This 355 had 24,000 km on it when we first saw it and was burning a litre of oil every 100 km. It was also jowling one spark plug every 100 kms and was misfiring on the same cylinder. When we removed and stripped the engine we found No. 7 cylinder excessively worn to 25 thou oversize and the two exhaust valves on that cylinder were covered with a hard white deposit on the curved port side of each valve.
On the pictures can be seen the washed clean top surface of No. 7 cylinder and the white deposits on the two exhaust valves. All the other cylinders were running as normal. The engine had no overheating problems and no loss of coolant.
Any suggestions or comments on a diagnosis? As far as the repairs go, we carried out the following: the valves and guides were all in good condition, including those of cylinder No. 7, so we cleaned them all, lapped them in and fitted new stem seals.
As far as the block and liners go we had a few choices, we could have replaced the one No. 7 cylinder piston and liner, at about $3000 for the two, but then one cylinder was new with no miles and the other 7 had 24,000 miles possibly causing engine imbalance, or we could have replaced all eight pistons and liners, a good way to go, but at a cost of $24,000 just for pistons and liners and a total bill of probably around $40,000. This was outside of the customer’s budget. So instead we had a set of oversize Teflon coated pistons custom made for it and machined the existing liners to take the oversize pistons.
We also noticed some bad connections and worn pins in the engine wiring harness so we replaced every pin in all the engine harnesses with gold coated pins and new rubber weather seals. We also replaced all eight fuel injectors.
Not bad for a car with only 24,000 km!
Calgary Italian and Classics 