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Guys and gals I got some questions that I was wondering about when it comes to building an engine. I would like to build a 3.7 with the goal of about 300 crank horsepower. I would like to know if anyone has ever taken the 3.7 apart to analyze the bottom end and determined how much horsepower the stock bottom end can reliably handle? My next question is on stand alone PCM's is there anyone that has experimented with one and if so how much does a system cost? My goal is that I would like my truck to have better power in the 2 and 3 gears. Also what is the feasibility of attaching the 545 transmission to the 3.7? Because I know that a great transmission can make a weak motor get the job done such as the new Ford Ranger 5 speed auto. Also on a side note how long do the new composite intakes usually last? Thanks all the input.
 

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Adding 90 HP to stock, that's a hell of an undertaking, but I'm all for it... :rck:

I'd love to drive a Dak with something like the Nissan VQ37VHR engine, which puts out 330 HP and 270 FT-LB. It's going to be tough though, with the old valve technology the Chrysler 3.7's have. All those ballsy Japanese V6's have variable valve timing, which really seems to be the way to go when you want to boost the HP per cubic inch. Nissan really seems to have it down; they even make a turbo 2.5 that puts out 300 ft-lb at 3200 ; that's better suited to a truck than our 3.7!

I've also read that forced induction with the 3.7 and 4.7 is risky business because of the short distance between the top of the piston and the first piston ring.

But good luck...I'm sure you'll learn alot about the motor whether you hit 300 HP or not.
 

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Im not sure but maybe a good exhaust, headers, a fastman throttle body, and some nice cams could get you as close as you can get with good reliability. Im not a fan of CAIs but maybe some full synthetic might also help.
 

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I forgot about cams, although you might have to enlist the help of an experienced motorhead / machinist and be prepared for some experimentation; I don't think I've seen cams for the 3.7, but I could easily be wrong.

I don't see anything wrong with CAI's myself. People hem and haw about whether they cost you torque or whatever, but any good thermodynamics student will tell you that if you reduce the pumping losses of any engine, net HP goes up.

Again, assuming you have the means to do anything you want, you could probably gain some compression by shaving down the block.

And of course, I'm sure you could get some pretty respectable gains by tuning the ECU/PCM.

As JM2007QC noted, you want the power with good reliability; thats where some good forged pistons would be $$$ for a forced induction setup.

If I had to guess at what could be accomplished without 12 months of daily R&D with a full machine shop (which would be totally awesome), I'd say 250 HP max. That would still be a mean beast.
 

· Biggerhammer
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as a machinist you will find some problems inherent in decking the block, the timing set and valve to piston clearances will all change, which means the valve timing will change also. your best bet will be to contact Crane or Comp. and talk to them, they are actually pretty reasonable on custom grinds but you MUST have a specific goal in mind when you talk to them, I, for one, would love to get my hands on a 3.7 to tweak.
 
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