McMark has a set left over from a -6 install he is doing for me: stainless headers. As far as I know he did not sell them before his move.

Picked up the engine today thanks John. Going to build a 2x4 stand this week so I can put the engine and the trans on the stand upside down and can build the exhaust as if it were sitting on a bench.. .. Need confirmation that the bracket c is the same as bracket b except for the spacing on the muffler bolt holes..

They aren't the same, the heights are different for the 1.7/1.8 and 2.0
See the rise in the heat exchangers on the smaller engines:

That's not good. Now I need a measurement so I can modify what I have to be able to get to work

You would need a 914-6/914 2.0 bracket . There's a few different 914 4 styles early to late it changed again IIRC.

Pic shows the 914-6/ 914 2.0 bracket.

OK, I thought I had a couple of 2.0 muffler hangers I could give Ben. I don't. I must have gave them away or put them somewhere I wouldn't lose them.

Ben needs some measurements. Can someone with a 2.0 muffler hanger give him the center to center measurements in the picture below. If a couple of guys pipe in and confirm them, even better.

I have one off my 6. I'll go out and measure it in a few.


20" c to c on header flange mount, 5" c to c on trans mount holes, 6 1/4" c to c from trans mount down to center flange line.

Thanks for the info. I will mod my mount and start mocking up parts.. I have to make a hard decision on these.. I really wanted to use a burns style collector as they are so nice but that could drive the price up another 450 in cost over just a simple collector like you see so often. I looked at headers by eds website as they offer a bunch of options but I can buy everything locally for about the same price and I can locally source all the flanges as well.. So to meet my target of 1500. It looks like it will be the simplier collector..

What is everyone's thoughts on this?

Design and build the best performance and quality product you can at a competitive price. Offer two sizes, heat and no heat. My .02

It began to rain in Baton Rouge and it continued that night, through the next day in New Orleans and into Florida.

I was excited to be able to pull my red lever on the center tunnel and crank the upper dash lever to the right, middle to the left and lower to the right and clear off my windshield in a few seconds.

Heat isn't always for heat... something to consider next time you say you don't need heat.

By simpler collector do you mean a formed collector vs. the nice welded ones with inner guide that Burns sells?

I would love a set of SS headers for my 3.2 with heat exchangers....I agree with wndsnd, design the best and offer with and w/o heat.

,its about defrost but really that's the wrong term in a warmer climate,you still need something to move air over the inside of the screen regardless of where you live.

Yes and no.. It would still be a welded assembly but much more like a formed collector..

FYI I was looking at Armondo's 914/6 GT site and saw this picture of the Monte Carlo 914/6 GT's heat exchangers...never seen anything like them before. It must have been so they could run defrost etc at the rally:
http://www.pbase.com/9146gt/image/41939268

I think I know what you're talking about but do you have a picture or link handy? I'm visualizing the collectors you can readily make with a jig in a bandsaw/chop saw like these.

Click to view attachment

Another option to heat exchangers is seat warmers. I plan to do that when I purchase new seats... actually I prefer them over heat. But it also doesn't normally get colder than 50f here in Cali.

Yes exactly

9 degrees this morning.

Cool. For the $450 it's a no brainer to me at least to go this way.

Updates?

Sorry been finishing the oil tanks up this is project number 2. I will be welding the tanks starting this coming weekend so then headers will happen.

Watching both keenly!

Well I have refined the oil tank process so I should be moving on to this project shortly though I don't know when this will be done thinking another 6 weeks before I get a good handle on them

Sounds good to me, 6 weeks seems pretty quick to me (I'm a procrastinator)

Well, I'm happy that your oil tank project is finally in production.
Now back to the exhaust. I know the main paradigm is equal length headers.
Are you going with this same mind set? I'm wondering if you have access for some dyno test on a stock engine vs say George's European headers that have been around for years - especially since the header is currently at the design stage.
Good luck with your new project.

So this project is going to start soon but I have been thinking maybe what the real market would be to make the heat exchanger kits for current headers?

So for an example I could make them for bursch or Georges etc as to not reinvent the wheel..

What does the brain trust think about that ?

I would consider that...

I am dreading late Fall...

If they work with Marty's (MSDS) headers, I'm game....think they'd work well (produce good heat) with his ceramic coated headers?

If not, I'll just get a whole header/heater box setup from you

I actually think the idea of a heat plenum that would fit to the existing header choices to be a good idea. As you say, why reinvent the wheel. And all the folks out there with the Bursch headers (I think those are the most common after market ones out there) would have the option of adding heat to there existing headers for way less than an all new set.

