Offshoreonly.com - A 408 sbc build... little help!

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Quote:

Originally Posted by Jackdonz (Post 3846546)

With aluminum, can I go with 64cc chamber size?

Yeah buts...if you get a bad tank at a marina somewhere you could be in trouble if you use el cheapo pistons

Ive been running a 10:1 406 in a boat for 2 decades.

http://www.youtube.com/watch?v=yYK78rm-KPI

http://www.youtube.com/watch?v=yiYbs97NSyI

http://www.youtube.com/watch?v=xfbNkf2FPk0

http://www.youtube.com/watch?v=M1jGIuv7JxI

Lots of Great SBC builds online here.

Uncle Dave

My 383 was 10.3 cr with aluminum heads . Never a problem . 5000 lb boat . Always trailered no marina gas .

http://www.summitracing.com/parts/wr...50-2/overview/ i like these . compression would be in the 9's and steel stabilizes the 400 block. just my 2 cents, ask an engine builder.

Quote:

Originally Posted by 88Fount33 (Post 3846525)

Be sure to drill the heads for the steam vent holes. Match the pattern in the 400 head gasket. That was the main reason a lot of people had trouble with these engines when they started building them. Since the bores are Siamese, steam gets trapped below the head and the engine overheats even though it has the right water pump and thermostat, and everything else is perfect.

Quote:

Originally Posted by Jackdonz (Post 3846512)

So with the 76cc heads and the mild cam.... how much hp should i get out of the motor then? Just estimate for me.... 260? 300?

I can always go with some different heads other then the sportsman heads. Im looking for 350-400 hp.

I sware some ppl dont read lol..

if it were me i would look at the edelbrock 70 cc 2.02 angle plug heads..with your flat top pistons that are in your engine this would be a safe head to use in your situation or you will need to put a dish style piston in the engine..

witha decent can and thease heads you will be over 400 ponys..go over to donzi.net and look up ghost,he has a 406 in his classic and can give you a idea what hp his is putting out..i have a 355 in my x18 and mine dynoed @ 434 hp..i have lots of work into mine tho..

i put a set of early sixties "fuelie" heads on a stock 400. i believe they are 64cc's. put engine in an old sundancer. large chunks of my pistons blew off. yes the heads were drilled for steam. then i did a rebuild with cast pistons, 76cc heads and it survived. wasn't really a performance application though. if this is a stock rebuild, what pistons are in it? hypereutectic (sp?) might live. cast will not. forged is best bet. this 509 casting is a two-bolt, not 4-bolt, correct? the 4-bolts were much weaker. for the 20 some inches you are gaining, i would go with a 350 block and stroke it.

Quote:

Originally Posted by the deep (Post 3846805)

My 383 was 10.3 cr with aluminum heads . Never a problem . 5000 lb boat . Always trailered no marina gas .

Wow. I definitely stand corrected!

Jackdonz - What cracked the block of the existing engine?