Thread: A SBC build
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08-31-2007 09:45 PM #16
your right sorry!!!!! lol.
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08-31-2007 09:50 PM #17
TY, the bigger the cam the more HP so the bigger stall you need. With the cam in the combo kit I listed I am thinking 3K stall or 3,500, a cam bigger will need more stall which would limit driveability.
So doesn't my cam need to be talored around my stall??????????????
Was thinking 4:11 but either 3:73 or 4:11 would work I can adjust tire size for the slicks I need (taller or shorter)
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08-31-2007 10:01 PM #18
chevy, i have been profiling cams for 20yrs.. you say bigger?? what is bigger there's a thuosand different thing as to cam profiles. lift doesn't meen your going to make power at 9000rpm. i can grind a cam that has .700 lift and all the power is down low or move the power up. the timing events of each cycle has more to do with were the power and torque curves are. the lsa of a cam meens nothing at all and those cams you posted are just a noise maker other then a power maker. but cool sound sells.. with the heads your looking at you can put alot more cam into it with a 3500 stall and 4.11 gears.. if you what me to profile a cam for you i can find a off the shelf part number that will make alot more power then the noise makers...Last edited by 500caddy; 08-31-2007 at 10:04 PM.
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09-01-2007 04:30 PM #19
Ya know what??? Unless you're running a Super Stock class and looking for 2 or 3 hundredths of a second to get on the index, or trying to find 3 more mph on your next pass at Bonneville, the "ultimate" camshaft is little more then ammo for the next bench racing session. With all the variables in a street car, and not running the engine at 100% efficiency and maximum effort every pass, the cam in the catalog with the definition most closely matching your intended vehicle usage and on sale at Sumitt for $99.95 with lifters will accomplish the same thing.... Matter of fact, the only place you would see the horsepower and torque difference is on the dyno... weather changes from 9AM to 8PM would show bigger gains or losses in HP. Being plus or minus 10 horse on the street is nothing more then bragging (or BS) rights..... A balanced approach to optimizing all the systems on a car and getting them to operate in a manner that compliments each other instead of one area negating performance improvements in another is a far better place to spend your money then a $300.00 custom grind, one off camshaft.....Yesterday is history, tomorrow is a mystery, Live for Today!
Carroll Shelby
Learning must be difficult for those who already know it all!!!!
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09-01-2007 05:45 PM #20
dave, your just joking with use right!!!!
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09-01-2007 06:55 PM #21
To get the most out of the answers that are given ,you need to list exact parts {which you did} and you also need to state budget{which you did } you also need to state intended use and acceptable driving manners for you.
One mans tunning nightmare engine ,may be another mans dream engine
Do you want max power ?
Max sound ?
Max speed?
Max acceleration ?
All of those non engine things come into play when ordering parts.
Soo .120 domes .035 down in the hole ,those need to match the heads you want ,will those heads accept a dome of that size and are they made for dome that shape?
You also need to know if the heads have the correct size cc for the domes you have to make the intended static compression{remember the later the intake closing point is to make the dynamic compression acceptable,the less stroke you use}If you have to have a cam with a very late intake closing point to make the dynamic compression work on pump gas,you loose alot of stroke,meaning less power,you want to use as much as the stroke as possible and not waste any by bleeding off compression with a long duraton /late intake closing point cam.
Theres no voodo or black magic needed,the heads are already dictated by the already purchased domes and the intended pump gas usage.
This info gives you the chamber size{cc} that will be needed.Second ,the rpm and cubic inches dictates the port size on the heads.Your already purchased lower end has parts good to a safe 6000 rpm give or take a few.This info tells you what you need to know for a port size.
Then based on rpm/cubic inches/static compression/port size ,now you can choose a cam to compliment that combination based on stats of your parts .
From reading your posts ,you need to do alot of reading on static compression/dynamic compression,quench and cam principals or you need to take all of the info you have and let a cam company or a member here choose one for you.
Also a point that has not been mentioned yet either is quench,you just cant open that up with a thicker gasket or a huge open chamber head and exspect it to perform well either.
