Well, finally decided to tear the 408 down and see why it had the incredible amount of oil blowby in the crankcase. The prognosis isn't good. Number 7 piston had a lot of deformation to the point that the piston rings looks like a big smile, obviously caused by excessive heat. Pistons 1, 3 and 5 also had deformation in between the top and middle ring causing a loose fitting top ring on one side. I suppose there had been a fueling issue on the LH side of the engine. I think the bores are fine on that side. I need to have number 7 bore checked to see if there is any out of round that might cause future issues on a new set of pistons/rings.
My next decision is to figure out how to build it up for the turbo. I have the option of -32cc, -28cc, -8cc (what came out of it) and many others. I also have my 64cc P&P Patriot heads and a set of stock 71cc LQ4 317 heads with dual Patriot springs already installed. I'm trying to decide if I should go very low CR using the -32 or -28 cc piston and install the 317s or go for the higher flowing heads and sacrifice a few lbs of boost.
I have a Bosch fuel pump I'm going to install before the 408 goes back in so the fuel supply will not be an issue. I am also going to bypass the variable speed fuel pump wiring and run a 1/2" fuel line to the intake along with my billet fuel rails from my old truck. I'd love to be able to push a solid 15 psi of boost on pump gas.
Suggestions? Am I nuts? (most likely)
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