How 2 make an HONEST 500hp in a jet? [Archive]

396_WAYS_TO_SPIT

11-13-2003, 03:39 PM

I am looking to get an honest 500 ponies out of my motor. Heres what going in it. Tell me what you guys think.
i have a 454 .30 block,12-1 compression(Forged) pistons,all arp bolts,850cfm holley carb, (781's) large oval port (ported) heads w/ 2.19/1.88 stainless steel valves,comp roller rockers,Hv oil pump(blueprinted), and a clay smith fuel pump. as far as the cam goes it will be a custom ground clay smith cam(picked out by Bergeron marine-locally). I have an A impeller that will probably will be cut down to an Ab. i am assuming the cam will be around 245@.50 with something like .600 lift. timing around 36degrees total. i am guessing on this one so it could be bigger. What do you guys think about this set up? i tried to use the desktop dyno and I got a little lost so I am now turning to you guys. oh and I might even put a little blue bottle on it as well but thats not definite!Bergeron marine is helping me set this up because I have seen his set-ups and they do run FAST! besides he runs a few superstock boats and they do the work on them so I am trusting his words.
396

396_WAYS_TO_SPIT

11-13-2003, 03:42 PM

Oh i forgot my question. What are you guys running for a honest 500hp set up? What are your motor combos? i am trying to learn some shit about the Chevy stuff now since I am working on my "other" boat;)
396

Clown

11-13-2003, 03:51 PM

Use The Blue Bottle

Jim Brock

11-13-2003, 04:46 PM

let george at clay smith pick you out a cam, he will probably give you a 304-8 , thats 615 lift 304 adv. duration 108 lobe centers, will work perfect with ab empeller, Jim

Squirtcha?

11-13-2003, 05:06 PM

I don't know shit, so can't even think about making any recommendations. I do however, have a question..........
Do you really need all that compression Michael? It'd be a shame to have to run race gas in it. I'd think 12:1 compression would be pretty darned close to the ceiling (if not beyond) to safely run pump gas. Typically I hear 11:1 is about as high as you can go safely on 91 octane and that's pushing it. I'd think you could back off the compression some and still hit your mark?
Just a thought. Racing fuels are damned expensive.

stump

11-13-2003, 05:20 PM

http://edelbrock.com/automotive/index.html
Click on dyno test results and then click on 454 performer rpm 533hp or 540 hp it will explain what they did.
I built this package from edelbrock for my boat it dynoed at 502 HP .runs on pump gas 93 octaine might run on 91 but i never tried.we have 93 at the gas stations here in north carolina .This package runs great .It is dependable.I did everything they said to do on the setup except bore my block .I had a standard bore new MK 4 block so i went stock bore pistons.

RiverCityJet

11-13-2003, 05:31 PM

I agree with Squirtcha, I'd only go with 10-1 cr with that setup just to be safe. You allready have the big valves so I assume? you have had these heads pocket ported as well?. To free up a few more poneys go with a full Roller top end. You didn't say what intake you are using, I've ran a Victor jr with a 2" spacer with good results. A OT header is a must for around 25- 30 hp, if not just for the cool look and sound factor;) . This should get you close to your goal.
RCJ

TexasJet

11-13-2003, 05:35 PM

OK I have a jet boat, so this is relevant to "Just Jets". The motor was built by Owens Racing Engines in Pearland, Texas. I will start at the top: Holley 850 D.P Pri,79, Sec 87. Performer II ( I think ) intake. Oval port heads, some head work done. SS inlet valves and inconel exhaust. 468CI, just under 10:1 comp., Cam: Crane A236/325-2-10, Dur. @ .050= intake 236 exhaust 246, lobe sep 110, Crane gold roller rockers. Motor is balanced. Dyno: 529 corrected HP and 590FPT. All this info is coming from the spec sheet and the dyno print out Owens gave me. 34 Deg of timing and I run 93 octane. Hope this helps.

