Cheap Hp mods

[jeepster21]

This winter I am thinking of hopping up my BBC 454 in my jet boat. The motor was fresh when I put it in and was rebuilt with Forged flat top pistons about 10:1 compression, aluminum intake, a little better roller cam, and a forged steel crank before I got it. The heads are the L29 or Large Oval port heads
I know the bottom end can handle more Hp.
What are some relativly cheap mods that I can perform to get around 450 Hp?
Different Carb?
Cam?
Roller tip rockers?
Intake?
I cant run headers because the neighbors alredy hate my boat.
Thanks

[tunneljet]

Through transom headers, solid roller cam, roller rockers, and spray:cheers:

[coslanzetta]

bigest bang for your buck would be cylinder heads....good set of aftermarket square ports or a good set of 990's...if ya have the doe...aftermarket aluminum...is the way to go and you'll save 100 lbs....slap a set of -2brodix 305cc's and that dude will pick up 150 hp from them oval ports....now adays those heads are boat anchors...no offense..lol...also put rockers single plane intake and a 950hp holley carb and it should make well over 500 horses...then put nitrous on it....lol hang on...

[jeepster21]

how much hp do roller rockers free up?

[wriedt1]

20 to 40 hp.

[DOUBLETROUBLE SS]

still need headers with them new heads and i would look at the patriot heads they flow around 350 cfm's i believe check out the website they come with ss valves and roller rockers i bought some for my 427 sbc there awesome had to dump the loggers for cmi headers i pull 589 ftlbs of torq at 4900 rpm on the dyno dont know about bbc prices but the heads and headers ran me about 4000 grand heads were around 1000 and headers about three thosand it of course you will need a new bumpstick too

[boatermike]

doubletrouble ss must not be able to read. he asked for cheap mods not some pie in the sky

[wriedt1]

You have good comp. and heads I would go for a cam swap, roller rockers with the right cam you should be able to gain the HP you want and more. Call Comp Cams help line tell them what you have and what you want they will give you some ideas on a cam. Here's the #1-800-999-0853 they were a big help when I did mine and right on the nutts with the RPM range.:cheers:

[boatermike]

ok heres a weird cheap mod that 4sure works ........its called e-charging.Echargers produce boost from electricity and supercharge your engine. essentially it is a squirrel cage fan ducted into the carb. the system is momentary and not intended for continuous use.#0 minutes of use is within reality. multiple e-chargers can be used and boost levels in low and mid rpm are substantial.build yerself one with a serious pair of fans that outflow the max your engine can drink and bingo!!! cruising speed throttle punch might be fun??????????? ats cheap mister!

[wriedt1]

:thumbsup:YOU FIRST...:thumbsup:

[455maveric]

ya if you could get fans that can move more cfm than the engine good luck a turbo spins at about 60000 rpm to 100000 rpm to produce enough cfm

[150aintenuff]

flat top pistons in a BBC is 8.0:1 you need a 40 CC dome to get a 10:1 ratio.... so first of all if you think you have 10:1 you would be mistaken... unless you were using very early large oval close chamber 427 heads which you arent... you can definatly benifit form cylinder heads, and a new rotating assembly.... or atleast pistons.... and cam and intake, and carb, and exhaust

hydraulic roller cam, and a full set of 1.8 ratio roller rockers


l29 heads are the early vortech 7400 heads and are not large oval port... they are 195 cc heads versus 262 cc ovals.... good torque head for sub 3600 rpm use only...


ditch the crappy heads..... and at a minimum get 990's in rectangle port... or better yet afr 305's a new set of slugs as you are only at 8.5:1 with flats and 115 cc heads...

so heres what you need for 450+ hp...


a true 9.75 or better :1 compression... with 40 cc domes

afr, dart, or any other aftermarket aluminum 305 cc rectangular head.

a mild cam, (230 duration at .050 max the old crane 741 or 761 is perfect for a boat .600 lift..

a good victor or equal rect. port intake, 800cfm+ carb


basically a complete start over

[150aintenuff]

ya if you could get fans that can move more cfm than the engine good luck a turbo spins at about 60000 rpm to 100000 rpm to produce enough cfm

not that hard.... just need big fan.... thats the poblem... space is issue.... most house box fans move in excess of 1000 cfm.... but they are 18-22" diameter...

[455maveric]

first yes a house fan will move that at 0 psi second you would need it to move much more than the engine to get any presure and you will need one hell of an electric motor to spin it. I would just through a small suppercharger on it due to the low comp easy to do and you are done no pulling heads and pistons get a 174 Wiend done problem solved. you should realy check to see what pistons you have and what cc heads to make sure you dont have low compresion or if suppercharging to high and the heads are fine for the HP you want . with header a good cam and intake you should hit 450 HP i would call comp cams up they could tell you what need for a cam and could tell you what intake

[455maveric]

What we all should be asking is why do you want the HP if it is to go faster then how much faster do you want to go. what is the boat speed now at what rpm and what impellor is in it that will help every one figure out what it needs due to if you want to see 10 mph increas and if you allready have 400 HP 50 extra HP is not gona get you there

