Originally Posted by Young Performance

Thanks Patrick. We are getting close on the engine. Should be on the dyno next week. I'll keep you posted on the progress. As for meeting you late at night, that's not a problem.We do whatever we can to make it happen.
Talk soon.
Eddie

Originally Posted by Young Performance

You would really be limited without doing a port work to the heads. They aren't great in the first place. You also wouldn't be able to do much with the camshaft since it is on the verge of reverting now. If you went dry on the exhaust, you could put a little more in the cam to help crutch the heads some. Not the most ideal thing. I would expect around 600-615 hp.
Eddie

Originally Posted by Young Performance

I'm not exactly sure what power it would take to make that boat run 110-115 mph, so my answer may be kind of generic. There are a few choices depending on exact power, fuel availability, etc. Let's say that you want 650 hp, with the ability to make more in the future. My choice would be to build a larger ci engine with a fairly mild compression ratio. We could do a 547 or 555 ci engine that could run on 89 octane. It would be a very mild, very tame engine. With the lower compression, there would be no issue adding a SC later on. Obviously, you would need to run a higher octane. The other option is to build something even larger, like a 598. You could run it on the cheapest, crappiest gas you could find and still make over 650 hp. Again, adding a SC in the future would just be a matter of bolting it on. You build both with top shelf parts to handle the SC, so in NA form, they are ridiculously over built. You would never have to worry about breaking a connecting rod, crankshaft, etc. It would have MUCH better parts than a 525, be hand assembled by me (or whoever built it), be tuned perfectly for your particular boat (not just generically for everyone), and look much better that a 525, for a very similar price as a new 525. Even though it was built by me (or whoever), it's still a matter of off the shelf parts (for the most part). If anything were to happen, it doesn't have to go back to the builder. It's still a BBC at the end of the day. That's another reason I use a MEFI ecm. Anyone with a Merc scan tool can diagnose a potential problem as if it were a 500 efi. It would use all of the same sensors as a 500 EFI that can be had from any Autozone,GM dealer, O'Reillys, etc. It doesn't matter that it is a larger engine with a different calibration than a 500 EFI. That has nothing to do with how it works. It's still an engine.

My point is that you have choices. A ton of people are scared to death by custom built engines. Them, or their buddy, has probably either had a bad experience or know someone that has had one with a custom engine. It may have been the choice of builder, or any other of 100 different reasons that it failed. Unfortunately, most don't know their choice of builder is the wrong one until it's to late. I agree that custom engines are certainly not for everyone. That's why Mercury will stay in business.
Eddie

Originally Posted by Young Performance

Obviously, I wasn't in there when it happened, but the best I can tell, a rod bolt failed. Neither of the bolts backed out, since the pieces of bolts with the threads are still in place. Looking at the rod cap, it appears that one of the bolts failed. Once that happen, all hell broke loose. You can see that the rod cap looks like it was peeled off the rod. That would indicate that one bolt broke and the cap could no longer stay in place. Why the bolt failed.....I don't know. It's an ARP 2000 bolt, which is a pretty damn good bolt. Certainly not the best bolt out there, but more than enough for a 525.

Merc does have a TSB on the rod torque. There is a change in torque value for the rods. I think it is only due to the fact that the lube they originally used on the bolts is no longer available. That's why we use bolt stretch. It takes the torque, type of lube, accuracy of torque wrench, etc. all out of the equation. It the only way to go as far as i'm concerned.
Eddie