Jordy

11-13-2003, 06:05 PM

Who are you dealing with at Bergeron? Phil or Brian? Brian was working his own dealio on the side before his boat crash and was back working at the shop while he was doing his therapy. He's a good guy and will take care of you. He built my pump for me when he was doing his own thing and did a great job. Call me if you have any problems. ;) :D
They do know the yellow boat very well down there. :D

Keithb87

11-13-2003, 06:20 PM

I'm not sure what my uncle-in-law is running, but I do know that he is running 500 - 550 horse and only 8.9 : 1 compression.
I think they bored the 454 to a 468. Like 60 over. The cam is a little radical, and the intake is kinda high.
Hell I'll ask him what he did. But we just put it in the Omega this week. and with all the rain we haven't even gone to the lake.
I'll check with him when he gets back from hunting .

Squirtcha?

11-13-2003, 06:40 PM

Originally posted by stump
http://edelbrock.com/automotive/index.html
Click on dyno test results and then click on 454 performer rpm 533hp or 540 hp it will explain what they did.
I built this package from edelbrock for my boat it dynoed at 502 HP .runs on pump gas 93 octaine might run on 91 but i never tried.we have 93 at the gas stations here in north carolina .This package runs great .It is dependable.I did everything they said to do on the setup except bore my block .I had a standard bore new MK 4 block so i went stock bore pistons.
Stump
Are you running the Edelbrock heads too? I'm curious as to how much Michael's oval port heads would hurt those numbers. Ya know.........if he did everything but the heads. The sheet looks good. Run a B impeller with that motor, and that oughta put him right where the ponies live.
http://edelbrock.com/automotive/autopartsphotos/graphs/7161hp.jpg

Jordy

11-13-2003, 07:03 PM

Oh, and I'd scrap the 12:1 idea. You've seen my boat run and I'm running under 10.5:1 running on pump gas. ;)

Cs19

11-13-2003, 07:11 PM

I think you may some up a little shy if you run the pump gas compression. Thats just my opinion.

396_WAYS_TO_SPIT

11-13-2003, 07:56 PM

keep the imputs comming guys;)
as far as gas goes I will be running av gas:) Thats the only fuel I run in my olds motor and she runs great. Besides the airport is only 10 minutes from the house and its only $2.00 a gal. Why pay $1.75/gal for shitty gas when you can pay .25 a gallon more for better cleaner gas?????Plus it smells better:D
Ok now I have input about the edelbrock chart. That motor is for a car (right). In a boat the motor temp is running cooler plus the wet headers are a little different as far as restrictions. Now you have 500 ponies untill you hook up to a jet. Then what ponies are you running? We cant compare a car motor to a boat motor!
Oh my intake is a weiand stealth dual plane! And the compression will be at 11.7-1(I did more research on the pistons)
Jordy, yes I am dealing with "Uncle" Phil(well..... thats what I call him:D ). we have had to many long talks about horsepower,compression,intakes,carbs,jets,etc! The only reason I trust his word is because i tried to prove him wrong and i fail too many times:eek:

77charger

11-13-2003, 08:15 PM

i think your comp ratio is good for power but a tad high for av gas maybe 11-1 would be better.As for cam choice i think jim brock has a good recomendation and i have heard alot of good about clay smith cams that guy is familiar with boats.

460 jus getn it

11-13-2003, 08:16 PM

12 to 1, jesusssssssssssssss:jawdrop: :jawdrop: :jawdrop:

Squirtcha?

11-13-2003, 08:26 PM

Originally posted by 396_WAYS_TO_SPIT
keep the imputs comming guys;)
Ok now I have input about the edelbrock chart. That motor is for a car (right). In a boat the motor temp is running cooler plus the wet headers are a little different as far as restrictions. Now you have 500 ponies untill you hook up to a jet. Then what ponies are you running? We cant compare a car motor to a boat motor!
Those are dyno ponies so that motor is neither in a car or a boat. It's on a dyno. The reason I was saying it'd probably make a good boat motor is because the horsepower and torque are coming in at the proper rpm for a pump running a B or maybe an AB impeller. You'd probably be running around 5500 rpm give or take with the B impeller and 520hp. Those sound like pretty good numbers to me.
Oh yeah, I agree with Jim Brock and Charger. I'm running a Clay Smith cam in my BBF and it's worked out real well.
Dude, if you just want someone to agree with the stuff you've already decided on, there's not much point in posting. You asked for opinions, I thought that's what you wanted.
Whatever ya decide to do........................good luck with it.

