troyc565

i am impressed with the amount of knowledge on this board & could use a little advice. i have a 24 foot vip vindicator with a mild 454 & 750 holley & bravo 1 that runs 60 mph with gps. i want to swap the motor from my drag car into my boat. i have a 800 hp dart block 565 with eagle crank & rods with 13 to 1 comp. & brodix bb2 plus heads with 2.30 intake valves that have been ported for lift up to .800 lift. i also have a set of rect. port iron heads with no port work. i am going to change the pistons to get compression around 9 to 1. & a marine hyd roller cam. my question is if the brodix heads are to large for a marine rpm motor or should i use the iron rect heads with no port work. i do use this boat for wake boarding & tubing at about 25 mph so it has to have decent low end power but it also sees alot of high speed runs to. i also have a brodix hv2001 single plain intake matched to the heads & a dual plane intake also. which intake would work best for my application. i think a max safe rpm would be 5500. i would like the boat to do 70mph

nwimbush

Well, there are a lot more knowledgeable people here, but I guess they're busy, so i'll at least keep you company.

I would guess the Brodix heads and intake are flow-tuned, for a given RPM since they are matched and from a drag setup?

With your 565 the objectives of 5500 max, reasonable low end torque, and 70 mph should be easily obtainable the iron heads, dual plan intake, but a slightly larger carb. The 750 would probably limit the 70+ runs

troyc565

i am afraid the brodix heads will make the boat slugish at low rpms also. i wonder if the 565 will use alot more fuel at cruise speed or will it be close to the same as the 454.

KAAMA

iTrader: (1)

What is the runner size CC volumn of your Brodix BB2 Plus heads???? Also, it would help if you could tell us what brand name of cast iron heads you have and what runner CC size they are as well.

You're right...pulling wake boards and tubing would require lots of low end torque. You'll want to try and keep the CC runner size of the heads on the smaller size and use a cam that gives strong bottom end torque as well.

I have a pair of 565cid naturally aspirated engines with 315cc AFR CNC ported heads, and mild cams and Dart single plane intake manifolds in my 32', 8500 lbs boat, but it sounds like my application is a bit different from yours although I have pulled some "tubers" around a bit with no problems.

RMBuilder/Bob Madara of Marine Kinetics in N.Y. would be a very good person to consult regarding your combination and selecting the right cam profile for it.

troyc565

here is more info on the heads
the brodix heads are 312cc intake runners out of the box. they have been ported for drag racing for high rpms.
the iron heads are gm heads, part # 12562920, they came off of a gm crate motor that is there 425 hp motor. the intake runner is 325 cc with 119cc combustion chamber & 2.19 intake & 1.88 ex.

cstraub

The BB2Plus on a 565CId engine will work just fine as long as the castings have not been ported to exceed 360cc's. I would run the single as for the CID you have the low end will not be affected that much by the single plane intake.

troyc565

how do you think the fuel consumption would be at cruising speed with the 565 compared to the 454.

jeff1000man

Those Brodix would have been PERFECT out of the box. Even if the port have been opened up they are still going to be better than the GM heads by design, so you are OK.

Get some flow numbers on the brodix heads. If you don't have them, go to a speed shop and get them tested on a flow bench.

THen call RMBUIDER. PM me and I'll get you his number. He has this stuff down to a science. Do not use an off the shelf cam, or call crane or comp and have them make you a custom, you will just be spinning your wheels.

THat is going to be a great engine in that boat.

Good luck with your project.

AS an added note. Check your fuel supply line from the tank and upgrade it to #8 if it isn't all ready. Upgrade your oil cooler while you are in there, and check all your hoses and lines for cracks. It is worth it in the long run to not have to go back and do it later. Use a TeamG intake and a 1050 DOminator carb. If you look on ebay, you can usually pick them up for around $100 for the intake and JEGS runs those carbs on sale every couple weeks.

Jeff

mrhorsepower1

I can help you with your camshaft selection. PM for details.