Time for a rebuild. Which way to go NA or Supercharged?
 

Motor is currently a 540 Merlin block with a 2.3 Whipple. Supposedly made 775 hp on the dyno, but I don't believe it.

Motor has been great for 140 hrs but had an incident where the threaded rod holding the flame arrester on came loose and fell into the blower locking everything up @ 4500 rpm. After replacing the blower, the motor is now using alot of oil, 3 qts per 100 gal fuel. Compression test showed numbers from 105 to 150. Leak down points to rings and valves. Pistons are covered in soot.

Now I am rethinking my set up. I love the "feel" of my current set up. Very responsive, strong pull and exceleration. At 4000 rpm I am at 60 mph, 4500 rpm I am at 70 with 0 boost. I am talking to a builder who prefers NA motors. I like my current cruise #s and wondering if a NA motor will give me the same.

Looking for reliability and a few hundred hrs before rebuild.

Any input is appreciated.

Not an expert by any stretch but my research says SUPERCHARGE .

I am also not an expert but I would talk with some other builders. I LOVE my Prochargers. Zero problems. Yes N/A engines are cool and I think with the right builder you will have a sweet setup. But I also think you will have just as good or better setup with a EFI, chilled, blower setup!

Good luck!

stay with the supercharger and rebuild the engine,you already have the hardware.if your builder does not like it,maybe its time to look at another builder.:party-smiley-004:

Mike, i have never used this builder. I know him and trust him to do what he says he will do. Too many dishonest bull****ters out there. I need to figure out the best way to go.

performance marine did a very nice job on my friends 540 whippled pantera 28. they are in lake george not that far from you. food for thought

Kendall, my boss was always a hardcore supercharger guy until he built 10.600 632ci carbed na's. Said he would never go back to s/c again. Zero problems for quite a few years and was beyond his expectations in terms of performance and fuel milage.

stay with the supercharger, if you pull it off it will feel like your draggin a achor,

fixx
 

have eddie younge refresh it if you want it to last...also lower boost with a bigger blower will make it last longer betwen rebuilds..

The cheapest way would be to rebuild what you have. You would also know what to expect.
Going n/a and maintaining current hp levels would take a lot of change, and$$$$.
Just my .02

I concur, stay with what you have, you're not using much boost until you really lay on the sticks, then there's that little extra bump in power that will keep that grin on your face.

Stick with the blower!

Hi Kendall hows it going.
Without the boost it would probably last longer.

Do what I did for a friend of mine...I built an engine that would be a good runner and strong on its own...then added a Whipple at only 4 lbs of boost which adds almost no stress to the motor and makes over 800 hp and close to 900 ft lbs. And it is fuel injected and is turn key.

I

You make me feel better about wanting to keep mine at 3.5 psi.. must resist peer pressure to swap pulley:evilb:

Turboz:D

You avitar is hot!

What's up Johnny!!

12 to 14lbs feels good to me

good lookin boat in avitar post some pics and let us know what u decide. Jaime

Doing okay, been a real tough year though. How about you brutha???

I'm not sure of your setup, but 775 hp is possible. The problem is that you have to be spinning that poor little blower for all it's worth. I won't usually do a 2.3 on anything over 509-516 ci. We just recently did a 509 with a side mount 2.3. It was a built engine, alum. heads, etc. and made over 800 hp with the 2.3. The problem was that I had to spin the blower 300% overdrive. At 5500 rpm crank speed, that's 16,500 of blower speed. It barely made 5 psi of boost. We were already past the efficiency of the blower, so I didn't dare spin it any harder. A 3.3 on the same engine would have made over 900 hp.

Even if you were only making 750 hp, you would need one hell of a healthy NA 540 to make that power. However, you will never match the torque. As for longevity, the NA engine will not live as long as a tame sc engine at that power level. You will be severly disappointed if you remove the sc, if the current engine is making anywhere near that power. You already have an sc engine, why get rid of it. I would look into a little larger blower. I'm not saying that just for additional power, but it will be able to make the same power easier than the smaller blower. Let me know if I can help answer any questions.
Eddie

Whipple 509 E.F.I. is the way to go for sure. You will not be disappointed period. Great fuel economy and nice power with lots of torque and a low PSI setting. My builder built me a great package with zero problems and 750+ hp on a very light tune.

I 100% completely agree with Eddie.

People assume because its ''naturally aspirated" its gonna last longer. In order to make lets say 750HP out of a 540, it will hardly be a long lifed mild mannered engine. Its gonna take a lot of compression, a lot of camshaft, and a lot of RPM to do it.

Now, with a blower, to make 750HP out of a 540ci, you can use the right blower, low boost, mild hydraulic camshaft, and easily make that power, and at a reasonable RPM level. It can be extremely user friendly around the docks, and no wake zones.

