540ci 700hp build recipe
 

I have searched and searched and every thread seems to be an argument about what parts to use and which are junk. I am looking to build an n/a 700hp 540 this winter (changed my mind on the procharger) and I am looking for a good recipe to build off. I already have a 741 cam which I plan to use. Other than that I have a 502 MPI with very low (under 30 hours) that I don't trust because of some issues I have had, so I am building again this winter I like EFI... But will prob switch to carb if it is easier and more cost effective. Any help would be great! If anybody needs a 1000hp diesel.... I can help with that! Just not sure on exact parts and specs on the gas side yet... But learning quick! Please just post combos that will get me close to my HP goal, I prefer good parts... As this is hopfully the last time I have to build a motor until I have my "dream" boat

A 540 with the 741 cam is 630-650HP all day, give or take aftermarket head selection and dyno.
Scat 4.25" stroke should be more than enough.

If the lower end is in good condition now. I would take the stroker money and put it into a set of bada$$ heads, intake and cam combo that would run great in a 502 and then upgrade the lower end at a later time when needed. You can get 650hp with a good built 502.

Rookie - anyone you know run the 298cc 24* Oval Race Rite ?

Just wondering howthese are in real world. Came out last year I think.

On paper they look impressive, but we know how that goes. LOl.

Here they are: http://www.brodix.com/heads/big-bloc...block-series24
BP RR BB-3 XTRA O™
• 100% CNC Ported
• 24° Valve Angle
• Flows Over 390 cfm
• 298 cc Intake Port
• Exhaust Ports in Stock Location

I'll be following this thread as I'm looking to do the same thing.

No, those look great! I'll talk to my head guy and ask him what he knows about them.

What size and brand head? if I stay 509?... Sorry above I said 502 MPI... It is actually a 509 MPI. So if I just do heads , cam, intake and exhaust what would I be looking at power wise after tuning? The pistons are forged SRP and the rods are Carrillo.... The crank is stock as are the heads.

The power is ALL in the heads. IF you want to build 700 HP you need better heads - I suggest AFR cnc'd. I had a 741 cam in a 509 and felt it could have used more. That cam is not enough for a 540.
With the right parts it would be hard not to produce at least 700 HP.

What size afr's? 315? I would like to use the 741... As I already have it... But would rather sell and get something better if I will be disappointed in the long run. I will prob stay 509" after talking to my builder. He recommended Brodix heads... But he can get dart and AFR also. I do like AFR as I had them on my mustang and they were bada$$.
And am I best to order them bare and have them built by a marine builder? Or do they come ready to bolt on marine application?

I'm no engine builder but from my internet edukation you definitely want bare castings and get them built up. Even the best mass produced stuff doesn't seem to be within specs for HP marine use.

509 Brodix BB1 CNC 260*270*@.050 .680" lift 112 lsa 9.5:1 compression 715hp @6300 rpm. Motor kept making horsepower to 7400rpm where the pull was ended because the desired rpm in the boat was 6300.

540 Merlin steel 320 525efi cam 9.5:1 650hp @ 5500rpm 630tq. No need to spend $3000 on a set of heads when $1,000 set of heads will do. For that matter with 540 ci's if 650 was the goal a GM steel head will do. If you want to spend $3000-$4,000 on a set of heads 750hp is a better target than 700hp.

Thank you for the reply black baja, those Brodix heads are the ones my builder recommend. Would either of those heads still work good on a 509?

Pretty sure that mpi will need a bunch of help to get much HP over 600, ( Smitty ) on this board has done a bunch of dyno testing with these intakes, might want to send him a pm and chat,

Are the Merlin 320's a good head for a 509ci? 650hp is my goal, trying to make my drive last a season without having to build it too.

I wouldn't use the merlin heads.but if you already have them.

That is so strange I was just reading up on those last night. How strange... Was wondering the same as you posted. Lol

He's gonna tell you the exhaust port is prolly to big and lazy. Lol. If they are what they claim my opinion is they would be an awesome head. Would love to try them on a bigger cubic inch engine.

I'm building a pair of 555/565 (undecided) and am aiming for 700hp plus at or under 5,700. Build so far is valokoized pro 1 310's, edelbrock sv-565 intake, 1050 dominator and unsure on cam however have two new billet 244/248-644/648 on a 111 custom grinds. I'd like a little more lift. Compression will be 10.5:1.

Just an FYI Gellner Racing was punching out 540's with virgin pro 1's, dart intake, 4150 1000 cfm Holley, same cam as above and making 650 around 6k rpm. Would make much more power with head porting and a little intake work.

