Yeah, the 25A or 30A generators on the 356s and 912s barely support the car's needs. The 55A on the 914 isn't much of a powerhouse either.

One would need to install one of those high-amperage alternators (like Pete (pnewman) sells) to be effective.

I don't know how much current the seat heaters draw

Just wanted to give this thread a bump since the weather has gotten cooler here in Indiana. Thanks again Brad for great info.

All I wish is that SSI (the new one) would make some 914/6 heat exchangers....

There are no oem ones being made but there are a couple different types made in Europe that look promising

There is ferrous and non-ferrous stainless.

Best way, IMO, is to plug,tape, seal the end and apply pressure, Even with a hair dryer to see if it is leaking.

Plug the end, use the hair dryer (I have a heat gun that i use in cool mode) and see if you have air coming out of the edges of a heat exchanger. Good excuse to fire up a cigar when it is not golf season....

Since the weather is starting to cool off I thought I would give this tread a bump. I am getting ready for my last swap meet of the season in Cincy this weekend and going through some SSI exchangers. One out of 5 that I have leaks. I just do a simple water test. I plug the muffler end and fill the tubes with water and let them sit for 30min. doesn't take long for water to find a pin hole or crack and start to seep out. The exchanger I have that is leaking water looks great, no dents, but one of the tabs has been repaired.

Be careful when buying SSI exchangers ask the seller to do a simple water test to verify they don't leak. I will also to Brad's air pressure test on the ones that pass my water test just to make 100% sure they are fine.

Just saw this, and it may explain the leak that I can't seem to find. However, I am not running stainless, but stock exhaust. I don't run heat, so that's not an issue, but the backfire is.

Does this problem happen with the stock steel exhausts too? I assume it would, but this thread seems to focus only on the stainless.

TIA

Can you do this with the hes are on the car? If not what is the best way with the heat exchangers on the car?

If the exchangers are on the car, a simple battery powered CO detector is probably the best you can do. Even on units that test out good, isn't it cheap insurance to have one in the car?

I dd similar PT to the SSI's i bought from Gerald, Plugged the round outlet ends & Filled the pipes with water as full as they would go with parts tilted about 45 degrees and left for 24 hrs, no change in water level.

It's not an impossible issue with stock mild steel pipes, but SS is more susceptible to becoming brittle with the heat cycles.

Yikes! Forget heat then...

Here is a link to another battery operated CO detector. The one previously linked is discontinued from Home Depot.


http://www.amazon.com/dp/B004Y6V5CI/?tag=g..._sl_s7wc0ilmw_e


Now I'm paranoid about my SS HEs. This isn't something I had thought about previously. Thanks for this thread!

???

That looks just like a set I bought off of Ebay... back when I didn't know any better. In theory that could be fixed. But in practice, it's not worth it... and probably dangerous.

Yep, had a perfect looking set of 2.0l exchangers took them off the parts car I could turn the end 180 degrees.

Whenever I bolt the heat exchangers to a motor, I check to see if they hold air by putting each cylinder to tdc and blowing into the muffler end of each port. I use a rubber stopper with an aluminum tube through it - something I made, looks like this, kind of.


This is also a good test to see if the exhaust is sealing at the head, which can be a problem, and can be done with the boxes on the car, just gotta take off the muffler.

Anyone have a clue as to who made them for "AA" back in 1979? Those are the ones I have & they seem to be just fine after 6k miles.

I'm pretty sure that SSI made all of the 914 four-cylinder ones.

--DD

Has the quality of the materials or craftsmanship on the stainless exchangers gone down over the years?
The factory exchangers rusted out after 4 years & nearly killed my Pop from CO poisoning, which is why he bought the stainless ones back in 79.

Don't think so. A metalurgist for GE aircraft engines always warned me that my 914 SSI exchanger pipes would rust. He said it was due to the type of stainless tubing used.

He advised using a magnet on the tubing and the air shrouds. One was magnetic and the other was not, This was a guy used to casting turbine blades as a singe crystal and with air passages within. Never run my SSI's so still shiney.

The engineering term is "work hardening" the problem exists from constant heat cycling till the SS fractures,you will notice the cracks are @ the start of the bends or in the middle of 2,the tube is under more stress in these areas.
The larger outside radius is always the thinnest part of the tube.
My experiences with this problem have indicated poor quality SS or the incorrect grade used ,old age also plays a part.
To add to the problem closing the pipes in speeds up this issue that's why you don't see cracks outside the heatexchangers,many aftermarket SS systems come with a warning not to use exhaust wrap for that reason,SS pipe get very hot.

Tangerine or headers.Not the end of the world.

So are you saying that if it is not magnetic it is less likely to fracture? I used to work GRC years ago not with metals though. I believe 304 and up are non ferris.

