Why don't you tell us all WHY a 509 with a 240* cam won't make 700hp? We deal with customers who have over cammed, over headed, piss poor combinations that don't make power every day. Typical internet builds like the ones you posted links to. It's all too common and unfortunate when people spend a bunch of good money and follow really bad advice on trying to make good, usable power. The 509 that made 709hp had no port work done, no vac pump, no crank trigger, no trick carb, and had a hyd. roller. Funny thing is, we did the first pulls with the customer's 850 Demon vac. secondary carb and the best it did was 652 hp and 641 tq. The customer was pretty impressed, even at that, till I bolted the 850 DP and a 1" spacer on. Just a carb and spacer were worth over 50hp, and no one would have known the difference had we not tried.
So again, instead of just repeating something can't be done, just because YOU say so, tell us WHY.

If you want to read about a bbc that made a little over 700 hp (900+) with a 240 @ 50 cam, you can go to web site with some fairly sharp people talking engine combos (yellow bullet). Look up a thread about "My 565" of Engine Masters experience".

For the record, I see Foxwell and Staub in the mix on that site but I don't see any famous engine marine designers over there. I also see head designers, NASCAR engine builders, Pro Stock engine teams, cam designers, spintron experts, as well as plenty of drag car guys. On a site with some heavy engine talent they seem to contribute quite well. It baffles me with this site's level of knowledge that we don't listen and learn a little better. For the record if Scott would have made that math error on yellow bullet several guys would have caught that and corrected it within 30 seconds (led by Stan Weis math expert). Maybe Scott didn't make a mistake and was testing us over here?

Gee, the just typical BS response I thought I'd get. I hate to tell you, but you don't have to get paid for building engines to have been there done that. Not even getting into the boats, how many engines do you think we built in 9 years of racing? How many do you think we had spares of? I have no idea how many or if any motors you have ever built, for your own stuff, but I will bet that it was no where near that number. Not to mention that to keep up in racing the tech changes most times during the season which means even more tear downs. You ever pull the heads on a motor in the dark at midnight in a mud field?

So yea no, I'm not an engine builder. ;)

So you just described straub and foxwell. because straub can't use a screwdriver, nor can he "rig boats, prop boats, set up x dimensions, tuning, , and so on" Neither does foxwell. straub sells parts Ask him to use a wrench and he's done. and in foxwell own name dropping "biography" note that he has listed ONE jet boat. Thats it. ONE. If you want to call a jet boat offshore, you need to get back on Google!

Because there are maybe 3 people here that know what it means and even less that care. This is NOT a drag race forum where 1 HP is the difference between winning and going home.

I didn't intend to turn into a negative, I just asked a question, for my own knowledge. I have neither bashed nor cheered either side in this.
Another question, same 540 with 315s will it be a turd, have less power, or an unusable power band?

And yet, you still cant answer why you are advising the 315 heads are the way to go, over the 305s , and what kind of gains will be seen

You keep reverting to how this isnt a car forum......well, many of the guys on those forums have built a good amount of offshore engines as well. You think alex haxby, dean gellner, richie zul, paul phaff, or many others, have never built a drag racing engine? And because they have, should we discredit their advice on a marine engine build ?

Darrin morgan and curtis boggs posts on those forums, should we ignore the cylinder head advice they give , because they dont normally deal with 600hp 509s with silent thunder exhaust?

Mike jones has a bunch of offshore engine builders that use his camshafts, and he posts on those sites. Should we discredit his valvetrain knowledge ?

Let me ask you. Offshoreexcursions 572 that made 750hp at 5900 with a 240ish straub cam, on an independent dyno, how does that stack up to your superb 637hp 509ci build ? Looks to me, he was making more hp per ci than your build. Was your engine dynoed with your silent thunder wet exhaust at that 637hp, or was that with dyno headers ? Do you have a dyno sheet on yours to post up, since you seem to enjoy discussing correction factors on others builds ..

Still same as us, yes I have pulled many engines part the night before going racin and such, hence my boats name is quickchange.... You don't know me, I don't know you, but neither are professional builders and advice is just opinions. Simple as that...

I can't explain it to you because you, just like foxwell don't understand how airflow on a MARINE engine works.

But hey, the Holley chart says that a 502 only needs a 600-650 cfm carb. Try that on a BOAT and tell me how it works for you

What about a 540 with 325's?

so you have to get paid to know anything for "fact"?

Nope, just saying you discredit others and you are gospel, we see it otherwise .... So what's the difference? Thought so... I know fact also but people don't care because I am not a engine builder by trade....

At that rpm there would be no difference that you could tell. The 315's might make the engine a little lazier, but not that you would probably notice. Certainly not worth the extra cost.

So now "marine engine" airflow is different than "car engine" air flow?
Well please, PLEASE explain that one...LOL...
Man, you really need to stop.

Please stop trying to act like you have the slightest clue, about what i "understand" . While you have been standing at the dock dreaming of those silent thunder days, Ive done plenty of carb tuning on 900 plus hp roots blown marine engines , NA engines, and some blow thru deals making 1200 plus hp. and certainly not the guy who would be recommending a 650 carb on a marine 502. My current 468s have twin 850s on them.

What carb did you have on those 509s ?

For someone who is supposed to be so busy building things you sure have a lot of time to waste posting on the internet.

Unlike you, I do have things to do that are more important than trying once again to teach you the difference between a marine and drag engine.

where did I say the airflow was "different"?