quiet riot

11-13-2003, 09:25 PM

I know it may be a little apples to oranges comparison here, but edlebrocks packages have always been pretty darn close from my exp. I've only done sbf's, but my current 351w is a perf rpm setup that charted out at 412 hp (at the time I built it by edlebrocks charts) @5200 rpm. I knew I wanted to cheat it a little so I increased comp from 9.5 to 10.2 and slightly increased cam lift, but still ran iron heads w/2.02 int instead of edlebrocks alum rpm heads. With wet centeriser man exh it turns a legend A imp right to 5k which is supposed to be around 430 hp. If you want to make the 500 hp mark, I'm sure you could do it by following their chart, and maybe cheat the comp and cam slightly up to make up for wet exhuast, etc.
I've also done a edlebrock 302 with their streetmaster setup, (precurser to torker, I think) and an performer 302 setup. They all seem to come in right close to edlebrock's predictions. Just remember, if you start straying much, like 12:1 comp, diff int man, porting, etc, make sure you get the cam to match the new setup. And remember, you still have to make it a lower rpm power builder for a jet (5-6k usually.)
With a 12:1 big block, If you match a cam and head work and intake, I think you should easily be looking at a higher hp range? I'm just about done with a 408 sbf, and I think I'll dyno it just for my knowlege, but its 12:1, plan on av gas, has good al heads, but with cam and intake matched I'm shooting for 600 hp. My machine shop and several stroker small block buildups I've seen are hitting this mark below 6k.
Just my .02
jd

H2OT PURSUIT

11-13-2003, 10:44 PM

Originally posted by 396_WAYS_TO_SPIT
I am looking to get an honest 500 ponies out of my motor. Heres what going in it. Tell me what you guys think.
i have a 454 .30 block,12-1 compression(Forged) pistons,all arp bolts,850cfm holley carb, (781's) large oval port (ported) heads w/ 2.19/1.88 stainless steel valves,comp roller rockers,Hv oil pump(blueprinted), and a clay smith fuel pump. as far as the cam goes it will be a custom ground clay smith cam(picked out by Bergeron marine-locally). I have an A impeller that will probably will be cut down to an Ab. i am assuming the cam will be around 245@.50 with something like .600 lift. timing around 36degrees total. i am guessing on this one so it could be bigger. What do you guys think about this set up? i tried to use the desktop dyno and I got a little lost so I am now turning to you guys. oh and I might even put a little blue bottle on it as well but thats not definite!Bergeron marine is helping me set this up because I have seen his set-ups and they do run FAST! besides he runs a few superstock boats and they do the work on them so I am trusting his words.
It sounds like you think highly of your engine builder. What does he say about that set up making the 500 HP your looking for???
396

SPECTRABRENT

11-13-2003, 10:55 PM

Cubic inches=HP
500+ inch Chevy.
Brent

PipesClean

11-14-2003, 06:35 AM

What's up bra?
Do you have any pics of said "other boat"? I'd like to see um.:D

Chris J

11-14-2003, 09:17 AM

Most dyno are nothing more than a large water pump. So if you dyno with your headers and hold the motor at your normal run temp your dyno sheet will be dead on.
I assume you plan to use the boat for racing. If you must run 12-1 get some square port heads and shoot for 650-700 hp. Using 12-1 with oval ports is like installing a racing cam in a stock motor (the pistons are hi rpm full race and the heads are lo rpm touque). In order to use the 12-1 to its fullest you need a long duration cam that will kill bottom end touque.
If you put a mild cam in a 12-1 motor the only thing you'll notice is that it starts very hard while eating up starters. Also if you plan to use the boat for tubbing or skiing better get some goggles the AV gas fumes will burn their eyes big time.

Phil Deez Knutts

11-14-2003, 09:49 AM

Originally posted by 396_WAYS_TO_SPIT
as far as gas goes I will be running av gas:)
Serious response here:
What are you doing for added lubrication? AV gas works great, but is lacking in lubrication. The trick to making your motor last long on AV gas is to add oil, not a lot. I will look up some magic potions for you. I believe one of the best secret formula's out there uses a combination of 2 stroke oil and Marvel Mystery Oil. Like I said, it is not a lot - but just enough to lube without smoking like a whakka.
The reasons airplanes get away with it is lower RPM, Lower Horsepower, and less complete burn at altitudes. AV gas is a fast burn fuel by design - not neccesarily what we are looking for, but the added octane overcomes that. But, additional lubrication is needed for long term durability.
Bumblebee Tuna

Blown 472

11-14-2003, 10:06 AM

You could build a blown motor, low comp runs on pump gas, no stress on motor til your houndin on it, will make 600 hp with oval ports and a flat tappet cam.

