Thursday, December 12, 2024

Ferrari 250 LM: engine (I)

Internal engine components, which will obviously not be visible once it's all built, include pistons, rods, a built-up crankshaft, valves (!), valve springs (!!) made of white metal, rockers, camshafts and the gear drive for the cams. 
 

Lots of drilling needed too, bringing my nifty little drill press into use. Pistons and rods are now assembled with wrist pins made of 0.8 mm brass rod. 
 
 


For those interested, the bore is 6.4 mm, corresponding to the 3.3 litre motor in the 1965 Le Mans winner, but the pistons at 6 mm diameter correspond to the 3 litre 250 motor. So while it might turn over, I would expect some serious piston slap and oil consumption at higher RPM.
 

Some additional time was required to assemble the rods to the built-up crank along with 5 of the 7 main bearings. Sadly these bearings are cast as a piece and you can't just drop the crank into the block.
 
Next will be to prep and paint the engine block components, because I suspect the crank needs to go into first one side, then the other, with the rest of the block assembled around it. Stay tuned...   

Tuesday, December 10, 2024

Ferrari 250 LM: Introduction

Recently I was obliged to buy Model Factory Hiro's 1/12 kit of the 1965 Le Mans winning Ferrari 250 LM. (I already had the 1/24 kit of David Piper's 1968 car). What a monster of a kit! 


Clocking in at 2.6 kg, the package includes internal engine components which can be assembled, or not, as they obviously won't show once it's all buttoned up... pistons, connecting rods, a crankshaft made up of built-up sections, valves (!), valve springs (!!), rockers on little rocker shafts (!!!). Puts the Auto-Union cylinder heads to shame. 


So while waiting for rivets from MFH to finish up the Jaguar, I started putting the engine bits together. This started with drilling holes through the cylinder head and valve springs to fit the valves and the camshaft bearing caps.



Next I put the wrist pins (cut from 0.8 mm brass rod) through the rods and pistons, which all needed drilling as well.


 

I am currently attempting to assemble the crankshaft. Stay tuned!