Just installed this cam C/L is 112 it should be 111 this is with
+2A if I go +4A its 109 what's best

You can't tell without testing it. If you don't have the capability of testing it then run it where it is. Did you check valve to piston clearance? You might not have enough VP to advance it another 2 degrees so before you move stuff around double check the clearance. The performance might change slightly if you advance the cam but it might not. There is no guarantee that it will be better, it might be worse or you might not notice a difference. There are lots and lots of variables in play.

So much info missing, intended usage, compression ratio, fuel type, cylinder heads, transmission type and weight of vehicle.

That cam has a lot of duration. If it’s not a drag car, it will be when you are done with it. I have a comp cam very similar to this and I would strongly encourage you to check valve to piston clearance, especially if you are using 1.6/1.7 rocker setup. This will be a rough idling beast, I hope that’s what you want. Good luck.

What stroke are you using?

Never used a CL greater than 108 on any RB with std. stroke. But that was a long time ago.

Usually 106 for a drag car, 3200lbs or greater with an auto with 4500 or higher stall.

With a much higher stall converter or low gearset trans maybe you can get away with the cam straight up.

indy max block 4.510 bore 4.250 crank indy -1 heads 1.6 rockers 345cnc cp custom dome pistons 15.5.1 compression
runs on methanol with rons terminator.I have run this cam before but have no record of where it was i know it was +2A old cam was damaged by a worn lifter so this is same cam but new grind

Check VP and do a full sweep so you are checking every 5 degrees before and after TDC. With a cam that big and those piston domes you need to check about 3 places for each so you know where the tightest spot is. Once you map out the VP clearance you will know if you can move the cam. Once you know if you can move the cam then you have to decide if you want to move the cam.

Changing the cam installed centerline is a second order effect on power. It rarely makes much of a difference. Having the valves hit the pistons is a very big problem. So figure out what kind of clearance you have first and then worry about cam timing. Typically cam grinders will tell you to install a cam 2 to 4 degrees advanced but that is mostly a rule of thumb.

I had a very similar combo, and went from a 278/288/110 Isky to a Comp 283/296/113 cam and didn't pick up much if any. I suspect it will like 108 installed centerline, especially if you have less than 6300 stall. My new 549 motor with bigger 572-13 heads picked up 5 hp down low and lost 2 hp up top going from 110 to 108, (284/296/114 duration)which to me will make the car faster.
Like Andy said, it probably won't be a big change between 110 to 108, and since most combos have converters that are 6500 stall or less, that lower rpm power is more important than bragging rights on a dyno sheet.

I would run it at where you have it now, 111 BTDC intake lobe centerline and see if it has too much bottom end or not

I run this same cam in my racecar. It's currently it is at 111. 4.530" x 4.500", 15-1 on gas, ported -1s. 1.7 rockers. Previously ran very similar cam. Same lobe family but it was .471 int and exh lobe lift, and less exhaust duration at 292, 112 LCA. Last ran it at 108 and 111. Didn't make much difference that I could tell. Been using Pac 1224 springs at 1.950". Very reliable. Actually idles fine at 1000 (though I run it at about 1300). Makes good power and doesn't hurt parts. Runs 9.0X@3350 anywhere.
Doug

this is my problem its at 112

A really good 1D simulation will show you the differences between cam timing scenarios, but requires input measurements that aren't especially easy to gather. Vannik's EngMod4T will show you the slight(presumable based on lots of other pushrod V8 sims) shift in power as it essentially moves the curve very slightly. Unless you are racing a non-index class the difference won't be noticeable. However, it is admirable that you are concerned and wish to install the camshaft at the specified position relative to crankshaft angle/piston position.

Changing the open and closing events such a small amount from spec won't hurt a thing, as long as you have adequate P to V clearance.

Happy motoring!

Something like this?

In my experience you will not notice the 1 degree off. The only other thing is how tight is your timing chain or do you have a belt? It is the tendency for the cam to retard itself under high rpms with a timing chain the looser it is the more it does it. So, if you have some slop in the chain go with the 109-degree centerline.

I even tried 113 once. To be honest it ran about the same where ever it was. All out best has been 8.96@149. It ran 9.00@150@113 degrees. The newer cam has run a best of 9.00@149. But with a 4.10 vs 4.30. Weather wasn'tt quite as good either.
Doug

After reading all the posts ,AND if you can run extremely consistent times, i would check available piston to valve clearance at 112 and 108. If you are good on both, you can start with the one you want, then try the other. Keep in mind the change may be very small, like three to five hp. That might only show .02 et change or less?

I have always thought all you are doing is basically shifting the HP and torque curves up or down a little in the rpm range. The cam I run I used to install it at 106 when I footbraked it. When I started 2 stepping it at 4500 I bumped it to 108. It did run a few hundredths better after I moved it. But it wasn't dramatic.

When I built mine I checked it from 108 to 114 to make sure it had clearance. Foe what its worth it is a footbrake car. Runns mid to high 1.2 60ft depending on ballast and timing.
Doug

Run it at 112, you'll never know the difference
Sorry for thinking it was at 111 ICL