Hi

my question is what is the benefit of high lift ? ( example GT11 cam 215/231 631/644 118 ) I think I heard from someone that this cam opens at high rpm

thanks

 

The cam or motor would not open at higher rpm due to the soley lift, but the timing events.... espeically a 118 LSA.... Don't quote me because I do not know all of the details of that cam, ramps etc... I bet the lift was used to add more area under the curve and get more air in combined with the wider LSA.... Duration is more important than lift, I would never trade off duration for lift...

High lift helps to maximize area under the curve..... You usually see more gains in torque as the lift increases... What it does is actually hold the valve open a tad bit longer.. But you have to be careful because lobe design plays a role as well.... Some times if the lobe is not designed for high lift you can run into a condition where it slows the air velocity down. Opening the valve past a certain point will not increase the flow to the cylinder... low and mid lift flow are more important to me over max lift flow.. So I would reccomend making sure you match the lobes with the lift.....

The lobes design has to be constructed or selected properly because if the ramps are too fast especially with the closing rate, not only will you have to worry about valve bounce and the added strain on the valvetrain parts, rockers, pushrods etc.....

The other miss conception is the % of time you will actually reach max lift, which is very low.... So you have to ask yourself is the extra Lbs of torque really worth the extra stress on your valvetrain....?

You just have to try to effectly selct your valvetrain parts, timing events , spring rates, and lobe design before playing with lift.... Its not really an open and shut issue..... there are tradeoffs and compramizes.....

I hope this helped in a plain text explanation....

 

So this cam is considered a small cam ?

 

Sound like a good street cam.... I always tell people to be realistic with their intentions..... I see so many people go get the dick dong mega cam, then come here and post because they cannot tune the damn thing or the ride sucks after 1 month installed...

 

1)ok but why all small cams have high lift considered to mild and big cams ?
2) Do you know if this cam opens at high rpm ?

http://www.lingenfelter.com/mm5/merc...Category_Code#

 

I think that is a general statement about smaller cams having larger lifts, that is more cam designer specific vs industry quoa....

What do you mean by if it opens at high rpms? I guess I am not understanding your statement....

 

what range the cam opens ( example 2500-6100) ?

 

I'm assuming you mean where is the powerband at. The cam cannot physically open, its a stick of metal . More duration > more lift. Lift is important, as is LSA and ICL, you need all of them to work together to make a good cam. Call a sponsor on here (all those shops listed on the right) and tell them your goals with the car. They will gladly talk you through it.

Btw, that gt11 cam is one strange cam. Huge split in duration, huge lift, loose LSA.

 

yeah the power bond but its just a phrase LOL
ok but is there any low end power and torque in this cam

 

powerbAnd not powerbOnd. but I have no experience wit the cam. some people claim it does, but big cams make their crazy power up top cuz they give it up down low. No cam can do everything 100%