Bottom end info?

[Captainkirk]

Thanks for the info.....that's the kind of stuff I'm looking for. Actually the lift/duration on the Crane is not far-off from what I was running. As for fuel, I was planning on mixing unleaded premium with 100LL Avgas at about a 15:1 ratio (FYI, 100LL has about 4X the amount of TEL as 80/87 Avgas....it was deemed Low Lead after WWII in comparison to the 115/130 Avgas used in the fighter aircraft which had a LOT more TEL in it to avoid detonation at altitude in supercharged engines). Let's just say I have my sources. Anyway, I appreciate your advice on the CR & the heads. I may have the J heads CCd a bit more tp bring down the true CR to 11:1 although I never had a detonation problem before (to my knowledge). I would hate to CC a set of X heads to match the pistons and ruin them for a stock 340 setup, if you know what I mean. It might be cheaper to have 2.02's installed in the J heads, if you think it would make much of a difference.
As for ignition, I was running the stock Mopar electronic ignition with a Mr. Gasket quick-advance kit & no vacuum advance.....it ran like a scalded dog! My machinist feels that this system is outdated and I should go with an MSD with programmable advance curve and rev limiter. I guess I have a lot of research yet to do on this.....the last time this motor ran was when Reagan was in office! (d'oh!)

 

[moper]

Well, As far as fule goes, I wont run Av Gas. I know a bunch of guys do, but I wont. I'll build for pump fuel well before I use race gas in a street car, and never run Av Gas. On the head issue...I'm strange I think. I dont care what I start with really, and I dont limit choices because of possible future use. I dont think you can go wrong building for what you want, and getting it. Dont sweat the future. If later you need them for something else, build for that situation when you reach it. The compression I'm talking about is not static. That's the one you want to watch. The cam is directly responsible for making the static ratio pump fuel friendly on not. So identical lobes can be either timed the way you need them (in terms of centerlines..so the closing point of the intake is early or later), or not. Go to KB-silvolite.com and play with the dynamic calculator changing only the cam timing. For ignitions, you need one that will do at minimum what you need it to. Mopar factory ones are decent, and with the right install and choice, you can run any street/bracket car with them. The multi spark and digital timing controls are better, as far as idle, low speed, emmissions and economy on a street car, but they may not any more power you can use. Why over build, unless the $$ is not an issue. I'll put my $45 ignition up against most MSD type ignitions on a typical street car any time. No need for billet and multispark, unless you need it, or need the easy adjustability it can give.