Personally I would always rather have ratio than lobe, but it's tough with stock type setups

Dwayne, do you mean checking for lift at the retainer with everything assembled to run? I'm still learning the lingo over here lol. We did check it and it was pretty close IIRC, I'll have to dig in my notes.

My real irritant was that I had ordered and paid for the 3/8x.120 wall pushrods for this motor knowing it had 300 lbs. on the seats and 780 lbs. opened and got 3/8x.083 wall
I guess(and hope) that there was a foul up in quality control on that set in production, I hope it wasn't intentionally done that way

I have Hughes 1.7's on my 511. No clearance issues with 3/8" Manton push rods.

My reasoning for using them was/is:

1) Most Moparts.com guys told me not to do so.

...

...

Just curious how rigid those rockers are, and whether any additional ratio was "built in" so the net loaded ratio was close to what they are supposed to be. Some brands seem to have this, some don't.

Yes, lift at the valve with full spring load and zero lash, divided by the actual lobe lift.
I realize this is actually checking the "system" net ratio, since there is deflection of other components besides the rockers, but IMO, unless the pushrods are seriously undersized the majority of the deflection will be in the rocker.

Just curious how rigid those rockers are, and whether any additional ratio was "built in" so the net loaded ratio was close to what they are supposed to be.
Some brands seem to have this, some don't.

I read Andy's article. It's a real eye opener.

But didn't you pick up a lot of hp in the other engine, going from 0.66 to 0.80? I thought that lift level put you over 800 hp and caused the block to crack.

It required a custom cam with awesome lobes to do it, but in this build, 0.75" lift level was chosen, resulting in 750 hp. Yeah, his ratio is 1.6 IIRC, but lift is worth noting.

http://www.hotrod.com/articles/how-to-get-755hp-from-your-wedge-mopar/

Wouldn't a NASCAR team cry foul and exit entirely if they were required to use 1.5 while competitors kept 2.0 ratios? If we tested a bunch of engines, wouldn't higher lift produce outstanding gains in many, if not most, configurations?

What are some things that can cause peak hp at 0.67" ? Just speculating:
Trick Heads claim to flow on par with ported E. Victor heads, but do they flow more like unported Eddy RPM heads? Were valve springs mislabeled or defective, resulting in float/instability that caps hp? Is duration curtailing effective CR? Is there something about the runners or cam that do not lack cfm on the bench, but do curtail velocity in practice? I don't know what happened in your test. You've given me something to think about.

In the meantime, imagine everyone demanding 1.7. Vendors get tired of broken part complaints and devise bulletproof systems. Everyone switches over. Armed with the knowledge that 0.67 is best, you request a lobe of just 0.39". Your 1.7 rockers get you to 0.67. Now you ask the cam grinder to drop the duration down. The rocker ratio adds a small margin of duration, but let's say overall it's a 15 degree drop in duration. Low rpm torque goes up. Driveability goes up. Valves close sooner so more CR is retained. People with dual plane intakes can ditch them in favor of single planes. Peak hp happens at a lower RPM, making dicey high RPM unnecessary. Low duration usually means less overlap, which means fewer hydrocarbons, if you're into that. And when it comes to forced induction, duration must be low.

But the article spells it out in black and white. I'll consider myself warned.


Thanks

Yes, lift at the valve with full spring load and zero lash, divided by the actual lobe lift.
I realize this is actually checking the "system" net ratio, since there is deflection of other components besides the rockers, but IMO, unless the pushrods are seriously undersized the majority of the deflection will be in the rocker.

Just curious how rigid those rockers are, and whether any additional ratio was "built in" so the net loaded ratio was close to what they are supposed to be.
Some brands seem to have this, some don't.

I tried to respond and this web site dumped it Pierre at Smith Bros. didn't offer to replace them after I pointed out that I had paid for the .120 wall and he wasn't going to replace the two bad ones until one of the shop supervisors came in and looked at both of them and told Pierre to replace them both for no charge.
Needles to say I normally buy Manton now at a better price and get what I order and pay for
Smith Bros. was here in Bend back then, they moved to Redmond, OR (23 miles further north now) several years back. I started buying pushrods from the original owner back in the late 1960s when they where in West Covina, CA, that guy was a real jerk His Son was a lot better to deal with His Son moved the business up here to Bend a long time before I moved here in 2005 and I think he sold it to the current owners in that time frame, 2004 to 2006