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Oct 27, 2015 11:32 pm
Oct 27, 2015 11:32 pm
Subject: Lagonda 11.9 crankshaft oil sealing or lack of
I purchased my 2 seater 1923 KK model last summer with the help of Ken Painter. I had been looking for a couple of years. I do not want to say too much about it as I will probably write it up for the club mag at some point. Suffice to say that it has had very few owners. The first had it as a 21st birthday present and kept it nearly 50 years. The second refurbished it over 10 years and sold it via dealer Performance Cars of Chiswick in 1982. The third owned it for 32 years and only did 150 miles, it then stood on blocks under a cover for over 26 years ...then I came along. It is likely to have done less than 50000 miles...but who knows.
Upon purchase it was found that the exhaust valves were seized, so badly that it required an engine strip down and they had to be drifted out! It was evident that an earlier engine strip probably in the early 1960s had included fitting Cord oil control rings to the original pistons and this had done the bores no good at all. So it was decided that a rebore with new pistons (modified Austin Light 12) was needed alongside everything else!
What I am interested in is the effectiveness of oil sealing for the crankshaft. The front seal is via the starting handle guide block which has a felt seal that sits against the timing chain cover. Thing is when you engage the starting handle on its spring loaded shaft, it wears the felt and leaves a gap around the felt. On stripping the engine I found attempts at sealing with silicon so I am guessing there was a problem.
The rear of the crank has a flange that runs in a groove in the rear main bearing housing. The bottom half of the main bearing housing seems to offer an oil tight seal, but the upper half looks somewhat vulnerable to oil flowing out, particularly going up a steep hill. (I have this the wrong way around , it is the top half of the rear main bearing housing that offers an oil tight seal as it forms part of the crankcase...the risk of oil flowing out is from the underside of the main bearing housing where is sits within the sump. Hope that makes sense)
Is this just a feature of the model that has to be accepted with a splash lubrication system? I have a solution for the front of the crank as the starting handle block has to be remade as it is very worn so I can easily provide a better sealing arrangement with a small redesign.
I know the engine is inclined to wear the number 1 and number 4 big end bearings due to oil starvation if you are on long steep hills...but is there a problem with oil sealing at the rear of the crank in particular operating conditions...driving up a steep hill?
With the engine in pieces, now is the time for me to resolve issues if indeed there are any issues. (I am not sure if there were any improvements in crankshaft oil sealing between 11.9 and 12/24 models, but guess the bottom end is likely to be the same)
Grateful for advice, no doubt from Colin...plus others please!
Thanks
Mark
I purchased my 2 seater 1923 KK model last summer with the help of Ken Painter. I had been looking for a couple of years. I do not want to say too much about it as I will probably write it up for the club mag at some point. Suffice to say that it has had very few owners. The first had it as a 21st birthday present and kept it nearly 50 years. The second refurbished it over 10 years and sold it via dealer Performance Cars of Chiswick in 1982. The third owned it for 32 years and only did 150 miles, it then stood on blocks under a cover for over 26 years ...then I came along. It is likely to have done less than 50000 miles...but who knows.
Upon purchase it was found that the exhaust valves were seized, so badly that it required an engine strip down and they had to be drifted out! It was evident that an earlier engine strip probably in the early 1960s had included fitting Cord oil control rings to the original pistons and this had done the bores no good at all. So it was decided that a rebore with new pistons (modified Austin Light 12) was needed alongside everything else!
What I am interested in is the effectiveness of oil sealing for the crankshaft. The front seal is via the starting handle guide block which has a felt seal that sits against the timing chain cover. Thing is when you engage the starting handle on its spring loaded shaft, it wears the felt and leaves a gap around the felt. On stripping the engine I found attempts at sealing with silicon so I am guessing there was a problem.
The rear of the crank has a flange that runs in a groove in the rear main bearing housing. The bottom half of the main bearing housing seems to offer an oil tight seal, but the upper half looks somewhat vulnerable to oil flowing out, particularly going up a steep hill. (I have this the wrong way around , it is the top half of the rear main bearing housing that offers an oil tight seal as it forms part of the crankcase...the risk of oil flowing out is from the underside of the main bearing housing where is sits within the sump. Hope that makes sense)
Is this just a feature of the model that has to be accepted with a splash lubrication system? I have a solution for the front of the crank as the starting handle block has to be remade as it is very worn so I can easily provide a better sealing arrangement with a small redesign.
I know the engine is inclined to wear the number 1 and number 4 big end bearings due to oil starvation if you are on long steep hills...but is there a problem with oil sealing at the rear of the crank in particular operating conditions...driving up a steep hill?
With the engine in pieces, now is the time for me to resolve issues if indeed there are any issues. (I am not sure if there were any improvements in crankshaft oil sealing between 11.9 and 12/24 models, but guess the bottom end is likely to be the same)
Grateful for advice, no doubt from Colin...plus others please!
Thanks
Mark