On Monday 15 January 2007 08:05 am, msnbcnnbcbs@hotmail.com wrote:
> I've been discussing my options with my 1999 3.9L Auto V6 R.C., and a
> close friend of mine who has done some engine rebuilds as a hobby has
> thrown a lot of ideas at me. I'd really like to stay naturally aspirated.
Something you didn't mention: what are you goals for this rebuild? Are you
building for top end HP, or low end torque? For what kind of driving (around
town? highway? track? off road?)? Max horsepower is only an interesting
number if you know what RPM that's being achieved at.
> 1. Rebuild the V6 either inside the truck or grab a junked one and build it
> from scratch. this would include a set of original heads ported/polished,
> new cam, the standard bolt ons (elec fan, headers, new exhaust, modded
> intake manifold, new injectors, throttle body, intake) and a new
> valvetrain.
Lotta work, but if you're going with mostly stock or close to stock specs,
you'll probably end up with close to stock performance.
Can the truck be un-drivable while you're working on it, or do you have to
minimize the down time? If your original parts are in good condition, and
you can live with the down time, I'd pull the engine and rebuild it out of
the truck. That minimizes your costs, since you're not buying a junk core to
start with. Plus, and this may be just a personal quirk, but I prefer to keep
parts that I know the history of. If you've put enough miles on this truck to
be considering an engine rebuild, presumably you know the history of this
particular engine. That, to me, is better than a junkyard block you know
nothing about.
Alternately, could you buy a cheap car to drive while the truck's being worked
on? Get something old but reasonably reliable for under $1000. It won't gain
or lose any value while you're working on the truck, then just sell it at the
end and get your $1000 back. I recently sold a '91 Sable that ran great and
had no problems for $500, for example. Something like that would be an ideal
driver while doing an engine rebuild, and selling it for the same $500 a year
later would be easy.
> My calculations working on the engine inside the truck would be 2700-3200$
> (rebuilding an old engine $3200+). According to him with this option, "I'm
> wont be very happy". I'm guessing its going to be 250-280 h.p. at the
> flywheel going this route? And 300+hp just isnt possible without a terrible
> idle? (or forced induction?)
Seems to me that you should be able to make some basic old-school kinda
modifications. Can you over-bore your block (original or donor) with some new
pistons to increase the cylinder volume? Stroke it? Use lighter weight bottom
end parts to increase the ability of the engine to spin up faster?
Have you talked to the aftermarket intake and cam companies? If you know what
targets for rpm, HP, and torque you're trying to hit, they may be able to
suggest a build that will get you there. You shouldn't have to build it with
a cam so wild that you get crap drivability or idle. Even if you don't know
exactly what numbers you're trying to hit, if you know generally what it is
that you want to do with it, they should be able to offer advice on how you
can get there.
Can you make 300 HP? Yes, but without specifying what RPM you want to make it
at, that answer doesn't mean much.
With the right rebuild, forced induction of some sort (NOS, turbo, blower) may
also be something to look in to. There's a lot of power available there, but
you're adding cost and complexity as well. If the bottom end can take the
additional power, though, a mild forced induction setup shouldn't be counted
out.
> 2. 360 short block kit, possibly from summitracing.
A V8 is always tempting, but adds complexity, cost and weight as well as
torque and horsepower. If you can make the same, or almost the same torque
and horsepower out of a lighter V6, you gain more seat-of-the-pants power.
> 3. Same as #2, but used the one set up for carbbed applications.
At this point, I'd probably go for an aftermarket stand-alone EFI setup before
I'd go for a carb. Unless you're good at dialing in a carb, you're probably
wasting power on a suboptimal setup.
> I know some folks have done this in the past, and was hoping for some of
> that 20/20 hindsight :) As for what I'm looking for, I'd really like for
> this to be worthwhile, I dont really have a target h.p. or E/T.
Research is cheap. Do lots of it, decide what your targets or goals are, then
start figuring out what you can do to hit those goals within your budget.
Don't start wrenching without goals, or you're likely to spend a bunch of
money and not be happy with the results.
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