Phil Deez Knutts

11-14-2003, 10:16 AM

Originally posted by Blown 472
You could build a blown motor, low comp runs on pump gas, no stress on motor til your houndin on it, will make 600 hp with oval ports and a flat tappet cam.
Is that corrected or uncorrected #'s?:D

Blown 472

11-14-2003, 10:22 AM

Those would be the magazine article correction factors.:D :D :D
It was a chevy magazine I saw the article in.:rolleyes:

396_WAYS_TO_SPIT

11-14-2003, 07:13 PM

Ok I did put a little more thought into it with all of the suggestions I got from all of you all. i am going to order a set of pistons that are around 10.7-1. how does that sound? Besides the price of those 12-1 pistons are $600 plus $100 for the rings :jawdrop: :jawdrop: :jawdrop: The 10.7-1 pistons are a little easier on my wallet;) What do you guys thing about that?
Oh and I have another block I can put a huffer on once this one is done;)
396

Mopar426

11-15-2003, 06:40 AM

12:1 and you would have to haul racing fuel to the lake. You can make well over 500 hp with todays technology on 92 octane. I agree with the others 10:5 Maxx!!. My engine runs 7.5:1 static and 12psi boost gets me 11:5, but I can cheat with the blower or under/over drive. I use Chevron 92 with a dash of octane boost and save lots of cash over AVgas.

78Southwind

09-02-2004, 10:49 PM

:cool: :D

LVjetboy

09-03-2004, 01:37 AM

"So if you dyno with your headers and hold the motor at your normal run temp your dyno sheet will be dead on."
Dead on, or dead wrong if you expect to run corrected hp #'s at the lake/river. Mags typically report corrected hp.
"Besides the airport is only 10 minutes from the house and its only $2.00 a gal. Why pay $1.75/gal for shitty gas when you can pay .25 a gallon more for better cleaner gas?????Plus it smells better"
Smells better I agree. And, "I'm runnin' Av gas" sounds cooler too. Got a wiff of more than one runnin' high at FBC and C3B. Does smell = performance?
Not necessarily.
How close is that airport to where you boat? If you can't fill at the dock that's a serious problem at some lake/river boat areas or events. Cart it in or pull the boat and go cross country for fill-up. My engine runs true lake power of 650 hp on 87 octane. That's dock gas at Powell (not pump gas). A compromise I chose that limited power but well worth it. Mead has an incredible 89 octane at the dock. :D
My point is, if you constrain yourself in the build, you may regret later. Gas octane goes down not up.
jer

396_WAYS_TO_SPIT

09-03-2004, 01:47 AM

Damn bro, you drug this post out again???? :D :D Well I have changed my whole flow and I am running rectangular port heads with 12-1 comp. Honestly I really dont give a damn what hp I am running;) All I really care about is my rooooooooster tail :D :D :D :D :D
396

LVjetboy

09-03-2004, 02:02 AM

"Honestly I really dont give a damn what hp I am running All I really care about is my rooooooooster tail"
Then run cheap gas like me you still got tail. :wink:
jer

starbuck

09-03-2004, 02:08 AM

i was running 12-1 compression in my vette. dont get me wrong it ran good. you will notice a difference with higher octane gas. without high octane gas you do not want to use that blue bottle. but i think your on the right track with that motor.

