Longrange4u

Hey guys, I am new to the boating world...

I have a 1996 22 Scarab with the Mercruiser 7.4 454. I have been looking around at different options for the motor to increase the power and rpm capability of the stock 454.

I have also read through the boards and seen bits and peices of stuff to do but not an overall reccomendation from one of you that is more seasoned than I.

If you had the above mentioned boat, and were starting from scratch... what would you do with the engine?

Do BBC rebuilds require specific things for marine applications vs street?

I have seen the 425hp rebuild kits that SDPC have...

Please keep in mind that I am military and I am on a budget... best bang for buck reccomendations only please. As I cant drop 10k for a short block.

boatn70

im definately not the expert here but, can i assume your talking a carb motor? or mpi? thatll make a huge difference in some responses here.
its my understanding...if carb.....find out which cyl heads you have, then cam intake and carb can be a good start on a budget.
im sure youll get some great answers from others in your same situation

kevin

Longrange4u

Ummmm It dosent say MPI on the engine... It looks to be carb... Again.... I am kinda new

Vinny P

If you are looking for a few more reliable horsepower, I have a 454 Magnum MPI 385 horsepower @ the prop , 415 @ the crank. I dont need it anymore. I would let it go at a reasonable price.

375stinger

ur prob better off findin a good low hour 454 or 502 that someone already put the money into. itll cost more to replicate than to find one done already

ECeptor

Buy Dennis Moore's book called "Big Block Chevy Marine Performance" before you buy any parts.

Read it cover to cover before you spend any money and you'll be miles ahead in the long run.

This guy literally wrote a book to properly answer your question...plus it's a great text to get you up to speed on BBC performance basics.

Kidnova

What ECeptor said. Dennis Moores book is a great read. Also, be patient. Lurk here and at other go fast boat sites for a few months and absorb as much info as you can, and ask questions....lots of them. There is a chitt load of knowledge available here. Good luck!!

Longrange4u

I have 330 now in the motor... I dont think I need a replacement, but instead maybe a 496 stroker kit.... a blower.... or hell just a good cam and heads.

I am unfamiliar with what the BBC reacts well to... and I am sure that there are some guys out there like me on a budget.

Longrange4u

Ok I got it... I will look for that book. I am also looking for the good budget things to do... I have seen the 425HP rebuild kit on SDPC... I have heard and read about the 496 stroker kits......

Heads... well budget heads... Edle Marine BBC heads? (750 a peice)

Thanks!!!

ECeptor

If you have a 330hp 454 then you have cast pistons (just like I do). They will not live long at rpms higher than the max 4,700rpm stock limit.

So, you can leave it as is and have a great bullet-proof engine, sell it as is and use the proceeds as seed money for a build up, or pull it and start rebuilding from the bottom up.

I'm leaving mine as is until I have saved enough $$$ to replace it completely.

If you want to use your current engine as a starting point you will need:
-good heads (oval port Edelbrock marine's would be nice)
-headers or better exhaust (thru hull, of course)
-high rise dual plane or single plane intake (Edelbrock RPM air-gap is great)
-refreshed bottom end with new forged pistions
-new cam (my guru recommends a Crane p/n 134561 236°/246° @ 0.050" duration and 0.553/.571" lift)
-compression in the 9.0-9.5 range with the aluminum heads should allow use of 87 octane unless you go nuts with the total timing.
-carb then tuned for the new engine.

get that book...I pick up on something new everytime I re-read a chapter.