Question for 7xchamp......
 

Hi,my name is Federico i'm an italian boy and Black Tornado(Marco another italian boy member of thi site)has sayed me that you have a great experience about engines! i would like to change my engines:2x330hp 7.4 v8 mercruiser that stay on magnum marine starfire 27.....and i would like put on about 420 hp for engine and take it around 450/470hp with the exhaust system!!!1
But i'm very uncertain for the choice of the model:new "496mag ho" or "old 502" or other else ,could you give me some advice?Remember that i love the rumbling!!!
Thank's federico.

Hi Frederico: First off, I love the old Magnums, I was production Mgr. at Magnum a few years back and tryed to revive the performance division, and build a limited edition 28` Magnum Sport, as well as come out with a new 39` performance model, however timming was not right, and I moved on. To answer your question. The 502 is no longer in the Merc production line. Racing division uses all 502 configurations from 525 through to the new 700 hp motors.
The inexpensive way to go is with the 496 420hp production motor and put the CMI headers on for nice sound and added hp. If you want to spend the money go for the 525 pkg. from racing division. It is a great reliable pkg. has 1 year warranty etc. If you do that you should re-evaluate your drive system. As I don`t know what drives you intend to run, it`s hard to advise you. I would recomend the Bravo one short sportmaster with the ITS option. That would get your X- dimension up to date and give you some great performance.
Pair of 525`s with the drive pkg. I just described will cost approx. $40,000 US each for complete pkg. and includes CMI headers.
I guess what you have to decide is your budget, and to answer your question, the 496 pkg. is the newest pkg. out. the 502`s are in the past for current production, except for race division. Good luck 7XCHAMP

scrich, if you think you may want to go 525s, there is someone on the boards selling a used pair right now.

Thank's 7xchamp and stormrider for the answers,i 've got a magnum 27 and put on it more than about 450 hp it would be dangerous, because run over 80 mph it would be really fantastic but with a 27 feet...i fly!!!... (also because i run in the Mediterrean sea,not on lakes, and it isn't very calm)!!!so i woud put a max between 420/470 hp for engines for arriving about 80mph(now with 2x330 i've touched 64mph in the best condition)...and i want a big big sound,like a THUNDER!!!!!!!!!
So i think that i'll oriented for 496ho with CMI exhaust.....
For bigger engines.... in future if i'll buy a bigger boat!!
bye,federico

80+ mph is no problem with handling. My father had a 27' Sport with Big Blocks, that ran a consistent 84 mph (sometimes 86 mph) - he owned it for 19 years, so there was alot of seat-time. You will love the boat.

FYI http://www.offshoreonlyclassifieds.c...o18780-en.html

and you sure you'll be running 80+ w/ 496s w/ cmi's?
525s might be $ well spent.

Thank's Smarty...do you know what model of big bloch were they?and have you some photos?federico

i've seen those engines but for me it's too much....

scrich, where do you plan on buying, over there?

If thats the case then go North Europe and you´ll find lots of parts and engines...

Stomrider, i must search someone that sells me them at the best price!!!6 october i'll go to genova boat show and i'll speak with someone of "mercury mercruiser" i know certenly tha during the boat show thera are very good discount!!!.....why this question?can you offer me 2 packages of 496ho with bravo one drives and cmi exhaust at very good price???federico

no, just not sure if you had to have merc, and if you were looking at aftermarket, to buy in europe or buy them here.
plenty of builders here can do a 502block w/ 450hp.

Not a sport ...Maltese
 

The Magnum That Mel is finishing up is a 1976,27 Magnum Maltese with 383's and Bravo's

Additional photos...it runs in the mid 70,s...don't even have it dialed in. Bud

can you find for me 2x502 (450hp)?

Two 454 cu.in. Chevrolet LS-6 motors, single 850 Holleys. Glenwood log exhaust manifolds, with custom tail pipes. Turned 27" Mirage Props 5200/5300 rpms. The TRS drives are on 32" centers.


Here ya go...

A few more pictures for you, these were taken three years ago.

was it a smallblock boat with 32" centers originally?

Scrich, check with JCPerf on this site.
He's located in long island, NY.
Built my engine for my old boat.
There may be others on this site to do it too, maybe for less.
Post in the general forum for what you are looking for.
My guess is you'll be looking at 15K each.
You may also want to try Laz Mesa of Mesa Balancing in south Florida.

Federico: What stern drives are you planning on running on the boat is a big question??????? I presume you have the TRS drives if you were running the Mercruiser 330`s. If so and you intend to stay with TRS you should have the transmissions rebuilt and modified for the bigger horsepower.
That`s why I suggested the Bravo drives etc. in my original reply to you. So it gets down to if you are replacing the complete engine pkg. or just the engines. If it is just the engines you will not need the bellhousings etc. as you will use your TRS setup, and have a direct replacement. Good Luck
7XCHAMP

Thank's 7xchamp...i'm looking for two engine package(engine and drive) and the the drive model is Bravo one!!!!!

Thank's stormrider for your councils........federico

if you are looking for a stock engine drive combo, the 496ho mag + bravo one is a great way to go. the others i've mentioned are custom builders.

Yes, it came from Magnum with the 350cu.in/395 hp Tempest package from MerCruiser, on 32" centers. It supposedly ran 74 mph right from the factory in 1974. Ocean Beach was the dealer. Exhaust headers were a problem, the CMI's would not fit (my father had a set made, and then returned). The 32" centers really limits what will fit with BBC's.

My father raised the outdrives, and had the props blueprinted. It was a great boat (and still is!)

Hey Scrich

where do you live in Italy?
I am visiting in Italy with my girlfriend for another 3 weeks i have been here for 4 weeks so far.My girlfriend is from Milan origanally but moved to the states 5 years ago.

I am staying on Lake Lugano in Switzerland at my girlfriends vacation house for the stay.
i was in Portofino a couple of weeks ago visiting.

When does the boatshow end ,i would like to go to it.

Hi tommy,i live in Rome and the boat show finishes today on sunday.....it was been good, better than the others years....bye Federico
p.s. but where do you live?

I didn,t make it to the show.Girlfriend had us doing other things.I have not made it to Rome yet ,only went as far south as Firenze and than went to the other coast to visit a friend in Ancona.

I live in Naples Florida .