Opinion on headers

[Mudsport96]

Cliff, i saw your reply to the thread about headers possibly causing a divorced choke issue. I was wondering you thoughts on when/what power level you think they are considered a need? My Nova has a set of the block huggers from Hedman that were on it when i got the car. Similar to the old corvette "rams horns" from back in the day. Ive never hurt the starter or burned a wire, granted shes only seen about 8500 miles. And since they are center dump they dont get close to the starter, so that probably helps. In all honesty they probably dont help my combo since i dont think it makes much more that 290 to 300 on a good day. That and it's pushing exhaust through an old set of Walker mufflers so anything ahead of that is moot.

[Cliff Ruggles]

Center dumps on an SBC are fine as long as they have thick flanges and don't blow out gaskets.  They typically have plenty of spark plug clearance so they don't torch the wires and far enough from the starter they don't melt it down on a long run.  I'd still run factory heat shields if they will fit and for sure route the wires down the back and up under near the motor mounts like the factory did.

From the testing I've done we see little if any power (torque) improvements with headers vs most factory iron manifolds to about 4500rpm's.  Headers typically provide more power at high RPM's, but only if the heads and cam are making power up there.

Its the same with intake manifolds and many other parts being sold for these engines.  If you have a stock or close to stock engine, especially a later lower compression engine with smog heads, intakes, headers, fancy cams and most other parts aren't doing much if anything for it anyplace, at least from what I've seen here.

One true statement that header and intake manufacturers make is that they save weight, but they do NOT make more power or not nearly as much more as we are typically led to believe......

[Mudsport96]

Ive often thought of swapping the Headers out for a real cast set of rams horns i have since they should be pretty close to mating to the existing exhaust. But, they are warped so i would have to get them machined flat again.

 
Ive never been too worried about burning out a gasket as they are homemade out of a roll of flexible asbestos i found at a garage sale years ago. And ive used it for various other things way more severe than just exhaust gaskets haha.

As for intakes ive got a ported stock iron one. I opened the center of the mounting pad like some pictures ive seen on here.  And then did a lot of research on where to open certain spots and leave others mostly from David Vizard. And truth be told it runs way better than the aluminum base edelbrock Performer ( which basically sucked everywhere) or Torker 2 ive had on it. And with the Torker 2 i went as far as bolting on an aluminum spreadbore adapter then TIG welding around the outside edge so i could blend the adapter to the manifold. After a month of work it could almost pass as originally being a quadrajet manifold. And it ran good from 3500 to about 5500, but the iron manifold seems to start pulling at 26-2800 and feels like it drops off at 5200ish. I'll give up 300 rpm on top for more in the middle.  Plus it drives better.

[Cliff Ruggles]

I could write scores of pages on testing intakes, carburetors, spacers, camshafts, distributors and other "high performance" parts.

I will put up some test results on here from time to time.  I have to be EXTREMELY careful doing this on other Forums.  There will ALWAYS be someone who will challenge the results or muddy the water by saying that some "guru" or well know "expert" used that part on this or that and made 8 zillion HP with it, and that I'm full of poop, etc. 

Just like the header thing, no one selling them is ever going to mention any of the negatives involved with them, and most are such a major PITA to install you certainly aren't going to be in a big hurry to remove them.......you'll go out and buy custom wires with heat resistant boots, mini-starters, header wrap, and greatly improved gaskets after you blow the cheap ones out a few times!........

[Too Fast]

I agree on almost all you said, Cliff.  However, for good 4-tube headers, I have found a big improvement on my Pontiac engines Vs. log manifolds.  So much better breathing over 4000 RPM.

Ram horn for SBC, I have no experience, but you are certainly correct about spark plug wires/heat shields/gaskets etc for LT headers. 

I will never forget the day I drove my 67 Firebird 400 4 speed way back in 1991, after a long tube install.  The power band expansion over 4000 RPM compared to the old log manifolds was eye opening.  At the drag strip I went from consistent 13.8 to consistent 13.5, that was the only change I made.

[Cliff Ruggles]

For sure you are going to find better breathing with the worst header out there vs factory "log" manifolds. 

Even with that said I helped a good friend and customer set up his 1974 Pontiac Trans Am for FAST Class racing.

He had to use crappy 4X heads, the iron EGR intake and "log" exhaust manifolds.  FAR from ideal parts for sure, then you've got to hook it on bias ply tires.

Remarkably he got the car well into the 10's in the 1/4 mile with those parts........