Ugh Frank,
I am in a completely different place than you think I am, and if you didn't bring up my name I was going to leave it alone. I really hate this kind of arguing on the forum and always have
I did the sims because I was reaching out with an olive branch so you didn't think I was attacking every time. The only reason I used my own valve sizes is because the exhaust valve would hit in your combo with the lift we run nowadays. I didn't expect it to be a thing based on the original question. I really thought by putting up the data that I was helping out. I am no savior, I also realized that sims are just educated guessers so I put two up and explained what I did for interpretation.
That beign said, by chance only at this immediate time, I am likely the only guy with 2 457s on the stands right now, one 4.25 stroke, one 3.98 stroke. Unfortunately, one owner won't dyno, and the other is built with all modern parts and will make significantly more power. So even if we did talk the side oiler owner into a dyno, the small bore would win and taint the data
What I can do though, is whatever combo you want, even if the valves would hit, I can run through a better sim that I have corrected for a 461 inch stroker with iron heads that I dyno'd last year. It is nearly identical to the actual dyno run. I did so by adjusting CSA, port length, and careful parts choices in the sim. By doing so, it should be as close as we can get and see what that sim only does. I can't do that until Saturday AM, but if you want, I'll do it, assuming you agree that we'll just see what it does with only a bore and stroke change.
If I could build two engines like you want, I would, but using your example for valve sizes, I couldn't cut the side of a cylinder wall to clear the exhaust and I don't have two guys wanting the exact same engine, especially with the lift range for a big exhaust valve on a 4.14-4.16 bore. BUT give me what you want run again, bore, stroke, valve sizes, and I will jam it in the better sim with no prejudice.
However, I do want to bring some things up. In the old days we ran 3/8 valves, often they weren't undercut stems, port CSA and taper wasn't great or even not considered. We used large chambers with big domes to get compression with big quench distances, and only the select few the Ramchargers talked intake port math and guys like Dama Elgin talked 5th cycle and primary tube effects.
That stuff is accepted now and changes things, it's different. If I can help it, I (and I think Brent, Blair, and Barry) don't build a serious iron headed FE with anything bigger than 11/32 stems, Brent is using 5/16 stems on his 352, we try to go smaller chamber and flat top or dish, with more efficient ports and use the primary tube for the RPM we run. On top of all that, we can run lift and cam timing we couldn't run before. I have to tell you, it's going to seem like I am fighting you, but I just look at the valve diameter as being sized for the port alone, like the right sized trashcan lid, I don't care how big it is, it just has to match the throat of the port that's right for the engine. A bigger lid works, but isn't better
FYI - The two 457s, the 427 based one has heavy Venolia domes, nearly a POUND more bobweight for each throw, mid 500 lift, med riser heads with 2.19 / 1.73 3/8 valves and a SFT with a tight snotty LSA and will be a TON of fun in a light car.
The other, 428 based, has CnC ported CJ heads, 2.15/1.67 valves, 11/32 undercut stems, a modern throat and port design, .600 lift, 112 LSA, 5 degrees less cam duration @ .050 and a dished piston for the same 10.5:1 the 427 block has. It's going to spank the other one if both were on the dyno. and yes, the CnC ported heads are about 10 cfm better, but they are better with the smaller valve and the port design does not get better with a bigger one
Regardless, even if I throw all those same parts, heads and all onto the 427 block, I don't expect it to make any more power than the 428 block. Actually that's not exactly true, maybe 5-7 HP at the peaks, but as I said, I believe it will lose somewhere else equally. Drag car, maybe that proves your point, street/strip, depends where you pay for it
Finally, I am not playing some sort of peaceful beatnik, I come to Jay's forum because it's very technical and friendly, we had the BS on the old forum, and even worse on the very old FE forum on Network 54. I put our last argument behind us because it took away from that culture....I have no intention to fight, this one round was only to offer the sim and tell you what I am doing.
If you take it any other way, as Brent said, I am out of this topic too. I have three FE strokers to get finsihed and/or to the dyno in a couple weeks and no desire to prove anything to anyone other than the owners of the engines. (Ironically, the third engine, as crazy as it sounds, has the smallest port in CSA and volume, the smallest cam and lowest compression one will likely make the most power by a wide margin, I will hang them on the dyno section as they are done)
Your call, post it up here and I will run it on the more involved sim, if not, we can let it die
