Looking to go nostalgic and build a fast road turbo Volvo 240 or 740. I have a new factory late "red block" with piston oil squirters. Have a new head casting coming. I want to stroke it from the stock 2.3 litre 96mm bore X 80mm stroke to either 2.5 litres with 96mm bore and 86mm stroke (which is a factory offering in the Penta marine version of this engine), or, more wildly, to just under 2.8 litres with 96mm bore and 94.5mm stroke. There is a stroker kit commercially available for 2.5 and 2.8 litres, billet crank, billet rods and nice lightweight Omega forged pistons specifically for high boost turbo application with a -11.3 cc dish. I have not found anyone in the UK with personal experience of the 2.8 stroker kit though. Is it too much stroke V bore size.....? I feel adding stroke is better than going bigger on bore, for two reasons. the 2.3 blocks don't have a massive reserve of bore wall thickness, so staying 96mm is safe. And 96mm bore is already quite big for a turbo engine with flame travel probably compromised if it were much bigger.
the head will be the 2 valve per cylinder single OHC, not the 4 valve per cylinder 16 valve DOHC head. I intend upping the exhaust valve diameter from 35mm to 38mm, but leave the stock 44mm intake valves alone. It will have a staggered duration aftermarket cam and run on Motec sequential injection and coil on plug direct ignition.
Anyone any thoughts on going 2.8 litre? I can't see me wanting to rev it much beyond 7250 RPM, and I am looking for as much area under the torque curve more than peaky top end power. if i got a genuine 380 BHP at the flywheel with a rook of torque I'd be happy.
Thanks for reading.
Edited by Chris Wilson, 06 February 2016 - 17:41.