Best way to make 600 hp?
 

It's 18 degrees out and I have no boat, the tax man looks to be pulling stuff out of my wallet instead of putting in, and I've eaten half a box of peanut butter pattie Girl Scout cookies, so here is a hypothetical question.

Assuming you have a pair of tired 454 Mags, the 420 hp version from back in the late 80's early 90's, what would you do to get a reliable 550-600hp, on a reasonable budget?

Just interested in how different folks would approach this - N/A, small blower, crate 502's, what? And what do you think the budget would be? I realize you could write Sterling a check for a gazillion dollars and get some new motors, I'm interested in something less drastic.

Again, hypothetical but it gives us something to talk about while we're waiting for the popcorn to finish popping on the Chief thread! :D

Re: Best way to make 600 hp?
 

KAAMA's got a pretty hot set of cams for sale that should get you close. :D

Re: Best way to make 600 hp?
 

I would go with a set of Scat nodular steel cranks, 4.250" stroke, set of 6.385" I-beams, and SRP pistons. Balanced you can get these kits for around $1700 each. Bored .060" you would have 496CID.

You have the 990 heads, so I would have them bowl blended and matched to a set Victor Jr. takes. Intakes will run you about $250 each. Port work should be around $1000 including valve job.

Go with hyd roller cam and lifters. Around $850 per engine

So for around $3500 to $3800 per engine you could have "500" inch mills in capable of a reliable 550HP.

Chris

Re: Best way to make 600 hp?
 

If you had 502's I would put a set of aluminum heads, Intake and bigger Cam but with the 454 I would go with the small blower to make the power.

Re: Best way to make 600 hp?
 

Yep, what he said!

Re: Best way to make 600 hp?
 

What if you had a 496 H.O. ?? Besides raylar's 7,000 dollar kit ??

Re: Best way to make 600 hp?
 

Don't you mean 320 hp? :D

Re: Best way to make 600 hp?
 

ET, as I understand it Merc made 3 big block motors back in the day - I assumed all were 454's.

1. 330 hp
2. 365 hp
3. 420 hp

Is this incorrect? I've seen a large number of boats, from Formulas to Cigs, advertised with the 420hp / TRS package.

Re: Best way to make 600 hp?
 

What I did was trade in my 454's to my engine builder, then I had him build me 2 Dart Big M 540's. They should be 575-600 reliable horsepower. At a low low price of 9,000+exhaust each.

Re: Best way to make 600 hp?
 

Docker- The 420 hp version had a steel forged crank, good rods, etc. It would be a shame to mess with those but trying to get 600 hp out of 454 inches means a solid lifter cam or as Tyler says a small blower.

Realistically for 600 hp in a NA engine you need 500+ cubes without going to radical. That means a stroker kit with new crank, rods etc. which you can price and have an engine shop do for you.

Looking at an older Formula w/ 420'?

Wannabe

Re: Best way to make 600 hp?
 

wannabe, that's what sparked this thread. Lots of old 311's that can be purchased - realistically - in the 30's. Trying to see if it makes sense to do some upgrades and end up with $40-50K into it. Sounds like you'd be better off with a lower hp 454 and just yanking them out when the time comes. That would also put you in a Bravo boat after '89 or so; I think the 420's only came with TRS drives, which really limits you to Konrads for an upgrade. And I can't see putting $15K-20K in drives on a $35K hull, *plus* power.

Re: Best way to make 600 hp?
 

dock , the 420 was a LS6 motor.jc performance is building a hot one for stormrider.

http://www.offshoreonly.com/forums/s...ad.php?t=95743

Re: Best way to make 600 hp?
 

cstraub has a combination similar to what I was thinking but if you're on a budget I'd be inclined to use the 454 components rather than stretching to the 496.
The small blower setups will get you there too but I'm not a big fan of blowers. Yeah, I know my boat has them. Only because they were on it when I bought it.
Message me or email me for details.
Maybe you can rent KAAMA's ship. It ain't seen water in a while.

Re: Best way to make 600 hp?
 

Damn Dave, quit beating up on Mark first thing in the morning! :D As long as he's not going for the "Too Old Memorial Trailer Queen" trophy, he's OK in my book. ;)

Re: Best way to make 600 hp?
 

