[gtofreek]

I'm starting the engine build for my GTO, finally. It's funny, but I've been an engine machinist/builder for almost 22 years now and this will be the first performance engine I have built for myself. Previously, since being a machinist, I have only built 2 engines for myself. The 2.8L V-6 in my S-10 pickup[stock], and a re-ring, and bearing job on a 389[stock] I did on a 66 GTO I had a while back.

I'm planning a N/A 400 for this project. It will be .065" over with a bore of 4.185", and a stock stroke of 3.750". This will make it almost 413" CID. I'm starting with a 1967 400 block that is .030" over now. I have cryo treated it already, now it's ready for me to grind off all the casting flash, and de-burr it. Then it will be shot peened to get it really clean, especially in the water jackets, and the look of new cast iron. I have a set of 1967 670 heads I will use also. My target for performance is 550+ torque, and 650 HP, and to run up to 8000 RPM, on pump gas.

Short block:
Will be filled to the bottom of core plug holes with HardBlock after threaded grade 8, 1/2" x 13 rod is threaded into block deck down to bottom of water jacket. Done to help stiffen the deck some.
Connecting rods will be Callies Compstar 6.700" BB Chevy H-beam with L-19 rod bolts. I will have pistons from CP in a couple weeks. They are 2618 material, and feature a short, stout, 2.5" long .990" piston pin with steel gas nitrided 1.5mm, 1.5mm, 3mm rings. They will be flat top. A stock 1967 400 cryo-treated crankshaft will be used after grinding the rod journals down to 2.199". Lifter bore brace will be installed. Block will be align honed with ARP studs, zero decked, and bored and honed with a torque plate, and ARP head studs. I'm going to run a solid roller cam that I will have Jeff Koerner, and Harold Brookshire help me design for exact needs. I have some Crower HIPPO roller lifters for it.

Heads: I'm starting some major reconstructive surgery on the heads this weekend. They will be nothing like a stock 670 head when i get done. They will only be recognizable by the casting number. I'm redesigning the combustion chamber, and trying to convert it to a fast burn design. I figure I will need these heads to flow 275 CFM or better to meet my goals. I flowed a bone stock port[#2 cyl.] tonight with stock valves, with no backcuts on them. I was very pleasantly surprised on how well it flowed. I have flown a lot of D-port heads, but never a 670. Most D-port big valve heads flow around 204/165 I&E. This head flowed 218/190! It is as cast. The thing that surprised me the most is the fact that the flow never turned over like most other D-port heads do. In fact, this head flowed more air up to .300" lift than a ported set of #62's that I have that flow 255 @ .450" lift. I'm going to try something unconventional with the intake valve. Below are the flow numbers from this head.
I have a Victor intake manifold I will be porting to match these heads when I get them done.

I will work side by side with Jeff Koerner to build the perfect Holley carb for it.

I'm trying to build this engine for $2000 to $2500. Since I can do all the labor myself, in house, I should be able to, or at least be close.

..........Intake_______Exhaust__E to I ratio
.100"= 82 __________54________66%
.150"= 118 _________76________64%
.200"= 149 _________98________66%
.250"= 173 _________115_______66%
.300"= 193 _________130_______67%
.350"= 202 _________143_______71%
.400"= 208 _________157_______75%
.450"= 211 _________165_______78%
.500"= 212 _________171_______80%
.550"= 213 _________177_______83%
.600"= 214 _________181_______85%
.650"= 215 _________186_______87%
.700"= 215 _________188_______87%
.750"= 216 _________190_______88%
.800"= 218


Pictures to come.