555 bbc wondering on upgrades intake, carb, headers
 

Hi i have 555bbc in a 25 outlaw it has afr 305 cnc heads, comp 240/248, 600/650 lift, the hp500 dart intake and a quick fuel 1000cfm 4150 setup with gil exhaust, i was wondering what you guys thought for more power if intake, headers, and carb are worth some gooh hp thanks

Carb should be fine.

Real headers (Eickerts ore one's with similar dimensions) with approx 18" long total tail length could/should be worth 30+hp on your set up. Maybe a tad more

MiscL
Make sure fuel psi stays at 5psi or more at WOT and top rpm
Raise your hatch just a few inches at OT and see if speed picks up..
Make sure your bottom is clean
Make sure your prop has no dings or etc
etc'
etc
etc
etc

Swap your HP 500 intake and Quickfuel 4150 setup for this. That should wake up the motor a bit.

https://www.offshoreonly.com/forums/...s-intakes.html

Yes those intakes look good bit im up at 10to1 so blowers would be tough lol, ive had a lot of people saying the hp500 single plane sucks as well is there any info on that

I have not pit it on a wideband its a 1000 quick fuel 4150, lots of debates on whether or nor to put a dominator on it, right now the boat runs 73ish depends on the day i thinking i have like 88p, i will look where did u end up for jetting

Was wanting to make close to 700hp, the boat seems to run pretty good its spinning about 5400rpm the prop says its a 25pitch mirage plus but have not had it looked at too see if thats what it is, id like to get close to 80mph thanks for all the help!!

https://cimg0.ibsrv.net/gimg/www.off...8b4c92d455.jpg
Spin the blower slow and you're good. With a new prop you'll blow past 80mph.

You can add this stuff to your fuel tank if you're worried about detonation.

https://boostane.com/

A blower would be sweet!!! im gonna push what i can with this setup, any thoughts on intake upgrades or leave it alone, and maybe some jetting ideas for your boats

Would you go 4500 intake and carb or 4150 intake with 4500 carb seems to be some discussions on that as well

You wont see any measurable gain going from qf 1050 to a dominator. I tested them back to back on a 660-685 hp bbc on dyno, zip, zilch. As far as intake, add a 1" open spacer and 1" blended 4 hole spacer on top of that or similar if you havent already and have room. Recently did this on a 555 on dyno, it picked up over 20 hp and similar tq. Exhaust, buy best exhaust you can afford, Smitty

Thanks for the input, what intake where you running just curious sounds,like the victor jr is better than stock dart single plane

The 555 i recently dynoed had a dart open plenum (from what i remember), (i didnt build it) dominator 1150, i think afr 335s, big solid roller and compression. Came in at 728 hp, carb spacers, timing, and jetting took him to 820 but were talking 750 lift solid, 13-1 on race gas, was a mud truck motor. His jetting was burn down lean when we started, he had taken power valve's out and went DOWN in jetting so it gained alot just from giving it fuel but it like the carb spacers/extra plenum volume, fwiw, Smitty

Ohhh dam went down after pv removal way lean, do you generally try to run pv on marine build or remove i know with street car we try to keep them, also do you know about where ballpark jetting would be on a setup like mine with that q1000 qf carb, im gonna pull mine tonight and look i think it was stock jetting but we will see thanks

Looks like stock jetting is 82p 88s and 4.5 pv in front

Also im running a 25p mirage plus how do you feel about a bravo 1 instead on the bajas

id leave the pv, make sure at idle and light cruise (2800 to 3200) your vacuum is above 5" so pv is closed, if not, go down further but most boats are in 70 map territory there ( 8 or 9" vacuum). Id prob start w 84 or 85 primarys and 96 secondarys, watch plug 1, 7 and 8 closely , color after wot run and jet down accordingly. If #2/6 look fat, dont start pulling jet out to make them happy as they are going to run richer just by nature of intake/cam

Thanks for the help arcticfriends do you think the setup cam ect this should make power to 5800, im spinning that mirage plus 5400 didnt know if i should try to get rpms higher or try bravo 1 prop

Getrdunn yes its like .612int/650exh, definitely need to find some headers do you like the brodix over the edelbrock victor or victor jr. Ive definitely had a few people tell me the stock dart kinda sucks actually straub said prob 20hp/30ftlbs just getting rid of it he said they were built to be ported and need it i guess

I found some cmi elbows tops, going to ok put them on and have not changed intakes i talked to dart they said mine can be ported for 250 plus shipping was devating that, where would you guys go with cam ideas duration ect.

