@JB356SR posted:If I fly cut the head to get a smaller combustion chamber will these heads work better?
You're better off to cc them first and figure out what you really have. There are kits for sale for this, or you can build your own. Check YouTube for how-to videos.
Here's some info on my 1776 which might help you.
I had a valve seat come loose a couple of years back, so I bought a new set of Empi heads with 40/35.5 mm valves and single HD springs. Off the top of my head, the chambers measured 56 cc. Once I accounted for deck height and ran the math, my static CR worked out around 9:1, which is right where I want it.
I'm using stock VW rockers on Gene Berg shafts and chrome moly pushrods. Not really sure what the cam is because someone else built the engine and I've never cracked open the case. I tried pulling the oil pump to examine the end of the camshaft, but it's glued in solid with aviation Permatex. The new heads aren't ported. The old ones were, pretty radically, along with the manifolds, so I bought a new set of Empi manifolds to match the new heads. It's running dual Dellorto 40s. Not sure of venturi or jet sizes because I've never needed to dig into it. My Pertronix SVDA distributor is timed at 30 degrees, I pull vacuum from ports above the throttle plates on both carbs, teed together, with a restrictor inline to smooth out the pulses.
I like the way my engine runs with the new heads. It's driveable anywhere above 2000 RPM, but the power really builds by 3000. It pulls strong to 5400 RPM, my self-imposed red line. I pushed it to 5800 once and power was still strong. I'm guessing it has a performance cam, probably a W110 or similar. I won't rev any higher because the valve springs are only good to 6000. I also don't fully trust the bottom end because I didn't build it. But I have put about 9000 smiles on it. (-:
When I first bought the car, with the old ported heads, matched manifolds and a Magnaspark II mechanical advance distributor, it had an awful dead spot off idle and no power at the low end. It was high strung, and no fun for just putting around. I blame that on both the porting, which reduces the velocity of air entering the cylinders under part-throttle conditions, and the distributor, which had an RPM based curve only. To be streetable, ignition timing needs to account for throttle position, especially at low RPM.
I hope this helps,
Eric