Field Marshall Series 1
Posted: Sat Jun 15, 2019 12:49 am
Hi all
I have recently been working on a 1946 series 1 Field Marshall.
I had it running when I bought it and noticed she was a little smokey. So I decided to fit some new piston rings.
while the head was off I pulled the piston out and checked the crank. There is a .004" tolerance for ovality on the crank pin. She is measuring in at .0025" so that is good no need to remove the crank. The big eng looked suspicious like it had previous ....
The front shell didn't seem to match the bronze end cap ?? and the oil tolerance according to Crawford's is .008" to .010" which seems excessive. I found an old "Farm Mechanisation" hand book and that stated minimum .006" oil tolerance.
So me and a retired engineering friend, set about milling the end cap shrinking the end cap to take up the slack. We then proceeded to rebore the big end back to spec. we decided to aim for the middle and go for a .007" clearance inbetween the two sets of specifications. It's only going to wear bigger, never smaller.
I am pretty well tooled up, at our farm. when I got into the vintage machinery scene years ago No one told me I'd need a fortune in tools to mend and repair them.
Thanks
Carl Hargreaves
Here is a quick video of her along with my 1948 VF crawler
I have recently been working on a 1946 series 1 Field Marshall.
I had it running when I bought it and noticed she was a little smokey. So I decided to fit some new piston rings.
while the head was off I pulled the piston out and checked the crank. There is a .004" tolerance for ovality on the crank pin. She is measuring in at .0025" so that is good no need to remove the crank. The big eng looked suspicious like it had previous ....
The front shell didn't seem to match the bronze end cap ?? and the oil tolerance according to Crawford's is .008" to .010" which seems excessive. I found an old "Farm Mechanisation" hand book and that stated minimum .006" oil tolerance.
So me and a retired engineering friend, set about milling the end cap shrinking the end cap to take up the slack. We then proceeded to rebore the big end back to spec. we decided to aim for the middle and go for a .007" clearance inbetween the two sets of specifications. It's only going to wear bigger, never smaller.
I am pretty well tooled up, at our farm. when I got into the vintage machinery scene years ago No one told me I'd need a fortune in tools to mend and repair them.
Thanks
Carl Hargreaves
Here is a quick video of her along with my 1948 VF crawler