Elbow tops arent really the best option for an NA engine. You need runner length on NA. Supercharged, runner size is usually more of a benefit than length.

keep in mind not all carbs are equal. Cfm rating is simply how much air they can move thru them. It has nothing to do with fuel atomization. You can try 5 different 1050 dominators, with different booster styles, venturi sizes, etc, and get 5 different results on the dyno.

bad idea!!!!

Hi guys i got the headers on elbow tops i wish the were sport tubes but the deal was right and i hot to dith the Gil system, it running pretty good no serious gains maybe 1-2 mph at best still neec to keep playing with jets and stuff, and still debating intakes swap, on the outlaw are you guys liking the mirage plus the best thanks

Hi guys its another year thinking of playing with props what do you think about a mirage plus i have on it vs a labbed bravo 1

Have you tried the spacers yet? I have a 524 with the AFR 305's that have been ported and a Brodix HV2000 intake that was ported to match the heads. I have a .623/.612 and 24/252 @.050 cam, also running 10.1:1 compression with lightning headers. I also have a 4150 1000cfm carb from Pro Systems. The 1" 4 hole tapered spacer will pick up the mid range and the 1" open will add to the top end. If you don't notice a difference something else is holding you back. I run a 30p labbed Bravo 1 prop and I get to the mid 80's easily. I will probably top out somewhere above 90. I never dyno'd the motor but based on my performance I must be in that 700hp neighborhood. I also highly recommend the Daytona Sensors ignition especially when you start getting a cam with more duration. My carbed boat starts and idles like EFI maybe even better with the Daytona CD-1 idle control. The design of your Spark Arrestor can impact carb flow as well. I went with a velocity stack style with a K&N 4"x14" marine approved filter anything smaller and you are pulling a vacuum at WOT.

Thanks for the input i am currently running a single 1" hvh supersucker blended 4 hole. Also running a factory hp500 spark arrestor thats a good thought on upgrading that. And it seems there isnt a bunch of info on whether that stock hp500 dart intake is hurting or would benefit from upgrading

also yes i am pulling 1" or 2" of vaccum at wot

1” is fine. 2” is not.
Take reading over carb (in flame arrestor) to see if it’s flame arrestor causing it.

Something to check too, many intakes have extra material at the port opening for port matching. I had to remove a ton of material on my Brodix intake to match it to the intake port on the head. Run a camera down your runners and check it. It's easy to port match your intake to your heads. If you are running the 305's the way they come from AFR the ports are somewhat smaller than the recommended gasket. take some poster board and cut it into a strip that will cover the entire intake face of your cylinder head and tape it securely to your head. Find your bolt holes and cut them carefully with a razor knife. place a few bolts in place to locate the poster board. if you take a hammer and tap gently around each port opening and I stress gently it will mark the port opening on the poster board. You can then cut the marked locations and transfer those to your intake. Take a die grinder and carefully open the intake runner to match. You will want to blend the runner so the port shape flows into the runners. A little WD-40 on the carbide cutter will keep it from loading up.

Thisislivin - manilla folder paper with a ball peen. Much easier than cutting.

Ooops, let out another speed secret. LOL. Just playin.

I do this more with exhaust ports vs exhaust header/manifold. You'd be surprised what you find. This is a bigger hurt on power than intake mismatch. Sometime Yuge.

If not sure what I'm saying use that as search terms and you'll find some old guy doing it this way. :)