[wriedt1]

If it is low comp. put it on the little blue bottle can't beat the HP for the money and with low comp. it really works well, And you'll get your 450HP when ever you want it for less than $600 And with NOS you can have something thats easy on fuel. Or spend $6000.00+for a new crate motor and your done. good luck with whatever you do.:thumbsup:

[jeepster21]

thanks for the help and for the hints guys, So what it boils down to, is a complete start over, Thats getting expensive. The reason i wanted more hp was just to get a lilttle more top end. It has a stainless impeller that is either an A or an AA cut. I havent ran it on the GPS yet but it pegs the speedo needle past 65 but i know its not going that fast. The rpms is right at 4500
Is running the little blue bottle hard on things?
Here is a little video of it running on the river. the soundand video quality sucks but at least you can see it move.
http://www.youtube.com/watch?v=tQAL04KmCz0&feature=channel_page

Ps dont make fun of my seats im going to get them redone this winter :D

maybe ill just leave it alone for now since it runs real good and is reliable and decent on gas.

[boatermike]

e-chargers do exist ,and do work.

[boatermike]

electric turbo's and electric supercharging is all over you-tube. plastic fanstastic but some have actual gains. What kills me is the lame fans they are using. the first ones of these i saw 15 plus years ago. this early model had four squirrel cage fans , each one pressurizing the air filter bonnet. the car definetely flew. i experienced this both onboard and FOLLOWING. although i in now way endorse hanging some hilly billy crap on yer slick machine i am suggesting that more horsepower can be foiund for cheap.and since many have weighed in i might as well post a few suggestions.

first off lets switch to some huge carbs and maybe a change of fuel or better yet lets just gas that bits up and begin with a hole sit load of timing and and experiment with the wonders of additives like..........nitromethane or maybe some redneck from the paint store toluene or just switch to alcohol and go jet-less with the holleys and seek out a rod thats a tad longer and make that piston come higher .

lets also try turning off the water to the exhaust for full throttle blasts.

also lets again visit the timing and realize it is a limiting factor,must be maximized at higher rpms , maybe a timing computer that can bump it a little more once a certain rpm is reached.

lets also visit valve timing and take a look at the timing chain and take a redneck leap and advance the cam one whole tooth, as in.........the dots dont line up.lets also make certain our rocker arm adjustments provide absolute minimum lifter preload without clatter so all valve close good for the "moment in the time space continuum" , maybe we could also rig up an injection rig for alcohol water mixture for gits a shiggles.

what type fans are you curently converting?
i got more where that came from if you want

[wriedt1]

Nice boat jeepster Sounds like it runs great. As far as NOS I've been running 150HP shot on a stock bottom end cast piston mopar 360ci for the last 15 years 11.90 at Rockfalls seconds at a time without a problem. Plan on putting it on my boat when I go for the SS impller. Power Shot is what I would go with ajustable from 75 to 150 once you tune your boat put on a wet system and your good to go.

[455maveric]

Some one call Ford, GM & Chrysler and get them signed up for there plastic fans I know they dont have a clue on making power

[Danger731]

I run a 100 shot through a 346 cu in my LS1 2002 Camaro. It has 120,000 miles on it.
Get a rpm window switch, fuel pressure safety switch and a WOT switch.Keep the bottle pressure constant with an automatic bottle heater and you are good to go. Adding all the safety stuff makes it much more reliable. It also depends on how well the motor was maintained. Frequent oil changes go a very long way to longevity.

[455maveric]

well looking at the impellor chart if you have an A2 then it looks like about 375 HP if it is a A then just over 300 HP. not sure what the boat is but i would think that if it is going around 60 MPH then it would be A2 and 375 HP. to get more HP first i would check and see if the big valves ar in the heads 2.19 int and 1.88 ex if not get them and do a gasket match and port clean up port job that should get you about 30 HP. then a better cam and roller rockers you should be about there .Oh I almost forgot when the machine shop is doing the valve job have them use some goodson bowl hogs to open up under the valves make sure they have them befor they do the job it makes a big differance

[boatermike]

negativity noted; thats ok maverick, i understand.

did i mention i rode in a quad echarger equiped chevy truck about 12 years ago and it was acually quite impressive?

well i didnt say it was normal or anything

has anyone looked into the e-charger concept or is it just to abnormal?

[455maveric]

Well i have heard all the claims of more power better millage and i dont see the top engine builders backing them and i do have a bit of understanding of engines i went to the School of Automotiv Machine in Huston TX back in1991 and had a shop in NH up till 2004

[boatermike]

you and the top engine builders have nothing in common so why let them dictate what you explore.

refusing to accept what im telling you about what i experienced is the same as calling me a liar. thats an insult. so now i can throw one back at you right?

your postings are obnoxious and quite often just arrogant . possibly you was the fat bully in school? when i seek real advice your not the person i wil be asking. in fact i look forward to not responding to your response to this. have a nice day mr 4 month member.

to everyone else here i apologize for the negativity.

