drives mopars wrote on 11-29-2001 09:53 PM:
i need to make decision friday
i have pw's in now banks 14cm
30# boost about 250 hp mustang dyno rear tires
is a rebuilt one from vally diesel in sacramento
any good or do you know
whats best for timing ? if 1. 45 what happens
if 1. 7 what happens
will top end power drop ?
bill drives mopars 93 4x4 dually
The only reason to go with a "marine" might be that it runs faster.
with a 14 housing, you very well could run up to 27-2900 and not have exhaust problems.
But, I would think that they could add a few hundred RPM to a regular pump without much trouble. That alone isn't worth 500 bucks. No way, no how. Changing the governor spring and testing it is only a 3 hour job. 200 bucks at most... and only the price of the governor and/or spring when you're rebuilding it anyway.
I have not been privy to how trucks run at 1. 7, but unless you're expecting to crank a lot more RPM's I would not start there. i'd start at 1. 35-1. 45, mark it carefully, and bump it ahead, after i'd established the baseline performance.
Here's what i would ask the seller: does the marine pump have any durability enhancements? If there are, are they really worth that money? If no, then I would ask, does it have better torque or timing curves you can't get iwth an automotive pump? If no, there's no way under the sun I would buy it. It could conceivably have a different face cam or hydraulic head, but again, there's not a whole lot of benefit to be had from rare parts... especially if you ever need to fix them.
Just because it runs faster, or the fuel screw is cranked up more, is no reason to have to pay a pile more money. That could be done to a regular pump for a small charge. It could be done for minimal on a regular rebuild of your own pump.
Frankly, when I got the bosch book out and the cummins book ,and started doing cross-references, i found the highest output NON marine (never had a book with a marine CPL or pump number in it. I don't know how they find them), the highest fuel settings were the auto pumps. Even the industrial engine pumps had lower fuel settings, meaning the horsepower was REALLY in the injectors, not the pump having more fuel.
Now, I don't know if I have cleared or muddied the waters, but to be simplistic about it, unless there's some reason, aside from a twist on the fuel screw, that's worth a lot - some exotic parts inside, there simply is no way i'd tell you to spend an extra $500. That's a lot of money to me, and I'm pretty sure it's not throw away money for you, either... You're just not going to get much for it, would be my best call.
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