Ferrari 250 LM: Engine internals

The engine in the 250 LM comeswith loads of internal components which could very well be left out, because no one would ever notice. However after some deliberation I decided to assemble as spelled out, and document the heck out of it. 

The pistons are cast in one piece, meaning the crank has to be built up. This leads implies lots and lots of bits, including wrist pins made from brass wire. 

Once assembled, the crank, rods and pistons flap around a bit. Also part of the build-up is 5 of the 7 main bearing blocks which are sadly not split. 

The engine block being made in two halves, it is impossible to insert the assembled crankshaft with 12 rods and pistons into the assembled block all in one go. Rather it is necessary to insert 6 pistons into one half of the block, carefully gluing the main bearing blocks to the block but not the crank, then carefully slip the other half block over the remaining 6 pistons and glue it all in. 

Of course I tried to turn the crank to see how well I assembled the whole thing, but it went a quarter turn before jamming, and applying a bit of torque caused the crank to break. So the last journal, carrying the rods for the last two cylinders, is now independent of the forward five journals carrying the remaining ten rods and pistons. You have now been warned: don't ask me to assemble your crankshaft if you expect it to turn.

The lower crankcase and oil pan are now in place and the crankshaft is forever sealed in there where no one will ever see it again. 

Next the valves and valve springs (made of white metal, sadly) went into the cylinder heads, and assembled heads were attached to the block with the appropriate gaskets.

The next step involved adding the camshaft drive gears in their front cover (also now hidden forever), the flywheel housing and the intake manifolds before painting the whole thing with a mix of 1/3 dark aluminum (ZP-M1004) and 2/3 light aluminum (ZP-M1001) from Zero Paints.  

Next were the camshafts, one per bank, and the rockers, each on its own rocker shaft mounted between two camshaft bearing blocks. For some unfathomable reason, the cam bearing blocks are not fitted to the head with a precast dowel and socket approach, but with 48 bits of 0.5 mm diameter wire, each 5 mm long. 

Finally the cylinder head internals were covered with Tamiya's brown panel line accent colour to mimic oil residues; I wiped the worst off the rollers on the rocker ends to mimic the machined finish here. 

This will never be seen again once the cam covers are on. However, it is now documented that I actually did it.

And that's it for now.

Jaguar XJ13: Complete (##10 for 2024)

Calling this one done. As MFH kits go, it is relatively easy to assemble, but there were some last minute squeezes. And unfortunately the bodywork doesn't allow for much viewing of the hard work on the chassis and engine compartment. 

As always paint is my weak point. More sanding/polishing etc. would have improved things, as well as more care in final assembly where painted panels are attached.  

What's next? No idea but there's a 250 LM that is well started. Stay tuned!

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...   

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!  

Jaguar XJ13: A riveting story

Ha ha. 709 rivets used, with an unknown number broken or lost along the way.

On to paint.

Jaguar XJ13: Chassis and dashboard complete

The chassis is now complete, mainly with the addition of various bits attached to the monocoque either side of the engine.

 

The opening oil filler cap is neat even though it will not be easily visible.

A fair bit of filing and cursing was required for the dashboard, but I am glad I worked through this before attempting to just slap the dashboard into place; it serves to tie the front and central chassis structures together and has to be right if body panels are to fit. 

 

 

Next: Bodywork and paint. This will begin with approximately 700 3D-printed rivets in 0.028" holes. Fun. Stay tuned! 

Jaguar XJ13: Monocoque and engine installation

The monocoque and front suspension is complete and the engine installed. Surprisingly this didn't involve too much drama, but it did require playing around with the assembly order.

Front suspension and the forward compartment are relatively simple. A lack of online detail photos make it hard to determine what should have been modelled here. 

This beast weighs in at 1258 grams so far; the little support legs underneath the chassis will be critical in keeping the white metal suspension parts from sagging from the weight as was the case with the Alfa P2.

As with the Abarth, the master cylinders are inside the footwell and this makes it relatively pointless to add any piping detail. 

Next is the dashboard and more detail around the engine compartment. Stay tuned!