Remember ,every bit a bigger cam gives you in power is taken away from the low end,3500 stall 6000 rpm redline 2500 rpm to effectivly use ,then reduce the stroke with a long cam..............sounds like trouble brewing.
With those domes ,I would look at aluminum heads,so you can use the 11 to 1 compression and not loose as much stroke,then purchase a cam according to the alu heads to get the correct pump gas dynamic compression.
Anything over 350 -375 hp with that 327 and yer just leaking in the wind, unless you get the lower end parts to support 7 to 8 thousand rpm,which you stated is out of the budgett.
The bigger you push that cam to run pump gas,the slower that engine will go on that budgett and a street converter.
If you just want burger stand noise,keep everything stock and cheap , use a comp cams thumper cam and save alot of money .
If you want max power and performance look into individual parts and not a kit or combo.
I think you are chasing those domes thru the entire engine ,trying to make em work,.120 domes are usually a racing item for race gas and require abnormal size heads on the street,making the combo complex to purchase parts for..................You would be money ahead to sell the domes ,after all they are new,and buy some good flat tops so you can use a normal selection of cheap standard performance heads,your gunna fight those .120 domes that are .035 down in the hole thru the entire build and be lucky if you can get the quench small enuff not to detonate on anything more than base timing and premium.
Unfortunatly you are not headed down the road to max performance,your headed toward a burger stand tunning nightmare.
Seriously ,you would be better off with a stock engine and a thumper cam and a 3500 rpm stall.
Most people like to learn the hard way unfortunatly,build the big cam /high stall motor for the street and then you will know what you need next time .Its gunna take longer than u thought and its gunna cost more too(plan ahead!)
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09-01-2007 07:05 PM #22
Originally Posted by 500caddy
Ahhhh, nope!!!! Way too much emphasis on horsepower these days, few want to address the issues in building a complete car with systems and components that work together!!!!!
Rather then just another SBC cam/head discussion, how about these questions??????
I'd be curious to know what kind of car? What's been done to the suspension? Frame ties or does it have a full frame? Roll bar or cage? What shocks on the front and rear? Travel limiters on the front suspension? Any traction bars? Open rear end or a posi? What's the car weigh, and have you checked the front to rear weight ratio? What does the car have for a cooling system? What's the ride height of the car? What's the pinion angle? What are the camber, caster, and toe in specs? What's the tire diameter? Tire compound? Line Lock? Is the rotating assembly balanced? What size fuel lines? What's the GPH rating on the pump? Pressure regulator with or without a return system? Any nitrous or other power boosters? Anything done to lower the unsprung weight?
These and many other questions determine the performance potential of the car, not just the stick with the funny little bumps on it!!!!!!Last edited by Dave Severson; 09-01-2007 at 07:53 PM.
Yesterday is history, tomorrow is a mystery, Live for Today!
Carroll Shelby
Learning must be difficult for those who already know it all!!!!
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09-01-2007 08:34 PM #23
Originally Posted by Dave SeversonIrish Diplomacy ..the ability to tell someone to go to Hell ,,So that they will look forward to to the trip
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09-01-2007 08:36 PM #24
dave, he was talking about the engine not a car combo!!!... i don't build a car, pick a gear, converter, carb, chassis and all the other stuff intill i build the power plant... how the hell do you know what to buy for the car if you have no clue as to the power and torque the engines making????if the dyno numbers and cam size etc are just for bragging then were the hell do you start your build??? i have built many 333-377 on pump gas with full roller cams that were .630lift or more and very streetable. i drive my nova just about every day and it has a socalled big cam. to me there's alot of old school thinking on this. as for this post the guy said he whats something that is boarder line streetable. well the little cams he posted are more like noise makers then power makers. you can go alot bigger with the right valve timing events on pump gas and make 425-450 only spinning it to 6000-6200 and for that matter i have spun 327 to 7000-7500 with all stock internals. as for converters when there advertised at a stall speed it all depends on the engine,gear,weight etc etc as to were that converters going to hit. i run a 8" 5000 in the nova but it wont go past 3600 and drives great. on the chassis dyno it has less of a slip % then the 3200 stall behind my big block that goes 4400.. i get guys telling me you can't run a 8" on the street well those guys haven't a clue as to how a converter works. i just think its very silly to not cam this engine right after spending the money on the heads. as for heads i get a real kick when someone says you can put a 210cc runner on a 327 it wont work right. well thats crap there the same guys that can't tell me the port speed or the low lift flow rates from one to the other so how the hell would they know. i have seen 230 runner with ten times a better port speed and low lift numbers then a 180cc runner. what does that all meen the 230 would work better then the 180 on a small cid engine and you wouldn't have the spin the hell out of it...i'm not trying to agrue dave. just the guys that refer to lsa on cams and runner cc on heads as to what they will or will not work on makes my crazy!!!!! i'm just trying to help the guy out and teach him about how the stuff works....pat i couldn't agree more with your commet to shawnleeLast edited by 500caddy; 09-01-2007 at 08:38 PM.
