S2VYSS

I just want to know what are the pro's and con's of large lift cams (.650+) for street use. Is it worth it running this much lift or is around the .600-.650 the most lift for the street?

Any help would be great, a little new to the art of cam's and want to learn

LSXNV

iTrader: (1)

Its not really the lift that dictates the cams "attitude". Duration and lobe separation are what makes a cam "lumpy".

S2VYSS

If the duration and lobe separation was around the 23x 24x and 113, would the .650+ lift be of any benefit?

orangeapeel

iTrader: (18)

I think you really need to understand valve events before looking at just 1 point out of a cam selection. The puzzle pieces will probably fit, but it won't be ideal most likely. Get my drift?

What are you wanting the car to do?
Is this a nitrous setup? S/C or Turbo?
Heads?
Manual/Auto transmission?
gearing?
Summit racing stickers?

Hard to give you nothing but con's if you don't let us know what you are wanting to achieve. Maybe you are wanting a solid roller setup. It's hard to say. Give us some plans and background info on the build.

S2VYSS

Well hear is what I am thinking about doing

220 as cast trick flow heads, as they come with 1.7 rockers, switching them out for some 1.8 rockers, fly cutting the pistons and pushing a .600 lift to around the .650-.660 mark. Thinking of having the combo around the 11.1 to 11.5 area

The plan later on is FI, be it Procharger or PD, I am undecided. When that time comes I will change back to the 1.7 rockers if the lift is too great

Its a M6 and the gearing at the moment is 3.45, however am I open to suggestions on the best diff gears

Wont be running any summit racing stickers, but if this increases HP I'm all for it

redtail2426

iTrader: (10)

the only benefit you will get is slightly more power,but under 1 condition.And thats if the heads can support it.Sure you can do it,but will the heads flow any better at 650 lift vs 600.Take a look at the as cast TFS heads,and try to find some flow numbers at .650 lift.I am pretty sure they flow less at .650 than they do at .600.So in that case not only would it put unnecessary stress on the valvetrain,it will even cost u some power.Running high lift is for the big heads that can support those lifts with much added flow

S2VYSS

Thanks for the answer

What heads do flow around the .650 lift mark?

What areas of the valvetrain will be under stress the most?

orangeapeel

iTrader: (18)

Probably heads meant for a 400+ displacement. In a nutshell I would stay away from extreme lifts like that and focus on the whole picture. You will be putting your springs through the gauntlet.

Always2Slow

iTrader: (8)

Unless your bracket racing or its a race car there is little point in running lifts like that unless you like spending a lot more money for small gains with increased maintenance.

99Bluz28

iTrader: (35)

IMO, not with the heads, as Cast.
Put the 1.8 rocker money towards: gears(4.11), head porting, or depending on the intake and exhaust you have upgrade them.

gtorep

iTrader: (18)

I have a big .650 lift cam in my current setup.... It only sees street duty 2x to 3x a week. Already changing valvesprings after 2000 street miles... Power is awesome but the routine maintenance and cost of maintenance is not fun at all.

studderin

iTrader: (28)

well that might be true if there was some law of physics that expressed how adding cfm on a flowbench will always make more power on a running engine. To bad thats not true, and easy to disprove. Its like using the hardness of metal as the only variable in raw strength to compare metals. Thats not going to work out good.
It should help guys the think what thouse cfm numbers are, and how a bench is getting them. And how much different that is, then what happens in a running engine.


gtorep, whats springs you running? Xbling

gtorep

iTrader: (18)

PAC 1521's, going to try Cryo'ing the next set, and shimming them .030 to try to get some more life out of them.

studderin

iTrader: (28)

wow, they have the finish upgrade, what did they saw about that? how beat up were the?
I have that lunatia set I'm putting some miles on Ill see how they do.

99Bluz28

iTrader: (35)

The 1521's are good to .70" lift, were they set to the recommended install height?

gtorep

iTrader: (18)

I think mine went south do to a wife that doesnt know how to properly warm up a car in the winter... It seemed that they started to show signs of wear after our month of 20d-30d weather. First it started floating around 6800, then dropped to 6400, finally floating at any kind of tip in wot acceleration. On the next set I also ugrading to a set of j2k rockers from the yella tera ultralights. Going to lighten up everything and set it a little stiffer.

Which of Ed's cams are you using now? Mine is a modified Hellion 244/255 .650/.650 on a 112+3

gtorep

iTrader: (18)

They were set per PAC's instructions, and within specs from the Cam card. I beleive mine went south due to driving and loading the car before everything got a chance to get warmed up.

LSXNV

iTrader: (1)

In short, no. Spend the money else where. You may get a pony or two but it won't be worth pushing the durability issue. I come from the mind set of short lift but high duration. My old Pontiac LeMans would run 11.7's using ported factory iron heads on a 469cid engine. I had about a .590 lift but my duration was 255i 266e @.050. And at 106degrees of lobe sep. its idle reminded me of the intro to "hot for teacher".

speedtigger

iTrader: (16)

Unless you are into competitive class racing, I would avoid pushing the limits on any part of your build. Using ultra aggressive ramp rates and ultra high lift might produce small amounts of additional power but the gains will be dis-proportionate to the amount of stress introduced to the valvetrain. I say use the proven parts that have a track record of exceptional performance and durability. Street cars are a lot more fun when they are not broken.


This definition from Webster's seems appropriate here:

gtorep

iTrader: (18)

Amen brother. Squeezing every last bit of power out of a small cubic inch motor is freakishly hard on parts...