New 572 builds hp guesses
 

Redoing my 572's. Tall deck, 4.560 bore, 4.375 stroke, 10.0-1 compression, [email protected] [email protected] .632 lift .632 lift 112ls hydraulic roller, promaxx 317 by Valeko flow 375 @.650, single plane intake with 1050 dominator. Will dyno one of them, what will they make??

Im not a pro guessing hp but i will say 720 hp!

Rob where you dynoing at? What cc did your intakes end up at. I would guess around same 725 range at around 5,800 or so. You using 1.7 rockers. I'd think that engine would like a little more cam and carb but you'll have good power without valvetrain issues. At the end of the day that's all that really matters.

740 with dyno headers is my guess.make sure to let us know your results.

What intake? Also did jim do any work to those also.

738@6000 safe tune, 745 lean and mean

this ^^^^

1.7 rockers, intakes are from my zz572 motors that gm rebrands. Jim said they look like a Dart or a Merlin maybe. Valeko has the intakes manifolds so he can port match them to the heads. The intake is for a 4150 carb, but we are using an open style 2 inch adapter to get us to a 4500 1050 dominator. Valeko is also porting the intake to to this spacer and actually doing some custom work with the spacer so it's sort of a hybrid between an open style spacer and the 4 hole hvh style. Jim said the spacer will act like a mini tunnel ram and create more volume. I am looking for dyno suggestions. I was going to go to Dick at More Power in Sparta MI because it's just down the road and Dick is a nice guy. But Valeko said his dyno is a little stingy.... Jim thought Smitty might be interesed??

Tom Earhart for the dyno. PM me if you need contact info. Jim knows him very well.

Rob, dick at more power is a great guy and facility to dyno and that's actually why I asked cause I know his numbers typically come in lower than others but who cares. Main thing is you get it tuned right. Toms a good friend of Jims and a good option also. If jims helping you with it and going to be there while dynoing then have I'd tend to leave it up to him. More power has always been more convenient for me as I lived right nearby and practically lived their at one point.

Will be a really neat dyno though using the original zz572/620hp cam. Basically heads and carb change. Keep us posted and good luck.
John

That dom on top of a 4150 intake with spacer going to work well. Cram all the air in there you can.

Thanks for all the help guys!! Obviously the biggest reason to dyno is to tune. However I was really hoping to see 750hp..... love to have a dyno slip that says 750's vs 720 or 730's. This is the only reason I wouldn't use Dick if his dyno really does read low. Dick is a great guy and have been there many times picking his brain:)

Not trying to be a smart ass, but the only dyno reading that matters is your gps. Hope you hit your number.

Ya... apparently a 4150 intake with an adapter to a 4500 carb can make more power than a 4500 intake!!

My advice for a good dyno shop / services.

Find a dyno guy who is willing to try things on the dyno. If a guy's idea is to set the timing to XX degrees, go up or down 2 jet sizes, and call it a day, is a waste of time and money. A good dyno shop willing to spend time with you, finding the optimum tune, is well worth the cost.

You'll always hear about how a certain persons dyno is "stingy" . If I had a dollar for every time i heard about so and so 's dyno being "conservative" I'd be a rich man. Then you'll hear the opposite, and guys talk about someone elses dyno , and say that dyno is "optimistic". Its always "my dyno is conservative" and "their dyno is optimistic".

Bottom line, look at a shops dyno facility. See what kind of data acquisition he has. You want that info, and it will help make things a little clearer on whether or not the numbers are in line. Its easier for the drag racers to test the validitity of dyno numbers, than us boaters. I've seen some dyno's at shops that look like they are straight out of WWII era. Barely any data aquistion, who knows the last time any calibrations have been checked, etc.

Slight side track.

Some days I have a happy GPS - only happens on max recall speed. Seriously. Think this make's it worth big $$$$ other than break out racers of course. LOL. :)

Do you have a carb picked out? PM me if you want to try one of norms highly modded 4150s, it beat the doms on my dyno hands down, 16-20 hp, I could arrange to borrow you one, Smitty

Rob I just spoke to Norm the carburetor guy he is willing at no charge to come to you Dyno session with two of his highly modified 4150s after you have your motor broken in and running on your dominator and personally tune them and see if there's a horsepower gain if you are willing to consider purchasing one if it works we recently saw 18 - 21 horsepower over a box stock dominator and a modified dominator on my 548 it's a no-risk offer let me know

What an offer Rob! You'd be crazy to pass that up! That's really cool of you to arrange Smitty.

I've spoke with Norm and really enjoyed our conversation, great guy that you just get a good feeling about when chatting.