Because you even have to ask me this question shows that you don't know anything about marine engines. (or I guess you think a 600 cfm carb is enough for a 502 marine engine). Maybe you should stick to drag racing sites.

you have a nice day posting while the rest of us that have work to do in our jobs get back to work.

Just quoting the holley book to you. you are so in love with google that I thought I'd save you some time.

So Dale, what's the deal on the heads? You have not posted the situation yet.. What's the deal?

I have enough hours and enough motors done to know BS builds when I see them. Just because I am not a "professional" has nothing to do with it. Just because you do it for a living, doesn't make you the expert. How many people thought Trick Marine was great???

I dont do it for a living that's my point...let me ask you what would you recommend for a 35 mistress to see high 70's to 80 mph? Using 540 platform?

Went 73 with 598hp 661tq 565's before

Zone 5, your technical insight on this thread, has been amazing.

Anyone is welcome to stop by the Piney Flats Industrial Park and drop in on us. The park entrance is 15 miles from I-81 and is 7 miles south of Bristol Motor Speedway. We lease 7500sq/ft of a 27Ksq/ft building. This houses offices, inventory, and cylinder head shop and our retail speed shop. We are open from 8;30AM to 6PM Monday thru Friday. Photo’s can be taken. You can meet us face to face or if you are going to PRI we are Booth 109 in the main hall in Indy.

I was going to start a thread about max compression ratio on a blower application, but I think I'll pass, I may pm folks individually to get their opinions, carry on with this senseless crap

Im at 9:1 , with 155ish cranking compression, 6lbs boost, non intercooled, 34 deg total timing. Been that way for many years. Intercooolers going on this winter, to see what they do for me.

Thank you for the reply.

That's about as far as I'd push a pump gas blower motor especially non intercooled. It's all about managing cylinder pressure. You can have more static and less boost for better throttle response and idling/low speed quality, or less static and more boost for more HP. Everything in an internal combustion engine is a compromise.

I prefer 8.2 to 8.5. The bigger the engine the lower I prefer. I tried going to 7.4 on some 605s. I usually use a theoretical compression of 184 psi max.

A blower.:D

If this was any other thread, I'd love to talk engines with you. But there is no way I am going there on this one.

Geez, all I have to do is look at the title and the number of pages to tell if a thread has turned into a pizzing match. If it has "cylinder heads" or "camshaft" in the title, and it suddenly balloons beyond 20 pages, you can safely bet that it has degenerated into a "he said, she said" type of thread. :( :eek: :helmet:

then post it somewhere else... I would love to hear your findings it's easy to post other stuff why not now? If your so great let's see what's offered

Ok Tim i will lol. Heads are bought, Dart 310 Pro One heads, so.............tell me what rotating assembly i should run. What compression should i run and what rpm should i shoot for to end up with 700hp and lots of torque throughout the rpms. Also what would be a good cam to run? The blocks are gen 5s.

My best advice....PM Eddie Young as that's another thing that will be war here lol

I'll say this: we do not have or own a dyno. The few complete engines we do here we use Bob Meyers of Automotive Performance and his DTS. Our induction packages have been dyno’d at Ricky Watters, Tony Skagen, Scoggin and Dicky, Mike Lewis, Al Parker, Owens Racing, Jon Kaase, Vrbanic Brothers, 3V Performance, Kuntz, Carrita’s, Dave Wesseldyk, Rick Rapp. To my knowledge not one customer has ever been told the numbers were BS. Some of these shops have actually become customers

can,t you guys see that zone5 likes to toot his own horn.he cant dazzel with briliance so he must baffle with bullchit.with every post he makes it becomes more clear that he likes to argue.at this point i pay little to no attention to him and the rest of you guys might want to ignore him.zone,i don,t have the time or desire to argue with you so when you reply to this post with your usual bullchit it won,t get me riled,in fact it won,t even get a response.

scott,i will be at the pri show.if i get time i will stop by and introduce myself.

I'll look forward to that. Thanks.

Really Mike? The fact that I (and many others) call BS on straub and foxwell is tooting my own horn?

I posted my background as requested. Seems that isn't good enough for you guys, (not being full time doesn't count) so you would rather listen to a guy who was kicked off this site and had to sneak back on with a different username. along with his boss who is banned from this site.

You seem to think that its okay for mild thunder to post total garbage and insults and thats fine. How about you call him out and explain that because he bolted a carb on an engine once that hes not an engine builder. But hey, he did stay at a Holiday Inn Express last night so he must know what hes talking about.

Ignore my post all you want. Why would I care? you have sunk to the same level as foxwell and straub and a few others posting on this thread. I thought you were above this, but clearly you aren't.

Point blank. What makes you mad and why you posted that above, is why you should Ask Mr Foxwell and Mr Straub exactly what you wrote above, and have them put their experiences of what they have done in a real life offshore or any other I/O boat. Down in the bilge, from tuning, to rigging, to repairs, to propping, to changing outdrives. Any and all of that.

I want to see that here and I want you to see the truth.

Zone you are wasting your time going back and forth with any of these guy's. straub and foxwell got kick off the site when this site meant something, the owners knew what was going on and the mods did their jobs. Those days are long gone and its threads like these that bring in the traffic that pay the bills. I am tired of fighting with these idiots, how about you start a thread over on BF about the chosen few that get to carry on over here and invite them there with mods to control the BS.

Damn! I just joined last year, retired Pro Drag Racer (asphalt) gone wet....what other sites might I like? I like TECH stuff...not bashing and measuring Dicks!