the rod bearings. To get at the rod bearings it is easier if the oil pump is removed. After unbolting the oil pump I opened it. The pump was badly scored and judged to be worn out! I was convinced at this point that the crankshaft and big end bearing were going to be a write off because of the condition of the oil pump! Amazingly the crankshaft and bearings were very good and the bearings re-useable. I can only assume that the previous person who repaired the engine did not check the oil pump!!

Well back to the pistons. These were removed for inspection, this is where it gets really interesting, the engine came with 5 ring pistons from new, we found oversize 5 ring pistons in the engine with only 4 rings on them, the oil rings at the bottom were all missing, who needs that fifth ring any way.

The piston clearance was checked and found to be okay which confirmed that the bore and piston were good. I decided to check the current piston ring gap expecting to find 25 to 35 thou well I was wrong the top two rings were at least 10 times that measurement. It appears that the person working on this before was not aware there are guildlines about rebuilding engines. Over sized pistons require the appropriate size ring set; check and replace the oil pump; do not grind the hardening off the cam followers (tappets). We found that a fairly new camshaft which had a badly worn set of tappets (cam followers), new tappets will be required and the camshaft checked for wear.

The cylinder head comes apart next so we are all waiting to see what the story is there!

Having worked on this car before I must say I am surprised by all the problems were have found considering how well the engine was running. More to follow - Bob!

Click here for the second page of Len and Kelly's MGB engine rebuild  

Click here for the previous workshop