Getting Head

Yeah, I looked at it quite a bit. It suffers from lots of issues, but to say there's nothing to be gained is a little pessimistic. There's the usual 5 - 7% just from cleaning it up. More than that will make velocity suffer though. At least from what I can see. ZPI claims a lot more for their head, but they also claim you need to remap the fuel to get it to work right which tells me they did something really dramatic to the flow, and I wouldn't call it all good. Most porting gains are incremental, not quantum unless you've completely refocused your power expectations and compromises.

I still need a set of valves before I can get started. It came with a lot of stuff, but valves and buckets were not included.

Something you need to consider about your 998cc engine is how much torque does it make? Where does it redline? Would you want an engine like that in your car? (OK, I would love it, but most people wouldn't, so they won't sell them like that).

I do say... looking at mine in my free time, the optimal flow path for air, rarely includes sharp turns, and our heads require just about a u turn. does numbers on the actual flow patterns... air on the outside of the bend goes very fast, suffers great frictional losses, and causes a pressure gradient force... which provides very disrupted airflow, all bad i think. Now i know that swirl charging or turbulent air helps mix the fuel better for better flame propogation, but that should not be happing untill the air is actually entering the combustion chamber (the whole swirl charged phenom of the 80's)

i really wish for an alternate verision... i would love to shorten up the piston trave just a tad, drop the deck hight slightly... maybe push the compression up and redline to maybe 7, 7.5. AND a new head. i want it loud, smelly and fast, like a bike

Actually, I'd like the FE head with more upward ports and a hood line to support a straight shot intake. One of the interesting things we see in cars that we don't see in bikes is the concept that a wider included valve angle is considered "performance."

Bikes have been narrowing their included valve angle since the 80's and finding more power because they don't have to fight the hood line problem. Initially they had problems with really high angle intakes because the design paradigm was the gas tank had to be mounted over the engine. They've got better solutions now, and most of the time the space that used to be dedicated to fuel is now dedicated to a huge airbox feeding very straight ports that look directly at the backside of the valves at narrow included angles. Narrow angles do reduce the valve area, but there are lots of other good reasons you can make a lot of power with smaller surface area combustion chambers.

I'm pretty convinced the car guys are just tolerating the problems with the hood line and going for a wider included angle because it makes a better port with the same hood line than a narrower angle with a much better combustion chamber.