Offshoreonly.com - 525 sc ?

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I just did a 600 hp/ 600 tq 502 for 242LS, pretty easy mild mannered.

That changes things if you already have the setups but you could always peddle them and go a different direction. Do you have blocks? If so what displacement.

Here is my 509, Dart Pro1 heads, Dart intake, 10:1, built by Jim Valako.

622tq, 684hp

Better start stashing some money for drives while you are at it. I'm starting to wonder how long out poor old Bravo's are going to last when they have 600+ ft/lbs going through them. :eek:

Quote:

Originally Posted by Rbesola (Post 4122804)

I just built similar engines. I started with hp500s though. Dropped compression to 7.6. Used a 525efi cam. Original heads. And 420 blowers, intercooled. Basically hp600 clones but intercooled and pushing more boost. I know you have to draw the line somewhere but id definitely overbuild it that way you have room to grow. Start with the 502 and the biggest blower you can get your hands on. Nobody said you have to use it to its limits. Heat is the enemy!

Cool. Are they in the boat yet? Will you be making it down to peoria this summer?

[QUOTE=MILD THUNDER;
Ive had the same engine combo for a long time, with different blowers, starting from 177, then 250, then 420. Each time I upgraded the blower, the boat went faster, at the same or less boost. 5psi with 177 netted me 79mph. 7psi with a 250 blower, netted me 83mph. 6psi with 420 blower netted me 88mph.[/QUOTE]

Great Scott! Do you see some serious ****!

Have lots of parts,Just trying to get the best most reliable combo single engine application.

Nice pics and impressive numbers.

How do you post pics, Am I limited by the type of member I am?

Quote:

Originally Posted by actionmarineguy (Post 4123070)

Thanks for all the input,
I know there are better options but have 2 complete setups sitting on a shelf.( Minus 1 lower pulley if anyone has one). just looking for a reliable setup with the Cool factor of the blower, I would be fine with the 525 hp but since I am building a engine anyway small improvements would be great as long as reliability is not affected. It does seem to be hard to find an off the shelf piston under 8.0:1 cr.

I helped out OSO member Wayne272 on something similar. We talked over the phone a bunch regarding cam selection and parts to use, etc. He had a pair of stock 365HP 454 Mags. With a cam upgrade (stayed flat tappet due to budget reasons), the 177 Blower, GM rect port heads, few other odd's and ends, stock shortblocks, he made 590HP at 5400RPM, and over 600FT lbs from a very low rpm, with a peak boost psi around 4.5psi. I think he's VERY happy with how his boat performs compared to with the stock 365 mags.

Real nice power from a basic setup, with no fancy parts. Just GM iron heads and crane flat tappet cams.

Quote:

Originally Posted by mike tkach (Post 4122824)

im curious as to why you went with 7.6 to 1 compression ratio and a 525 efi cam?

Went with that cr mostly because if it was good enough for merc, its good enough for me. But also because i plan on different heads, a 110cc head will put me at 8 flat. The efi cams i had upgraded last year when it was still na. Didn't see much reason for another custom grind with plans of different heads and exhaust in the near future. Im quite happy even with this setup as they push my bathtub 87mph on just 6psi and stock merc/gil manifolds!

Quote:

Originally Posted by hogie roll (Post 4123136)

Cool. Are they in the boat yet? Will you be making it down to peoria this summer?

In the boat ready to go once mother nature starts cooperating. Couple hours on them already to get my first couple oil changes out of the way so were ready to boat. I think the first trip to Peoria is going to be for the 4th. Most likely stay at EPBC. What do you run? Ill have to keep an eye out!

If you go with a small blower and want to make efficient power, you need more compression and NOT more blower speed. With aluminum heads 8.25 :1 is no problem. Huffers look good and are fun but cost money and are somewhat high maintenance...kinda like a stripper.