Yes, that is very close to where I have calculated it also. I was off before with my intake closing degrees @ .050. Thanks for getting me on track. Where before I was concerned with to much cylinder cranking pressure, now I wonder if getting closer to 160 would have much benefit. I like to think it would but what is 14 pounds worth in power? Taking another .020 off the heads and equalizing the quench pads of the heads in machine work $$$. I know what they will charge for normal surfacing and don't mind that but by the time enough is removed to get good quench and compression I think I will be faces with more machining to get the intake to head fit correct. Please share your thoughts on all of this. I know in the end I would have been better of power wise to go with after market heads and different pistons but I am already deeper than planned on this engine and the factory heads, to a point I am willing to go deeper but will have to draw the line at some point.
The quench dome pistons are a neat idea, but a lot of work to setup properly.
My 360 engine used the KB-232 pistons that only had a small 0.050" quench dome.
With those pistons, the connecting rod pin ends needed to be narrowed to 1" to start with.
Then I equalized the head chamber depths, and had the block machined so the pistons were near zero deck height (I think 0.001 or 0.002" below?), then had the heads milled so the quench area was about 0.050" from the head surface to match the step dome.
Then I mocked up the engine without the head gasket (using 0.040" head gasket to set quench distance), the quench dome was just slightly lifting the head off the block. The reason was the step dome is straight, and not contoured to clear the raised "eye brow" area around the valves on the stock iron heads. So the quench dome needed some slight contouring to match up the the head chamber correctly. I would be careful if you decide to mill the heads, as it could be more work if the step dome does not match the chamber correctly like in my case. Really, I just put it together, it looks like a nice combination.
As for the factory heads, I had at least 20+ hours of labor in porting, equalizing the quench distances and head volumes, cutting the spring seats and guides for the performance valve springs and seals, opening up the pushrod holes for 3/8" pushrods (small block), and opening up the tall center head bolt hole for oiling when using head studs. And that was on top of the cost of new valves, guides, hardened exhaust seats, valve job, and milling both the block and intake sides of the heads. I believe the compression ratio did come out to about 9.5:1 which is what I wanted. I used the Hughes SEH1620AL cam with Crane 1.6:1 rocker arms (0.528"/0.536" lift), and the engine runs better than I though with what I considered a small cam. This was built to be a torque/RV type engine in my RamCharger, and it worked really good, but I rolled the truck. I'm thinking of taking the 360 and swaping it for the stock 318 in a Coronet 500 I originally bought as a parts car, but is too nice to tear up just for parts.
I haven't had problems with Hughes, but I usually just buy parts from them. Overall, I haven't really had problems with vendors. Many years ago I bought some wiring harnesses from one vendor (I don't even recall their name) and the harnesses had all sorts of issues, like wrong connectors, wrong gromets, wrong length, basic junk.
