Choosing a cam-shaft part 2

[common 27]

 Well I've started on my motor build.Received my 440 source stroker kit yesterday. Its a 400 to 451 kit. It will have Edelbrock heads and around 9.5 to 1 compression. I've decided on a purple shaft cam with .528 lift or the .557. Will the 557 be too big for the street? My only other big block was a _ _ _ _ _ and it ran very well with a .505 lift. Cowboy didn't get much help  picking a cam,so give me your opinions please. Also will the Holley street dominator be a good manifold for this motor?  Thanks,common    By the way this will be going into a B body

[Chryco Psycho]

The Holley street Dom is a great intake to use , it sits low enough to put a large air cleaner on top & flows very well
9.5:1 is perfect compression with Iron heads but very low with alum heads , I would be aiming for 10.5:1
The 528 will work great with 1.6 rockers , the 557 is too large I M O , it will go to 7000+ rpm easily , personally I would be looking at some of the fast ramp designs From Engle or Lunati for best performance ,
What are you looking for primarily , street engine can mean a lot of different things , realistically where will the engine spend most of it`s time RPM wise ?How much % wise will you be cruising on the highway , what gear is in the diff , are you wanting milage from this engine Lift has very little to do with how a cam works , the duration & overlap controls how & where the cam works & then get a good amount of lift for the duration you use , a 240 @ .050 duration cam will idle well & have good vacuum for power brakes & can still have .580-.620 lift , I can help with specific grind #s if you provide more info on what you really want from the engine / car

[common 27]

Well I guess what I want is an engine that does it all. It's 15 miles on the highway to get to the nearest town and right now it has 456 gears in it.I will probably change those later. Gas mileage? I'd like a little bit! It will be run hard each time it's driven but in terms of percentage that will be 10% or less.So most of the time will be highway and town cruising with the occasional    I just want it to run very well.I've looked at about every cam site on the internet, but don't really know what to look for I guess. It does seem that they are all similar. What does the fast ramps benefit and how can you tell them from one which isn't?

[moparniac]

the .528 cam rocks.....with 1.6 rockers is .561 lift..... wide centerline and good duration!!!! best overall cam mopar made as far as im concerened.....also the holley street dominator intake 

[Chryco Psycho]

First there are Cam articles in the archives but basically the duration & overlap control where the cam makes power so you can compare a cam @ a given duration for example 240* @ .050 & see what lift the cam has , for example Engle has a KV1 grind with 239* @ .050 & a lift of .546,this is a fast ramp cam , more lif allows for more breathing potential if the heads will flow & more power without affecting the powerband where the cam works , the KV1 has a 2000- 6000 powerband [ Englecams.com ] this is typically what I use in most street engine for a powerband & most flat tappet cams have approx 4000 rpm powerband so if it starts to make power around 3500 it should be good to 7500 so you need to pick a cam where you want the usable power range . Now with  456 gears you could potentially use a big cam & take the engine Rpm up quite a  lot , if you want to run the engine that hard all the time

[common 27]

 Ok I looked at the KV1 cam at Englecams.It states it is for racing only will that matter as far as durabillty? Also if a rocker changes the lift does it also change the duration? Would you use the KV 1 with 1.5 or 1.6. I also checked the Voodoo cams which states they have a fast ramp.  I'll look in the archives  for some info too.

[cowboy]

 

[Chryco Psycho]

the 1.6 rocker will increase duration slightly
I have a series of Lunati custom grinds I use , similar to the Voodoo series
the racing designation for theose cams is ok as well , I use similar grinds on the street engines I build all the time , it does require higher spring pressures etc

[tactransman]

Also if a rocker changes the lift does it also change the duration?

CP,how can it change the duration at all if the opening and closing times are not changed?


It sounds like you are building a very nice engine!

[common 27]

    Well I still don't know what to use. Would you say the Engle then over the .528? The KV1 soulds like a very good powerband.Would it use 1.5 or 1.6 rockers? Also what is the power band of the .528? I actually have gotten carried away with this build.It was to be a stock 400 rebuild with a mild cam,now look what I've done    

[Chryco Psycho]

either cam choice will work , I have seen engines with the .528 make very good power , I have also used the Fast ramp Engle & Lunati grinds with great success , for a street engine I would use 1.6 rockers with the .528 & just 1.5s with the Engle or Lunati or you will need very high spring pressures to keep the valvetrain stable with 1.6 . Also keep in mind the advertised lift is - the lash spec & the Mopar cam with 1.6 but - the .32 lash nets approx .525 lift where the Lunati & Engle use a tighter lash of .016 so .570 lift - .016 still nets .554 lift at the valve

Terry with the fast opening of the valve using a 1.6 rocker the valve is at .050 lift sooner & this is where flow really starts to happen & it stays above .050 lift slightly longer so even though the open & close points are the same the duration of the lift where flow happens is increased slightly

[tactransman]

Terry with the fast opening of the valve using a 1.6 rocker the valve is at .050 lift sooner & this is where flow really starts to happen & it stays above .050 lift slightly longer so even though the open & close points are the same the duration of the lift where flow happens is increased slightly

So the "effective duration" is changed.