It sounds like you guys are describing my race engine. Here are the details:434 ci FE, Shelby 4.375" bore aluminum block, Scat 3.600" ultralight billet crank, MGP 6.800" BBC aluminum rods, JE 15.8 to 1 pistons, .875" lift solid roller cam, Jesel lifters, Smith Bros tapered pushrods, T&D 1.8 rockers, Dove raised port MR heads w/ raised exhaust port (380 in / 295 ex) and 56 cc chambers, Danny Bee belt drive, carbon fiber tunnelram intake, two DaVinci HP 1000 annular booster 3 circuit carbs, belt drive distributor, Peterson two stage external
oil pump, Moroso 4 vane vacuum pump. It makes around 875 HP naturally aspirated at sea level. In my 3150 lb '66 Fairlane we launch at 7500, shift it at 9500 and it has gone 8.97 @ 151 mph at 1300 ft corrected altitude. You can check out some pictures at
www.oceanstateperformance.com and click on the "customers" link. You can also see a couple of pic's on "my CC photo gallery". BTW, the engine is for sale if anyone's interested. Take out some cam & valve spring, mill the dome off the pistons, and maybe put a single plane single 4 intake on (or leave the carbon fiber) and it would be one hell of a Cobra engine.
As for some of the other questions I can shed some light from personal experience.
1) The first crank that I used in this engine was a reworked 361 (3.500" stroke) piece that saw 9500 rpm with not problems. I changed it to save wieght ( 56 lbs billet vs. 64 lbs steel). I have 2 of these steel cranks for sale as well . One 3.600" w/ BBC rod journals and one 3.500" w/ SBC rod journals.
2) A rod longer than 6.850" in these engines seems to make them very peaky. Probably has to do with the dwell time at TDC. The hot set up that I'd like to try is a short deck block with a shorter rod, shorter compression hieght piston, and narrower intake manifold with a straighter intake valve shot. I had some promises from Genesis for a thick deck block that I could mill down but it never happened.
3) I would highly recommend the T&D rocker system over the Jesel in any application with big RPM and spring pressure. The T&D base plate setup picking up off the 5 head bolts is far superior to the Jesel bolting to the 4 stock rocker stand locations. The only down side to the T&D's is the required milling of the heads but IMO any engine at this level won't be going back to stock rockers again anyways so it's a non issue.
4) Valve springs are a big maintenance item in an engine like this. The best I've found so far are from PSI and we get 15 passes on a set. They setup at 380 lbs seat pressure and are used up at 300. I've tried Manley "Nextech" (2-3 passes before we'd be changing 1 or 2 per pass), Erson same as Manleys, Comp's 6-8 passes.
5) The tunnel port head will flow big CFM on the intake side but we can make more power with a raised MR type port with similar CFM and much better air speed.
So that's my .02 cents on the subject. Someone give me a call and take this engine off my hands so I can start the next project. You'd definately be the man with the meanest engine compartment at any event you went to!!
Thanks CC,
Pat Burke