I have 1.55 RR's and CC305...

my friend has 1.6 RR's and CC305

he's saying that the 1.6 makes at least 15RWHP over the 1.55's.. Others say thats not true.... I don't think this is the case either...

what do you guys think? will it make THAT much diff If i was to go with 1.6 over 1.55s?

 

yes they do give a nice gain.I could feel a big difference.I would recommend getting them.

 

yes.. i would agree.. if you go from stock to 1.6... but i already have 1.55's... not much diff between the two.. or is there?

thanks

 

I dont rmember what the stock ratio was...doh..but if you figured what your lift #s would be with 1.6 vs 1.5..I bet it would give you 10-20 hp.That would justify the cost enough for me.

 

i thought it wasn't lift that really gave you the HP but more the duration of the cam...

PS... anyone know the lift #'s between a 1.6 and a 1.55 (not 1.5) on a CC305 cam?


thanks

 

more lift gives you more air going in,also more ''under the curve''.Pumpin more air =more power.You would also have to make sure your springs are up to it.

 

If you are looking to squeeze every bit of power out of it,and are running out of options,then try them

 

OH my spring can Handle it

 

Are you sure they are 1.55s Pro Magnums are 1.52

 

the difference between a 1.55 and a 1.6 RR is going to be negligeble. Look at what people gain going from stock 1.5 stamped rockers to 1.6 RRs, maybe 7-10 rwhp. so going from a 1.55 that's already a roller tip to a 1.6 isnt worth it. It might net 3-4rwhp.

 

see.. thats what I think too...

 

i think the gains from roller rockers come from the friction reduction of the bearings more than the increased rocker ratio.

 

right.. and since i already have that loss of friction... i'm in the clear...

 

Turbo_Z: That's pretty much right.
Also, when switching to roller rockers, the main benefit comes from the reduction of friction via the roller fulcrum (the center section), not the roller tip. I recommend Comp Cams 1.6 Pro Magnums. If I had to go back, I would get non-self-aligning rockers and guideplates.

If you want to find your lift after installing 1.6 ratio rockers, the CC305 is 510/510 lift on a 1.5 ratio rocker arm. 510 * (2/3) * 1.6 = 544.

Hope this helps,
JR

 

Tell your friend you dont think they will make a difference, so he needs to let you try his. Take it to the dyno. If it makes 15 RWHP or more, then you buy a set. If not, you laugh at him and tell him he can't have them back, cause it doesn't make a difference.