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yeah, but if your goals are only 450hp you dont need AFR heads and such. But they aint all that much more money compared to other aluminum offerings so I"d go with them. THen just use a smaller cam and make an easy 450 and be very very driveable and street friendly
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yeah, but if your goals are only 450hp you dont need AFR heads and such. But they aint all that much more money compared to other aluminum offerings so I"d go with them. THen just use a smaller cam and make an easy 450 and be very very driveable and street friendly
Well more power = better for me, because no matter what I'm still going to have to rebuild the suspension parts and everything, so why not spend a little and get a little more? I may even take this down to the track a couple of times and see what it can do if I get that much power. I think I'd rather go with the 500+ setup, because it's really not that much more money, and the parts I'd be using have a better rep among the people I've talked to so far.
I just want to clear this up, the bigger the carb doesn't mean the more power you can build or power that you will gain.
You can have a 500hp motor with a 600 cfm carb.
Let's break it down now.
383x6300= 2412900/3546=698.1
Now if you aren't going to be at WOT constantly, go with a 750. If it's a full time street car it would need a 700 cfm carb.
I just want to clear this up, the bigger the carb doesn't mean the more power you can build or power that you will gain.
You can have a 500hp motor with a 600 cfm carb.
Let's break it down now.
383x6300= 2412900/3546=698.1
Now if you aren't going to be at WOT constantly, go with a 750. If it's a full time street car it would need a 700 cfm carb.
Yeah I know the carb doesn't really mean more power, but you'd need a big enough one to handle what your engine puts out, right?
I'm thinking about maybe taking my car to the track a couple of times once it's finished, so maybe 750? or that 770? I can probably find a 750cfm carb from Holley if the 770 is just too much. Thanks again guys for all the help, definitly gonna be a better project in the end because of these forums.
The formula mentioned by zraffz is correct, however it's assuming 100% volumetric efficiency. It's (CID x Max RPM)/3456 (the conversion from CI to CF to get like terms) x VE percentage. Using the example above, it's ((383 CID x 6300 RPM)/3456)) x VE = Required CFM at WOT. If you can't figure out your own VE, let's assume it's ~85% with your setup. That would be ((383x6300)/3456) = 698.2 required CFM. Taking into account that your VE is around 85%, multiply 698.2 by .85 and you'll get 593.47, but that's only required when you're sitting at 6300 RPM and WOT, which is a very small amount of time. That said a 600 CFM carb would be fine for what you're working with. Anything over 650 would be overkill assuming 85% VE, especially if it's a daily driver for street only application.
Last edited by chcgobearsfan3; 10-24-2009 at 11:32 PM.
Reason: Clarity
Heres my experience/opinion on whats the best or most affordable but reliable setup for a 383 build. First off, forged is the way to go, if you can afford it. The best deal on a rotating assembly ive seen out there is located at WWW.CNC-MOTORSPORTS.COM there are a ton of options, but i like the kit with these specs: SCAT 4340 Forged Steel Crank, SCAT 4340 Forged I-Beam rods with ARP bolts, Forged Dish Pistons, Total Seal Classic Race Plasma Ring Set, Clevite 77 H Series Rod and Main Bearings.
I noticed on the link to enginekits.com that the crank is made of 5140 forged steel versus 4340 forged steel, with your original goals, i would say go 5140 and be happy, but once you stated you were thinking of turning over 500hp and maybe an ocasional run down the track i think its worth the extra 30,000 PSI of strength gained with a 4340 crank. The setup above would give you a 9.2 compression ratio when running with 76cc heads, which equates to a million good things, but mainly, 1)running well on low octance fuel 2)later potential for supercharger/turbo setups. Im not saying this is the best deal, im just pointing out a few things to keep in mind with a rotating assembly.
So now on to heads... Everybody always jumps up and screams AFR heads no matter what is asked or what your budget is. I could post something and say im trying to find heads for $400, and somebody is bound to tell me to save my money and buy AFR's... says something about the quality of the products, and i admit they are a great set of heads. HOWEVER, as with all aluminum heads your number one fear is going to be overheating. Once that happens youre left with 2 very expensive warped door stops. So spend lets say you spend at least $1400 on bare AFR heads, then you better spend 600ish on a performance radiator and water pump and oil pump and pan to keep those heads cool. Im going to recomend going with a safer set of heads such as Dart Iron Eagle Platinum heads. at $589 each (assembled) you can get a set that flows (after porting) just as well as, if not better than, the AFR's will out of the box. Oh, and did i mention cast iron heads will take a nice overheating and keep going? Keep in mind that daily drivers tend to overheat when sitting in traffic, and that powerful engines tend to overheat when ran for any long term duration, such as in traffic.
Just my 2 cents, sorry if i rambled on a bit. Im doing the same basic build right now and have reasearched every single aspect to the point where I could probably write a book.
AFR's are usually 1470 shipped to your door complete assembly ready to bolt on.
And I wouldnt worry about overheating. Use TPI Dual fan setup and TPI L98 radiator from 91-92 camaro as I believe they are the aluminum rad. I just used my stock 89 Rad reconditioned from local radiator shop and NEVER had an issue with overheating.
Just throw in a 170 Tstat and program the fans to come on earlier, or put on on a manual switch so you can turn it on whenever. Stop and go traffic? Just throw the switch and keep fan pumping air. Once you start moving, turn it off
Very true. I guess i just dont like what if scenario involved. Lets say you fail to notice your temp going up, or your temp gauge goes out. Or thermostat gets stuck. But thats just me. I guess i just like the fact that cast heads are a bit less worry free. But i do see merit in the fact that if youre gonna drop 3k on the engine, whats a couple hundred more for a top of the line cooling system anyways... just when i thought i was sold on getting cast heads you had to go and ruin my "solid" plan...
Just going by my experience as well as a few others. Aluminum heads dont mean overheating. But your right, you do need to watch out for the "what if" scenarios. I suggest aluminum because they are lighter and most aluminum heads destroy the available iron castings out there in performance. Dont have to spend 1450 on AFR's as there are some aluminum heads in the 1100-1200 buck range that are decent enough for high hp goals.
I just havent seen any real fast iron headed motors.
If you go iron head, you either need 76cc chambers or a big dished piston to get compresssion down to 10:1 or less. Aluminum with right camshaft will tolerate just over 11 to 1 on pump gas
14psi, street tune 
