Thanks everyone,
Bootlegger, I tried the OS site before posting, the data they used to have about older engines seems to have disappeared! Mark and Jim, thanks for the offers of help, I may yet need them!
I eyed up the liner and bin and said what the heck, I then found my cheapie vernier calipers (all good kit packed away during fitting out of new aeromodelling workshop!) and found the major axis of the now elliptical liner. Placing the liner between a bread board and small chopping board (still in the kitchen!), I gave the assembly a smart karate chop. The piston now entered the liner! So I assembled the engine, it has good compression and all is well except that the piston tightens up a touch at BDC. I will run it in when weather allows and either the whole lot will wear out, or it may be usable!
I was thinking that I could possibly make a Q ship engine by using the LA46 P/L in the FP40! Well I thought that it may stop the Fox burp that plagues the FP40. The crank and con rod of the LA46 are the same as the FP40 and even the wrist pin of the LA40 is the same part as that in the FP40. Looks to me as though the only difference in the LA46 liner can be either it's OD or the deck height of the crankcase. I can almost feel a lathe job coming on! Now if I strip down my NIB LA46 and measure up...............hang on, this is where I came in .........I can then drop another liner!
The Tower P/L is a direct swop for that of the FP40, so I may well be in touch Jim. If I wear out something else as well as the P/L when running in (out?), then I may well get back to you Mark!
Thanks for the help,
Andrew.