Hi All,

Couple of questions:

I remember reading that the original Hyperpak had problems with fuel puddling. Did Doc's/Clifford's Hyperpak have the same issue?

Is there a curve showing where the Hyperpak makes it's power? I understand that the long-ram 413s made power on the high rpm range but also had a good amount of mid-range torque due to the tuning of the ram intake.

Has Clifford resolved their shipping issues with HyperPak manifolds, or is it still a crapshoot?

Thanks for any and all input.

-Mac

Doug's the one to answer definitively regarding fuel distribution. There weren't any published power curves for the original Hyper Pak, but maybe someone's got dyno pull printouts for a recent build (Doug...?).

As far as Clifford, I cannot think of a circumstance in which I'd be comfortable risking money on them. That has been the case for at least a decade and I don't see it changing any time soon.

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Thanks Dan.

I just looked up specs on the original 225 Hyperpak:

HP: 196 @ 5200
TQ: 212 @ 4200

Interestingly, I believe that peak torque on the long ram 413 was realized at a lower RPM as compared to other manifolds (450 ft lbs at 2800 rpm).
Of course, cam profile was a factor as well.

If not Clifford, then where else could I get a hyperpak?

-Mac

There are lots of variables like you have responded on the Hpak intake.

Cam, exhaust, timing, carb choice, rear ratio, tranny all play important roles in where it comes in at...Also, another choice is whether you leave the big gaping open plenum, or split the plenum in half (in which case the intake gets very good low end response and better streetable midrange...like a pseudo-dual plane manifold)...

as an FYI, with a short cam and a small carb with dual exhaust, the "sweet spot" starts around 3200 rpm or so and ends about 5500 (but will still pull up to 6200 rpm)...it is much more "fun" during that range than below it (although it is still much more than any super six on the road, and much more torquey than a short ram intake)

The down side to the setup is cold weather driving, without some kind of heated intake/heated air setup it gets kind of "salty" below 50 degrees.


good luck,

-D.idiot

There are some dyno number on a H-Pak 198 in this thread:
http://www.slantsix.org/forum/viewtopic.php?t=18685

For my H-Pak stroked 225, the power is real nice between 3000 and 5500 RPMs and not that bad up to 6200.
DD

Watch the for sale ads. Used ones pop up all the time.

Clifford dumped a bunch of "seconds" on the market for a while. Casting quality was crap. The bad ones usually only had one carb pattern drilled on the pad.

I have bought 2 of them off the Internet. One had 10 minutes run time on it and the other new in the box. Keep your eyes open, they are out there.

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Mac ...
Keep in mind that the new Hyper-pack copies have larger I.D. intake runners than the original manifolds. That should give you maximum torque and horsepower at a higher RPM range than the factory specs.
.... V.