This is the first one. I'm building 2 more right away. Soon we'll find out just how much heat is available with a high performance header.

Here is another view showing the seal where the tubes come through the back side.

Looks nice!! Keep us posted on how effective it is!

Any during pics?

Andrew

Way to go Chris!

What is that goo you're using for the seal(s)?

The HE's on my aftermarket headers are just a box with holes cut for tube exits, so they lead air pressure, no seal whatsoever.

Those aren't welds, are they? What about thermal expansion / contraction issues?

This picture is upside down (of course). It shows the interior, and how it is assembled where the stub pipes connect to the header. The baffles (arrowed) should improve the heating performance over a simple box around the tubes.

I want to comment on these, but I dont want to piss you off. So here goes.

I have never seen anyone pull this off and succeed in something that lasts.

The tubes will expand and contract at a different rate than the sheet metal.

I think your idea is great. I do think it will have heat, but I also think it will rattle over time.

My suggestion: make a forming tool that punches the hole for the tube to pass thru the sheet metal instead of welding the tube to it. When you punch the hole.. make it 30thou smaller than the diameter of the tube so it is a press fit over the tube.

Like this. Just an idea. I know you want to make these last and I dont think it would take you too long to make the dies for punching the metal for the holes.

B

I appreciate your comments Brad,
Since your criticisms are constructive I don't get pissed off. (actually I was hoping you would comment. Besides, you can't possibly get me as upset as when you got me onto this board for the first time. )

My intent is for the box to be removable, not welded to the tubes. That way it can be easily retrofitted onto existing Super Header systems, or removed for summertime track use if desired. By sandwiching the upper half of the box between the flanges I hope it will be secure, and not rattle. The holes where the tubes go out the back have some clearance filled by a piece of ceramic batt (similar to fiberlass insulation) that is screwed down to the surface of the box. I don't want heat robbing air leaks.
I expect to make my design more sophisticated over time, both to improve performance and ease of production, but it is unlikely that the heat exchanger will ever be an integral part of my headers in the way the SSI units are made. Superior engine performance will always take precedence over creature comfort with my product.
One concern I have, which relates to a comment made on a previous topic, is the possibility of CO poisoning. I don't want to make a box that hides welded tubes permanently, just in case there was an exhaust leak. I may include a CO detector with each unit I sell, just to be safe.
One thing I haven't resolved yet is how to get the heat to both sides of the cabin. I have determined that there is pretty much no possibility of adding another box to the driver's side exhaust tubes, so all the heat will have to come from the passenger side of the engine. Can the air control valves up front be modified to redirect the warm air, or does there have to be a splitter in the engine compartment?

Much easier to do it in the engine bay. Space is tight in the front section.

Just bringing this back to the top since it's being discussed. Here's another pic as well.

We're finally having some decent weather in New England so I went for a drive yesterday to test the effectiveness of the heat exchanger I installed on my street 914.
A few weeks ago I warmed up the engine with the goal of driving the car to work, but the blower motor wouldn't run so I parked the car without driving it.
I had some free time to work on it yesterday so I swapped out the blower with one that actually functioned. After replacing that I still wasn't getting any heat in the cockpit. It turns out that several years ago I had blocked off the end of the heat tube where it comes out of the long. behind the speaker with a spray paint can cap. The old flexible hose was nfg and I had forgotten about blocking it off to prevent engine smells from getting inside. Once I replaced the hose I had good warm airflow for defrost or toe warming (to the pass. side only).
The next step is to make a splitter in the engine comp. and see if I can get a good amount of heat to both sides.