Cam phase suggestion advice
Your thinking on the cam is right. But in your case the 108 centers the overlap, which is a meager 45*. If you install it at 111 (1* retarded) your EFFECTIVE overlap will change to 38* .. If running headers this will give up some power potential, but if running log manifolds, it matters not, you will be giving that power-bulge up anyway.
The thing is, each degree of advance/retard in your size of cam is maybe around 1.5psi, so 3 of them adds up to only 5psi at most.
If you truly were at max-pressure of say 168psi with a tight-Q,and are running log manifolds, then, I wouldn't be scared to run it at 111, because it will move your powerband up just a lil, which, at the new pressure of 163 will not affect the bottom end very much , and you can't lose power that you don't have, vis-a-vis the logs.
But I see some other hiccups.
1) the first is the PV clearance. YR said;
Unless that piston has NO valve notch, you have something wrong.
There ain’t no way in all of hell with under .500 lift that valve should hit the piston. Not even close.
So something is really wrong, unless I don’t know what Lunati “702” you have, which is possible.
And that is exactly right. You need to get this worked out first, to get any valve reliefs cut, which will ADD ccs.
2) If your valve timing is out, you will change your PV clearance, because the closest the piston gets is not at TDC . On the exhaust stroke the piston and exhaust valve are, for a small period of time, heading towards each other, before the piston chases it back to the seat which in your case will not happen until the piston has reached 22* ATDC.
But simultaneously, the intake valve
begins to open at 23* BEFORE TDC, so it is now on a collision course with the rising piston. As the piston goes over the top, the intake chases after the piston.
Like YR says, with pistons down in the holes, and only .475 lift (1.5 arms) there should be plenty of room in there. The fact that your valves are kissing the pistons with unmachined decks and no gasket, is sortof pointing to the intake valve not being where it is supposed to be, or you are not using the correct method of measuring, or something appears to be wrong.
In any case, here is a quick test; with the degree wheel still on there, and the #1 piston at TDC compression, go to #6 cylinder and drop the lifters in there. Then stand a straightedge upright longitudinally over the 4 edges. Next, move the crank back and forth just a hair until ALL 4 edges are touching the straightedge. Now read the advance/retard. It should be within a few degrees of TDC. If it is out by more than (guessing) ~4* then Something is wrong. This is a quick-test, not intended to be dead-nuts accurate, but it will easily find a gross error.
3) You gotta do something about that .002 dip on the decks, between the holes. But simultaneously, you must not bring your Q into the zone of .050 to .080 which is, on most accounts, flirting with detonation. So currently you have .056 (pistons below deck) plus .028 gasket = .084 so you have only um nowhere to go,lol. If you went to the .039 FelPro, that adds to .095 so now, you can cut your decks to whatever, up to pistons proud .010. With an .045 Q-target, that would be .050 off the decks. That's gonna cost you, about 3 passes per side. And you will end up with way too much pressure.
So, IMO, the easiest course of action is to use the .039 gaskets, which are killer at sealing, and let the Q fall in at .084 which is outside the zone and adds a couple of more ccs, and increases your PV clearance all at the same time! So now we are up to 11+60+8.6= 79.6 before cutting valve pockets and at stock bore, that comes to
9.2 Scr. and the pressure is predicted to be 153@200ft elevation. Yeah that's a lil low, but be comforted to know that, that will probably run on 87E10. To get the performance back at the bottom a 2800TC will do nicely.
Now, what I would do;.
Is clean up the decks, with a minimum cut, say .010 ,which is 2cc, then go back to the rest of the previous plan.
The Q is now .074, at the top of the danger-zone. But recall that; A) this is only a problem at WOT , and B) only if the chamber has problems, and C) or hotspots, or D) runs lean, or E) with too much timing. I think I can tune around those with closed chamber iron heads. The total chamber volume is now 9.1+60+8.6=77.8 for an Scr of
9.38, and pressure of 156@200ft, BadaBOOM! This is before cutting any valve reliefs, if required.
This should still burn 87E10, except if the .074Q makes trouble, then move up a grade, you got plenty of room.
So now, say you do have to cut some reliefs, say 2cc worth, that drops the Scr back to 9.2 again with the Q still at .074, and the pressure drops to 153 again.
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Your combo is in an awkward way because of where the Q wants to fall and where the pressure is ending up. It sorta needs a specialty piston, like a Step-D cup.
That cam wants a 9.8 Scr, (with iron heads); but with flat-tops, the Q falls into the NO-Go zone. A step D-cup could solve that.
As would alloy heads,lol, then you could run a lotta, lotta, pressure.
As would a different cam, with a later closing intake valve.
