Ya but wont the advertised lift used change from company to company as much as it does type? I thought thats why the standardized .050 was created.

Either way, I was just trying to over simplify things. Sometimes I suppose, that in the end, that makes things worse.

Happy Holidays!

 

Yeah the advertised can move around a lot. If you plot a SR lobe vs. a Hyd Roller lobe in a chart from a Cam Dr file you can see a lot of similarities if the lobes are the same .050 duration. Problem is the lash makes the Hyd run like a smaller cam due to that lash. That's why the winners of this years Engine Masters put more lash into their setup before their final pulls.

Bret

 

Confused now....

Put more lash into it? Wouldnt that lessen the cam?

 

Yep that's exactly why they do it. It also bumps the DCR a good amount.

The 509's were running 260 deg cams at .050 with over .700" lift and upwards of .800"

Thats a TON of cam for a 2500-6500rpm range with the right sized heads.

When you add lash you pull up the TQ curve almost everywhere below HP peak. A 1-2 ft lbs gain everywhere is worth it when you are really close to the next guy in total score in that competition. It's just not going to live very long but 3 dyno pulls isin't too much.

FWIW Lennart Bergquist who won this year is no dummy. His shop car is a 357cube Comp Elm that's over 1000hp NA. At least it takes that much power to move a 2300lbs car 182mph in the 1/4.

Bret