Plus his success has already been proven, Definitely at the top of list next time I buy carbs!

http://www.compfuelsystems.com

Smitty, that is very generous!! My new Holley 1050's literally just showed up today...Are you offering a dyno service? I am also having Jim doing these custom 4150-4500 adapters. I feel like I am to far along to switch up now but they sound like they rock!!! I read your 548 post and they sure proved themselves there!! Can you let me know on dyno and carb pricing??

What im saying is if you get your motor on a dyno over there, break it in, tune it with your setup, its up and running, lets for example say you make 738 hp, norm comes next day, at no charge, you warm up motor, make a baseline w your dominator, you make same 738 hp, norm then bolts on his carb, you make a couple pulls so he can dial it in, lets say you make 756 hp, a 18 hp gain. Now, you wanted 750 hp, bam, you got it and then some, sell the dominators! Too bad you didnt borrow them! Scenario two, makes same hp, thanks anyways norm, no harm, no foul, lol! He recently sent his 3 barrell 4150 to a guy in new york, has two normal front venturis then a oval secondary, made 823 hp on a class iron headed mud truck motor, think he said they made 21 hp over there other carb. Stuffs cool, not cheap though, he gets 800 to 950 to put 15 to 20 hours of work in a existing carb or on top of price of new carb. Myself if i could write a 900 check for a extra 20 reliable bolt on hp i would! Norm wants to break into.marine market, tim full forces QF 1050 made 655 or 654 on my dyno within a hour of norms carb making 673 ish

As far as dyno service, im retrofitting new software and sensors on dyno which will prob be two weeks before its done, would be 750$ to get motor on, broken in, tuned and back off, you bring or buy your own fuel, plugs, etc. I would have to know ahead of time to coordinate it with days i could be there all day, Smitty

Just a thought rob but you could always just buy another 2" spacer and try the norm 4150 carb. Based on smittys ongoing trial and error I would have to say that norms Carb would likely give you near same gains plus or minus a little. Either way you'll have a nice solid reliable build. I don't mean to dwell on the fact how glad I am your keeping the same cam and intake. It would be cool though to see one of norms 4150/850 carbs on your build but then again you have a good foundation and your in good hands with Jim. Try everything you can while given the chance. That's what I've always liked about more power is I've had pretty much free rein of the dyno room without being rushed. But again I know Jim and Tom are pretty tight so really don't matter. Tom is a HP wizard with knowledge that many could only dream of having and then some. I'm referring to the area your in. You also have Dave Wesseldyke down there on the SW side of GR but I have no personal experience with him.

I think your on the right track.

Thanks Smitty, I will keep in touch as I get closer to having these ready!!

If norm came he could bring a 2"4150 spacer to try too, its possible even if your not interested in switching carbs he may still want to come run his carb just to do a comparison, keep it in mind

The real bummer is I just my holley 850's, and it sounds like Norm could have built off of the carbs I just sold... His website says he uses Holley's and being a 4150 I am assuming he starts with either an 850 or a 950. My 850's were only 3 years old and like new:(

The way I see it if you make a 100 hp gain with basically little bump in comp, heads and carb your doing more than great. I'm surprised Jim didn't talk you into cam swap. Look at offshoreexcursion 572 builds as a comparison with more cam and cnc afr heads with SV intakes if I recall.

That's awesome. Wish there were norms around!!!

I definitely will!! Even if it's not in the budget now if we ran them just as a comparison I would know if they worked for my buold and I could purchase them down the road and get my 20hp when the wallet thickens.

So speaking of cams, what would be some suggestions to take full advantage of my new heads, comp ratio, and keeping good valve train reliability and a hydraulic is a must. I cannot remove the valve covers with the motors in the boat! And what hp gains would be seen over my current cams??

Flow heads, make sure you have all other info and what boat it's going in and call 6-8 cam grinders, pick the one that is most offered, that's what I did stay tuned for results lol

If you go down that road Jim will lead u in the right direction. Ask him about the grinds he used in the 540sc's he did over on the east side of the state. They work well with NA builds also but I think you'll be ok with your cams considering the gains your going to have in the head flow unless your going to wanna really turn up the r's.

Btw don't let the carb thing bother you but by all means if norm is willing to come down to dyno session to help out and try a couple different carbs. It's a win win for everyone including himself. Like you said you can always strap a couple of his on down the road. This is the kind of stuff that can keep you from sleeping at night. The time when you should get some sleep but your mind goes into hyper hp drive. Lol... happens to all of us.