I would start with GM's new 572, to make big horse you will want big cub's. My last boat had 600ci and they made 775's and were real dependable. Put 125 hours on them and never evn had to change the plugs. All Seasons Marine built them in Boulder city Nevada. But you gota have the drives to hold them, mine where 3A's. Steve

Re: Best way to make 600 hp?
 

I only new of the 454's (over different years)
as 300, 310, 330, 365 and 385.

I could definitely be wrong (and probably am) :D .

I know the 502 to be 415hp. ????

Re: Best way to make 600 hp?
 

EvilTwin
Add to the 454 cid the 340 inboard, 370, Cyclone series 400, 420, & 425. And the roller cam 450.
Oh yeah turbo 475 and SC 525.
And probably a few more.
BTW, the only reson I know these is because I'm old and have had the 330, 370, 400, and 525SCs in my boats.
Gary

Re: Best way to make 600 hp?
 

This is a question I've wanted an answer to for a while, thanks for starting the thread. I have one difference, I have BowTie blocks I'd like to work with. As I understand it, they will accecpt a larger bore than the regular block. Might make it a little easier to get those HP#s. Anyone know about bore sizes with those blocks?

Re: Best way to make 600 hp?
 

My boat has the 454/420's. I think it was merc's standard hipo engine before the advent of the 500 hp. They hadn't developed the blue paint at that point.

Re: Best way to make 600 hp?
 

I have cnc ported iron heads and our own camshafts we also have our own forged pistons and we bush the stock rods. We put a new wiring harness on and a mefi 4 ecu so we can program it ourselves.

Re: Best way to make 600 hp?
 

I kind of figure 600 hp is a fairly reasonable number. Not mega-bucks and mega-maintenance, and Bravos stand half a chance living behind it. Unless I hit the lottery, I don't see me having much more than 600 hp anytime soon... :)

Re: Best way to make 600 hp?
 

Dockrocker, there were several Merc 454 packages offered over the years; 330, 365, 370, 400, 400 Cyclone, 420, and I've probably left out a couple. I'm not sure if the 440 was a 454-based engine. There was also a Bulldog way back when but I think it was a 540.
All but the 330 (310 in some ratings) had forged pistons , forged cranks, big rod bolts, four-bolt mains (MK IV), rectangle-port heads and aluminum intakes. Everything below the 420 had Quadrajet carbs.
If you're going to buy one of the older boats like the 311 you might consider limiting the horsepower to 500 or a bit more due to the transmission and TRS outdrive horsepower limitations. They seem to stand up quite well at 500 hp.

Re: Best way to make 600 hp?
 

The 440 was a 454 but did'nt really perform well compared to the 420. The cam was a little big and it gave up some torque. The 400 cyclone and 420 or 425's were very similar except for thr exhaust (400 Cyclones had the cast iron).

Re: Best way to make 600 hp?
 

SOOOOOOO Back to the orig question and away from the Merc history.
I have a couple of spare 454 mags,carbed and would like to know how to get to 550HP or so without reversion with Revolution Marine(Gil copies)exhaust. Can this be done with stock heads by just raising the compression to 9.5 and putting a cam of say 228/238,, 550 lift ,, the good bottom end should take 5800RPM for as long as you want to buy gas. How much more would it help to use a solid lift cam? I'm talking flat tappet here as I don't want to pay for the conversion I'd rather invest in a big cube roller block to begin with than do that.What about 1.8 rockers? Seems like a great way to cheat the cam into thinking it's a roller. How much does a hyd hurt? Should I start another thread for this part? Thanks

Re: Best way to make 600 hp?
 

Docker:

Posting to this thread, to refresh some older 454's w/o going to crazy should be about $2500 apiece and get you realistically 525-550 HP. This is very doable and will work w/o taxing the TRS drives and get you 3-5 mph. You really will need to do this anyway cause your daughter will push the throttles to the stops if she's a chip off the old block. :eek:

Wannabe

Re: Best way to make 600 hp?
 

the Blower Ideal is more expensive but you can save the carbs and intake and put them back on if you sell the boat in the future, and put the blowers on the new boat.