Subject: 4.5 litre engine problems and upgrades
Despite being a relatively new Lagonda owner and being totally in love with my car I suspect I am about to offer views which are unpopular to many but which I feel are honest and will helpful to future owners.
The restoration of my LG45 Saloon has been an enormous undertaking and rather than follow the usual path of changing the body to a tourer I was determined to go to whatever lengths were necessary to preserve this elegant Saloon. Photos of the restoration are available for club members to view on the club website and you can see that no attention to detail has been spared. Every single part has been removed, inspected, and repaired and only if the original part was beyond saving, replaced. The restoration was carried out by Adam Pointer and he and I scoured the earth for original parts.I should stress that this restoration wasn't purely an exercise in maintaining originality at all costs.
When completed my intention is to drive this car thousands of miles each year and so it is to be a real 'user' rather than an ornament. Originality is important but reliability is a necessity.
However, the car has so far turned out to be a big disappointment because, in my opinion, the original Meadows engine is fundamentally flawed. (I said it would be unpopular but please bear with me.) The original engine was completely stripped, cleaned, and examined. The crankshaft was re-ground and balanced and new bearings fitted. The original bores and pistons were within tolerance and only new rings were thought necessary. Waterways were properly flushed out and the water pump and oil pump were overhauled. Evans Vintage coolant was selected to minimise corrosion and the effect of any increased pressures due to overheating.
Looking through the original factory service records which I obtained from John Leo I knew that the original S2 engine had been replaced by Lagonda in 1947 with a S3 engine. The previous having only lasted 57,000 miles despite regular decarbonising. It is unclear whether the S3 engine was brand new or reconditioned but when I acquired the car with 64,000 miles on the clock the barrels had already been fitted with steel liners. All this suggests that this is an engine design that was not particularly reliable. My superb mechanic Adam Pointer and I trawled almost every page of the forum and every book we could find to research potential problems and also spoke to other owners but found nothing we should be wary of so were satisfied that we had done a good job.
After about 150 gentle, low rev, miles the car started to run hot despite coolant temperatures showing a steady 70 degrees. How do I know it was hot? Uneven running and melting HT leads - that's how! Plenty of advice was offered regarding ignition timing and possible fuel vaporising which was all sensible and for which I am very grateful. However, I don't think that was the problem. After about 500 miles the I stopped the car whilst going up a steep hill because running was so poor and I managed to pull into a convenient petrol station and immediately switched off. Coolant temp shot up to over 100 degrees and I began to suspect an air lock somehow on the bottom hose possibly caused by cavitation of the pump. There was a lot of frothing in the top of the radiator. After 25 mins it cooled down and I set off again. The car ran for another 150 miles but in truth it never really recovered and a week later at exactly the same point on the same hill the same thing happened. This time though, I was unable to pull into the petrol station so was forced to stop on the side of the road in a very dangerous position that ultimately caused the busy A249 to be closed by the police. They asked me to try and move the car but even after 30 mins it hadn't cooled down at all and was seized solid. The car was then recovered by the AA and shipped to my mechanic Adam Pointer in Norwich where investigations have taken place.
Number 1 piston was seized with the gudgeon pin having been so hot it was blue. Number 2 had also been hot and had also damaged the bore. Calls to Julian at LMB and David Ayre were very informative and I am eternally grateful to them for their advice and opinions. Both were of the same opinion as to what they surmised had probably happened.
Firstly, they pointed out that the bores of the Meadows 4.5 litre engine are arranged in 3 pairs which are extremely close together and cylinder head stud holes are also close to the bores which can result in minor but significant distortion when the normal studs are screwed down. Adjacent bores are just 3/16" apart which creates a hot spot between bores which is quite a distance from the coolant channels.
David Ayre specifically warned against cylinders with liners as the addition of a steel liner within the cast block introduces yet another barrier to heat dissipation. In fact on my engine we could see that it had become so hot that one of the liners had actually started to slip within the bore! This could have caused even more damage if it had fallen into the crank but thankfully it didn't get that far.
It is also noted that there are coolant transfer plates in the side and rear of the engine but not at the front. I presume that it was felt that any heat problems would be around the exhaust manifold and at the rear of the engine rather than next to the radiator fan. However, what we surmise had happened is that when travelling up a long steep hill the front cylinders became over hot because the majority of flowing coolant was directed to the rear of the engine leaving the front cylinders with insufficient cooling and the front of the engine cooked itself.
Here is the really frustrating thing. Both David Ayre and LMB tell me that this is quite a common problem and one which they both have had to overcome in the same way. How I wish we had spoken with them a year or two ago.
The remedy is apparently to have a new cylinder block cast from better material and with better waterways. New pistons made from alloys suited to the application and to a better design. New connecting rods - again specifically designed for this application. And cylinder head studs with shoulders that close up against the face of the block and which do not exert lateral forces.I now have all parts on order and hope to be able to report that the problem is completely sorted in due course. It has been a frustrating and eye wateringly expensive experience and I would not want anyone else to go through it so would be interested to hear from anyone else that has endured the same or similar problem. I feel that it is important that we get honest and accurate information 'out there' so that these fantastic cars can be enjoyed to their full potential and so that potential owners understand what to anticipate.
Best wishes, David
David Bracey
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