building my 460 for 600 hp @ 6000 rpm with forged pistons and aluminum heads. static comp ratio @ 11:1. how much cam do I need to bring dynamic comp ratio down to run 93 octane? I have seen it done with really big cam and 12:1 (.750 lift 256/262 dur.)but how small can I go? waiting to here back from Comp Cams but thought I would check here also.

 

Honestly and i am only answering this cause frankly suprised no one else has. The VERY first thing you need to do is get your expectations and goals more realistic then come back and ask questions to get where you want to be.
Can a 460 make 600hp? sure, But realistically not at 6000rpm and not on pump gas. Yes the engine masters guys did it, and I could do it too but do you have any idea how much they had to put into those engines? and basically the longevity of the engine masters setups leaves a lot to be desired, those engines are running on the verge of self destruction and detonation. basically at the end of the dyno pulls those engines were junk for all intents and purposes.
Next do you honestly have any idea what 600hp feels like? most people have no clue, in fact most people get behind an honest 400hp engine and are shocked. To give you an example an honest 450hp is going to put a 5000lb vehicle at 13 seconds in the quarter at around 103-105mph and thats respectable in a street vehicle. And a 450-500hp streetable pump gas 460 is not that hard to obtain.
Now if you want a race engine fine say so and forget pump gas and just get down to building it and ask away.

 

so much for a friendly, helpful, community of ford lovers. sorry for wasting your time monster. so long!

 

Just trying to get you to be realistic is all. If you feel I am being mean so be it. I try to help out a lot when I can but everyone wants 600hp and wants it cheap and at low rpms. yes those are all lofty goals and would be wonderful but the wide world of engines just doesn't work like that. If you want 600hp at 6000 rpm on pump gas your going to have to run a stroker to get there. IF you want to run pump gas then get the compression ratio in line with a pump gas engine, using the cam to compensate for poor planning like too much compression for the fuel needed to be run is just plain a bad idea and will in the end HURT your power.
An engine is a system you can't just throw parts at it, you have to plan out what you want, what you need and what is realistic and within your budget. Also needed is what the purpose of the engine is. HP is a mathematical formula not a measured number thus the RPM is a big factor and this has to be figured. This is why i say you need to be realistic, if the limit is 6000rpms due to rods being used then your goal of 600 hp on pump gas in not really obtainable.

 

Let me put this another way, a 600hp @ 6000rpm pump gas 460cid engine running too much compression to get there and using a cam to bleed off that extra dynamic compression is first off not well thought out. That much cam is going to peak and run way above your 6000rpm limit. next it's a ragged edge engine to get there meaning that it's running constantly at the edge of destroying itself.
So if you don't care if the engine lives beyond about 30 minutes run time or your going to be rebuilding it constantly as long as it meets your goals then say so and we can work within that. But I am trying to save you from wasting a bunch of money having an engine blow up and you be disappointed in the process.

 

Well said monsterbaby. eperky he's not flaming you, he' trying to save you money and this is a friendly, helpful, community of ford lovers. You can make big reliable power with your motor but step back and do some research. My truck makes 450 rwhp on pump gas. (with a Dyno sheet to prove it) 11:1 and pump gas don't mix well.

my .02

 

I AM doing research and was just posing a research question. I did not get an answer. What I got was a condiscending and presumptious essay telling me I don't know what I want or how to do it. I appreciate the knowledge level of other posters but don't plan to hold anyone to any tips they might give. I know questions don't always have simple answers but I was just throwing it out there.

 

You did get an answer. An honest and straight forward answer. You just don't want to hear it. You are setting guidelines that won't work for a street motor. But you won't listen, pay attention to what monsterbaby said. There just isn't an 11:1 pump gas motor that will live and 99% of the street guys claiming horsepower higher than 400 are liars. You need to get out of la-la land and back into reality.

 

I am listening. I understood everything you guys said, but you guys made a lot of assumptions about my build and my knowledge. I apparently struck a nerve. I always heard the only dumb question was one you don't ask. I never said I was building a street motor, never said in this post what I was building this engine for, never asked for input on what 4 or 5 or 600 hp felt like, never said I knew more than you guys(you sure told me though). You didn't even give me credit for having a clue about dynamic compression ratio. go back and read the start of this post and tell me who needs to pay attention.
If anyone else cares I am building for a class that can't be stroked and can't use race fuel. I want to build a rotating assembly as tough as I can. H beam rods and forged pistons. So someday if I want to go crazy with power adders I'll be set. I am having trouble deciding on pistons to match aluminum heads I have a line on, they have 74cc chambers.
Flat tops move compression to 12:1, found some 11cc that go 11:1, and then 22 or 24cc that drop to 9:1. Cam choice will obviously play a big part in compression and subsequent power band and output. I have heard the bigger the cam the more static compression you can get away with. I would like as much power as possible(like everyone else).Here lies the question posted at the top.

 

No one was nasty to you or said a nasty word one until you got snotty about the responses. Anyone that thinks all it take to make horsepower is a cam needs some basic engine dynamics.

 

do you have to pull a certain amount of vacuum?i would look into getting a custom ground cam done.i would be interested in what comp had to say and i hope it isn't one of the "i only can read the catalog" robots on the tech line that you talked to.

 

no rules about vacuum. I sent an e-mail to comp, haven't heard back yet, we will see.

 

Lets start his over shall we? Tell us what your doing, what heads you have, why you think you want to run pump gas at 11:1+ compression or why you want to run pump gas at all if this is not a street engine, what the plans are for it, is they a cid limit, is this a an engine that is already together give me some back ground, but to just come in and ask for a way to compensate for something setup wrong (to much compression for the type of fuel) or something that indicates things like want something that is unobtainable then I will tell you to get realistic mainly because to many guys try to do something like build 600hp on limited budget and then complain when disappointed or to build one that isn't going to live and then cry when it blows so I try to save them the time and money and make them re evaluate the build.