Be careful listening to to many cam guys you'll be all messed up in the melon. You get to big you'll lose your velocity and ports will become lazy and lose efficiency. Let the heads do their work.

Yes, he likes to start with a holley 4150 850, he also builds dominators but swears until you break 800 hp and especially in the 600 to 750 range a dom will never beat a 4150 that flows equal air. Once you have 2 carbs that flow in 1150 cfm range, its not air flow as they flow same, its fuel atomization and flow curve of boosters etc. I would love to see his 4150 against a dom on a different dyno than at my shop as i have had people imply the testing i did was canted to favor his carb. I dont sell carbs, i actually hate them as i am a efi guy, i was just beyond impressed as to what i saw testing 4 different carbs on my motor. I always figured a custom carb done right was worth 2 or 3 hp, not any more!

Norm dislikes the 950hps and qf bodys that also look like the 950s, he says though they look cool with their casted body that looks hand worked, the flow sucks compared to leaving the divider wall between primarys and secondarys and working it, to effect of 20 or 30 cfm, he says the guy who designed that which i think was braswell sorta knew this but holley went with it because looks sell

velocity key while maintaining good signal. Head and intake port velocity gets brought up often but carbs nowhere near as much while funnel affect works also but back to back testing challenges that theory but again each build can be different. Looking forward to the results moving forward. This kind of thread is great for everyone.

There is no better test, than trying things back to back on a dyno. Swapping cams, is a pain in the azz obviously, and rarely done. Swapping carbs out, no brainer. Easy as pie. But sometimes, what works on one engine combo, may not work on another. Something as simple as the camshaft events, can change the way things respond. A cam with more overlap, might respond really well with a bigger carb, than an engine with less overlap, or different timing events.

You can have an engine that shows it's using 980 CFM worth of air to make 700hp on the air turbine, and then change camshafts, and have an engine thats using 1030 cfm of air, and make 700hp, or 680hp. If the additional airflow is going out the exhaust via overlap, or exhaust timing events, or a dozen other things.

You gotta decide on the cost as well. Dominators are typically more expensive than a 4150 carb. Tim Full Forces carb, costs about 750 bucks if I recall. A custom 4150 carb, can cost twice that. When we dyno'd tim's engine , in full Marine dress, with his exhaust and accessories, a couple changes to the jets, and his air fuel ratio didn't vary from 3000 to 6000rpm by much more than about 2 tenths of a point. In the boat, if I recall, he also had a pretty linear fuel curve for cruising, and wot. For an off the shelf carb you can have at your door in two days, I'd say thats pretty dam good.

20hp gain is a nice gain for sure. Would I spend the 1600-2000 dollars for an extra 40hp (twin engine boat), myself, probably not. I am a cheap bastard, and in my boat, 40hp total, is probably worth 1, maybe 2 mph at best. I'd be more concerned about the fuel curve of the carb, and whether or not I can make changes to it. Thats why I got rid of my old 1990's holleys for the 4150 quick fuels. I like screw in air bleeds, screw in power valve restrictor jets, and so on. This way I can tune easily on the water with a wideband. Trying to fine tune a twin carb blower motor, with only main jets, can be kind of limiting.

I know that eddie young borrowed a quick fuel 1050 B2 blower carb from us. He had built a mild HP500 upgrade. Mild cam, brodix heads, dart intake, basic budget combo. It made a chit ton more power than the stock HP500 carb. Of course it took some tuning as the carb was setup for a twin carb blower application, but none the less, when all said and done, he picked up a ton. I don't remember the exact number but it was like 60HP to the better. That was an easy sell to the customer after trying that carb out on the dyno back to back with the original carb.

big cube engines like a wider lobe sep. I think 114 would be better to carry torque flatter and longer without drop off and more lift where the sweet spot of flow is in heads. Torque is what pushing a prop. I'm gonna say ur set up will be close to this pic dyno sheet. Zz572/620 in my last boat. Engines wouldn't pull past 5450 in my last boat [ATTACH=CONFIG]565973[/ATTACH]

Icdeppl's 548ci 900hp carb'd roots engines. Twin 1050 quick fuels, out of the box idle circuitry. Engines stone cold after startup in this video. He runs no water stats, so the engines never build any heat in them. They will idle at 950 in nuetral, 700 in gear, and idle all day long without fouling a plug, or stalling while shifting around the dock with 17.75" cleaver props.. I've seen some high end big name built 900hp roots engines, that surge like a MF'er, stall out when shifting around the docks, blacken the transom after 1 day on the water.

https://www.youtube.com/watch?v=a2R0Ly41uvo