Okay, so at Mondello's today, we hatched the plan of attack.
I have emailed Tooseevee with some of the details, and some requests for measurements.
Basically, we need to have more space at the valve to let more air in.
If cams or rockers are not wanted in the job, then that leaves bigger valves. So, that's what we plan.
The approach is more valve area via bigger diameter valves, and to unshroud the bigger valves by doing some re-shaping of the combustion chamber to allow better flow out of the bigger valves. This will also require new valve seats.
The chamber will be cc'd prior to the work, so we know the starting volume of the chamber before we do anything to it. After we do the flow relief work around the valves, we will weld up some aluminum in another part of the chamber, and grind it and shape it to help out the flow over there in that part. And we will adjust the chamber volume with this added metal to have the same cc volume as it had previously, so that the compression will not be adversely affected. When it's done, the chamber will have a somewhat different shape, much improved, bigger valves, but the same cc's of volume and compression.
In this case of larger valves, it is possible that even with the standard lift, and depending on how far down the bore the piston is at TDC, we may have to provide clearance for the valves by fly-cutting valve relief pockets in the piston crown. This is not an unusual procedure in performance work. Then we have some room to work our plan without the piston banging into the valves over TDC.
Basically, we have to do something to get more room to let air in around the valves. Cams, rockers, or bigger valves. Pick one, or more.
And to all you other AVL owners out there who may experience issues with interference in piston-to-valve clearance over TDC, we can fly-cut your piston too, if you need it, and it is a quite inexpensive procedure to do. Much much cheaper than a new piston. There is a limit to how far it can be cut into the crown, but if you are doing big time lift mods that go beyond what we are doing in this job, then you will need another piston anyway, and most of you contemplating anything like that would already realize this.
So, we have a pretty good plan here. Depending on how the location of the piston at TDC works out, we may or may not have to do anything with that. If we do, then it isn't too expensive of a job to provide clearance relief cuts in it, and this gives a route to anyone else with an AVL needing to do that. Just send in your piston if you need it done.
Of course, this job gets all the other Fireball stuff like the beehives and Fireball valve gear hardware and installation methods, and the performance coatings too.
Waiting for a response from Tooseevee about it.
Tom