I posted this last year, heating season is here again. These are big cracks, a tiny one you would not be able to hear would still be dangerous. These are not accident damaged. If you have a set on your car, grab the carbon monoxide detector from home and take a ride with the heat on and windows rolled up. There is a detector used in small aircraft also available. The last photo is how we now test for leaks using air pressure. Brad

So just the shell is stainless?

Thanks Brad! I have seen a set like that. Just because you have SS exhaust does mean they are not fatigued.

i believe the pipes are stainless too - a magnet should not stick - some though do have steel muffler flanges.

i assume high heat is hard on stainless ??

brad - how frequent would you say this is ??

would capping one end off and filling them with water be a good enough test ??

jim

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Just assuming here, but is the washer/rubber dongle for a compression seal fitting for the opposite end of the hookah? If so, where did you source the rubber puck? Also, what's the max pressure for the volume and an acceptable drop over "?" Time?

Sorry for the soliloquee(sp)...



Dave

Those are available in the hardware store I think. Tighten the nut and they squish and expand. Also automotive emergency freeze plugs.

Or in the plumbing section. aka wing nut test plug. These are great detectors and affordable. They start at $3-$4. http://www.aircraftspruce.com/search/search.php

Great responses. All noted in my broken Carolina Anglish...

Thoughts on the 2nd part of the question? I can look in the Factory manual when I get home if you guys think it's in there...

I've seen a cracked one.

This is a great thing to check. Thanks for posting this.

Jim The whole heat exchanger is stainless except the earlier muffler flanges. The pipes are a magnetic stainless (304?)

Brad, 304 would be non-magnetic as I remember. 400 or 500 series would be magnetic (more iron, less nickel - from my days in the restaurant equipment industry).

SSI says the heat and salt caused this but I have heard from owners in no salt areas with this problem.
Frequency? I pitched a couple before I cut these open but I have probably sold 50 used pair since they became available in the 70's.
Any method including water should work but there is a possibility of a tiny crack not showing with air or water.

I don't have set test procedure for the air pressure, we use 10 psi, the time period until the air bleeds off mostly depends how good the test plugs work.
Be careful not to aim the expanding rubber plug (hardware store item) at anything during test! Brad

One way of using this method is to hold each pluged end in a bucket or tub of water to see if the seal is leaking thereby eliminating the question if the pressure drops is it coming out of the pluged ends , kinda like the old tire puncture location test. This should be very doable for folks wanting too check their heat exchangers , great idea that I will do when the time comes to use / not use mine . carbon monoxide= DEATH. Recently some folks in a town north of me died in a RV from a faulty generator exhaust , this happened over night , next morn they were gone , 5 peeps total . Also on another trip to an event where tents were allowed , a fella , his son ,and his son's friend didn't wake the next morn because of using equipment inside the tent , dew sealed the tent so it couldn't breath and they were gone also.
Thanks Brad for posting this procedure as it may help a lot of guys as to the usability of thier heat exchangers.

Jack

Sounds like we should see if someone is willing to make new SSHE's even though the price would be PRICEY.

Racer Chris at Tangerine?

ALL Stainless?

Something to consider.

Life is good, but CO is bad.

I don't use heat, but this scared me good. I checked mine when off the car last spring by filling them up with water and looking for leaks pipe by pipe, but it was all good, still, no fun to gas oneself unknowingly.

John

I've previously gotten oil (from a leak) into the SSHE's. As it's burned off, I've seen smoke through the ventilation system occasionally.

The oil leak was fixed about 300 miles ago - I think/hope - with new pushrod tube seals.

If I drive around with my heat on and a CO detector, will it go off due to the remaining oil residue? Or will it actually tell me whether my pipes are leaking?

As these cars age, things do wear out. Even things you think would last forever.
Probably time to get a simple carbon monoxide detector - this stuff can kill you very easily.

Thanks for posting this important information, Brad

if you dont need the heat, simply remove the hose from heat exchange to flap box, and manually push the flap all the way closed. Or, remove the flap box too, and put a cover plate over the heat/defrost opening. No more worries.

However, if you need the heat. Move..

Some where all stainless others were not. I recall when I sold a set of brand new in box SSI heat exchangers, the buyer wanted me to check the flange with a magnet. They were all stainless but another set I had were not.

I'm pretty sure they are available new from Mittlemotor - pretty but pricey.

http://www.mittelmotor.de/webshop/englisch/mm.htm $1,200

I had a 1.7 set of SSIs on my 914 and after many attempts at tightening up what I thought was an exhaust leak at the head found out the pipe has a crack at the first bend inside the clamshell (noticed this when I was looking at it at night and saw fire shooting out).

Removed that set to install a 2.0 set I have had for years and years. On the driver side unit, noticed there was a crack at the point where the pipe entered the clamshell which was caused by stress from the other end not quite lining up to the exhaust hanger. Had to be pulled over about 1/4" or so. Over time, the crack formed.

OK... on to my final set of 2.0 exchangers. No visible cracks but one of the pipes can be twisted slightly back and forth so that is also useless

Three sets of SSI exchangers... all three sets have at least one side with issues.

I was hoping to get some heat into my 914. Think I will block off the driver side and just hook up the passenger side. Then will see about having the bad exchangers repaired

A simple cheap insurance is one of these. You can pick them up and may airport FBOs (fixed base operators) for less than $5. Just look up learn to fly and your local airport and call to see if they have them. Or buy from ASA directly.

http://www.asa2fly.com/Carbon-Monoxide-Det...2_product1.aspx

Let me suggest you don't repair the bad SSI's. We hammered on the internal pipes on the cracked ones and the metal shattered. A repair is not worth the risk. Brad

my daily driver I switched to gas heat, Nice dry clean heat. Plus a flic a of a switch its heating no engine running.