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09-01-2007 08:45 PM #25
must be some thing in the water in MICH i have used 8and 9s stalls on the street they work great and big BIG cam s i try to keep the lift down abit if i know it may kill the springs and the guy low bucksIrish Diplomacy ..the ability to tell someone to go to Hell ,,So that they will look forward to to the trip
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09-01-2007 08:51 PM #26
it's the motor city pat. all i can say at this point is everybodys doing it around here and i have been doing it for the last 15yrs with know problems. it must be the something in the gas outside of michigan.
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09-01-2007 09:07 PM #27
Originally Posted by 500caddy
My point was this...There is so many things on a car other then the camshaft that will effect it's overall performance, not just the dyno numbers but the way the car works in a real world environment. From a been there, done that standpoint I've whooped a lot of big horse engines with little or no chassis and suspension work with my lower horse engine in a car that works properly. I just think it is equally as important to suggest to a guy building a car that there's more to going fast then a lot of horsepower!!!!
As for the comments to Shawn,,,,, I don't have an engine shop either. Guess I shouldn't be allowed to discuss engines???? C'mon guys, the engine and it's power is important, but certainly not the only aspect of the build to consider...... If it was all about horsepower then we could just go to the track, compare dyno sheets, and declare the biggest horse engine the winner????? That's just not how things work, is it? I think it's misleading when making engine suggestions to not find out how much horsepower the car can handle without blowing the tires off the car.....Yesterday is history, tomorrow is a mystery, Live for Today!
Carroll Shelby
Learning must be difficult for those who already know it all!!!!
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09-01-2007 09:22 PM #28
As for the comments to Shawn,,,,, I don't have an engine shop either. Guess I shouldn't be allowed to discuss engines???? .....[/QUOTE] nope never said that this form can be many things? it can be condense dribble i come to the table i may not back every thing i say up with real dyno numbers buT any thing i post you can bet your ass i have done it or i would not post it. all i ask was how many big cams has he run thats it. you can take that any way you want or just look at it as if he has done it thats itLast edited by pat mccarthy; 09-01-2007 at 09:50 PM.
Irish Diplomacy ..the ability to tell someone to go to Hell ,,So that they will look forward to to the trip
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09-01-2007 10:18 PM #29
dave when i get out from behind the dyno i have a stock suspenion nova on drag radials that runs 8.30 street driven. if i what to go fast i have a chevelle that has 1900hp and runs 7.60@over 180 has been driven on a 400mile round trip. runs those time on a 10.5 slick. but we were talking about a 400-450hp engine all the things that you list aren't real word needs. slapper bars and sticky tires and the chassis stuff is done.. i just have a hard time giving advice and not telling them how to get every last hp.. i would like to have to much power then not enough. as for me i can never have to much power. i can just tune some out.
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09-01-2007 10:28 PM #30
Your right,,,,none of that is real world, only horsepower matters!!!! Got some pics of these stock suspension cars that run in the 7's and 8's???? Guess I've really been wasting my time building good chassis all these years, huh????Yesterday is history, tomorrow is a mystery, Live for Today!
Carroll Shelby
Learning must be difficult for those who already know it all!!!!
I wanted to complain about this NZ slang business, but I see it was resolved before it mattered. LOL..
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