540 bbc build advice
 

My 454 330hp is destroyed so now on a mission to build a 540 bbc. I am going to use the following::

Dart sportsman block 9.80 deck 4.500 bore
scat 4340 crank
scat H beam rods
all arp hardware
9.5 to 9.8 :1 comp forged pistons Je/Mahle
My goal is torque 675ft, hp 680 plus lot's of car guys
up here but lil marine experience so hopefully this will work. Im hoping all this can be accomplished by 5500 RPM So Im Thinking Howards cam
121615-14 14* lobe
.640in / .640 ex
296 in ,, 308 ex adver
243 in// 255 ex @ 0.050 dur

or howards 122455-12 12* lobe
.680 in / .680 ex
306 / 312 adv
253 in,, 259 ex @0.050
comp cams 1.7 mag roller rockers and roller lifters
both cam hyd roller

I have lightning headers already im going to use (water jacketed)
boat is a 23.5 polwer play power quest bow rider Bravo 1

edelbrock performer rpm r rec intake

whats is the best cam, hopefully no reversion??
and head choice
afr 305 rec or
brodix race ready rr bb-2 plus 119 chambers 312 intake port
or another choice ??

carb I have a holley 750 and 850 possibly both of these are still too small??

Thanks Gene
.

Somewhat similar to yours is my base motor my blower motor is built around, 540 with billet rods, 4340 crank, Dart 9.80 block, afr 315 cnc heads and a modified mpi fuel injection. My cam is very close to your 1st cam choice, my motor made 657 hp and 660 something tq but my compression is only 8.2-1. With more compression, a better manifold as long as you pick the right cam and heads 675 hp will be fairly easy. A few guys have built 675-700 hp n/a motors out of 540's on here, a friend of Bob Maderas made 700 plus hp with a fairly large cam BUT in retrospect he has said he wishes he would have went just slightly smaller and had better driveabiility. If you want your cam perfect give Bob a call 585-654-8583, in the end his price for a hyd roller custom spec'd is about the same as what you would pay for a out of a catalog cam anyways plus he is a AFR dealer and can get you your heads for what you'll pay for them most places too unless you are buying used ones, Smitty

I talked to Bob yesterday he is getting back to me this week, kinda was over whelmed with the info, trying to wrap my head around 112 and 114 lobe sep, and amount of dur @ 0.050 I need , why did you go with 315 instead of 305 afr?

Because my motor was built for running with a Blower and I wanted to maximize power, the 315's offer more flow. I did dyno it and occasionally run it without the blower though, Smitty

Came up with after talking to Jan at lightning headers afr 305 and
231 in
239 ex
621 in
624 ex @0.50
112 lobe on a 108 center on intake any ideas
on hp and tq with above recipe ??

Ran that cam with a 110 ls in a 454, topped out around 5200 rpm.

305 is too small for a 540. No matter what some may say. Marine engines ask for tons of air. 315's are better

That cam seems weak for a 540CI. I think in order to meet your 680HP goal, your gonna need to spin the engine. That cam will probably fall off way to soon power wise.

I also would consider a different intake manifold. Go with a single plane for what your doing. It will outperform the dual plane edelbrock, at the rpm level you will need to turn to make 680hp, which i feel will be closer to 6000rpm than 5500.

The 750 carb will be way to small. 850 will be marginal. I would personally go with a 1050 Dominator.

A friend of mine has a pair of 540CI, bowtie blocks, Lunati cranks, Dart heads, around 10:1, I think they are 320CC, I forget. Solid Roller cams, single plane intakes with dominators. He turned them to 6000 in his boat. They did around 700HP on the dyno. They are radical motors though. I forget his cam specs, but they are up there in duration.

All this motor in front of a open bow 23ft'er with a bravo drive might get sketchy. The drive probably wont last too long, and that hull probably wont feel safe above 70mph. just something to consider.

Thats less cam than a Merc 525efi uses. WAY too small for a 540

Anybody have an idea to what this collaboration of parts might make and or with 320 afr or brodix heads instead of the 305 afr's?? closes ideas, speculations or even off the wall lol ?? The boat did 55mph with the 330hp 454 in with peanut butter heads in it, so now trying to hit 70 mph is my goal. Thanks