30ft motion twin 400r

**AZMIDLYF** · 12-03-2015, 10:59 AM

Originally Posted by Brad Zastrow

Real boost put to them??? I believe they are at 20+ pounds now according to Merc tech I spoke with. That is an insane amount of boost to run on pump gas with out detonating. The 400R engine is making more horsepower per liter than just about any production car in world. It is a 2.6L, 2600cc or 158 cubic inch engine making 400 HP. That like a 350 Chev engine making 872 hp on pump gas and have a warranty. I do not think there is lot left to be had out of that 2.6L engine and have a warranty and run on 93 octane.

Wow, I was curious as to where the boost level was on these.

**scawd the dog** · 12-03-2015, 11:31 AM

Originally Posted by Brad Zastrow

Real boost put to them??? I believe they are at 20+ pounds now according to Merc tech I spoke with. That is an insane amount of boost to run on pump gas with out detonating. The 400R engine is making more horsepower per liter than just about any production car in world. It is a 2.6L, 2600cc or 158 cubic inch engine making 400 HP. That like a 350 Chev engine making 872 hp on pump gas and have a warranty. I do not think there is lot left to be had out of that 2.6L engine and have a warranty and run on 93 octane.

Brad:

We saw 30-32 lbs of boost on the lap top on the water testing.

**Instigator** · 12-03-2015, 11:52 AM

Originally Posted by scawd the dog

Brad:

We saw 30-32 lbs of boost on the lap top on the water testing.

Wow!

i have to say that when Merc finally released the Verado I was shocked it was only 2.6 L.

**AZMIDLYF** · 12-03-2015, 01:45 PM

Originally Posted by scawd the dog

Brad:

We saw 30-32 lbs of boost on the lap top on the water testing.

400hp at those boost levels...

**Flightplan** · 12-03-2015, 03:11 PM

Anyone know a formula to determine the naturally aspirated power from these boost numbers using a 400 hp basis. I know how to add boost to NA power, not how to reverse it.

if I were to just guess, I would say NA power of this little 2.6 liter would be around 125 hp and the rest is boost. Lordy. I had no idea they could run that kind of boost on pump gas.

In general (boost+14.7) / 14.7 X N/A power. This equation is ideal so raised charge air temps take away from this and a restrictive exhaust can take a lot away from this.

**AZMIDLYF** · 12-03-2015, 06:04 PM

The 30-32 psi is what is alarming.

I also think 125 hp N/A estimate seems low. Hell, the 4 cyl N/A weezer in my daily makes 158 hp.

**mjwalters** · 12-03-2015, 06:13 PM

Interesting the negativity in this thread. Are these the same guys who begged mercury 4 years to produce a 400 horse engine? And as we all know mercury is still the only game in town for performance motors. I don't think this motor has been out long enough to form an opinion

**mjwalters** · 12-03-2015, 07:29 PM

I know this motor is a heavyweight but the fact of the matter is good light-weight two stroke motors are gone. I really don't see how they can remove much weight from this package. I believe the boat builders will just have to adjust

**Mr. Demeanor** · 12-03-2015, 09:40 PM

Cmon guys, this motor isnt for us. Its for big boats.
Our little niche isnt worth considering for any manufacturer.

**powerabout** · 12-04-2015, 05:52 AM

Look what omc v8's were designed for
To make big heavy boats go fast.

**AZMIDLYF** · 12-04-2015, 10:14 AM

How much does the Xcat version weigh?

**Rock_River_Marina** · 12-04-2015, 10:24 AM

Originally Posted by Mr. Demeanor

Cmon guys, this motor isnt for us. Its for big boats.
Our little niche isn't worth considering for any manufacturer.

Yup...

**Brad Zastrow** · 12-05-2015, 10:11 AM

If the 400R is running 32 pounds of boost that is very impressive engineering. The most boost you can run on a standard 502 big block is 5 pounds without intercooling on pump gas. 8-10 pounds is safe with the good aluminum heads with intercooler. I used to run race gas at 12 pounds on a 598 with 16:71 blower.

**Instigator** · 12-05-2015, 11:01 AM

Originally Posted by Brad Zastrow

If the 400R is running 32 pounds of boost that is very impressive engineering.

Absolutely agreed and was going to post similar. From what I see/read, a highly loaded, recreational/automotive application is typically limited to 5 - 7 lbs.

32 on pump gas is unheard of in my world.