1.5 - 1.7 rocker ratio

rumblefish360 said

I agree. Another thing popped into my head from an old write up about this. Though it was a flat tappet and not a Hyd. roller as I listed. The lifter as it seemed was not able to keep up and there was a HP loss.

Click to expand...

I know which article you're talking about. Since a higher ratio rocker increases the rate of lift, it would naturally have higher velocity rates. However, if the geometry is correct, the valvetrain will still be stable with the correct spring. I think they just took one set off and bolted another on in that article, IIRC, and never changed anything geometry wise. Then when the valvetrain got unstable, it was the lifters fault for not keeping up. I've run big blocks with hyd flat tappet cams and 1.7 rockers for years, and they don't have problems with the lifters "keeping up", or any valvetrain instability for that matter. I don't buy the claims in that article.

I'd say go for it. Hydraulic cams don't have lash ramps to worry about, so the higher ratio means nothing to the lifter following the lobe. It's always in contact. Just make sure the true geometry is spot on.