quote:
Originally posted by jack deryke:
I've been reminded that DeTomaso put non-stock parts into some of the later engines, so all bets are off re your present cam. I always recommend calling the cam grinders Help Line and getting advice from the people who make them for a living, when shopping for a cam. But in my opinion, the cylinder heads you have will dictate much of what parts you can profitably use. For instance, you will probably not have dished pistons, even with closed chamber cylinder heads, nor should you use them.With iron closed-chamber heads, you can get away with 10:1 compression ratio as long as you run a cam more-or-less as you mentioned. Such a cam will bleed off cylinder pressure at low engine speeds, and at high engine speeds cylinder filling is less efficient so pressures never go up to the detonation-point. The engine doesn't care what the ratio is, only the physical pressures. Just be sure to use matching valve springs and discard any multi-groove valves, as they will be stock welded units that will fail with extended hi-rpm use. With open chamber heads, you have a less efficient chamber and 9:1 is about all that can be used. This last will probably call for DOMED, not dished, pistons. As far as oiling mods, a completely stock oil pump works fine, and remember there are two different kinds of oil restrictors in the kit- those that go into the cam lube passages and the single one that restricts the left-side lifters. By all means use the 4 that restrict oil flow to the cam but discard the one to the lifters & you'll be fine.You should end up with 25-30 psi at idle & 60-705 psi at 3000rpm, with the engine hot. The stock gauge reads about 1/2 of reality, BTW.Your 800 CFM Holley is meant for extreme top-end running or drag racing. I recommend a 600 or 700 CFM, dyno-tuned to the engine. This makes the engine more responsive & fun to drive at low speeds while only giving away a few horses at the upper end, and gas mileage is also more reasonable. I got 20 mpg with my 700 on a recent 900-mile trip.
Thanks Jack
I think the best thing to do before buying any parts is to wait untill i pull the engine out and see what's in it, i do have a 650 dp which i will tray soon,
Thanks again