Double check my engine builder please 340 stroke

MObarracuda said
Ok...more info from the engine builder...I used the calculation tool he uses to verify the numbers. See attached photo

New info...
1) my block was tall and the deck height .018 above the piston
2) To keep the costs down for machining and due to the limited piston selection it drove the builder to select the Icon IC744 pistons are flat top that have 5cc eyebrows cut into the face. This minimized the amount of machining to the block and heads to achieve C.R. ratios and maintain rocker arm geometry.
3) the pistons have (8) .4 cubic inch or 6.44cc gap between the cylinder wall and piston that is .015 wide and .222 deep down to the first compression ring that adds cylinder Volume. (See pictures and the calculation tool allows for this measurement)
4) the cams advertised duration 253/266@20 deg or 276/294@6 deg. The intake closes at 76 degrees (actual zero). I used the 76 degree number in the calculator. Note: asked to install the cam with 4 degrees of advance.
5) the engine builder says the Static compression ratio will be 11.57:1 and the dynamic between 8.1 @ 1160 elevation or 8.4 at sea level.
6) I asked him about crank pressure. He said 225psi. I asked him if that was high. He said he has other engines out there with aluminum heads st 225psi and it is no problem. He said if my heads were iron he would have stopped at 180psi.

It helps when you have all of the answers. I hope these answers help everyone following the tread and who have contributed their thoughts and hands on experiences. I will get the motor assembled and let you know how it goes.

PS my builder said if I was shaky on setting the timing at first to run some 110 octane gas to get it dialed in to avoid detonation while I worked it out the initial timing.

View attachment 1715103145

View attachment 1715103146

View attachment 1715103147

1. Deck height is positive if the piston is down the hole. It is negative if the piston is out of the hole. So you have a negative deck if the piston is above the deck and a positive number if the piston is lower than the deck.
2. You can deck the block and head until you hit water and it won't affect rocker geometry if you have shaft rockers.
3. Crevice volume on modern Pistons is rarely more than .2 CR.
4. That's not much cam timing for the CR you have.
5. Tune up will be critical with that CR. I'm not sure I even like the cam you have, but all that money spent and you are going to handicap it with exhaust manifolds.
6. Aluminum and CI heads can run the same CR. That has been proven many times. If you can't run a CI head over 185 psi you'll have the same issue with aluminum heads.