Jordy

09-03-2004, 06:48 AM

Well I haver changer my whole flow and I am running rectangular port heads with 12-1 comp.
396
12:1??? You're insane. I was at just under 10.5:1 with those heads on the yellow boat. With the new heads I'm down to 9.8:1 and I'm pretty stoked about that. Now it will run on pump gas and live. I was running right up against the line with that last build and had some detonation issues because of it.
As far as the 11:1 comment on pump gas, maybe, and I mean very shaky maybe with aluminum heads. Wouldn't catch me playing there though, maybe with your engine. ;)

396_WAYS_TO_SPIT

09-03-2004, 08:07 AM

12:1??? You're insane. I was at just under 10.5:1 with those heads on the yellow boat. With the new heads I'm down to 9.8:1 and I'm pretty stoked about that. Now it will run on pump gas and live. I was running right up against the line with that last build and had some detonation issues because of it.
As far as the 11:1 comment on pump gas, maybe, and I mean very shaky maybe with aluminum heads. Wouldn't catch me playing there though, maybe with your engine. ;)
I am dropping the heads off today to have them set up along with my block :D :D i am getting butterflys already :D I will be building next week. Then is all downhill from there. I know its a little late in the season but I will still be out there even if its october :D
396

396_WAYS_TO_SPIT

09-03-2004, 08:08 AM

"Honestly I really dont give a damn what hp I am running All I really care about is my rooooooooster tail"
Then run cheap gas like me you still got tail. :wink:
jer
Tail is one thing.........but I want a monster tail :D :D :D an it takes hp to get it up there;)
396

Jordy

09-03-2004, 08:30 AM

I will be building next week. Then is all downhill from there. I know its a little late in the season but I will still be out there even if its october :D
396
I just got my longer exhaust pushrods, got my intake back from being ported and polished. Now it's just a matter of buttoning up the little things and I'm there. :D

Rampager

09-03-2004, 08:33 AM

I've done a fair amount of reading on comp ratio's since I blew the last motor and I'd strongly suggest you read up on what the manufacturers are doing.
Detonation kills boat motors, I think we all know that and jetboat motors maybe even moreso.
Mercruiser motors that make over 500 HP rarely see 10:1 and often are less than 9:1
That begs the question of why bother taking the chance?
I'd opt to buy good forged pistons, stay less than 10:1 and concentrate your efforts on the whole package. I'm sure thats what the big companies do and they do get the results and the relaibilty they need to sell the product
I don't think you need more than 9.5 :1 to make 500 hp easy
Cheers

jstwkd

09-03-2004, 09:15 AM

you buy mine that puts out 600+ mark on pump gas...LOL
12-1 is to high 11-1 with alum. heads is the highest you can go and still run 92.alum disipates heat faster..but you are right on the mark..of loosing it ..Mine is running 9.6-1..if you want power do some bad ass heads..with a strong bottom end

396_WAYS_TO_SPIT

09-03-2004, 09:36 AM

I just got my longer exhaust pushrods, got my intake back from being ported and polished. Now it's just a matter of buttoning up the little things and I'm there. :D
Whats up jordy? When you going to have that biiiioooottcchhhh done;) I just finished mu tunnelram and that baby looks mean as hell.She sure is going to suck some gas down;) All I need to buy for the motor is some braided line,fittings,and a timing set. Then I will be firing that biiooootch up for cam breakin and tuning. But I still need to do some body work on the hull before she gets new skin;)
Oh and one more thing........That DAMN yellowass paint was a son of a bitch to get off them heads :eek: I was sweating my ass off all day in the sun being burned with aircraft stripper :eek: I think I added a few layers of color to my skin doing that :D :D
396

Taylorman

09-03-2004, 01:27 PM

MudPumper

09-03-2004, 06:01 PM

396, My motor dynoed 485 HP @5400 rpm with 9.3-1 compression. Peak torque was 552lbs @ 3770 rpm. My heads are iron large ovals with stainless valves, no port, polish etc.... I have a stock steal crank and stock rods. The cam is .513 lift 309 duration. I'm running a performer RPM manifold with stock Holley 750 dbl pumper. I'm turning an A/B impeller at 5200rpm and the boat gps's a consistent 77mph. The motor is very mild and didn't cost much to build. With a better manifold and the right carb and some mild head work I'm sure it would make over 500hp. I would say your quest for 500 hp is a simple one. I run MSD ignition and the boat fires easily and runs smooth on 91 octain. For what I have, I am very pleased with my performance but knowing how easy it was I would have set the bar around 600hp because I find myself wanting more. I hope this can help and good luck.
P.S. Don't forget, pump work and setup play a HUGE role in what kind of speed and performance you will get out of your jet. I gained 7.5 mph my just having the bowl and impeller detailed and adding a loader. I'm not running a shoe or rideplate.