Show whole topic
Apr 03, 2015 8:12 pm
Apr 03, 2015 8:12 pm
Subject: Re: 4.5 litre engine problems and upgrades
Thank you for all the advice, suggestions and wishes of good luck that I received following the engine problems I encountered with my LG45. It really was a great help. Without wishing to tempt fate I believe I have now sorted those problems and have a car that will be reliable and which can be driven extensively as I had always hoped.
So, what have I learnt and what conclusions have I reached?
Following Julian’s advice, the new was machined with 0.006” clearances for the pistons. Unfortunately, fitting the new block, conrods and pistons was a much more involved process than it should have been. All were bought from the same source but there were problems fitting them. For instance, the block was not supplied fully machined and the conrods did not have the correct offset to suit the old crankshaft and neither did the big end fit the crank. It was necessary to machine the inside of the pistons to provide the offset necessary so that the conrods could be used. It was also necessary to machine clearance slots in the block so that the conrods didn’t foul. All this created unnecessary frustration, delay and expense and was very disappointing.
A new oil pump was also fitted.
Once assembled the engine was set up carefully and it fired into life without any difficulties at all. As reported previously I took Julian’s advice and ran the engine from a water tank so that we could flush out any crud before connecting it to the radiator. I used demineralised water and NOT Evans. Using the water tank also gave an excellent opportunity to check the flow rate being achieved across the whole rpm range. This confirmed that everything was performing properly and so the car was completely reassembled.
Before road testing we attached adhesive temp sensors to the block, head, water transfer plates and radiator hoses so that I could see the maximum temperatures reached. Last week I did a 200 mile test over 4.5hrs and it performed perfectly. Good oil pressure throughout and a steady water temperature of about 65 degrees. The maximum temp recorded with the engine bay sensors was 73 degrees. I did another 50 miles and then the head was pulled down and oil changed. I’ve since covered another 250 miles and the car is running and sounding great.
Looking at the original block, conrods and pistons I think I could have probably re-used the block and conrods if it had been rebored to 0.006” clearance, fitted with new pistons and if I had used water instead of Evans. No1 piston had seized to the gudgeon pin which clearly implies excessive heat and possibly insufficient oil circulation.
Anyway, despite the obvious costs involved, and unnecessary problems with the new parts, I don’t regret using new components. Having spent so much time and money already I really needed to take every option available to give me a truly sorted car and that is what I now have. Hindsight is wonderful but I needed as close to certainty as I could get.
I hope that this will all be useful to others and hope that the lessons learned will prevent anyone else having similar problems. If I can be of any help to anyone else please get in touch. Likewise I would be grateful to hear any comments or observations that may arise.
I hope to see you at the Lagonda Club AGM in October – I’ll definitely be there!
Thank you for all the advice, suggestions and wishes of good luck that I received following the engine problems I encountered with my LG45. It really was a great help. Without wishing to tempt fate I believe I have now sorted those problems and have a car that will be reliable and which can be driven extensively as I had always hoped.
So, what have I learnt and what conclusions have I reached?
Following Julian’s advice, the new was machined with 0.006” clearances for the pistons. Unfortunately, fitting the new block, conrods and pistons was a much more involved process than it should have been. All were bought from the same source but there were problems fitting them. For instance, the block was not supplied fully machined and the conrods did not have the correct offset to suit the old crankshaft and neither did the big end fit the crank. It was necessary to machine the inside of the pistons to provide the offset necessary so that the conrods could be used. It was also necessary to machine clearance slots in the block so that the conrods didn’t foul. All this created unnecessary frustration, delay and expense and was very disappointing.
A new oil pump was also fitted.
Once assembled the engine was set up carefully and it fired into life without any difficulties at all. As reported previously I took Julian’s advice and ran the engine from a water tank so that we could flush out any crud before connecting it to the radiator. I used demineralised water and NOT Evans. Using the water tank also gave an excellent opportunity to check the flow rate being achieved across the whole rpm range. This confirmed that everything was performing properly and so the car was completely reassembled.
Before road testing we attached adhesive temp sensors to the block, head, water transfer plates and radiator hoses so that I could see the maximum temperatures reached. Last week I did a 200 mile test over 4.5hrs and it performed perfectly. Good oil pressure throughout and a steady water temperature of about 65 degrees. The maximum temp recorded with the engine bay sensors was 73 degrees. I did another 50 miles and then the head was pulled down and oil changed. I’ve since covered another 250 miles and the car is running and sounding great.
Looking at the original block, conrods and pistons I think I could have probably re-used the block and conrods if it had been rebored to 0.006” clearance, fitted with new pistons and if I had used water instead of Evans. No1 piston had seized to the gudgeon pin which clearly implies excessive heat and possibly insufficient oil circulation.
Anyway, despite the obvious costs involved, and unnecessary problems with the new parts, I don’t regret using new components. Having spent so much time and money already I really needed to take every option available to give me a truly sorted car and that is what I now have. Hindsight is wonderful but I needed as close to certainty as I could get.
I hope that this will all be useful to others and hope that the lessons learned will prevent anyone else having similar problems. If I can be of any help to anyone else please get in touch. Likewise I would be grateful to hear any comments or observations that may arise.
I hope to see you at the Lagonda Club AGM in October – I’ll definitely be there!