RTz

Sandy, Oregon. Braap, it seems we live in the same town, do I know you?

Justin Olson has been doing a pretty nice job of modeling the manifold in Solid Works... . . . . . .

Davy beat me to it... very professional welds. Pardon my ignorance, what is the purpose of the larger upper tube size?

Hartley 2.8 liter V8, weighs 200lbs, develops 400 HP at 10,000 RPM, and 'sounds right'... http://www.h1v8.com/page/page/1562068.htm

Nascar.

I believe its correct to associate the latch change with the door reinforcement... that happend circa '77, near as I can tell.

Don't forget the single-plane crank!

Thanks. DXF is 'in the mail'.

You make it sound as if that information is readily available and, somehow, a "race setup" is appropriate for a street engine. Am I reading you wrong?

Maybe you two should get a room

For what its worth, Finish Line Coatings refuses to ceramic coat the interior of an intake manifold... ingestion risk should any of it 'depart', they claim.

Looking good Justin. I have a couple comments, if I may... I wouldn't (and didn't) do that. Considering the weight of the plenum, over the years, the pounding could work at the welds. None of my welds at the tubes carry any weight. I ran my tubes the full 1" depth (into the flange), beveled them, and welded them on the mating surface (fly cut afterwards). This way the flange carries the weight and the welds only 'keep it together'. In other words, at the time of this picture, there wasn't a single weld, but you could stand on the outboard flange... The above picture is what my original drawings reflected (regarding the bolt bosses). While it is more attractive, I feel that method would allow more deformity to develop in the gasket. I'm of the opinion you'll get a more consistent seal with your original, 'flush' bosses.

'tis a fact.

Pop, I *thought* I saw them for sale at a nearby dealership about a month ago. I could be wrong, but I'm not sure how I could mistake identifying a car of its... um... high profile

"BrianV8Z" stopped by a couple hours ago. He retro-fitted Pro-comp "Ultralights"...

Are you confident that you have adequate dwell/discharge settings? The 52mm TB is probably justifiable. 3rd should work. Just be mindful of using low gears... the car may go through the RPM bands more quicklly than the O2 can respond, giving you a misleading indication.

Is this the internal HEI coil or an external conversion? Most internal HEI's wont 'do' much RPM. Mixtures are dependent on many variables. I've seen a huge change in 'correct' mixtures with a simple swap in injector style. Its impossible to give you anything other than a guideline. In my experience, I often find 13.0 to 13.3 (NA) to be pretty close, BUT its not always a truism, and further, I find what the engine likes can be RPM dependent, or at least, more *sensitive* to the ratios being 'correct' in one range vs another. My point is that the way to find this is on a dyno. A distant second is very careful, methodical use of data-logging. External variables are more difficult to control with data-logging, but I've had good results in the past. The premiss is to overlay the RPM graphs and compare the rate of change of RPM's. Assuming no wheel spin, consistent road gradient, etc, etc, you'll know if the engine liked the change and what RPM it improved the power. You can do sweeps, shifting the entire map, richer or leaner, and compare the RPM plots. Disseminate, and try again. Its laborious and inefficient... better bet is the dyno.

Agreed. The N42 manifold runner size is only 53% of the intake valve (stock L28). There will be gains realized with a larger runner. At 1.5" ID, you bring that number up to about 74% of valve size.

Justin is referring to this flange... Its an old picture, prior to buffing out the tooling marks. For more recent pictures, different views, and the intended use, click.. http://forums.hybridz.org/showthread.php?t=117607 Justin is right, and they're raised a bit as well. The flange is currently sized at 1.753" OD. There is some amount of latitude in runner ID with alternate wall thickness tubing. With the runner height as-is, anything smaller than 1.5" ID will put the floor of the runner above the floor of the port. To some extent, some of these variables could be manipulated, beforehand. Justin and I will continue our plot to build a few. Until then, keep us posted on what you guy's want.

TBS, Care to test mine?... http://forums.hybridz.org/showthread.php?t=117607 I'll provide you with DXF's if you want to have a go at it.

In my opinion, the most prudent thing to do is to take it to a dyno shop and tune, tune, tune. 12.6 AFR's might be a little on the fat side for an NA motor. Dyno will tell you what the motor likes, including ignition timing. If nothing else is gained, at least you'll have solid ground with which to assess future changes. You might be getting ignition drop-out... what ignition system are you using?