[screamingchief]

Originally Posted by ponyakr

What about the 744 RA3 stick cam. I've heard at least one guy really badmouth this cam.

Sigh...

I know I'm that "one guy",I even remember when & where that happened,but FYI Don I did'nt badmouth that 744 cam @ all,That's just how you reacted to being told something you did'nt already know.

See,the problem lies with the fact that you were recommending using that 744 cam to guys and telling them they could use "stock" valvesprings and pressed in studs and such,and all I did is inform you and anyone reading that thread @ PSP that was a bad idea,as even the factory used stiffer springs and screw in studs as SOP due to that specific cams lobe design and it's known tendency of being hard on valvetrain pieces.

That 744 cam has a lengthly background story that apparently you have no idea about.

You gotta stop being so hyper-sensitive to things like this Don.

I'm sure you're gonna wanna climb up on the cross after this post too...

But there's no valid reason for you react like that,as I harbor absolutely zero animosity towards you Don,I just like to see good info being passed along on these forums,and as such I will readily correct any subpar info being passed along as gospel,I do such just to help those other folks that dont know any better than to trust said subpar info/advice.

Have a nice day.

Bret P.

[ponyakr]

I just thought of a couple of more questions on the 744/2802 cams. Even tho the 2802 has a lot more lift, can it get by with less spring pressure than the 744, because of having a smoother profile, rather than the "bullnose" lobe, as someone described it ?

I assume this "bullnose" is similar to the NHRA Stocker grind profiles, just not as pronounced. Is this correct ?

What exactly was the higher spring pressures that Pontiac used on the RA3 and SD455 engines, with this 744 grind cam ?

The popular spring for many Pontiacs seems to be the Crower 68404's. So are these springs strong enuff for a 744 grind, or will it take something stronger ? Will they work on the 2802 ?

http://www.summitracing.com/parts/cr...3wrBoCKazw_wcB

[Steve C.]

I'm always curious why the Pontiac community often calls for or can be stuck on low valve spring pressure. Even to the point some get their panties in a wad over it, like the opposite is evil We even see this with aggressive XE lobes.

My old Crower catalog says the popular 68404 spring is rated 113 lbs at 1.600" IH. So what happens with a bit more, like many of the aftermarket cam companies often suggest. While touting adequate pressure these companies will always make a point and call for more not less pressure to control the valves.

Ok, the main disadvantage with higher spring pressures is that stiffer springs don’t last as long as springs with less spring tension.... but are we really looking for a 100,000+ miles of driving on most of these scenarios.


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[ponyakr]

I've got another dummy question. I've read a lot about guys using 1.65 rockers. In my mind, using the laws of physics, or whatever, using 1.65 rockers will put more stress on the pushrods, lifters and cam lobes. I assume this, since more force must be applied to the short end, in order to apply the same force at the valve end of the rocker.

Since the force needed to depress the valve springs, is the same, regardless of rocker ratio, it makes sense that the higher the ratio, the more force required at the short end, to open the valve. Does this make sense ? Or is it ridiculous ?

Let me simplify it, with this question. Will using 1.65 rockers put more strain on the pushrods, lifters and cam lobes, than using 1.5 rockers ?

Why would it matter ? Well, if you're gonna put a lot of street miles on your engine, wouldn't less pressure on the cam lobes make the cam and lifters last longer ? I assume this would make a difference in how many street miles a flat tappet cam could last ?

I've read where some recommend breaking in a new cam with just the outer springs installed. Since there have been so many problems with cams going flat, even if you plan to run 1.65 rockers, would it be a good idea to use 1.5 rockers for cam break-in ?