NKissau

Looking for options to upgrade the power in my boat. I am happy with the boat as it has fresh paint, interior, trailer, etc... Just looking for more power. My goal is to have a cruise speed in the mid 60's while running around 35-3800RPM. I don't like to run my stuff hard, but more and more on these organized fun runs/poker runs it seems that you have to be able to cruise at these speeds if not faster just to stay in the pack. I know my same boat runs roughly 85 with 575hp. I already have XR drives, so for now those should do the job. My question is, do I just pull my perfectly good 502's and have someone build them, or do I try to sell them and put the money toward a set of new motors? I can pull the motors and re-install, but I'm not looking to do the actual build myself. Budget for this is 20k. I can probably get 10-12k out of my motors. I know prochargers would be roughly 20k, but how much do they hurt reliability? We do some long trips and I don't want to be worried every time we venture hours from shore. What else is out there? What have you guys done? Has anyone traded their motors in to one of the company's in the classifieds? Some of those deals look too good to be true.

1MOSES1

I'll let the more experienced guys answer then engine question...but if reliability is paramount and you plan on increasing horsepower the next weakest link are the xr's even if you are able to find nice relaible power.

NKissau

I'm assuming I'll end up somewhere in the 550-600hp range. I think the XR's can handle that, the boat gets on plane easily and I don't beat on it. But I agree at some point, the drives will probably need attention.

F-2 Speedy

I would build the 502's great platform to build 509's or 540's............509's would be cheaper, reuse the rotating assembly and buy new pistons, are your 502's mpi or carb........good set of aluminum heads and cam change...........remap the mefi if FI, 10K a side might be a little low, just depends on what you want

BBCLiberator

You can get that power very easy out of 502's -- Call Bob Madera, he can set you up with the correct cam/combination/valve-train, hell 550 with the stock heads is pretty easy if you have the right manifolds, that would be the biggest expense. My budget 502 made 539 horsepower through wet manifolds -- SM manifolds with short risers. Had I had longer risers, or dry he could have been more aggressive on the duration. But like I said this was done on a pretty subtle budget than compared to most around this site.

I had a local engine builder do the build/assembly at a hole-in-the-wall shop downtown Detroit, one of the best kept secrets around. You would never even know it is there, referral business only. He picked the engines up complete carb to pan, and returned it the same way. Mine was a Gen V so it involved a complete roller conversion etc.

NKissau

They are 502 MAG MPI completely stock. I'm not at all against using my blocks. But I know the horror stories about getting motors rebuilt. I don't want to fight with an engine shop for a year, when I can just swap them out and go boating.

jbraun2828

Sell yours and buy a set of 525's, should be close to your budget.

NKissau

That's the way I am leaning. I just don't think it's quite enough for what I'm trying to achieve. I like the idea of the cobra 570's but their reputation scares me.

SB

If you have to sell your current power, I would install the new to you power and use them a bunch before you sell yours.....and then when you are totally convinced your new to you power is good....then....decide to keep or sell your original power.

F-2 Speedy

your 20K budget is not going to get you a pair of 525's complete drop in......... look in the classifieds, their about 18K a piece and then figure exhaust on top of that, Id be surprised if someone would give more than about 7-8K for your complete running 502's even less if their high hours, Im not hatin just reality...