Wildman_grafix

Easy of engineering packaging turbos over a SC? Controlling the heat on the turbo's and trying to deal with lag was a huge engineering task, that they succeeded with. Have you ever been in a engineering role for a production product?

Lots of things go into it, and a ton of engineering to make something reproduce-able time and time again. Doubt it was the easy way forward.

TeamSaris

The QC4V engines are nothing short of amazing. For what they cost, they should be. But they really, really are. Turbo lag is nonexistent and if you get the chance to really throttle one in some sporty water the waste gate sounds turn you into a human tripod pretty fast. Just epic.
Ill just throw my fairly educated 2 cents in here-
The 1075 platform was much easier (and cheaper) to work on. The 1075 still idled great and had great manners all around. Would they be able to make reliably1500+ with that platform? Not with the ease of operation the QC4V engines have.
We maintain quite a few boats with the QC4V platform from one of the first sets of production 1100s to a set of 1350 dual cals in a 42x. 9x of 10 the client has a flawless trouble free summer. But that 1 out of 10 chance something happens the odds of us or any other Merc Racing dealer being able to just "fix it" quickly are slim to none. We've bought all the Mercury special tools required for yearly maintenance (valve lash mostly). They weren't cheap. And changing all three impellors even in a full stagger boat is quite the feat.
I love the QC4V platform. I really do. Its Mercury flexing. It's the epitome of what's truly possible in a "production" engine.
I also love that it hasn't and I don't believe ever will really affect the custom engine market. Let's face it, even if cost was the same...they're DTS only, Dry Sump only, technically you aren't allowed to put mufflers on them, they're HUGE, require some decent yearly maintenance, are tough to work on, and when the **** does eventually hit the fan, crate it up and send it to Merc via your local racing dealer.
So for the guy re-powering his BBC boat, a set of 91 Octane 1100hp Whipple engines from me, Teague, Tyler, etc are going to be a lot painless and a lot less expensive. And these days, if your EFI blower motor doesn't idle as nice as the QC4V package, get a different builder. Because it should. And for what it's worth on our 1100s in the average poker run boat...valve job at 200-250 hours. Full rebuild around 400. Not that far off.

Skater30

You nailed it! The only thing I will add is that in my experience (not having owned a set of QC4V, but having several friends with them), all of the QC4V motors are underrated. From the acceleration and top speed numbers they produce in known setups, they seem to be around +100HP more than they're rated imo (368/1100s @ 170mph, 46/1350s @ 160+mph). And there's no motor on the market from any aftermarket builder that can equal the torque and power of the 1350 on 91 octane pump gas - at least not in my experience (my PSI/14-degree head/557 Sterlings needed 110+ to make 1350). No doubt it all comes at a price though (which is more than I can afford), as a friend of mine just last year pulled the 1350s out of his Skater 40 and sent them to Merc for their 100 hour rebuilds - his bill was $177k! So when you factor in the cost of $200k (include labor, shipping, etc) every 100 hours, it's costing you $2k per hour for all that performance - on top of the huge buy-in cost. Not cheap in my books, but also unequalled on gas you can pull up at any dock and fill up with.

TeamSaris

Id be willing to bet the way Whipple's blower technology is going that a pump gas 1300hp engine is within reach. We're making 1100 on 91 pretty conservatively. Finding HP once your over 1000 is a diminishing return but I think the technology is there. The days of 1000+ hp engines requiring 14* heads, race fuel, heck even to be solid roller are long gone.
We're making damn near 1000hp with a 509, relatively small heads and hyd roller valvetrain. And that's on my dyno which is incredibly depressing compared to most with the exception of Mercury engines.
Perhaps that's why you think they're underrated? It isn't Mercury, it's everybody else claiming their engines make more than they do...
We're sending a set of brand new 900s to a Mi to a client with a 36 Skater classic. I have no problem letting the boat be the real test of HP. We've had quite a few big name engines on our dyno that don't make anywhere near what they're claimed to. Mercury engines make exactly what they're supposed to.
Edit: I haven't had a QC4V engine on our dyno for obvious reasons.

boostbros

today most good builders can build equal or much more power and run it in multi mode for different fuel quality the reason is parts have gotten much stronger and eletronics have come a long way for control systems mercs locked computer can be replaced by motec or several others the 4 valve has advantages at certain rpm but at higher power levels it disappears steve morris and his smx engines are over 5000hp yet can be run on pump gas and driven on the street the engine with out boost makes over 950 hp that not a bad number its much more than the merc at 865 with out boost and the cost is way less.... shockingly so the rebuilds are reasonable too this has happened in the last few years

precisiondetails

Great thread with lots of real world info

and it’s not about OBs LOL

Skater30

Pete has told me on several occasions that his boats are a dyno. Back before Merc motors were in just about every Skater built, when his customers would tell him how fast they were going with so-and-so's motors, he'd tell them how much power they were really making. Part of what I base my 100HP under-rating on the current QC4V motors is that my 36 ran 163 w/ Merc 1075s that were originally in it, and QC4V 1100 motors in a 36 or 368 run 170. I use BAM's boat speed calculator all the time with incredible accuracy, and the jump from 163 to 170 is way closer to a hundred HP gain aside, not 25. Also, when my buddy Rick Bowling repowered his 37 Talon with Merc 1350s from his Brummet 1500s, he didn't lose many mph - and everybody knows Carson Brummet motors are legit. I'm not trying to be a Merc QC4V fanboy, because I don't even own a set (and likely never will), but I definitely will say that every boat I've ever been in with a set runs incredibly for the stated power. From the speeds I see with my 36, I'm guessing your customer with the 36 classic should be right at the 150 mark with your 900s in it.

Skater30

Automotive engines can't even be discussed in the same conversation as offshore boat engines. Put any of those car engines in a big boat and they wouldn't work (most would probably not even get the boat on plane, or blow-up trying). Pete has plenty stories about those exact scenarios happening several times through the years. Most recently, I think the best example are the Goodwin motors that were supposed to set the offshore world on fire. I don't think there's a boat left with a set in it, they've probably all been rerigged with different power by now.

Jpzaluski

and just to think, I came on here simply looking for a spare motor lol

jeff32

great read for sure !