Brett

I just checked my 1.7/1.8 SSI's and neither the tubes or the shields are magnetic which means the are 300 series SS, probably 304 one of the least expensive grades and should be good good choices. The 300 series are called 18-8 grades which is 18% Ni and 8% Chrome with most of the balance Iron.
The magnetic grades are 400 series and are just 12% Chrome balance mostly Iron. These grades can be hardened by heat treat so that's what hunting knives are made from.
BTW I pressure tested mine are are OK.
Barefoot

Hey 'teeners, It's time to bring this up again. There is a lot of good information on this thread about the SSI's. Also keep in mind that CO can impair your judgment.
What might have been the root cause of a 914 accident?
Don't dismiss how dangerous this can be! Brad

Little late in bumping this thread. Never to late to check those SSI exchangers you have waiting to install.

Thank you Garold. This IS an important thread for 914 owners. Garold or I or someone else should post this, at least, every heating season. Don't avoid using SSI's but be sure to check for CO if you do. Brad Mayeur

Right Dave, John Danials at Stainless Systems made all of the 914 heat exchangers back then, before he sold the operation to Dansk just a few years ago

This rule is for any and all heat exchangers.. Keep in mind that is the same procedure they do on all small aircraft to ensure everyone is safe..

We have just seen an SSI on the Facebook group that had one of the two header pipes completely detach. This was obviously something that failed all the way around, and would have been leaking a massive amount up to that point.

SSIs are good, but very much not immune to problems!!

--DD

Nothing is..

You can get a battery powered CO detector for $20 at Walmart or Amazon, so why not carry one in the car to be safe. Folks keep forgetting that even the best parts do eventually get old and brittle.

I have one in the car.

Who is making SS exchangers?

For a 4cyl no idea. For six's lots of us.

Hmmm ... good idea

I think Dansk is , they are on E-bay and AA carries them as well, George can chime in, he would know manufacturer. Also several sources for SS mufflers from European makers that now are selling on ebay as well.

Aircraft Spruce you can buy little button CO detector for around $5, good for 12 months once opened. Stick it right beside the tach.

Those are cool ... I'll have to get a couple of them

I wanted to post this again. I was just reminded with another cracked stainless heat last week. Brad

Thanks for the heads up. Just ordered a $20 battery CO detector from Home Depot. I prefer an alarm to the card type so I do not have to check it. Also it will last longer than 12 months.

Yikes.

This thread is a good reminder to find other solutions for a bit of heat (heated seats, "hair dryers" for a defroster, gas heater, etc) for the interior and/or an electric A/C system with heat. Cost of heat exchangers vs keeping headers—particularly on a six—is a decent head start down these roads.

Yep. I have a pair of 914 Rubber's seat heaters destined for the '71 914's reupholstery job ... thinking about picking up another pair for my '66 912 too

I disagree. Especially in places where it gets cold. Heat exchangers work great and the cars were built with them in mind. Every winter there are threads seeking alternatives that never pan out. If you plan on enjoying your car for the next 5, 10 +++ years, heat exchangers are worth the investment.

Even my stock 1.7 car without an electric fan in the engine compartment, was a joy to drive on a 20 degree winter day. Driving with the top off on a cool fall day while the heat rolls through the cabin is heaven.

Ask Michael about heat in his car or Steve or any of the southern Cali folks that have real heat exchangers they make the difference in the car for sure. We are actually working on a simpler hopefully cheaper heat exchanger for the -6 cars to basically mirror the driver side heat exchanger to the passenger side to save costs and bring the price down but retain fantastic heat and introduce a better merge collector at the same time.

I don't at all disagree that heat exchangers are effective—I enjoyed a set of SSIs on my Type IV for 20 years, and if anything they made too much heat. So I can see where they're heavenly in colder climes.

However, those pics of SSIs (which were exceptional quality...) do make me wonder about alternatives. I don't need much in the way of heat in my 914. I usually turned the heat down on cold days, and can see where heated seats and defrost would beenough. And...A/C is more and more appealing to me. I understand electric A/C systems for Emory's 356s are pretty good these days. Makes me wonder about such a system for a 914—because where I live, and for how I use my 914, a lack of A/C is the #1 thing that keeps me from taking the car on certain drives.

I've been driving my 914 with plain headers for several years now, and the times I was bummed it didn't have heat can be counted on one hand, maybe two—but I'd still like to add heat at some point.

Still interested in this—and a cursory review of electric A/C (apparently without heat…) suggests old-school A/C is still far better.

Have also considered one heater box and one header for my 914 given my use and limited need for heat.

One thing I don't love about HEs is what Brad brought up in the first place: There's really no way to check the condition of the pipes unless you take the clamshells off...which is tough to do when they're welded on.

The header pipes can be filled with water to check but that might not find the smallest cracks. Brad