I would also suggest looking at a very abbreviated design. My stock set with the "full metal jacket" treatment makes lots of heat.,, more than needed except maybe in the most extreme situations and who among us is out driving their sixes at zero degrees??

The aviation style "heat muffs" are much smaller ( https://www.aircraftspruce.com/pages/ep/car...rsheatmuffs.php ) and the single one in my plane makes a lot of heat. Besides price, the biggest benefit might be that a smaller, well engineered muff would allow for a lot more room to adjust valves. I have not attempted a valve adjustment with the stock HE's in place (is it even possible??) but was able to do one with Bursch headers in place.

What say the masses ??

What I would need is a set to model off of. Anyone have a pair they want to loan me and I will make a set of heat exchangers for them?

Heat muffs might be a good option.

I have an old set of what I think are Burschs that I would lend out for the cause. I will post some pics and maybe someone could confirm what they are.

I am not a good candidate to beta test the muffs. Got my stock HE's on and they are not coming off any time soon!!

Like I said, one heat muff on the plane makes good heat in a very drafty, un-insulated cockpit. I am sure a left and right in a 914 would be way toasty.

I tried to get factory 6 HE's reproduced about 16 years ago. Dansk told me the original factory tooling had been scrapped, and they weren't interested. I even shipped a set of factory 6 boxes round trip Europe.

I looked into modifying 3.2 and 3.0 factory boxes, which I think still might be a viable option, but I just dropped the whole idea and started collecting as many 914-6 exhausts as I could get my hands on

From the research I've done on this, I'd suggest the following:

The factory did an excellent job designing the 914-6 exhaust system so, you may want to consider replicating the factory boxes as close as you can. They flow really well and the primaries are close to equal length. This is why you can have a 3.0 or 3.2 with the factory boxes, and it doesn't really feel totally choked. Why reinvent the wheel?

Do not produce a product that has weld seams inside the heat collector shells. You will not find a single factory Porsche heat exchanger with welds in the collector shell, and for good reason.

Agreed I made hundreds of sets of headers for rarlyl8 with my other business and was bound by there designs. Now I am not. I really think the bigger market is to make heat exchangers for current header options out there.

You can't make heat exchangers out of mild steel, there's a high probability that it will cause carbon monoxide poisoning at some point in the future.

All Porsche exhausts since the 70's have stainless alloy tubing and mild steel shells, or all stainless. The newer the car the higher quality stainless to the point where it's all stainless. The reasoning on the boxes with mild steel shells is that they would go bad long before the tubing.

In the early development of the 911 the factory exhaust systems had porosity problems inside the heat collectors that failed and caused carbon monoxide poisoning. Subsequently they changed in how they made those.

with the 911 market we made the heat exchangers out of aluminum and made them So they can be removed for inspection or replaced from damage. I have an extensive background in in Porsche exhaust ala former owner and designer of m&k exhaust and previous to that I worked in aviation building products for companies like aircraft spruce, the wag aero group, leading edge air foils etc. That said I thinking a removable solution would be attractive to folks that already own headers that work for them.

Ultimatly stainless over stainless preferably 321 would be the best solution to any cracking, porosity issues along with a back purge..

I say we try one set up

Another thought I just had as I was looking at my 2.4 on the stand that it has 993 heat exchangers which can be purchased for about 350 a set that they could be a solution. Yes not equal length but a pretty nice design large primaries, excellent heat exchangers , all stainless construction.. By the time you rotate flanges and make extensions total investment of under 1k and very little negatives.

I wonder if I have an extra set in the shop?

Ben,
I have a factory set of 914-6 exhaust I will loan you for the build up. PM me your shipping address and contact info.
Thanks

That's exactly what I thought with the 3.2 style, but I'm sure the 993's are better in terms of performance.

Way better . This was a common upgrade for 3.2 cars when I owned m&k exhaust. Brian does not do them anymore because he doesn't own those fixtures.

Quick question, if Brian doesn't have the fixtures, who does?
Especially if someone wanted a set done?

I do.

Interesting about the 3.6 heat exchangers...Scotty said 3.2 are too much work to be worth it on a 914, not sure if he's had a set of 3.6 to play with.

I have a new set of MSDS headers if you need a set to fab HE prototypes.

Quick update as I work one the Gt steel rocker flares I am having a friend start drawings and fixtures for the header and heat exchangers based off of the original ones but going 1-5/8" instead. Heat exchangers will be similar to stock as far as shape but will be fabricated.. Once we have a sample to show people we will start a group buy..

(2) Pair please.

Any estimate on GB cost?

I'm interested in a set of 1-5/8" heat exchangers for sure.

Target for group buy is 1500.. I will firm this up this week..