Wednesday, January 31, 2018

Porsche 356 C: intro and engine

I managed to get my hands on a copy of Fujimi's excellent 356 C.



This kit, which was apparently designed for the European market, has a very high level of detail compared to some of the curbside kits of Japanese sedans promulgated by Fujimi, Aoshima, Hasegawa and others.

I got started on the motor, which was one of the 4-cam, roller-bearing devices cooked up by Ernst Fuhrmann. The kit even includes a molding of the crank, rods and pistons, which I will paint and display rather than bury inside the crankcase. Interestingly it shows that the cylinders are offset by half the bore, and each rod has its own crank journal; like the 911 motor, rods are not paired on a journal. Unlike the 911, which has a full complement of 7 main bearings (plus an 8th in front of the timing chains), this one appears to have only three.



It will look good next to the other Porsche twin-plug heads in the collection (908 and 917). The 356 motor used two 4-cylinder distributors; I've got a pair of 4-cylinder distributors from Morgan Automotive Detail which should work well.



What a complex little motor! At 1:1 it was said to require 120 hours to assemble, with at least 8 hours just to set the timing of the 4 cams and two distributors. At 1/24, Fujimi has provided lots of very fine detail, and a few pictures will illustrate this.



The basic engine block, barrels and heads, with carbs, fan and belt drive, is about 30 parts.



By the way the fan shroud has to go on before the carbs ... just because I did it backwards doesn't mean that is the right way.



Adding to the complexity, it appears that the distributor drive housing goes on over the belt drive, so changing a belt means removing the distributors ... is this offset between the crank and generator/fan a last throwback to the lowly Beetle? There is not much else in common between the two besides the flat-four layout.

Decals meant to mimic the wire mesh on the air filters were dry and cracked. Alternate plans may be needed. Perhaps the built-up crank will push me to make a small diorama with a garage bench and some tools.



I hate closeups like this, because they show every little flaw. But the screwups, like the broken fan belt or the visible seam running down the side of the cylinder heads and barrels, are essentially invisible to the naked eye. The picture does show, however, the shaft drive from the exhaust cam to the inlet cam; separately there is a shaft angling horizontally out from the bottom of the crankcase to the exhaust cam. All of this was joined by bevel gears, and setting the timing involved some complex approach to rotating the bevel gears relative to their drive shafts in minute amounts. All this, of course, after assembling the Hirth roller bearing crank.

I am now letting the glue for the distributor caps, from Morgan Automotive Detail, set on the distributor bodies from the Fujimi kit. The wiring looks complex but there are lots of pictures online illustrating the routing.





Four cams, two distributors and eight spark plugs, all to extract 130 hp from a two litre motor with four cylinders.



 Realising that some builders may want to display the motor, the kit comes with a motor stand. In order to make this realistic, the transmission (which stays in the car) has a clutch throw-out bearing and fork, and the engine comes with a flywheel and ring gear. No clutch, however ...

The kit will make the 356 B or C; I'll go for the C, which had 4-wheel disc brakes, and save the VW-style rims and drum brakes for the spare parts bin.

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