Thanks for the warning. I haven't looked real close but the 2.0 pipe with the crack actually developed a hole so it seems it could be brittle.

Makes buying these things used a bit of a risk, doesn't it?

If you have any pictures of your gas heater and it's installation, please share them with the group. I'm sure people would love to see them.

Also, thanks to Brad for the warning!

I just put my car back together and drove it for the first time in about 4 years. One change I made was to install 2.0 SSIs that I bought from Brad at a swap meet probably 12 years ago. I also blasted, painted, and installed a really greasy set of branch pipes and j tubes that I bought. I let them soak in my parts washer for several days, and they were still pretty nasty, and as you know, there is no way to really get to the inside completely.

Anyway, I took it out tonight to get gas. I filled it up, went in to pay, and when I came out, the cockpit was filled with smoke. It didn't really smell like exhaust, so now I am wondering if it is residual crap burning off the inside of my restored parts, or if I have leaking SSIs.

Can anyone think of a way to test them on the car?

You could get a CO detector card, turn the heat on full with the top down, and run the car around with the card by the heat outlet to see if there is any sign of CO. Alternatively, CO detectors are available for RVs that run on 12 volts.

If you did restore the old heat exchangers, I would imagine that you will have a lot of residual stuff burning off the first few times you use them.

It pays to be safe if you're not sure.

John, These are the best looking set I've seen yet I looked them up but it desnt look like you can get them in the states. Any other vendors carry these?
thanks Joe

I picked this up at HD Racing today. $28 is a small price to pay for peace of mind. I would recommend one for anyone running heat with an air-cooled engine.

CO Detector

I am contemplating where to put it. I may velcro it under the dash, just put it in the glove box, or place it behind my seat. From what I have read, CO mixes pretty freely with air, meaning that it is unlikely that there will be a "pocket" of CO under the dash, or up by the windshield.

More reading on CO:
Amazing survival story
CO detector types, reviews

Just an idea Ken , remove the heat exchanger hose on the cabin side leaving it connected to the heat exchanger . Run the engine and aux fan also to test for CO2 right off the heat exchanger itself . that should tell you if the exhaust is leaking into the clamshells, and not risk too much inhalation of fumes . Basicaly testing the air volume before it reaches the cabin. Good luck with your findings and let us know what you find.

Jack

Thanks for posting this nugget.

We all love our 914s but no one wants to be buried in it especially while still driving down the street.

I found something similar on a pair of factory bus heat exchangers, though those have a cast aluminum heat sink around them and are steel. I had the sheet metal off of them. I put a rubber stopper in one end, modified another stopper with a cut-off a bicycle tube air valve stem for the other end. I submerged it in a rubbermaid-type container. Using a bicycle pump, there were numerous tiny cracks, fissures difficult to notice by eye that bubbles easily came out of.

Bus ones also have asbestos fiber lining all inside the sheet metal but that's another issue.

Racer Chris's custom headers with heat exchanger are looking better and better.

Chris, group buy of an even 10 units for $499.95 each?

One less thing for me to worry about having the WRX engine in there........

my first encounter with a sshe that had a crack in the pipe within the tin area. during my test, one pipe out of four clearly had some air bypass. i cut the tin off and basically the air was escaping thru basically a pin hole along a fissure. as you can see this crack is minor compared to brad's examples. thanks to brad for pointing out the potential for this occurance and his testing proceedure.

here is a link to some info on COHb levels as read by the kiddie night hawk detector shown in a post below.

as you can see, I plug on end and tape around the head end as to have a clean surface to put my mouth on, so I can blow orally to check for leaks, works fine.

http://www.safetyproductsunlimited.com/co_alarm.html

What About the common steel HE's? Do they crack like this too???

Other Solution: Keep the roof Off.

Thanks to Brad and this thread, I don't drive with the roof on without this. It has registered as high as 33 PPM while I have been out on drives. Not much, but not zero either.

$28 at Home Depot = cheap insurance.

Click to view attachment

Great thread!

This is my first air-cooled car. I do have exhaust leak (haven't looked for it yet) and the thought of a leak coming through the heater did cross my mind but wasn't sure how to check/know for sure. The CO tester in the cab is a great ideal everyones needs to know/do. Needs to be told to all new poeple somehow. Maybe in a check list for newbies. First things to check out when getting a 914.
My 6 year old rides in the car with me. Alot at stake by not knowing.
I'll be getting one before I take my car out for a drive again!

2013 bump on an important thread

Thanks for the bump. Today I removed my stock HXs and getting ready to install SSIs tomorrow, now I will do a leak check first.

I'm back to thinking about electric heaters for the air-cooled cars

Last year Dansk purchased the SSI brand and added the 911 HBs to their inventory.
I wonder of they are the supplier for the 914 HBs sold by Mittlemotor Deutschland ?
Anyway, the cost of liability insurance on making this product sounds higher than the mfg. wheels and suspensions
I never would have expected a high QC'd product like the SSI to fail.
Marty

$28 O2 sensor that could save your life

Good reviews too.

Good luck with that!

Electric heaters for VW bugs, etc. have been around since the 60's, they never work worth a shit.
Too much of a draw on the alternator.

I have never had that tight of a car to worry about CO or drove it often enough in the cold enough to want heat But I would be interested in seeing the gas heater in action

Webasto and Eberspacher are the two most common ones around. VWs used them all the time, as did early 911s (they fit in the smugglers box). I've only seen pictures of one installed in a 914, and have never met anyone who's seen one in person.

They do work great, but also have the CO risk if the heat exchanger inside the unit cracks. CO monitors are the safest and cheapest way to go IMHO!

heated seats