keskiviikko 25. toukokuuta 2011

Getting there

Bottom end is now fully assembled with heads and all. Lift is 16.4mm at the valve, right as it should be. The rest is just bolting parts together and waiting for the gearbox to be finished by Alhomatic.

Some setbacks

Things didn't go as planned. I assembled the bottom end and as soon as I torqued it to specs the engine seized. Instead of trying to find the reason myself I took the whole engine to Pekka. He has all the right tools and skills to find all problems and so he did. The cam bore in the case was too small and flywheel side bearing was conical. Also the cam needed some clearancing between the lobes to clear connecting rods. After a week I got the engine back and now it spins easy. Excellent work by Pekka but what else can you expect?

Oh yes and if that wasn't enough also one of the conrods was defect. The thread was broken and there was no way of using it. Well, better to find it out now and not when the tachometer hits 8000 rpm. Thanks to Sami from our garage I got new set of rods in an instant. Also thanks to Aircooled's Tomppa who sent me a new set of rods as warranty. Great service.


3mm taken off form the camshaft.

lauantai 7. toukokuuta 2011

New cam

Now this is what I would call a camshaft. It's JPM's custom grind roller Raptor with 294 degrees @ 0.05" and 10.93mm lift at cam. Max power should be at 7300 rpm. Just perfect for a street engine and best of all the spring pressures it requires are far less than traditional american grinds.
Comparison between Pauter vn011(left) Raptor (middle) and Shawn Geers' wildest grind (right) shows the differences. Raptor is quite fat and keeps the valve open really long. According to JPM that is exactly what I need if I want 2.9 liter engine with 50mm intake valve to breathe easy above 7000 rpm.