So Scott reached out to me for an update. A couple of things to update.
The car is still together and running. I found that through out all of Drag Week the coil on cylinder #5 wasn't firing. Which would answer why it was having trouble spooling the turbo and having massive blow-by. Basically making 240Hp on 5 very rich cylinders. I found and fixed that and boy-howdy does it spool and go. It will start burning rubber at a rolling 40mph and 10psi. I wound it up to 20psi and 6100rpm a handful of times then the headgasket let go on the #5 cylinder, out the side. I suspect the thousands of miles, etc with #5 not firing may have started to push the gasket hydraulically. I had added a TON of fuel to the system to stop it from running lean, when in reality #5 was pumping straight air into the exhaust and the other poor cylinders were soaking in fuel.
But I've changed the head gasket, and it runs but I haven't re-tuned it much (pulled some of the fuel out, but needs more). I fired it up last weekend and did a burn out just because. I still haven't finished assembling my good engine, with the forged rods and pistons, ported head, re-ground cam, etc. I want to take the car to a local chassis dyno to see what it's doing on all 6 cylinders at 10psi and 15psi. I suspect just under 400Hp at 15psi, but its just an estimate. It was making about 175Hp N/A at ~5,000rpm, so double that, maybe a little more.
I'm also looking at changing out the intake that Scott made for one with a Webber carb unit modified for EFI and a boxed in plenum. Scotts is a good intake, but I think the longer intake runner length will be beneficial. The picture I have mocked up a box that is similar to the intake I have now, but will really have the throttle body moved further away from cylinder #1 and come in at a 45º angle. I'll weld bellmouths to each runner for smoother air entry. I think I'll be able to get my thermostat housing to fit with it as well and go to a conventional flow cooling. Get the water hoses away from the turbo.
I'm probably ending my Photobucket subscription in January, so not sure what the pictures will do.
As the car sits now, it has a 1969 Pontiac 250 with garbage cylinder walls, but new gaskets and bearings. A factory 4bbl cam, hand ported head by me, about 8.3:1 compression, a chinese GT45 turbo fed by homemade headers, twin-scrolled front three cylinders and rear three paired. 1.75" primary pipe to a t-4 flange and a 4" exhaust out the turbo to the rear axle then reduced to 3" over the axle. 3" intake tube from turbo, through 3" intercooler, to the intake. A 4L60e transmission and a 8.5" rear axle with 4.56 gears in it now. The EFI and transmission are controlled via a Megasquirt 3/3x. Bolt on crank trigger and a modified distributor as a cam sensor. $40 in junkyard LS coils and brackets for ignition and some mid-tier 80ph fuel injectors.
As for the intake, I'll have to go digging for some pictures to show how it was finished for my use. The general work was the runners were a bit too narrow for the OHC so some plates were TIG'd to the runners to thicken them up. I assume that would not be an issue for the Chevy L6's. The injector ports were drilled, the throttle opening was widened to the size of throttle body I am using (45mm?) and a casting hole in the back of the plenum had a plate welded to it. The ports were opened up to match the porting on my head. There is a nice line of sight from the injector tip to the back of the valve. The downside for me was the fuel rail interferes with the thermostat housing. I'm not sure if this is an issue on the Chevy L6, I haven't looked. I could probably shorten the rail a little and make a custom thermostat housing, but I haven't given it that much thought.