Also, the beauty of going with a larger compressor like Eddie says, you always have the option to take that low boost 750HP setup, and crank out some more power with a pulley swap if desired.

Are you having a heavy flow day? Have a cranberry juice and start loosening those pulleys champ. That's a 90mph paint job on your boat, not a 80mph one. :party-smiley-004:

Lmao! Now I got a paint job to live up to!?

Go blown or go home!!!!!! :signs069: HAPPY BOATING.

The motor I built is 540 CI, roller cam 9.5 to 1, 4 lbs boost on 93 octane EFI motor. Makes 800 HP at 5500 and close to 900 ft lbs at 3200. The torque is killer and man can you feel it :)

Pretty identical to mine except fuel delivery.


http://33outlaw.zenfolio.com/img/s2/...40782808-2.jpg


540ci Bow-Tie blocks, Dart heads w/ marine valves, BDS 871 blowers – only running 3 ½ lbs of boost, Nickerson 980 carbs,


EDIT: I`m at 8.4:1

I See Dead People
 

Very nice and real close to what i have in mind .

If you think that feels good, you should feel 16.5 :)

under 800 is relatively easy with na motor. had a 9.5-1 motor that would run on 87 that made 750 hp with stock 1050 holley. lasted 3 yrs and the last yr we got 6 races out of it.

it seems that alot of "marine engine builders" push blowers to make easy HP without having to put high end parts in the motor. i don't see the reason for blower unless trying to 900 to 1000 hp or more.

i'm not DISSING anyone here, just pointing out the fact that it can be done. just gotta do the research. there is always a trade off somewhere, i find it funny when someone says you can get x-amount more hp just by adding a blower vs na that would have to be built better ? doesn't that say something about the blower motor ??????

you can put lipstick on a PIG but its still just a pig...............

Curious, what cubic inch was this N/A 800HP mill that ran on 87 octane?? Any dyno sheet??

I guess mercury racing, sterling, chief, Teague, zul, young, and a bunch of others just been pushing blowers on their customers, because they are too stupid to know how to build a Naturally aspirated engine......pffft, what junk parts they use.....they must have been using iron peanut port heads, flat tappet cams, and cast cranks in their builds.

565 cu in

mild, apparently your a blower guy and not too educated on na motors or motors at all. look at the top few guys i hear most often - sterling (probably the best hands down), young, potter and chief. almost all of them offer an NA motor in the 750 hp range. so i don't understand your statement ????? they start with blower motors when you get above that.

i was trying to mildly point out that after the top few guys that are well known, there seems to be a large amount of builders doing stuff in the 700+++ hp range with blowers. why? i'm going out on a limb a nd saying that they can build a half-azz motor stick a blower on it and make good looking dyno wall clippings.

so in short i would rather have sterling or young 750 na motor vs a merc 700 sci. which motor you think has better parts ????

please educate yourself and do research.

LOL :D

I'm running Tall deck N/A engines that dyno'ed right at 800HP @5900. All of the best parts and a fantastic hydraulic roller setup that let's them idle about 650 rpm's around the dock in gear. They are 9.6 to 1, run 93 octane fuel and have 210 hours on them without having removed the valve covers. I'm curious to see how long they last as they aren't showing any signs of weakness.......yet :D

I will agree that the blower motors win the "cool factor" vs. N/A!

My point is 800hp from a 540ci on 87 octane would hardly be a user friendly long life low rpm marine engine and run on 87 octane??

just from my personal experience i've been pretty happy with my na motors. most of the guys i talk to start out with less expensive motors add a blower, start putting on bigger pulleys. end up with a wad of junk

maybe eddie could chime in hear about his NA motors and when its time to step up to a blower setup. plus explain the longevity between the too.

my opinion theres way too many variables between motor and parts used to how much you boat. then you have how hard you push the engines ect ect............

Agreed .....100% :)

I believe it all boils down to your personal parameters . Boat type , boating style , size of wallet and speed you desire to run will determine the necessary horsepower level . With longevity in mind i think right around 700 + - horsepower is where the lines start to blur as far as n/a vs s/c but your personal boating parameters will dictate which way to go .

87octane on a 9.5;1 motor? wtf?

I think what TaterDave is trying to say is that builders will use crappy and cheap parts and then put a blower on to compensate.
ummmm ok :readinghelp:

Blowers provide reliable power at a discount, In an automotive application the conventional modifications cost about $58 per horsepower, the supercharger kit's horsepower cost under $34 per horsepower.

Which would you rather have I guess depends on preference, I`ll take mild cam, low compression, low boost 800hp blower motor over a high compression, wild cam, high rpm NA motor.
Blower motors TQ and HP numbers will be higher across ENTIRE RPM band not just peak at 6000rpms
Id say it depends on drive too with a Bravo I`d go NA, you don`t want that tq of the blower down low
:party-smiley-004: