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#1
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how much flow??
i have a 428 (i assume its stock) im considering going with a roller cam setup. i have a set of big vlave 16's that i got bare and i put all new everythign in them with a "minor" port job. they cleaned up the intake and exhaust sides from what i can tell i assume they didnt touch the bowls. i have no clue how much lift the springs can handle until i find the reciept on the heads and ill look up the springs. i also have a set of 1.6 roller rockers,edelbrock rpm intake,headers,and x pype. i have 3 goals with this car. 1 i want it to have in the ballpark of 500 hp at the wheels. 2 i want it to be consistant low 12 sec 1/4 mile car. 3 i want this car to be streetable enough to drive around town. car has auto tranny and stock rear end. im curious as to how big of a cam i should go w/o overkill and how much flow i need out of these heads to get the job done. id appreciate any suggestions as to what to get me there. id like to get a set of 3.73's to help out some and anything to help me get traction. i know ive asked this question before but i would like to hear suggestions. its tax time so i can get more done to it. also i have a freind that is die hard chevy guy that likes to bad mouth pontiac so i gotta shut him up. i want to make him look stupid for thinking he can beat my 428. can anyone help me out with suggestions on what works ? if not a roller cam then what ? i have a comp cams XE 268 H that i was trying to sell but the guy backed out of (i told the shop that i wanted street manners more then speed at the time because it was my daily driver but ive changed my mind since then and got a diffrent vehicle.) i thought about talking to pontiac dude with a supercharger but CR woudl be off the charts. i need this to work on pump gas. thatll throw a wrench in the plans.
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#2
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A 428 like that should easily run low 12's. Probably quite a bit quicker,maybe even enough to get you bumped for no roll bar??? Street manners are'nt too bad IMO,and with 3.73's and one of those Jim hand "special" continental convertors,it'll be a monster 428! Do what you need to so you can get a 1.7" installed height,and then use either the comp 995 springs or the crower 68405 springs,and use the good viton seals,this would handle the comp solid cam no problem. Simple stuff mostly,and I'll bet it'll shut up those chevy guys in a "heartbeat" ! LOL!!! |
#3
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Takes alot of motor to make that amount of RWHP! Not entirely sure how realistic that goal is for what your describing here ??? 500 HP at the flywheel sure.. |
#4
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I run 11's with 400 rwhp, 3790lbs,FWIW -Jim
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#5
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well 500 at the wheels would be bragging rights for me. not as important as the 1/4 mile times. i thought it would be cool to say i have a street car that has 500 hp at the wheels. all it takes is time an dmoney right ? if anyone else has comments good or bad with what im trying to know let me know id appreciate it.
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#6
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i wanna say the springs are crane. i want to say i went with the 1.6 roller rockers because the lift on the 1.65 would be too much with the 268 H XE. does this sound right ?
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#7
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for 500 RWHP, you may as well jump right into a set of E heads, and a BIG roller cam...
500HP at the crank will be a much more streetable setup, and still have plenty of bragging rights. |
#8
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well e heads and a big roller cam sound out of my budget for now. so ill settle for the low 12's.
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#9
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We have a fresh set of 48s with hardend exhaust seats, race ported, ferarra valves, Comp springs and retainers. They were for my brothers street motor, but he went to eheads. never been bolted on since they were done. If intrested i think he would give them up for a grand. Let me know if intrested and i will see what he wants to do.
Rex |
#10
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i put brand new ferrea valves in my #16's with brand new everything else. im just curious as to the minium flow should be expected to get the numbers im looking for. i know a lot of this will depend on what cam i will pick. to get this number how much port work will need to be done ?
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#11
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[QUOTE=screamingchief]I'd suggest the comp 290b6 solid flat tappet cam myself,use the money you save on the roller hardware and put it into porting the heads to appx. 250-260 CFM @ .500" lift/28" of H2O,as your going to need the better head flow to get the power your looking for.
Do what you need to so you can get a 1.7" installed height,and then use either the comp 995 springs or the crower 68405 springs,and use the good viton seals,this would handle the comp solid cam no problem. what are the specs on this cam ?
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#12
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[QUOTE=how much port work will need to be done ?[/QUOTE]
We spend about 30 hours on each iron head. Its alot of work. Rex |
#13
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Quote:
Part Number: 51-659-5 Engine: 1955-1981 Pontiac 265ci-455ci 8cyl. Grind Number P 290B-6 Intake/Exhaust Valve Adjustment (lash): 0.026" in./ 0.028" ex. Gross Valve Lift: 0.594" in./ 0.587" ex. @ 1.65 rocker ratio Duration At 0.020 Tappet Lift: 290 in./ 304 ex. Valve Timing At 0.020: Intake: 39/open 71/close Exhaust: 78/open 46/close These Specs Are For The Cam Installed At 106 Intake CL Duration At 0.050: 255 in. / 266 ex. Lobe Lift: .360" in. /.356" exh. Lobe Separation 106 Recommended Valve Springs #995-16 |
#14
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wouldnt that cam be too big to run on the street ?
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#15
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But it kinda depends on what each individual is willing to put up with. If you want to run fast,your going to need to make sacrifices of some sort. Could it be done with less cam,yeah sure,but you'll need to be sure to bring your A game with you as far as your combination and tuning would be concerned. But just how serious are you here? You started out saying you were thinking roller cams and wanting 500 RWHP,now your complaining that this solid is "too big" for street use,so what's it going to be,are you really wanting a low 12,high 11 second car,or what? I mean I'm not trying to be pissy or anything here,but it just seems to me you have'nt a clue what its going to take to consistently run the numbers you've discussed here. You will need head flow numbers like those I mentioned! (minimum 250 CFM or better) You will need decent gears and convertor! (like your 3.73's and the J.H. special mentioned) You will need a decent cam! With the heads your going to run you will have a healthy CR,and this will require a healthy cam to run this on the street with pump gas. Sure you could run a hydraulic cam with lesser numbers,but likley it'll be just as troublesome (if not more-so) as far as "street manners" are concerned as this solid would be. IMO it would take a hydraulic like the XE 284 to do what you want here,and that'll be just as "rowdy" as this solid would be. And a roller wont make all that significant of a difference as far as "manners" are concerned to justify the significantly higher pricetag for that reason alone IMO,and especially at the expense of better headflow or such. There have been a ton of discussions about this cam on this board,do a search,you'll see what others think about it... |
#16
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Here are a couple of slightly "tamer" solids to consider possibly,though I cant attest to their abilities as confidently as the 290B's.
Lunati: #407A2-LUN Advertised Duration IN/EX: 282/292 Duration @.050 IN/EX: 248/255 Gross Valve Lift IN/EX: .503"/.518" Lobe Sep Angle / Intake Ctr Line: 110/106 Valve Lash IN/EX: .018"/.018" RPM Range: 2000-6200 Crower: #60311 Engine Application PONTIAC V-8 Grind Number 292FDP ADVERTISED CAMSHAFT SPECIFICATIONS: INTAKE: Duration: 292º/Lift: 0.504"/Clearence Hot: 0.022" EXHAUST: Duration: 302º/Lift: 0.516"/Clearence Hot: 0.024" The specifications listed above are based on a rockerarm ratio of 1.5 IN/1.5 EX RECOMMENDED VALVE SPRING INFORMATION: Part # 68405,Dual X,Approximate spring pressure: valve closed: 105/115 LBS. valve open: 275/290 LBS. The information below is for degreeing cam only. Correct only at .050" tappet lift INTAKE: Opens: 16.0 BTDC Closes: 52.0 ABDC EXHAUST: Opens: 62.0 BBDC Closes: 10.0 ATDC LOBE SEPERATION: 112º Duration at .050": Intake: 247" Exhaust: 252" LOBE LIFT: Intake: 0.336" Exhaust: 0.344" If using "Lobe Center" method of degreeing, cam should be installed on an intake centerline of: 108º Now something like these would be the minimum I'd consider for a solid cam like this would need to "get the job done" here. I'm sure something like these in most any brand of cam would work well also here,the ultradyne/bullet cams work extremely well in pontiacs as well. The UD cam I'd choose for this combo would be their 280/292,247/259,.525"/.551",110 cam as the minimum here IMO. HTH. |
#17
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all of the above and a 300hp shot of nitrous ought to get him 500 @ the wheels!
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#18
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well the 500 hp at the wheels isnt that big of a deal. i was just curious what would need to get me at that point i figure if im dumping all this into my car how much more would i need to get me there. on the other hand i dont want to dump all this into it and not get the power/speed im expecting. right now my 428 has 6X4 heads on it its a dog i expected a lot more from it and i seriously considered selling it i am very dissapointed in it. low 12's (consistantly) is more important to me. i realize you cant put a exact number on the flow i would need because the cam is a factor in what the engine will do regardless of flow. i was just looking for a baseline for flow. someone suggested that i would be better off going with a roller because it will have better "manners" and it will act like a hyd cam with about 20° less duration. for the price tag id seriously consider it because i could get away with more if what i was told is true. i know that im gonna have to give somewhere and i cant have the best of both worlds but i dont want it to be so bad that i couldnt enjoy it on the weekends it would be worthless to me then. and not to be pissy in return but i just asked if it would be too big on the street that in my book isnt complaining. id say this car will be 60% race,20% road, and another 20% somewhere in between. youre right im not 100% certin about what im getting into here but thats why im on here asking questions about this stuff. you guys have done this before and know what will work and what wont. dont get me wrong i appreciate the comments because with the advice you guys give me it will save me time and money and headaches.
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#19
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this is a pontiac motor (428) not a SBC,ford, or import. if i need a 300 shot of spray to get 500 at the wheels then id be better of selling the dam* thing. what suggestions do you have to get this to hit low/mid 12's ?
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#20
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you will need minimum 240 cfm to get anywhere near 500HP at the crank...and that most likely will take a lot of tuning of the combo once it's together. if you don't have any experience with head porting, and don't have access to a flowbench, i would really recommend going with the E-heads, and the comp cam that has been recommended, and you'll have low 12 second or better potential without having to put much effort into it. this would be your cost effective way to what you want with what you have access to. E-heads, and a good roller would get you 500HP in the bag, and the roller could be slightly smaller. but plan on at least another grand. |
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