[455maveric]

well sorry you fell that way but i just haven seen Roush racing or yates engine using them and Jack Roush will put any thing on his Street engines that he sells to make more power I know that I am a nobody in engine building but like I said I havent seen the top Guys doing it . Now could it be Done yes you could power a Paxton type supercharger with an elecric motor but it would take like at least a 10 HP motor to power it thats gona be pretty big then you nee enough electricty to power it and it takes 744 watts per HP so that would be 7440 watts if you use a 12 volt system then you will need 620 amps so your gona need a bigger alternator

[150aintenuff]

ITS ALL A FUNCTION OF GEARING, and truthfully a paxton or roots style blower would possibly be the worst way to utilize echarging... to much friction losses... and 10 hp is assinine.... it only takes 1.5 to turn the space needle..... why on earth would a small fan or cage style blower that feeds the engine air versus the engine SUCKING IN air take 10 hp.....

[150aintenuff]

as for the original poster... you have approx 330 hp..... and most likely an A impeller...

those heads are killing you in terms of hp....


when you get the coin... heres a tried and true 640 hp NA on a 454 based 496...


AFR 315 cnc heads,
496 rotating assembly in 9.75:1
crane 741 hydraulic roller
1.8 ratio rockers
victor dominator manifold
1050 dominator
4.5" exhaust or 4" exhaust with jacketed pipes and tips
key here is AIRFLOW into and out of your engine.

stock stuff is restricted on both sides....


640 hp dyno proven and reliable when assembled correctly... several people have duplicated the 496 /640 over at OSO and on boat freaks.. the motor described was actuallly a moderators on boat freaks.org... just build up right and over build it and it will last forever... every component in a stock 330 hp 454 is designed to handle approx 500 hp with out failure, so if you build 600 make your parts stand up to 800 and your longevity will be same as your old stocker was

[455maveric]

Wow he only want 450 HP not 650 so the heads that are on top would get him there with out spending a whole bunch of money I am sure those stock ovel ports will flow over 250 CFM and that is enough to make 450 HP and a bit more

[boatermike]

timing play, fuel additives, spark plug reading and adjusting,alcohol/water injection, dry stacking exhaust for full throttle bursts,custom do it yer self nozzle reducer/focus device, all of that is cheap.

heres a typical day playing, first we add some fuel addtitives in exactly the directed amount times 2 and we take a real spin and see how it reacts,then we stop pull the plugs one at a time and adjust gaps open on colder or wetter cylinders and close the gap a little on any hot ones. then we spin again and come back and read again. second time out we replace coler plugs if they are still colder and use regular gap on a plug one step hotter for those cold cylinders only. then we spin again. lets enjoy that for the day and then return back to regular plugs, save timing tricks for next ride. next ride we find better fuel addatives and start with clean quality race gas, then addatives, then plugs then timing then nozzle focus.

cheap

[455maveric]

I thought i would post a link to this racing site they sell the E supercharger it is there test page they show a 15 HP gain and the thing takes 57 AMPS to run at 13.88 volts or 791.16 watts now I dont know if you put 10 of them in there will give you enough boost for 150 HP maybe and like i said that would be 7911.6 watts or about 10 HP
http://www.electricsupercharger.com/test-results.html

[boatermike]

i found it both interesting and funny. sure its not very good and neither is spiked gas. timing manipulations can yield big results though and those mods are cheap or free. plug reading and tuning can do a lot also.

have you tried any of that?

i also am wondering why nozzle focus isnt on the cheap mods list

i really like the boat in question and wonder if engine hatch or stereo or neon lights or any of that foolishness might be on the mods list, cause thats always fun 2

[jeepster21]

i found it both interesting and funny. sure its not very good and neither is spiked gas. timing manipulations can yield big results though and those mods are cheap or free. plug reading and tuning can do a lot also.

have you tried any of that?

i also am wondering why nozzle focus isnt on the cheap mods list

i really like the boat in question and wonder if engine hatch or stereo or neon lights or any of that foolishness might be on the mods list, cause thats always fun 2

Nope no engine hatch is going to be built, Maybe something over the drive shaft, since it has destroyed many life jackets and a few ropes over the summer. I dont need a stereo because it cant be heard any way and neon lights are for rice burners lol
As far as plug reading Ive only taken them out the see if I am running to rich or lean and thats as far as i have gone.
What is nozel focus?

From what I have been reading I might have to start saving some money
at least for some rectangle port heads and an intake
The manifolds that are on my boat are supposed to be from a 496 and supposed to flow pritty good

All of you guys have good ideas on what I should do and thank you for your help so far

Here is a pick of what manifolds are on the motor

[boatermike]

if the nozzle opening is reduced buy a sleeve that improves the focus of the water stream into a smaller pattern that is smoother the result can be less hole shot more speed. the reduced orifice size would increase pressure.

very little effort seems to be applied to the better focus of the jet stream by anyone.

and of course i have witnessed the positive affects on a friends jet boat but it was so custom that none of the big builders ever knew about it cause thats the way it is with real good stuff sometimes.