Originally Posted by killick
So, having not touched an since high school, and now retired from the Navy, I decided to start 'tinkering' to see what I could remember. I decided to try find an old 350 to play with over the winter, so what actually happened was I picked up someone else's project engine:
Freshly bored 406, polished crank, new pistons, rings, cam, oil pump, flex plate, balancer and a few other odds and ends - most of the rotating assembly..
What I still need are
intake (likely some sort of FI)
Somewhere I have a note with recommended head numbers, but the part I *do* remember is that the PO recommended 76 mm combustion chamber for a lower compression ratio. And to get the heads drilled for steam holes.
Some way of figuring out what will work well with the current parts.
Any pointers towards what I should be looking at for the top bits would be most appreciated. I'm way out of practice and don't really know what to be looking for when it comes to the options available these days.
The engine will likely be going into a 68 C10, or possibly a farm find 48 dodge, complete with farmyard bullet holes - if I can convince the 80 year old owner that he's likely not going to be doing anything with it...
Is the short block assembled or do you just have all the pieces you listed?
If you have them unassembled, give all the info you have on the parts. Piston diameter, piston compression height, part number if you have it, rod material, rod length, etc. There are lots of smart guys on this board who can help you assemble a motor that will do what you want it to, but we must know every little detail of what you have now in order to help you. Do you have the EXACT diameter of the bore?
You may want to use heads with a larger combustion chamber volume or you may want to use a more conventional head with a dished piston rather than what you have. You will want to engineer the build at somewhere around 9.0:1-9.5:1 static compression ratio with iron heads and no more than about 10.0:1 with aluminum heads if you plan to run the motor on pump gas. The more static compression ratio you run, the more cam you have to run to prevent excessive cylinder pressures that will detonate on pump gas. It's all a balancing act, involving all parts that must work in symphony with each other toward a final goal. It's what's referred to as a COMBINATION.
This afternoon, I DynoSimmed a combination for one of the other members of this board that used ProFiler heads. These are excellent aluminum heads that come in 64, 70 and 72 cc configurations and could be matched with the proper piston crown configuration to make the best static compression ratio to meet the needs of your build.
See the Sim here on post 18....
Help with HP