So what is a good solid performing head for $1500-$2000 a set? Would I be better off working over the stock heads that were just rebuilt?

Interesting. One would think the SV565 would have too much cross sectional area for a low rpm 555/565.
looks like I'll be doing some digging on this.

That's small block territory.

Not for your hp goals.

Is the Brodix bb1 sts cnc 280 a good head for my goal? I know there not cheap.. But my builder swears by them.

Who is the builder monster?

Ray and victory. He didn't specify which Brodix head... But putting 2 and 2 together I figured the bb1. We spoke a few months ago and I am collecting parts now for a November-December build. I decided I am going to leave the rods and pistons and crank alone and stay 509. This motor was built last September by another builder... And I am going to have ray just check it over, because I have had some issues with it, and he will add the heads and cam for me. Then I will figure out the intake and EFI tune!

Ray builds lots of endurance stuff.

I'd have him buy the heads bare and build them.

Yea that was my plan, to buy bare and have him build... Just not sure which head to buy. Maybe I am better off just letting him make the decision.

Those BB-1 heads have a .600" raised exhaust port. May have to do some transom mods for your tailpipes. The 24* CNC 298cc Race Rites I believe have standard exhaust height.

Speaking of which, what exhaust do you have or will you use ?

That intake manifold is going to squash your dreams. Read up on it.

I will be using lightning headers... I have been reading on the intake... Seems going carb maybe my best bet. Is anybody modding these intakes to make power?

Quick search looks like ASM offers an option. I thought I read a vendor on here works them too... I will have to do some more searching

If you have a builder have him spec the build. It's a little easier for them to stand behind their build when they spec the components. Also, when the numbers don't make what you paid for it is a little easier for a course of action.

Agreed!
It's gotta drive engine builders nuts when customers (with all good intentions and just trying to be educated) come in and say "so and so on such and such website says these are the parts I need to be using".
Kind of like going to the doctor and telling them what's weong with you because you read up on "web-MD.com".

My comments aren't directed at you monster, just a general observation.

Hahaha I never thought about that! Makes perfect sense! I am going to let Ray handle it. I just like learning and asking questions. Thank you guys for the help. If I could get a doctorate in "fast boats" I would be in college yesterday.

Educating yourself is excellent. But, your engine builder is the expert. Also, specific HP goals can be achieved through different recipes. And your builder might have one that he is comfortable with and has a track record with it.

Isn't this fun. Lol... This is the kind of stuff that can keep you awake at night. Just curious what gm castings you have currently. Most that I've seen are pretty much done at .600 lift/320 cfm so that alone would limit your cam amd combo options which ultimately wouldn't get you where you would like to be. You have some good input from others who have been there and done that so to speak. Gm heads in the right hands can still make some power however would be costly. Even your good aftermarket heads have much to be gained with porting and bowl work. CNC heads would be your best bet however a little pricier. 320cc Pro filer heads is what I would look into at an affordable price and flow well out if the box and can get some pretty good gains with little work.

Sounds like you wanna NA build but if you strapped a 420 mega blower on you'd be able to use both your heads and cams and achieve over and above your hp goals for probably the least amount of money. Seen several low hour used ones go very affordable over the last few months.

Just an option I'm sure you've kicked around.

Absolutely! It's fun to learn and good to gather as much info as you can going in.

Like using the highly recommended. Bob M? What a HUGE mistake tht was for me...

Buy heads bare have them built, I would really do some talking on cams that's for sure, ERSON ground great cams for my old engines... Wish I contacted them with current ones...700 hp with efi gonna be very tough it at all possible, I may be wrong though

MER recently built a 555ci. Solid roller, 10:1ish, dominator, made 720ish HP with the "custom" spec'd cam from the cam god. Yanked that cam out for a cam he had laying on the shelf he got from howards years ago, that looked like a better fit for the combo. Ended up at 770ish hp. Did lose a smidge of midrange torque, but nothing major. Definitley worth the HP gain.

What kind of rpm I wonder with said cams at hp you stated. That would be interesting to know.
Tks
John
Btw what shiney 4 blades you running? :party-smiley-004:

That BB1 head is a bad azz head Brodix doesn't advertise it much because the CNC porting is proprietary and is not done in house they have to send the castings to STS for the porting...

I wanna say around 6400. This was a jesel valvetrain setup , engines going in a 33 fountain with speedmasters.

You see me this weekend ? I was up in Grand Haven