Friday, May 19, 2017

917 K Gulf Oil: Complete

OK, enough with the trucks, back to the good stuff. The 917 just needed final assembly.

But first I spent a fair bit of time with a polishing kit to try to get rid of the orange peel in the paint. I got a lot of it out, but it's tedious; plus I wound up going through to the primer in a couple of places. So the lesson is: avoid orange peel in the first place.

So the paint is a bit sloppy, and this is certainly an area where I could be doing better going forward. Decals went on OK, glass went in OK (the white Micro Krystal Klear glue still shows here as it hasn't completely set).

The HRM motor sits in there nicely, taking up over half the wheelbase. What a monster. I've ordered another motor to build up as a separate display unit. (The Fujimi motor is very basic and takes advantage of the fact it is all hidden once assembled.)

Comparison with the 956 is interesting. Water cooling is a big difference. The 917 managed about 100 hp per litre on air cooling alone. There is an upper limit to this, however, due to the fact that heat transfer coefficients from an aluminum head to air are at least one order of magnitude less than to a liquid. So you need huge surface area in the form of finned cylinders and liners, or you use liquid cooling and move the finned area elsewhere, such as into the door frames as seen here in the 956. The radiator surface area needed in the 956 is substantial, and this is just for the heads -- the 956 motor still had a big fan for the cylinder liners. Of course in a 956, there is something like 600 hp from substantially less than 3 litres, so more than double the specific power of the 917.

All in all a good kit, the HRM motor is an excellent addition, and I probably could have been a bit tidier with it all. Lessons learned will serve for the other four 917 kits on the shelf ... Completion ratio is now a whopping 33%.

No comments:

Post a Comment